So Dinosaurs Could Fly ! – Part I

A look at diminishing atmospheric pressure

Guest post by Andi Cockroft

In an unrelated article of mine on Isostacy and Mean Sea Level posted here, I mentioned in passing a thesis paper by Theresa Cole (here) and here: ColeTheresaN2011MSc – which included this graph depicting an observed fall in global annual mean atmospheric pressure since 1916 (from NOAA I believe)

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Figure 1 Historic global annual mean atmospheric pressure at sea level between 1916 and 2007

A recent exchange with Theresa, has caused me to revisit this apparent anomaly, and wonder where this is all heading – and indeed how long this has been going on !

But why the heading – So Dinosaurs Could Fly ?

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Figure 2 – Artists impression of Quetzalcoatlus with its 45’ wingspan

Well, seems that engineers are of the opinion that the pterosaurs were just too heavy to get off the ground given today’s environment, and they must have been helped by far denser air.

Denser air of course means a higher pressure – I have seen estimates ranging from about 3.5 to 8 times that of today. Let’s pick a mid-point of say 5 for the purpose of this post. (I trust these are not the same engineers who state categorically that a Bumble-Bee is incapable of flight)

So from 100Mya to today, how has air pressure gone from a possible 5000 mbar to 1013 mbar of today? And why is it still (possibly) continuing to fall?

Questions that spring to mind are:-

· Is our atmosphere being sucked out in to space?

· Is the composition of the atmosphere changing and so getting lighter?

· Change in water vapour?

· Increasing CO2

· Burning hydrocarbons + O2 -> CO & CO2

· Volcanic eruptions

· Release/Uptake of gases from/to the ocean

· O3 -> O2

· Is an increase in temperature causing a somehow related increase in pressure?

For those who might not remember, I remind readers I do not have strong scientific qualifications in meteorology, hydrology chemistry etc., just an enquiring mind – so feel free to disagree with my arguments here.

In researching this post, I came across many conundrums. Many contradictions or seemingly incongruent theories. But hey, let’s look at what is out there starting with young Earth and work forwards to see what we shall reveal.

I also found myself using those well used weasel words such as could, may, might, suppose etc. Sorry, but given the nature of the discussion – this is just what it is a discussion of some possibilities – not proven fact!

So, just looking at the graph in figure 1 of the past 90 years:- Temperature may have localised effects, but in general, global mean atmospheric pressure at sea level is directly proportional to the mass of the entire atmosphere – the current accepted mean value is around 1013.25 Mbar. So any warming observed over the past 90 or so years should be ruled out as causation – warm or cold the air weighs the same (within reason)

A drop of 1 Mbar may seem trivial over 90 years, but at that rate mother Earth may run out of atmosphere altogether in just 100,000 years !!

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Figure 3 Three possible alternatives for the atmospheric pressure early in Earth’s lifetime, given that it was at ~5 bar, ~100 Mya.

Going back 100 million years, for a pressure equivalent to 5000 Mbar, there would have to be either (a) a lot more air, or (b) different composition – or a combination of each.

And of course the raging question – how has a 5000 Mbar atmosphere reduced to todays 1013.25 Mbar?

The Levenspiel et al 2000 paper is well worth a read, and has been cited indirectly here as part of 450 Peer-Reviewed Papers Supporting Skepticism of AGW caused Global Warming here, and referred to at WUWT here.

What was the air pressure for the 97% of Earth’s life before the age of dinosaurs? Levenspiel et alhave three possible alternatives, as shown in Figure 3.

  • The pressure could have been at 1 bar throughout Earth’s earlier life, risen to 4–5 bar ~100 Mya (just at the time when the giant fliers needed it), and then returned to 1 bar (curve A).
  • The pressure could have been ~4–5 bar from Earth’s beginning, 4600 Mya; and ~65 Mya, it could have begun to come down to today’s 1 bar (curve B).
  • The atmosphere could have started at higher pressure and then decreased continuously through Earth’s life to ~4–5 bar ~100 Mya and down to 1 bar today (curve C).

The third alternative seems to be the most reasonable, so let us pursue it. We will also look into the composition of Earth’s atmosphere, but we will first discuss Earth’s surface and see how it affects the atmosphere.

From http://www.engineeringtoolbox.com, the specific gravity of some common gases can be found in the table below:

Gas Specific Gravity
Acetylene (ethyne) – C2H2 0.90
Air1) 1.000
Alcohol vapour 1.601
Ammonia – NH3 0.59
Argon – Ar 1.38
Arsine 2.69
Benzene – C6H6 2.6961
Blast Furnace gas 1.02
Butadiene – C4H6 1.87
Butane – C4H10 2.0061
1-Butene (Butylene)- C4H8 1.94
Isobutene – C4H8 1.94
Carbon dioxide – CO2 1.5189
Carbon monoxide – CO 0.9667
Carbureted Water Gas 0.63
Chlorine – Cl2 2.486
Coke Oven Gas 0.44
Cyclobutane 1.938
Cyclopentane 2.422
Cyclopropane 1.451
Decane 4.915
Deutrium – D2 0.070
Digestive Gas (Sewage or Biogas) 0.8
Ethane – C2H6 1.0378
Ether vapour 2.586
Ethyl Chloride – C2H5Cl 2.23
Ethylene (Ethene) – C2H4 0.9683
Fluorine 1.31
Helium – He 0.138
Heptanes 3.459
Hexane 2.973
Hydrogen 0.0696
Hydrogen chloride – HCl 1.268
Hydrogen sulfide – H2S 1.1763
Hydrofluoric acid 2.370
Hydrochloric acid 1.261
Illuminating gas 0.4
Isobutane 2.01
Isopentane 2.48
Krypton 2.89
Marsh gas 0.555
Mercury vapour 6.940
Methane – CH4 0.5537
Methyl Chloride 1.74
Natural Gas (typical) 0.60 – 0.70
Neon 0.697
Nitric oxide – NO 1.037
Nitrogen – N2 (pure) 0.9669
Nitrogen – N2 (atmospheric) 0.9723
Nitrous oxide – N2O 1.530
Nonane 4.428
Octane 3.944
Oxygen – O2 1.1044
Ozone 1.660
Pentane 2.487
Phosgene 1.39
Propane – C3H8 1.5219
Propene (Propylene) – C3H6 1.4523
R-11 4.742
R-12 4.174
R-22 2.985
R-114 5.9
R-123 5.279
R-134a 3.522
Sasol 0.42
Silane 1.11
Sulfur Dioxide – SO2 2.264
Toluene-Methylbenzene 3.1082
Water gas (bituminous) 0.71
Water vapor 0.6218
Xenon 4.53

1) NTP – Normal Temperature and Pressure – is defined as air at 20oC (293.15 K, 68oF) and 1 atm ( 101.325 kN/m2, 101.325 kPa, 14.7 psia, 0 psig, 30 in Hg, 760 torr)

Since specific gravity is the ratio between the density (mass per unit volume) of the actual gas and the density of air, specific gravity has no dimension. The density of air at NTP is 1.205 kg/m3

To change the “mass” of the atmosphere to any meaningful way would require say a 75% mercury vapour composition – something not altogether conducive to life as we know it. The alternative is of course just a lot more atmosphere.

Turning our attention for a moment to Earth’s twin, Venus, formed in probably very similar environs, yet Venus retains an atmosphere composed of CO2 and Nitrogen, with a pressure equivalent of around 90 Bar. Venus is closer to the Sun, so receives greater energy, but that cannot in itself account for the very significant differences in today’s environments.

Levenspiel postulates that the creation of Earth’s companion Moon stripped off much of Earth’s mantle, leaving it a rather fluid lithosphere compared to Venus. It is this fluid lithosphere that has allowed continental drift to rearrange and directly affect the planet’s atmosphere. Couple that with a slightly cooler Earth (less sunlight), allowing liquid water to form, and the basis for removal of CO2 is formed.

If say 4 Bya, Earth did have an atmosphere with a 90% CO2 concentration, with a high atmospheric pressure, Levenspiel proposes that simple dissolution in water would see a 50% reduction in nett CO2 atmospheric concentrations.

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Figure 4 History of deposition of CO2 as carbonates. The red area represents continental deposits that “float” on denser material and are not subducted. The blue area represents ocean deposits. These are frequently subducted and therefore relatively young.

But it doesn’t stop there

Several cycles take place to remove CO2 from the atmosphere, not least by dissolution in rain, combination with minerals on land and ultimately flowing into the oceans and deposit as sedimentation.

True, some subduction at plate boundaries would recycle carbonates through volcanisms and back into the atmosphere, but over time a gradual reduction of CO2 takes place.

As carbon life-forms take up even more carbonates to build homes for themselves, then die and bequeath these homes to the sea floor as sediment, more and more carbon is tied up as rock.

In Potential Errors in Estimates of Carbonate Rock Accumulating through Geologic Time (pay walled here), Hay calculates that today the continents contain at least 2.82 × 106 km3 of limestone, which are the remains of deposits over the past 570 million years that have not been washed to sea or subducted back into Earth’s interior. This is equivalent to a CO2 atmospheric pressure of 38 bar. If we add the carbonates found on the ocean floor, the equivalent CO2 atmospheric pressure rises to 55 bar.

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Figure 5 Progressive lowering of CO2 pressure due to carbonate formation and deposition on Earth’s surface.

Adding all this together more than accounts for a 90% CO2 concentration at 90 Bar being reduced over time to a much lower say 20% CO2 and 4 or 5 bar – just right for the pterosaurs to take wing.

Whilst all this was going on, plant life took a turn all of its own.

Evolving from the primordial soup, cyanobacteria initially removed Iron from the oceans and created Oxygen. It was this oxygen that then led to multi-celled life-forms and ultimately diverging between the plants and animals such as protozoa, fish, land animals and dinosaurs

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Above: A laminated rock formed by the growth of blue-green algae (i.e., cyanobacteria)

So, if we now accept that 100Mya, there was an atmosphere with about 20% CO2 and say 5 Bar pressure, would plant and animal life have thrived under such conditions? Do we even know that these values were anywhere near accurate?

If we believe the aeronautical engineers, pterosaurs needed a denser air to succeed – that estimate is between 3.5 and 8 times current density (=pressure). So that part of our assumption looks OK on the face of it – yes air would have had to have been more dense.

And what of O2?

Well perhaps it comes down to some type of proxies – yes our old friends !

clip_image013We do know that there were some pretty impressive flying insects around back then, and it seems well known that insects breath through their “tracheae” – narrow tubes – rather than having lungs or gills. These tracheae transfer O2 directly from the surface of the skin into the organs of the body. The ability to uptake O2 is governed by the length of the tracheae. Big insects naturally have longer tracheae, so uptake less O2 – that is unless O2 is served at higher concentrations and/or pressure so the body can get all the O2 it needs.

Since we know there were huge dragonflies and cockroaches around during the Carboniferous and Permian (300-250Mya), it seems to support a postulation that O2 concentrations were of the order 35% back then, compared to today’s 20%.

Meganeura, a genus of dragonfly from about 300Mya had a wingspan of up to 65cm (2’1”), and Meganeuropsis Permiana from about 250Mya grew even larger – up to 71cm (2’4”).

Neither survived to compete alongside the pterosaurs however. Many believe the concentrations of O2 dropped too low to allow such mega fauna to survive beyond the Permian.

In Part II, I will pick up on your suggestions from comments here, and look to what has happened to reduce Atmospheric Pressure from 5 Bar to 1 Bar, and why it continues to drop today.

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239 thoughts on “So Dinosaurs Could Fly ! – Part I

  1. We are running out of air!

    Quickly – we must convene a UN-supported set of conferences and get all the citizens of the world to breath less. Breathing more rapidly than one breath every 8 seconds will be an offence – or maybe we could simply tax people on their breathing rate….

    We had wondered when they were going to tax air – it looks like the time has come….

  2. Oh, dear. You’ve also opened the dual cans of worms that Venus is actually a new “young” planet (@10K years by some catastrophists’ estimates) still cooling and losing atmosphere, and that gravity has increased since dinosaur days (which would account for massive critters that apparently couldn’t survive today.

    Note that I do not subscribe to either idea; just pointing out that moderation is about to get interesting. (On the bright side, I don’t think “chemtrails” can figure into this. [grin])

  3. I had an email discussion a few years ago with Steve Nerem of the Colorado Uni, which is where the sea level numbers come from. I had noticed that all the increase in sea level came from the adjustments due to global average atmospheric pressure. Without the adjustment the sea level was falling. Each depth reading must allow for the local atmospheric pressure, as a low pressure will increase sea level at that point and a high local pressure will push the water out of that area, decreasing the depth. To determine whether the local pressure is above or below global average, you have to know what the global average is. They assume that the global average is changing over time, and work with that changing number.
    The point I was trying to make to Steve Nerem is this: If the satellites take thousands of readings per day, then they will be taking some readings where the pressure is low and some where it is high. The adjustments for local pressure must therefore cancel out. The adjustment for local pressure compared to global average should make no difference because over thousands of measurement they have to average out.
    Steve Nerem couldn’t see my point and I didn’t have the time to analyse what is wrong with the adjustment process.
    I maintain that if you take thousands of measurements all over the globe, the average pressure at those places must be the global average pressure, and the average adjustment due to local pressure must be zero. The fact that the University of Colorado showed more sea level rise after the adjustment means, IMO, there is something wrong with their adjustment process and it is exaggerating the sea level rise.

  4. 2006 – 1916 = 90
    1008.6 – 1002.2 = 6.4

    Since we know that climatology operates in liner straight line trends (sea level since xx, temperature since xx, sea ice since xx, CO2 since xx, etc) and the atmosphere is a major factor in climatology then the liner straight line is the correct method to use for paleoatmosphereology expraolationology.

    The trend is 7.1 per century.
    Dinosaurs existed 230 million years, or 2,300,000 centuries ago.
    7.1 per century times 2,300,000 centuries equals 16,330,000.
    So the global annual mean atmospheric pressure was 16,331,002.2 Exactly!

    The Dinosaurs actually walked on the outer edge of the atmosphere. However their methane emissions diluted to atmosphere to the point that the surface tension could no longer sustain their weight. Like a needle in a glass when the surface tension is broken, they came crashing down to earth with incredible velocity.

    This is why we find dinosaurs a) Flattened, and b) Deep under the surface of the Earth. The location and condition of their remains proves the above paleoatmosphereology expraolationology.

    Please refer to the respective national archeological theologies for the raw data.

    Mike

  5. How about burning hydrocarbons´hydrogen sucks oxygen out from atmosphere and turns it into water.

  6. One would suppose that it is not improbable that the solar wind and magnetic activity could act to remove some of the outer atmoshere. I seem to remember eading as a child that air entrapped in an Egyptian tomb had ~ 2% more O2 than current air.

    A primordial atmosphere could also have contained more longer cgain hydrocarbon gases, perhaps even some aromatics although these tend to be more toxic.

    Co2 in greater concentrations seems a logical proposal but doesn’t that mean the Earth died due to the runaway greenhouse effect ?? (Actually I do not believe that hypothesis at all.)

    Also a denser atmosphere would mean there is no faint young sun paradox as the adiabatic lapse rate would be greater and the tropopause would be higher in the atmosphere – does this sound right as I believe a huge atmosphere is the reason for Venus’ high temperatures due to very high compression of the atmosphere ?

  7. eyeball 1.0 suggests that air pressure is related to temperature. Which it should be. But, which drives which?

    I would be interested in seeing if solar UV matches the pressure. UV driving the stratophere height….

  8. “Is an increase in temperature causing a somehow related increase in pressure?”

    Don’t you mean “decrease” in pressure?

  9. Am just about to settle down to read Theresa’s paper over a cup of tea and a slice of toast (liberally spread with Marmite) but I do like your thinking…..

  10. Perhaps I missed it, but I could not see Andi’s name as author in this post. One could get the impression that Anthony was the author, if one didn’t go to the link.

  11. Presumably a denser atmosphere would have more energy intense winds and consequently produce more wind borne dust. This in turn should produce large deposits of loam especially in comparison to modern times. I am not aware of anything in the geological record that indicates this.

  12. Fascinating article – just wanted to say, though, that “mega flora” in your 2nd to last para should be “mega fauna”.

  13. Even if animals could exist at that concentration of CO2 it would not explain how the large terrestrial dinosaurs could walk on land, and there are fossil tracks that support this.

    Lowered gravity would explain both especially with a denser atmosphere, but in searching threads on this for years have not come up with a satisfactory answer, other than ‘forbidden’ answers that deal with close association with other planets,( V anybody?)

  14. · Is our atmosphere being sucked out in to space?

    I guess so. I am a mathematician, but from my physics days I remember being shocked by that. I have found the reference in Volume 5 (Statistical Physics), §38, of the monumental Physics Course by Landau and Lifshitz.

    The idea is: the distribution of molecules in a classical gas is given by Boltzmann’s Formula:

    n = n_0 · exp ( -U / kT)

    where n is the distribution of molecules, U the classical potential affecting the gas, n_0 the molecular density when U = 0, T the temperature, and k Boltzmann’s constant.

    So for example, since the gravitational potential near Earth’s surface is U = mgh, we have:

    n = n_0 · exp (-mgz / kT)

    So, as is well-known, the density of the atmosphere decays exponentially when you go up, for low altitudes.

    If the altitude variation is bigger, the full Newtonian potential U = GMm / r^2 must be taken, but since U tends to zero when r tends to infinity, we have that exp(-U/kT) does not vanish at infinity.

    Therefore Boltzmann’s formula predicts that the state of equilibrium for a gas under Newton’s gravity is to expand with nonvanishing density to the whole space.

    Of course, Earth’s atmosphere is far from equilibrium, and the relaxation time for such a big system must be astronomical. Even so, physics certainly hint at a constant loss of gas to space.

    Sorry if this was too long, or my English too limited. I am not a professional physicist, by the way. But Landau is was an eminence.

    Manuel.

  15. The first line of enquiry should be to establish the veracity of the atmospheric pressure graph. In the cAGW debate it has been questioned as to whether an average global temperature has any meaning and how do you actually measure such a thing. Could not the same charge be levelled at average atmospheric pressure (how many measuring stations, location etc).

    Still, an interesting topic nonetheless. I do enjoy the variety you get on this site, keep up the good work Mr Watts.

  16. If you increase the air density, yes you will certainly increase the lift but at the same time you will also increase the drag, meaning that that you probably have not gained a great deal. Looking at reconstructions of what pterosaurs looked like it seems obvious that one must define their flight rather like Buzz Lightyear’s ie “falling with style”. Their wings are far too rudimentary to take off and fly like a modern bird, rather, I think they must have chucked themselves off of cliffs and ridge-soared or maybe soared the thermals which in mountainous areas are frequently well over 10knots up which should be more than enough for a pterosaur to climb.
    It is rumored that a Boeing 747 was soared the length of the New Zealand Southern Alps in wave. So there is loads of energy up there to exploit if you know how.

  17. My first reaction was the ideal gas law: PV=nRT, and if the atmospheric temperature increases as most believe has occurred over the last 90 years, then value for PV must increase. Yet, NOAA pressure data shows just the opposite, i.e., P decreasing. Consequently, the slight increase in temperature can not explain the small pressure decrease.

    However, I don’t think you can rule out atmospheric warming just yet. As an example, a lower pressure could be explained (as you imply in the post) by a composition change. From Engineering Tool Box; “When water vapor content increases in the moist air the amount of Oxygen and Nitrogen decreases per unit volume and the density decreases because the mass is decreasing.”

    Revisiting ideal gas law, and re-writing it to include gas species density, from Wiki we have:

    P = p (R/M)T

    where;
    p = m/V; density
    M = molar mass in grams/mole

    So if density (p) of the gas mixture decreases due to higher concentration of water, then pressure would decrease proportionally. Remember, moist air is less dense than dry air.

    Maybe someone can model this pressure as a function of known or averaged water vapor concentrations as a function of time and then compare to the NOAA pressure chart.

  18. Many of the large dinosaurs could not have walked the earth unless the gravitational force was much lower than it it today. Their bodies would have simply crumpled. Plants were larger also. Why gravity was less beats me. How it effects the atmosphere also. But with less gravity these birds could well have flown.

  19. You seem to be describing an atmoshere in which bricks would float. Is there any paleo record which might point to density or pressure, or are we confined to inferences from carbon fixing?

  20. What a fascinating article, the reason why myself and many others visit your site continually. I can hardly wait for the next article. I would like some comment if possible, in part 2 on the Pressure/Temperature theory that has been discussed recently, If pressure was higher way back, then it should also have been warmer, according to the theory. I look forward to see if your article and future comments has any support for this controversial theory.

    Best regards
    Keith Gordon

  21. When they’ll find penguin fossils in 50 million years from now, scientists will conclude that the atmosphere must have been 2500 denser in our days ;)

  22. I would have thought that water and CO2 was the ‘key’ to all this – given that we have a flipping lot of it! but of course if the atmosphere had bucketloads more atmospheric CO2 (before deposition via carbon based lifeforms?), it would have meant higher density and surface pressures.
    The thing is that everything changes at higher pressures – at 4 to 5 bar, the boiling point of water is around 150degC, so presumably evaporation would be less (assuming similar to current atmospheric temps) and air density with less water vapour would be higher? but that would mean less clouds = lower albedo = higher surface temps,etc, etc…
    Hmm…seems like a lot to speculate on……!!

  23. Some people have suggested that gravity was less, as the big dinosaurs would not have been able to stand with today’s gravity. Presumably that would also have made flight easier.

  24. Has anyone compared this to the sea level record to check for inverse proportianality??? Could this offer a better explaination of observed sea level rise than the “evil capitolist polluter” explaination offered by the Malthusians?

  25. Fascinating (yet again), Anthony.
         And please don’t forget to subtract all the air held under pressure worldwide in vehicle tubes and tyres (tires); sporting balls; and myriad other balloons and bladders.

  26. Great article. Looking forward to part II
    Some questions re atmospheric pressure. Surely it is the amount of atmosphere and the mass of the planet that determines what the atmospheric pressure more than it’s composition? As Venus has an atmosphere that is mostly CO2 which has a specific gravity of 1.5 does that explain why the pressure is nearly 100 times that of earth? I put this question to a Nasa expert in response to an article suggestion that the high temperature on Venus was CO2 driven, but his response was they didn’t know why the pressure was so high. From what I can find the depths of atmosphere are: Venus = 250km; Earth = 100km.
    Slightly off to one side: What I remember from physics was temperature went up with pressure in a fixed volume. Planetary atmospheres are not confined and on Earth we have extremely hot and cold weather with high pressure systems. I understand high pressures are where the air builds up (gets deeper/higher) and lows where it’s drawn out, both by either a slowing or speeding up jet stream respectively. Therefore atmospheric temperature may be more to do with the speed with which surface temperature is removed, high pressures being slower than low pressures.
    Off a bit more to one side: What if the extremely dense atmosphere on Venus was acting like a giant Newton’s cradle and transferring heat right around the planet?

  27. Earth and Venus are twins, with the exception of the moon. They probably started out with roughly the same composition, with about the same amount of CO2 and water. This makes sense as they formed in the same part of the original solar dust cloud. So, to distill your musings above : Earth with the creation of the Moon gave us Plate Tectonics, this combined with the distance from the Sun allowed the retention of water, which in turn lead to the carbonate cycle. Venus however never had plate tectonics, which combined its proximity to the Sun lead to disassociation of water, which has lead it to have a 90bar CO2 atmosphere. Life then also turned up on Earth. Life is also very efficient at removing CO2 from the atmosphere.

    If a Mars sized impactor not hit the Earth in the Early Heavy Bombardment, we would have had a smaller Earth with no plate tectonics and an atmosphere like Venus’s. There would also be another Mars out there somewhere.

    It is somewhat amusing to contemplate that given the CAGW view that humans are destroying the planet by burning fossil fuels, we in fact are most likely extending the habitiability of the Earth by many millions of years by injecting CO2 back into the atmosphere.

  28. Air samples from amber suggest atmospheric composition at 100MY only differ greatly in that there is about 35% 02. Assuming same total N2 would result in about 23% higher air pressure but 2x the partial pressure of oxygen (up to 0.4bar from 0.2bar), helpful for making larger insects.

    Nitrogen and Oxygen bleed away into space extremely slowly due to magnetosphere, so the only means for loss of pressure is geosequestration, which seems very unlikely for largely inert nitrogen. I can’t see a mechanism that would allow Levenspiel’s suggestion of much higher pressure to be real. http://levenspiel.com/octave/OL_images/DinosaurW.pdf

    That 20% increase in air pressure in a 35% O2 atmosphere is not enough to make it possible for 15m wingspan Quetzelcotalus to take off and fly in no wind, but it adds another 2000m depth to the atmosphere thickness. That thickness at typical lapse rates means about 15-20K average increase in temperature taking global average to 25-30°C as well as greatly increased rates of heat convection from equator to pole (polar regions much warmer, tropics just a little). Convection = wind so maybe reliably much stronger winds helped to get big bird aloft.

  29. Neither survived to compete alongside the pterosaurs however. Many believe the concentrations of O2 dropped too low to allow such mega flora to survive beyond the Permian.

    Fauna?

  30. The first thing that made me suspicious of the global warming BS was the knowledge from my geology studies that CO2 levels had been much higher in the past and yet the Earth hadn’t gone to hell in a handcart.

  31. Quite interesting! Some comments:

    Life may be the direct cause, why we have continents and therefore plate tectonics. Cyano bacteria produced the oxygen needed to oxidate the rocks into lighter forms, that make up the continents. See:

    http://en.wikipedia.org/wiki/Talk%3APlate_tectonics%2FArchive_1#Minik_T._Rosing

    I support the idea, that the atmosphere was more dense in ealier times. Our neighbor planets, Venus and Mars, have more than 95% CO2 in their atmospheres, and they don’t have life as we have on Earth. The Earth would most likely have a dense atmosphere with much CO2, if we didn’t have life.

    Gravity is hard to grasp completely. The equivalence principle tells us, that gravity locally is the same as constant acceleration. But higher in the atmosphere, the gravity is less than at the surface, which correspond to less acceleration. So what if the atmosphere is constant in weight over time (a short time like 100 years), but it take up more space? Then more of the atmosphere would be higher above the ground, where the gravity is smaller. Would that mean less pressure at the surface? (The atmosphere could take up more space by thermal expansion, if it’s hotter.)

  32. I don’t know much about pterasaurs but I recall they had hollow bones and were up to the size of a modern day glider.

    There is an idea which I’m sure you’ve encountered about a reduced gravity earth in the past:

  33. The atmosphere is not a static system and pressure is constantly varying at any particular place over any period of time due to temperature changes, wind speed changes, topography, particulates and, importantly, how much is being lost to space versus being generated from the crust (e.g. volcanic/tectonic activity). Trying to find an average for such a complex dynamic system is difficult – trying to find a trend from this non-linear average is meaningless.

    There also seems to be much confusion about atmospheric dynamics amongst mainstream scientists, who often confuse atmospheric pressure and weight, which are two different things. The atmosphere is a gas and you do not weigh a gas by measuring its pressure. Pressure is a vector in all directions, but (because of gravity), weight is a vector in one direction only, down. The atmosphere does have mass, but weighs nothing. To get a good estimate of the total weigh the atmosphere you would need to freeze a column of air stretching from the ground to the top of the thermosphere of one square meter in cross section and multiply the weight of this by the surface area of the planet, Counting molecules of all the different types of gas making up the atmosphere and adding their molecular weight could also work.

  34. A drop of 1 Mbar may seem trivial over 90 years, but at that rate mother Earth may run out of atmosphere altogether in just 100,000 years !!

    Look on the bright side. There is absolutely no need to worry about the Earth becoming like Mars in 100,000 years’ time. Don’t you realise that global warming will finish us all off long before then?

  35. Interesting. I agree that if these dinosaurs did fly, rather than glide down slope in mountainous areas, the air pressure/density would have to be higher. It was also warmer back then and, no not GHG’s, but an increased air density will increase temperature due to adiabatic compression due to gravity. Back in the Carboniferous there were very large insects which leads to the conclusion that the O2 levels were higher and air denser again leading to higher temperatures which also helps with insect metabolism.
    It seems that you are on the right track.

  36. Blokedownthepub claims that past CO2 levels were higher than today. Correct! The Ordovician had levels up around 8000ppmv and suffered a severe ice age.

  37. Some study I read recently suggested that when atmospheric pressure reaches some critical value (above modern values), the Hadley-cell pattern changes dramatically to a “single cell” configuration in each hemisphere, something like Venus. This is a more efficient thermal transport configuration, and is the reason polar temps were temperate-like in ancient times as opposed to today’s arctic temps.

  38. Correction to penultimate paragraph: “mega flora” would be large plants; you probably want “mega fauna”.

  39. I’d like to see the model that these ‘engineers’ used to determine how pterosaurs flew. Do you have a link for it?

    See, there are some details of the fossil record that strongly suggest these ideas of pterosaurs needing ‘higher air pressure’ don’t hold up. Other much smaller flyers, contemporary with pterosaurs, show adaptations for flying that suggest the air then was pretty much the same as air now. Birds in particular. All flying birds, large and small, have a feature called an alula on the leading edge of the wing. It adds wing area and increases lift during low-speed maneuvering like landing. The first known bird with an alula dates back to about 131 million years ago – the mid-Cretaceous. Birds with alulas are also known from 115 million years ago – not that long before the 100-75MYA window talked about in your source. And of course, birds from after that time also have alulas. If air pressure was that much higher, conferring that much additional lift, then why did these early birds need an alula?

    Biomechanics analyses are notorious for being nonlinear — that is, small changes in the input can lead to enormously out-of-proportion changes in the results. I know that people have built pterosaur-shaped drones that fly quite well in today’s atmosphere. I also know that Don Rumsfeld’s much-mocked quote about knowns and unknowns applies strongly to prehistoric lifeforms. There are things we know, and things that we know we don’t know, but there are also things that we do not know we don’t know. There are also an awful lot of things we think we know, but ain’t really so. The fossils don’t tell us everything, and we should not ever assume that they do. As a result, I simply don’t trust esoteric analyses like this that arrive at extraordinary results.

  40. The story of Noah and Noah’s ark is being told in many nations and peoples as a legend. Nevermind the apparent variations in the story from people to people, due to the fact that it is being told so universally all over the world, would seem to suggest to me that there was a time in the past when part of the whole atmosphere came down on us. Noah reports that after the big flood he saw a rainbow for the first time in his life. That would seem to suggest, as reported by others even earlier, that life existed without rain or snow falling down. Deposits of coal found in Antartica seem to support this argument.
    So apart from blaming high CO2 – although I do not deny it is a good possible factor – I would definitely also investigate the possibility of a much higher water vapor content in the atmosphere.
    The assumption of 5000 bars seems plausible to me – it explains that conditions for life were much more favourable for living longer and being bigger as well. That explains the exisitence of a certain town in south America as well that is still raising many eyebrows to this day. It might perhaps explain Stonehenge as well.

  41. Increasing gravity??? I don’t think so. The film clip appeared sensible for about 12 mins. then went haywire. Where did all the extra material come from? Why did we not loose all atmosphere 300Ma ago since it is gravity that holds the atmosphere in place?

  42. Makes sense to me. I would be utterly surprised if atmospheric pressure had not been higher than present. To be honest when I think of the early Hadean era Earth I always picture it with a 90 bar atmosphere, just like Venus.

    I just never really considered the implications or rate of a declining atmospheric pressure and the modern world we live in… It’s funny how a person can have two different modes of understanding. The one that you live in everyday, and the theoretical… and every now and then you bang the two together in an epiphany and go “D’oh, I shoulda realized that!”

    So if the theory is correct, there are some very interesting implications concerning CO2′s non role as a climate driver for starters, and it becomes more of a concern as to how long life sustaining amounts of CO2 remain in the atmosphere coupled to a decent atmospheric content/pressure.

    I look forward to the second part of this post….. Interesting stuff!

  43. The “bumble bees can’t fly” canard just won’t die. Here’s the absolutely true story I found on the somewhere Internet, or someplace else. I’ll provide a citation some time. Honest.

    Engineers at one of the large aerospace firms were working with a computer program designed to analyze the efficiency of jet aircraft wings. Keep in mind that fixed-wing aircraft are gliders, aerodynamically–as opposed to birds and bugs which use their wings for both thrust and lift.

    A bee invaded their space, and got swatted. Somebody got the bright idea to measure the bee-corpse’s wings and plug that information into the program to see what popped out. Clearly this is far outside the program’s design parameters.

    The program’s output actually meant that bumble bees can’t glide. Which is true, but that’s probably pure coincidence.

  44. Anthony is correct, temperature cannot change the total mass (and therefore the average surface pressure) of the atmosphere. It DOES change it locally, though, but vertical circulations and horizontal redistributions of mass are involved, for example, low pressure formation in one region must be matched by higher pressure elsewhere.

    Also, don’t confuse density with surface pressure. Water vapor is less dense than dry air, but if you add more water vapor to the atmosphere, the surface pressure will go up. It’s like adding a log to a bathtub full of water…the log is less dense, but the total weight increases.

    I tend to think that it is the existence of life which has sucked almost all of the CO2 out of the atmosphere, since Mars and Venus have atmospheres which are almost 100% CO2. But I don’t have an opinion regarding how high atmospheric surface pressure was in the past. Not enough data. :)

  45. So Dinosaurs Could Fly !

    Sure, and just like us, they preferred 1st Class (but the leg room in Coach was h-u-u-ge compared to today). ;o)

    The wild card I’d think would be what happened to our atmosphere as the earth encountered other stellar systems while we’ve been moving about the universe. Depending on the encounter, the earth might add to its atmosphere or have some of it stripped away.

  46. Now if you would propose that a decreasing atmosphere might be harmful to humans or a national security risk, there just might be a very large grant coming your way. I believe the equation (known as the Hansen equation) is:

    h-d+F=$

    where h is hypothesis, d is data and F is fear.

  47. While many people laugh at the “expanding earth” theory (just like some laugh at AGW skeptics) – simple logic says this…. each day, tonnes of dust and micro meteroites fall to earth. I`ve seen some estimates that claim up to 200,000kg per day. If it`s 100 tonnes per day (100,000Kg), then in just 1 million years, this equals 36 trillion Kg. Now if the “100 tonnes” per day is actually more like 1000 or 10,000 tonnes per day ( we have no accurate measure)…. then the expanding earth theory has some validity. We ALL know that the planets formed by accretion of dust and rock…. why do we assume this just magically stopped 4.5billion years ago !! Of course it slowed down to an almost stop – but it could not have stopped completley. Obviously some of the crazy “expanding earth” theories that claim earth has doubled or tripped in size are crazy, but if you do the possible numbers, then it`s quite plauside that a 10-20% increase in the past billion years may have happened.

  48. “which included this graph depicting an observed fall in global annual mean atmospheric pressure since 1916 (from NOAA I believe)”

    Oh Oh! Mr. Watts: Can you remember this link: http://wattsupwiththat.com/2012/06/01/phil-jones-gives-a-talk-at-knmi-in-de-bilt-meanwhile-temperature-and-paleo-researchers-are-still-blowing-off-data-requests/

    I am looking for the source of that graph and cannot find it on NOAA or anywhere else so far. You have to produce a credible source for that graph and data.
    Now I have the feeling that Cole 2010 made that graph up.
    Besides Cole 2010 cannot open in Internet Explorer as well as in Google Chrome. It gives warnings that downloading this file could seriously harm or damage my computer. So I won’t open it.
    Please would you give us the link on NOAA or from any other harmless scientific organisation so I can verify that this graph is not fictional!
    It is a very interesting piece however.

    REPLY: Your paranoiaware is probably set too high on your computer. I had no trouble downloading the Cole PDF file, stored at Google docs. Since you’ve demonstrated you probably can’t get past this limitation (or won’t), I’ve placed the file on the WUWT server and updated the link. The post is by Andi Cockroft in New Zealand.

    Note that the difference here is that I solve the problem rather than writing back “Why should I make the data available to you, when your aim is to try and find something wrong with it?” like Dr. Jones did. – Anthony

  49. Carl Chapman says:
    June 2, 2012 at 12:47 am

    I had an email discussion a few years ago with Steve Nerem of the Colorado Uni, which is where the sea level numbers come from. I had noticed that all the increase in sea level came from the adjustments due to global average atmospheric pressure. Without the adjustment the sea level was falling. ,,,,,,,,,,,,,,,,,,,,. The fact that the University of Colorado showed more sea level rise after the adjustment means, IMO, there is something wrong with their adjustment process and it is exaggerating the sea level rise.
    ========================================
    exactly…..measurements show sea levels falling……adjustments/math/assumptions show sea levels rising

  50. “A drop of 1 Mbar may seem trivial over 90 years, but at that rate mother Earth may run out of atmosphere altogether in just 100,000 years !!”

    Yes but how many years until humans expire b/c of lack of air pressure. Or will we all be wearing spacesuits 24/7 by then? This could be Algore’s new cause.

  51. There are two periods when, at least, oxygen was significantly higher. The Cretaceous, 100 MYa 29% and the Devonion/Carboniferous, 400 to 300 MYa at 30% (briefly 35%) which made for higher air pressure.

    This also allowed for giant insects in the Carboniferous for example. Giant spiders, giant dragonflys. One of the more interesting things it also allowed for was giant forest fires. With oxygen over 30%, forest fires were unstoppable and could burn half-way across a continent. Some of the coal is really just repeatedly burned-down forests.

  52. Figure 1 looks very much like a proxy for atmospheric temperature, excepting the 1970s and 1980s. Which fits with my theory that the measured surface warming during that period was a spurious signal from increased solar insolation, due to decreased anthropogenic aerosols and didn’t result from increased atmospheric temperatures.

  53. Agree with Les Johnson that it’s not clear that this is guest post.

    I can see AW’s small-minded foes getting their tight tights in a twist and flailing away in a twittering frenzy over this passage…

    For those who might not remember, I remind readers I do not have strong scientific qualifications in meteorology, hydrology chemistry etc.

    REPLY: My error, now repaired. This is in fact a guest post by Andi Cockroft, but he put his home address etc at the top along with his name and I deleted the whole lot, neglecting to put his name back. My excuse is that it was late at the end of the week when I composed the post – Anthony

  54. I think the increased oxygen levels are a more likely reason for the mega fauna. That would explain the size of the dinosaurs. They were essentialy supercharged. It might also explain their extinction if they weren’t able to adapt to a lower oxygen level.

    Since Venus is closer to the sun and smaller you would expect that the solar wind would have stripped more of it’s atmosphere than Earth’s. The moon was also closer to the Earth in the past so could it also have caused more striping of the atmosphere?

  55. Ok, notwithstanding the pterosaur vs dinosaur discussion, we don’t know that the large versions could actually fly. Just because they were built sorta like birds, and looked sorta like birds, doesn’t mean they could actually fly like birds. Evolution and hybrid vigour being what it is, there is just as good a chance that the biggies were no different ecologically than modern counterparts: flightless, maybe a little gliding, probably mostly evolutionary dead-ends – literally, the down-side half of the foodchain. We simply don’t know if the flight crew evolved out of the big dummies, or the other way around. You could argue either, and it wouldn’t surprise if both were true.
    There is this unfortunate characteristic of physical scientists to pretty much always misunderstand the range of adaptiveness built into complex organisms (trees, pterosaurs, climate scientists) as a result of their evolutionary progress. This would have been substantially true millions of years ago as it is today. It is an unwarranted and naive assumption to assume that old necessarily means primitive in terms of adaptability to their environment.

  56. Vukcevic,

    Interesting graphs, what do you think happened in the1920s? It seems an event or collection of such kicked off about then. Similarly something happened in 1972 and 1992/3. What?

  57. Once a “particle” of air reaches escape velocity, ~18k mph, and has a clear shot, it can leave the earth’s gravitational well permanently. Surely energetic particles or photons from the sun would be capable of washing some percentage of the atmosphere from the earth.
    Then there is that whole business about the speed of light not being constant. If that’s possible, maybe God decided to change the gravitational constant one morning when he discovered his design bureau had super sized some reptiles beyond accepted design limits.

  58. I believe gravity is increasing. Everyone I know, including myself, weighs more now than 20 years ago. :-)

  59. Some fundamental physics/thermodynamics for discussion:
    The pressure of the atmosphere at the surface of the earth is strictly due to the total weight of the gasses above the point in question. It is basic physics. It does not matter what the temperature of the gas is above the point in question. Also it does not matter what the gas is.

    Since PV=nRT, in a constant Volume, the pressure will rise as the increase in absolute temperature. The volume of the gas in the earth’s atmosphere is not constant. Temperature rise will not affect the atmospheric pressure at the surface, again the weight of gas above the earth surface is the determining factor.

    The suggestion that burning fossil fuels, due to removing oxygen from the atmosphere as water, decreases the atmospheric pressure is questionable.
    The answer would depend on the relative amount of Carbon versus Hydrogen in the fuel that varies considerably. Coal has much less hydrogen than natural gas. Burning carbon will increase the weight of gas at least initially until the CO2 is absorbed somewhere. On the other hand the Hydrogen will burn to water vapor. Someone else needs to clarify what percentage remains in the atmosphere versus how much falls as rain removing oxygen from the atmosphere.

    I also have some trouble understanding the theory that the gas surface temperature will rise as the the surface pressure rises, compressing the gas) due to a higher column of gas, more mass of gas. True in a fixed volume the temperature rises as gas is compressed as in an internal combustion engine. However, the process involved for the increase in planet pressure is not adiabatic (no heat loss) for a planet’s atmosphere. Over time the gas will loose the heat to the gases at higher elevations. Possibly someone could explain further.

  60. I’ve always wondered what effect a large, species destroying asteroid would have on Earth’s atmosphere. Would some of it “splash” into space, never to return?

  61. There is a NASA project to obtain the first quantitative measurements of atmospheric pressure on the early Earth, from the Archean Eon >2.5 billion years ago:

    It hopes to:
    1) improve our understanding of Earths early environment;
    2) constrain the development of biogeochemical cycles, notably nitrogen;
    3) calibrate greenhouse evolution models by providing data on whether greenhouse forcing gases were major or trace atmospheric constituents;
    4) permit testing of hypotheses about Archean oxygen levels; and
    5) provide tests for astrobiological models of planetary atmospheres.

    Two paleobarometry techniques will be used. The first uses a methodology based on a proven and published paleoaltimetry technique (Sahagian, 1994, 2002) involving the determination of vesicle size distributions from the top and bottom of uninflated basaltic lava flows, then applying the ideal gas law to obtain pressure.

    The second marries raindrop formation theory (Lorenz, 1993, 1995) with empirical studies of raindrop impact-crater volume (Ghadiri, 2004). Since atmospheric density controls the final size and velocity of raindrops, fossil raindrop imprints on sedimentary surfaces can be used to extract atmospheric pressure.

    The significance of the proposed study applies to NASA Strategic Sub-goal 3C.2 “Understand the processes that determine the history and future of habitability in the solar system, including the origin and evolution of Earths biosphere”

    http://astrobiology.nasa.gov/exobiology/projects/archean-paleobarometry-2

    It is indirectly related to a Caltech hypothesis described in the paper, “Atmospheric Pressure as a Natural Regulator of the Climate of a Terrestrial Planet with Biosphere,”:

    http://media.caltech.edu/press_releases/13266

    “As the sun has matured over the past 4.5 billion years, it has become both brighter and hotter, increasing the amount of solar radiation received by Earth, along with surface temperatures. Earth has coped by reducing the amount of carbon dioxide in the atmosphere, thus reducing the warming effect. (Despite current concerns about rising carbon dioxide levels triggering detrimental climate change, the pressure of carbon dioxide in the atmosphere has dropped some 2,000-fold over the past 3.5 billion years; modern, man-made increases in atmospheric carbon dioxide offset a fraction of this overall decrease.)

    “The problem, says Joseph L. Kirschvink, the Nico and Marilyn Van Wingen Professor of Geobiology at Caltech and a coauthor of the PNAS paper, is that “we’re nearing the point where there’s not enough carbon dioxide left to regulate temperatures following the same procedures.

    “Proof of this hypothesis may come from other research groups that are examining the gas bubbles formed in ancient lavas to determine past atmospheric pressure: the maximum size of a forming bubble is constrained by the amount of atmospheric pressure, with higher pressures producing smaller bubbles, and vice versa.”

  62. I hadn’t thought about it but it would not be surprising to find that the atmosphere has decreased in both density and volume as much of the carbon and oxygen has been preferentially bound up into rocks by biological processes (coal and petrochemicals and limestone etc.) over the last 4 billion years. Our atmosphere is gradually being converted into rocks. Over the past 4 billion years we probably also collected a great deal of space dust, comets, asteroids, etc. gradually adding to the mass of the planet. Higher atmospheric concentrations of both carbon and oxygen would also help explain the larger plants and animals that existed hundreds of millions of years ago.

    Interesting to think about these things.

  63. I wait in baited anticipation to see NASA apply this data as an excuse to reduce the rate of sea level rise the way they conversely used GIA to increase it. I suppose I shouldn’t hold my breath…

  64. Robert Morris says: June 2, 2012 at 5:50 am
    ……………..
    Hi Robert
    Planet’s polar areas appear to respond to the solar cycles to a degree of intensity which is not possible to explain by the known incoming power measured either by the solar irradiance or the magnetic indices. I came across the Arctic ‘link’ couple of years ago

    http://www.vukcevic.talktalk.net/SSN-NAP.htm

    and the Antarctic’s more recently

    http://www.vukcevic.talktalk.net/SSN-dBzA1.htm

    One of constraints of the present day science is that ‘all unknowns are known’, hence if someone comes across something new, unless the accompanying physical mechanism is offered, a label of ‘pseudoscience’ is the best one can hope for. It is our fortune that was not the case in the past centauries when in the fields of electricity and magnetism, great discoveries were made.

  65. Someone mentioned it upthread and it’s something I’ve wondered about too: is the amount of gas compressed into pneumatic tyres, tanks, bottles, footballs and so on of any significance at all in reducing the pressure outside of these items?

  66. Andrew30 says:
    June 2, 2012 at 12:48 am
    —————————————————-
    Andrew30, hold my hand. We’re going to walk into the white building over there. They have cookies and you can draw on paper with different colors.

  67. I believe that water transport to the top of tall trees is attributed to leaf transpiration pulling a very narrow column of liquid from the ground. (As opposed to being pushed up by ambient atmospheric pressure–which would limit lift to approximate 32 feet.) I’m wondering how a much heavier atmosphere might affect this system. Would water transport change because of a change in transpiration? Could an entirely different system of transport evolve not based on capillarity tension? What effect might there be on maximum plant height?

  68. Why do we have to change the atmosphere to satisfy one big bird? Shouldn’t anicent composition, temperature and pressure of the atmosphere satisfy all other species first? Then let the one or two paleontologists argue over the last one remaining. It probably didn’t even fly.

  69. Fascinating, thanks Andy and Anthony.

    Oxygen levels higher… CO2 levels a lot higher… atmosphere a lot thicker so more buoyant and warmer… offsets the Faint Sun… makes pterosaurs flight and gigantosaurus long necks that require blood lifting biologically workable maybe… but what about gravity?? Now could the planet have spun faster, thus causing an effectively reduced gravity?

    OTOH, biologist Rupert Sheldrake says

    How constant are the “fundamental constants”:
    …Newton’s Gravitational Constant, Big G, is the one that shows the largest variations. Towards the end of the twentieth century, as methods of measurement became more precise, the disparity in measurements of G by different laboratories increased, rather than decreased. Between 1973 and 2010, the lowest value of G was 6.6659, and the highest 6.743, a 1.1% difference. These published values are given to at least three places of decimals, and sometimes to five, with estimated errors of a few parts per million. Either this appearance of change is illusory, or G really does change. The difference between high and low values is more than forty times greater than the estimated errors (expressed as standard deviations)…

  70. Notice the rapid decline since the 60′s. It’s all those rockets which have punctured the surface tension of the atmosphere and allowed all the air to escape into space.

  71. i always thought 1 atm pressure was 1016 millibars….a higher atmospheric pressure in the distant past could explain the dim sun paradox…vast amounts of co2 and o2 that were once in the atmosphere are now in the crust of the earth…as for engineers claiming pterosaurs could not fly…they cant figure out how the dragonflies do their stuff…you learn something new every day

  72. In ancient times, we know that there were giant flying critters. Such could not exist unless the atmosphere was thicker back then. Therefore I at least have known for decades that it was, because that was the only possibility. What I ask is, that being true, why did you not know this?? I have known for years that the ubsurd idea that they flew by using seashore winds was impossible, no such number of flying lizards could survive being so dependent on such limited winds, to say nothing of the insects. What you now need to ask is, what blind spot allowed you to believe the obviously impossible for so long? Is it because someone with an important scientific sounding title did not say it, because it was not in the scientific textbook(even though the obviously absurd seashore theory was)? Do you still have this blind spot? What else might you therefore still be blind to? People who come here supposedly do not ascribe to the idea that it is true just because some person in a white lab coat ( or like Algore say they have one) says so. Perhaps that is not true, perhaps people here are far more susceptible to the argument from authority fallacy than they believe. Perhaps it is time to reexamine why you believe what you believe.

    Since I knew that the ancient atmosphere MUST have been thicker back then (it would also help giant non flying critters to breath), I have looked for evidence of how this happened, and found it. A while back, scientists discovered that the protection from atmospheric stripping by the solar wind supposedly afforded by earths magnetic field was less than believed, and it was being stripped. I have also known about the moons tidal effects helping strip the atmosphere for even longer. This is not even counting trapped air bubbles found in antarctic ice, which showed at least two atmospheres of pressure a mere 200,000 years ago or so (also more CO2).

    The reason you have just heard about it until now is because scientists have become such specialists that they don’t even know what is going on down the hall. If it isn’t happening in their increasingly narrow specialty, they don’t know about it. besides, they all fight for the same piece of the budgetary pie, and thus only care about the importance, come budget time, of their small department. Other departments are the enemy. I doubt that the dinosaur people will even hear about this (despite the continuing absurdity of their flying reptile theories).
    In Germany the concept of the “Fachidiot” is well know. It describes the chap who knows more and more about less and less, to the point where he is incapable of functioning outside his own narrow field. In the English-speaking world, we recognize the expert as the person who avoids the small pitfalls as he sweeps on to the grand fallacy. The generalist, the person who has experience of diverse areas, and the man with insight are necessary counterbalances to Fachidiocy, for it’s not academic background or endless doctorates which are important in revealing scientific truth: the quality of the arguments is more important.

    And as for the science, here is the question now, why do we have any atmosphere at all? With the rate it is being stripped, something must have been adding to it for a long time, what was and is that something? How much and of what is being added? Also, how much atmospheric pressure will counteract the early faint sun “paradox” (paradox to people who are “Fachidiots”). Now that you know that the absurd idea that our atmosphere was not always exactly like it is now is false, what other paradoxes does this clear up? What other things do you “know” that are, in fact, completely wrong?

  73. I went through this same reasoning some 30 – 40 yrs ago but I also considered the tuatara, a 100 M-yr old NZ reptile like animal, which operates close to oxygen deficit through it’s lifetime. When it (and dinosaurs et al) evolved the partial pressure of O2 must have been somewhat higher than today.
    How much of the atmosphere was blown into space 65 M-yrs ago by the meteor(s) and what effect could that have had on the 02 partial pressure? What effect did a sudden reduction in O2 partial pressure have on dinosaur respiration, i.e. did dinosaurs et al evolve w/ less efficient hemoglobin than mammals/birds of the day?
    Over the years I have seen estimates of Earth’s atmospheric pressure (Mars too!!!) of about 250 bar 4 B-yrs ago based on the present known rate of atmospheric loss into space. Note, some of these high oxygen estimates above, ca. 35%, have to be balanced with a large increase in CO2 because RUBISCO, the CO2 fixing molecule in photosynthesis, has an operating envelope of O2/CO2 partial pressures. At 1 bar and 300 ppm CO2 RUBISCO becomes non-productive at 27% O2!

  74. From one non scientist to another: If the atmosphere was considerably denser, the ppCO2 should have been considerably higher, resulting in a significantly different carbonate compensation depth in the oceans, altered pH, and associated differences in aragonite production by marine organisms. Is there significant evidence to support this?

  75. I wonder . . .
    a) . . . whether an atmosphere with high concentrations of carbon dioxide and/or oxygen would be as well-mixed as the current atmosphere – either with regard to altitude or spatially?

    b) . . . if an oxygen enriched atmosphere (“35% back then”) would be highly combustive? I’ve seen 23% and up given as a mix above which this becomes an issue.

    [However, North American Aviation proposed using a 60-40 oxygen/nitrogen mixture for the Apollo command module {NASA wanted and got 100% oxygen} so both the 23% and the 35% may be safer than I’ve thought.]

    http://www.wired.com/science/discoveries/news/2009/01/dayintech_0127

  76. By the way, this fits well with Nikolov and Zeller’s picture of the ancient past.

    For those who are interested, who wondered about N&Z seeming to challenge the Second Law (a reasonable doubt Anthony had, for one) please wander over to Tallblokes Talkshop. I’ve written Part One about my visit to see the experimental work Graeff has been doing, that seems to uphold the necessity for a modification in the Second Law, not in its essentials, but in one detail that has been believed but never, until Graeff, actually tested.

    Of course, I believe this work is extremely important. Nullius In Verba and all that.

  77. We’re not talking flying dinosaurs here! We’re talking a disappearing atmosphere that will kill us all, probably by 2100!
    There is no question about WUWT’s leadership role in bringing scientific sanity to the public on the issue of global warming (aka, climate change). In my opinion WUWT earned equal leadership status as a prototype for other websites on other issues.
    Obviously the IPCC is readying new pseudo-science propaganda weapons for deployment. I not sure what they are calling the thing … maybe something like “sustainability of climatically induced bio-diversity and extinction losses under projected human growth and socio-economic systems” … whatever. The definitions will surely be sharpened and test launched at the upcoming June 22nd Rio Conference. It is being led by our old friend (now a multi-billionaire) Maurice Strong. Now is the time to start a rigorous examination of the Rio agenda and the assumptions of its outcome.
    I hope WUWT continue to be willing to play a leading role in this strange journey.

  78. I’m not a scientist. My understanding is that only hydrogen and helium are light enough to reach escape velocity. I would imagine a lot of Helium has been produced by radioactive decay in the last 4.5 billion years, yet the atmosphere is not Helium-rich, it’s just 0.00052% vol of the atmosphere (Wikipedia – which lies).

  79. M Wilson says
    (by implication, referring to the given link)

    Scientists have speculated that temperatures warm enough to maintain liquid water were the result of a much thicker atmosphere, high concentrations of greenhouse gases or a combination of the two.

    Henry says
    As I said earlier, I also believe water vapour could have been much higher and temps. could have been much higher.
    Whether CO2 is a GHG, is another matter. I do not that as proven beyond reasonable doubt.

    http://www.letterdash.com/HenryP/the-greenhouse-effect-and-the-principle-of-re-radiation-11-Aug-2011

  80. Another “average” graph that does not reflect the reality of atmospheric exchanges and climatic evolution…

  81. Fascinating topic. The atmospheric pressure argument is far more compelling than the gravity story (magic anyone?).

    Raindrop studies however seem to refute it to some extent, but, perhaps twice modern levels was enough?

    Air density 2.7 billion years ago limited to less than twice modern levels by fossil raindrop imprint Som etal Nature 484, 359–362 (19 April 2012)

    Here we show that raindrop imprints in tuffs of the Ventersdorp Supergroup, South Africa, constrain surface air density 2.7 billion years ago to less than twice modern levels. We interpret the raindrop fossils using experiments in which water droplets of known size fall at terminal velocity into fresh and weathered volcanic ash, thus defining a relationship between imprint size and raindrop impact momentum.

    http://www.nature.com/nature/journal/v484/n7394/full/nature10890.html

  82. The ‘engineers say bumblebees can’t fly’ thing is one of those urban legends of science. Bumblebee flight is understood quite well. It has great appeal, however, to the ‘those scientists think they’re so smart’ crowd.

  83. agwnot says:
    June 2, 2012 at 2:17 am

    Pilots know when humidity increases, lift decreases, so yes, water vapor affects the density of the air. That observation is true when water vapor displaces air locally, i.e. when otherwise the air pressure is the same, higher humidity results in less lift. What you attempted to argue was the contribution of more or less water vapor in the total atmosphere. If there is more water vapor, that means all your p’s need to add up to more than we have now. And since all the other p’s don’t change, the total pressure goes up with more water vapor when the other components are constant.

  84. Fascinating. If Levenspiel et al’s arguments for a very thick atmosphere high in CO2 is correct, it implies that rather than not having enough CO2 in the ancient atmosphere to account for the Faint Sun, we have way too much. The Earth had a liquid ocean. At that amount of CO2, that thick of an atmosphere, I would guess that without something to counteract the warming effect, the ocean would evaporate away. Evidence of a thermostatic control mechanism on the Earth’s temperature?

    Paging Willis?

  85. The Sea-Expansion Hypothesis: Because sea-water is compressible, the observed secular decrease during 1966-2006 of sea-level atmospheric pressure caused the observed secular increase in sea-level during that same interval.

    Or less formally, sea-levels have been rising not because of AGW, but because the earth’s atmospheric pressure has been decreasing. True or false?

    As an exercise in citizen-science, WUWT readers are invited to post their personal assessment as to whether the Sea-Expansion Hypothesis is tenable.

  86. Are we sure the pterosaurs were flying in the atmosphere? Might they have been something like proto-penguins, or air breathing manta rays?

  87. ggm says:

    June 2, 2012 at 4:58 am

    While many people laugh at the “expanding earth” theory (just like some laugh at AGW skeptics) – simple logic says this…. each day, tonnes of dust and micro meteroites fall to earth. I`ve seen some estimates that claim up to 200,000kg per day. If it`s 100 tonnes per day (100,000Kg), then in just 1 million years, this equals 36 trillion Kg. Now if the “100 tonnes” per day is actually more like 1000 or 10,000 tonnes per day ( we have no accurate measure)…. then the expanding earth theory has some validity.

    —–
    So 1,000 tonnes/day gives 365 billion tonnes in 1 million years. The Earth has a [current] surface area of about 500 million square kilometres (very roughly). So that’s about 730 tonnes per square kilometre. Or 730 grammes/square meter/million years. Over 200 million yeras that’s a non-negligible 146 kilograms/square meter; with a density of twice that of water [and it might be more] that will increase the diameter of the earth by about 146 milimetres over those 200 million years.
    Moving three inches further from the centre of mass [and an increased mass, too!] will not reduce gravity all that much, I suggest.

    Have a wonderful Jubilee Weekend!
    Auto.

  88. Legatus says:
    June 2, 2012 at 7:31 am

    In ancient times, we know that there were giant flying critters. Such could not exist unless the atmosphere was thicker back then.
    [---]

    We don’t actually know this. We presume it by comparison to modern proxies. We can calculate probable weight to area ratios based on the anatomy of the species as we know it, and with the use of well established and tested ratio ranges for a wide variety of aerodynamic and partially aerodynamic surfaces, deduce a likelihood of flight, but we will never actually know it. Therefore, to conclude denser atmosphere from the anatomy of a sparse number of ancient critter samples is simply a wild-eyed flight of fancy.

  89. “Neither survived to compete alongside the pterosaurs however. Many believe the concentrations of O2 dropped too low to allow such mega flora to survive beyond the Permian.”

    Did you really mean “megaflora?” Insects aren’t flora. Perhaps “insect megafauna”?

  90. Are those pressure data from 1916 to present good data? Were stations added or subtracted? Is there any impact from smog in urban areas? Oh, wait, sorry, I’d forgotten that such questions just aren’t to be asked in polite company.

  91. These gentlemen think pterosaurs could fly quite well at todays atmospheric densities. A very good paper. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0013982

    I used to make my living as an aviator so I have some familiarity with the requirements for flight. their analysis and the program they used to do the aero computations make sense. 1/2 rho V2, the energy of air flowing past a wing, doesn’t require an adjusted rho from increased air density to enable pterosaur flight capability by their calculations, although it would certainly facilitate flight.

  92. Venus may be the odd one out due to thermal overturn of the crust “recently”. That might have resulted in a tremendous CO2 release into the atmosphere (as well as the SO2 which we also observe. Mars, too, with the massive Hellas, Argyre and mostly-submerged impact scars on Mare Borealis, might well have lost most of its atmosphere, with its present atmosphere, being regenerated from vulcanism (such as Tharsis and Elesium).

    The high percentages of CO2 being suggested for the time of the pterosaurs would be toxic to animal life as we know it.

    Too many assumptions, too many variables, too many unknowns.

  93. I made the observation that we often see CO2 concentrations in ppm or ppmv, but seldom in partial pressure.
    I think it matters a great deal to the study of climate history whether a given CO2 concentration occurs in a 1013 milibar atmosphere or one of 5000 milibar. I think the question of atmospheric pressure in the geologic record is addressed too little.

    http://wattsupwiththat.com/2012/03/03/new-questions-on-isostacy-and-mean-sea-level/

    As for the question of what is the shape of the atmospheric decline curve, it really ought to be exponential.

    As for replenishment, we have heard of the huge volumes of basalt erupted in the Deccan Traps and Siberian Traps. What might be the range of gas volume errupted with the extruded basalts? Is it a significant amount? If insignificant, then it is difficult to imagine vulcanism adding much to the atmosphere in the past billion years.

  94. So about 2.8 million km3 of calcium carbonate estimated to be in today’s continents. Rough calcs suggest this equates to 780 giga tonnes of C and 3140 x giga tonnes of O locked up as CaCO3. If this deposit was originally all in gaseous form – Co2 and the balance as O2 – it would nearly double the mass of the atmosphere ( est as 5000 giga tonnes).
    O2 levels would be about x2 what they are now…..35-40%, and CO2 level would be about double the current…..around 6gigatonnes.
    Not nearly enough to explain the much higher concentrations of 2000-4000ppm we see from paleo records.

  95. RogerJ says:
    June 2, 2012 at 5:23 am

    “A drop of 1 Mbar may seem trivial over 90 years, but at that rate mother Earth may run out of atmosphere altogether in just 100,000 years !!”

    Yes but how many years until humans expire b/c of lack of air pressure. Or will we all be wearing spacesuits 24/7 by then? This could be Algore’s new cause.

    Hmm, the human body seems to adequately compensate for far lower air pressure (475 millibar, or so), so we should be good for another 50000 years. Obviously then, you should learn to relax and breathe deeply and slowly, if you’re planning on living 50000 years.

  96. If air is “stripped” from earth, would it not also be “stripped” from giant gas balls like Jupiter?

    Then where does it all go? Might it not “condence” out in the Ort belt, as mini-comets?

    Then might it not “rain” back onto the planets, as shooting stars? This would complete a nice, neat cycle.

    Furthermore, once you have this cycle, (a bit like evaporation-leading-to-clouds-leading-to-rain,) you might have times of cosmic “drought,” with few comets, and times of cosmic “rain,” when on any given night there would be several comets in the sky.

    What convinces comets to leave the Ort belt and plunge towards our sun? A passing brown dwarf? The shock wave from a super nova? Whatever it is, it seems possible such a nudge might send a thousand comets towards the sun, rather than just one.

    None of these comets need to hit the earth. They just need to cross the earth’s orbit, leaving a trail of dry ice and dust.

    I remember one night when I looked up into the sky as the earth passed through the orbit of a comet that zipped around the sun nearly a century earlier. The entire sky was filled with shooting stars. There was no time when two or three were not falling at the same time.

    Suppose this went on for years? Would the amount of gas our atmosphere held increase?

  97. Oxygen is dissociated from the oceans and injected into the atmosphere by cyanobacteria. The reverse of the sequestration of CO2 as PH and carbonate as regards the mass of the atmosphere. Maybe we should be worrying about oxygen. Oxygen concentration fell like a rock in the major extinctions. Cause or effect? And then there are the banded iron formations to demonstrate ancient fluctuations…

  98. [forgive any redundancy of above comments, have not reviewed all yet]

    There are four parameters for flight…gravity, thurst, lift and drag….if we assume gravity constant, then consider ‘thrust’….it is impossible to envision a magnitude changes, since the Jurassic, of muscle or bone, strength or weight….both ‘lift and drag’ are proportional to atmospheric pressure, giving slow moving, but double wingspan flight….this from ‘Slaying the Sky Dragon’…

    “Compare the 65 million year old Pterodactyal Quezalcoatus Northopi and it’s eleven meter (thirty-six foot) wingspan with todays largers Peurvian Condor wingspan of five meters (sixteen feet). In addition compare the Meganeura Dragonfly with half meter (twenty-two inch) wing span and today’s Atlas Moth and it’s quater meter (eleven inch) wingspan.”….page 253….

    The atmosphere is being continually eroded by solar wind, lunar tidal pulls, meteor impacts, volcanic outbusts that pull gases beyond exit velocity and by molecular decay, as in N14 to C14. But, the Earth is being constantly replenished by ‘elemental’ gases. Helium, Radon, Argon and the other formerly called “Inert Gases” provide a useful measure of production and extinction rates. [may post another reply after reading all comments, thanks]

  99. As already mentioned, but worth getting the point across: Pterosaurs are flying reptiles, not dinosaurs. Not all big reptiles from the past are dinosaurs – in fact many were not. Dinosaurs were just a very successful branch (OK, really two branches) of big reptiles. You guys pride yourselves on being scientifically correct – so this ought to matter – you may someday be involved in “The Great Dinosaur Cover-Up” where government scientists prove dinosaurs never existed using highly massage satellite data (you will not be allowed to see the raw data because it would just confuse you).

    Birds are in effect flying dinosaurs… Birds can fly – I know this because I have seen it. I am sure some government organization has a carefully normalized database showing this is impossible and its all my fault for burning logs in my fireplace, but I am sticking to my observations – Birds Fly.

    Pterosaurs may have been gliders more than active flyers – there may have been higher winds where they thrived (or the scientists could just be wrong). There are other ways to provide additional lift without reverting to super-heavy atmospheres. Say 20% more pressure and a higher wind average and you might get enough lift to make the possible-problem to go away.

    Also, a higher oxygen content would lead to more efficient muscles – maybe the muscle strength for a pterosaur is calculated incorrectly.

    (Higher oxygen would also have led to some pretty mean run-away fires – I wonder if there is evidence of this?)

  100. mfo;
    The second marries raindrop formation theory (Lorenz, 1993, 1995) with empirical studies of raindrop impact-crater volume (Ghadiri, 2004). Since atmospheric density controls the final size and velocity of raindrops, fossil raindrop imprints on sedimentary surfaces can be used to extract atmospheric pressure.
    >>>>>>>>>

    It assumes that rain falls at terminal velocity only. Wind conditions can result in rain hitting the ground well below as well as well above terminal velocity and frequently do. Without knowing wind conditions at the time the impression was made, how could they possibly know with any degree of certainty that the rain drop was at terminal velocity?

  101. Bill Tuttle;
    Radio-controlled models, actually. Aircraft designer Paul MacCready built and flew a half-scale Quetzalcoatlus in 1986.
    >>>>>>>>>>>

    Yeah, but the key here is to note that is was “half scale”. The “square cube law” applies here. Double each dimension and the surface area (which provides the lift) would be four times as large, but the mass would be EIGHT times as much.

    Besides, he built his model out of wood and all the fossils we’ve found so far were made out of rock…

  102. I think I’ve got the answer. The moon used to orbit far closer to the earth than it does now. So, when the moon was very close to earth and overhead, the gravity experienced by the giant flying reptiles would have been substantially reduced, enabling them to fly.

    The other three weeks of the month they sat around and whined about how their offspring of the time were so much more disrepectful than when they were hatchlings.

  103. The problem with the theory of 35% oxygen is the burn rates. Working in petro chemicals they set up a HLA (High Level Alarm) for any concentration greater then 24%, due to the increased reactivity of any material in that environment. Clothes, paper products and especially petrochemical products become dangerously flammable with that small increase. In that, there was some testing of the danger of a 35% environment, and here is a refutation of the concept, abiding by a 35% possible concentration:

    http://www.fs.fed.us/ne/newtown_square/publications/other_publishers/OCR/ne_2004_wildman001.pdf

    But still the world would be very flammible. For fun, 1947 War videos Chemistry of Fire:

    And note that there are special cleaning requirements for tanks that have pressurized air with more then a 23% oxygen level:

    http://www.luxfercylinders.com/frequently-asked-questions/aluminum-scuba-cylinders-in-oxygen-enriched-and-oxygen-service

    There are quite a few detramental affects to high oxygen levels, and while it might not be a normal affect for this theorizing, would be an affect that might counter the abilty of the Earth environment from being able to sustain 25% or higher oxygen levels.

  104. mizimi says:
    June 2, 2012 at 10:00 am

    thanks for producing the numbers, mizimi.
    next case.

  105. ….continued from above….

    on the ‘faint Sun paradox’….i did try to engage Dr Lindzen on the dinosaur wingspan/double atmosphere explaination following the Jan, 2010 Lindzen-North debate at Rice University and in subsequent emails….[non-responsive]

    on the ‘dense air/sea level’….water is classified as non-compressible, certainly in the range of this discusion….

    on the….’total loss of atmoshere in 100k yrs’….this is linear projection, where erosion and decompositon would be logarithmic decline + continious ‘elemental’ atom additions….expect several million years….

    on….’dinosaurs couldn’t walk today’….i can bench press TWICE as much weight when i’m underwater….atmosphere with ~8 times pressure would provide some buoyancy….to walking & flying lizards….as for ‘flying pigs’….only AGW can provide buoyancy for that….

    [thanks for the discussion Andy & Anthony...as an engineer, i share Andy's persepctive]

  106. Chart 5: It’s interesting that the decrease in CO2 due to both continental and ocean deposits accelerated near the end of the Devonian, 350 Mya, and leveled out at the end of the Permian’s ‘Great Dying,’ 250 Mya. Then the slope increased as life re-established and flourished, baring a few cosmic impacts.
    Anyone notice , this is an inverse ‘hockey stick’ portending doom caused by marine organisms continually and permanently removing CO2 dissolved in the oceans? I’m no longer sympathetic of ‘Whale Wars.’

  107. The earth has gained mass through the years through impacts and dust accretion, and some of the early atmospheric components have solidified. Meanwhile, the earth’s rotation continues to slow as the moon’s orbital velocity increases. Could it be that increasing density is decreasing circumference, further increasing surface gravity?

  108. The amount of atmosphere loss to space probably isn’t linear. It probably changes due to solar activity, strength of Earth’s magnetic field, volcanism and temperature. For example, over the past 3 million years the Earth has been generally cooling. This would cause more gas to be dissolved in the oceans.

    I don’t think it is accurate to extrapolate a linear rate of atmospheric loss based on the very recent behavior of barometric pressure. An active sun will strip more away. A weaker magnetic field will allow more to be stripped away. Increased volcanism will add some, etc.

  109. “Well, seems that engineers are of the opinion that the pterosaurs were just too heavy to get off the ground given today’s environment, and they must have been helped by far denser air.”

    Unfortunately this is wrong. People who study pterosaurs consider that they were fully capable of powered flight, and in some respects superior to birds (though they were certainly more clumsy than birds on the ground).
    And if it was possible to fly with a much higher wing loading a hundred million years ago, why did birds and insects have wings as large as today?.
    Also an atmosphere as dense as 5000 mb would probably have a ground temperature higher than the boiling point of water in the tropics (calculate the altitude of the tropopause and multiply by the wet adiabatic)

  110. I’m not sold on the square cube law on the pterasaurs. If the additional wingspan were mostly tendon and cartilage with a thin membrane of skin providing most of the lifting area, these critters could have achieved much large lifting areas with only modest additions of mass. All it takes is one hallow bone finger spar to elongate out another meter or two with that skin stretched from the femur to the fingertip and a huge surface area is achieved with very little addition of weight. Add a little lifting body mechanics to the torso and this thing may have been perfectly capable of flapping hard enough to find an updraft and soar.

  111. Another alternative explanation is that the force of gravity has increased. Given the fact that prehistoric gigantism is hardly limited to aerial creatures, it seems that such an explanation — however strange it might seem — ought to be entertained by those with open minds.

  112. Lucy Skywalker
    Zhi-Ping Li and Xin Li may have a breakthrough in determining G and relating gravity to electromagnetism. See:
    Quantum resonance scheme to measure the gravitational constant G

    By the method of quantum oscillation, we get the accurate result of gravitational constant G in vacuum: G = 6.6722779(13)×10^-11 N·m^2 /kg^2

    They model gravity as varying inversely with the dielectric constant relative to that in vacuum, or inversely with the square of the local speed of light relative to that in vacuum.

  113. Interesting read. I could only respond with “Well, if you say so.”

    I have never seen an ostrich fly. Same would be said of a penguin and presumably the dodo bird. Did anyone see a dinosaur fly? Now I have see a lot of crap flying with regards to the atmosphere by ‘scientists’ over recent past.

    And then there’s the issue of fish with wings. And of course, the issue of imaginations with wings.

    “The ability to uptake O2 is governed by the length of the tracheae. Big insects naturally have longer tracheae, so uptake less O2 ….. ” Edit?

  114. Owen in Ga says:
    June 2, 2012 at 12:04 pm
    I’m not sold on the square cube law on the pterasaurs. If the additional wingspan were mostly tendon and cartilage with a thin membrane of skin providing most of the lifting area, these critters could have achieved much large lifting areas with only modest additions of mass. All it takes is one hallow bone finger spar to elongate out another meter or two with that skin stretched from the femur to the fingertip and a huge surface area is achieved with very little addition of weight.
    >>>>>>>>>>>>

    My comment was about the model, not the pterasaur. The model was half scale. Make the model full scale, and it would have four times the surface area and eight times the mass. So constructing and flying a 1/2 scale model proves… not much.

    On the other hand, there is little doubt in my mind that the pterasaur’s were capable of flight. The notion that they were “just gliders” doesn’t sit well with me. Their legs were far too short for them to be anything but completely ungainly on the ground. The notion that they could perhaps climb a tree or a cliff to get the altitude to launch themselves just doesn’t seem plausible to me from looking at their skeletons.

  115. Well, frankly, much of this article is wrong to misleading. That oxygen was a greater percentage of the atmosphere in the times of the dinosaurs is well known, with samples from bubbles in amber showing often 30-35% oxygen compared to 21% now. But that has been used to explain the giant insects without any several-times increase in total atmospheric pressure to several bars: a strange and different assumption.

    For large Pterosaurs, it has been estimated, for example, that a 10 meter wingspan individual had a weight of 70 to 250 kg ( http://en.wikipedia.org/wiki/Quetzalcoatlus ). They were large in wing area, but they were very lightweight relative to their size.

    For perspective, existing Great Bustards and Kori Bustards fly with up to 20 kg weight but at a lesser wingspan of around 2.7 m maximum. In terms of wing loading (weight per unit area of wing surface), as a thought experiment, if you took one of the current birds and scaled it up to 10 meter wingspan, increasing its dimensions by around a factor of 3.7, it would have around 3.7^2 or thus around 13.7 times the wing surface area, so a bird massing around 270 kg with 10 meter wingspan could have compable wing loading. Compare to the prior Pterosaur mass figures.

    Especially considering thus how Pterosaur wing loadings were semi-comparable to those of some existing birds, not several times higher or something extremely different, there is no reason to conclude that Pterosaurs needed several times higher atmospheric pressure than now; the higher percentage oxygen would help them already.

    (For additional perspective, a 10-meter wingspan large Pterosaur is around as much wingspan as a 11-meter wingspan Cessna 172 aircraft but with a factor of 5 to 16 times less weight, relatively more kite-like, which is what would allow it to fly at far lesser speed than the Cessna’s ~ 50 mph stall speed).

    Besides, Figure 5 of this article is not valid. For example, regarding the faint early sun paradox:

    “One of the early attempts at solving the problems has been basically to adjust the greenhouse effect and you can do most prominently by just adding more carbon dioxide to the atmosphere.” “We’re not happy about it because we have deposits from the ocean at that time, and these deposits contain iron oxide minerals and we know from the observation of how they form today that this kinds of minerals cannot form if there’s a very high amount of CO2 or carbon dioxide in the atmosphere and the greenhouse solution to the faint sun paradox required about 30% CO2 in the atmosphere, but what we could see is that its very much lower.”

    “There is a lot of geological evidence to suggest that the continents on earth have grown over time, so there were very little or no continents 4 billion years. Of course there’s about one-third of the planet is covered by continents today. And continents are much lighter in colour than ocean and therefore, if you had less continent, you would have a darker earth and it would’ve absorbed more heat from the sun if it’s darker. So that’s one part of it. The other thing is that in order for the sun to be able to efficiently heat the surface, it needs to be able to penetrate the clouds and today a lot of the sunlight is reflected by the clouds; but again clouds are different today than they were on the early earth because at that time, we didn’t have the type of organisms that produce chemicals, an active part in cloud formation today.”

    http://www.nature.com/nature/podcast/v464/n7289/nature-2010-04-01.html

    (The preceding quote is how the claim of CAGW alarmists that extreme levels of CO2 back then explain the faint early sun paradox is false, while there is an alternative better explanation as implied).

    CO2 concentrations over the past were more like this:

    Even 7000 ppm is about 0.007 bar, nothing even remotely like this article’s graph claiming up to 2+ bar.

  116. Adding a bit to my prior comment:
    As an additional illustration, http://en.wikipedia.org/wiki/Argentavis is estimated to have flown just 6 million years ago with up to 70-78 kg mass and to do so by 7 meter wingspan. For a Quetzalcoatlus pterosaur
    to fly with 70 – 250 kg mass when having 10-11 meter wingspan is not even too surprising in comparison, when a combination of up to 60% more wingspan and up to a comparable amount more wing chord length
    would mean up to multiple times the wing surface area. There is no real reason to assume atmospheric pressures were multiple times higher back then and plenty of reason not. 30-35% oxygen in the age of the dinosaurs instead of 21% oxygen now but at roughly comparable atmospheric pressure to now (in the sense of not multiple atm) is the standard estimate.

  117. tty says

    http://wattsupwiththat.com/2012/06/02/so-dinosaurs-could-fly-part-i/#comment-999596

    Henry says
    As I hinted on earlier it seems the way earth was wetted
    (according to the most ancient scriptures)
    was mostly not from the top to the bottom
    (Noah did not see a rainbow before the big flood)
    but from the bottom to the top.
    This clearly suggests a different type of atmosphere.
    Actually all the water vapor and CO2 in the air at 5 atm. would act as an anti greenhouse gas so it would keep earth cooler, not warmer.
    this is something generally misunderstood until you read and munderstand this:

    http://www.letterdash.com/HenryP/the-greenhouse-effect-and-the-principle-of-re-radiation-11-Aug-2011

  118. While the bumblebee story may be a fable, I have one that is true. I met a gentleman by the name of Willard Custer who had invented an aircraft wing called (no surprise) the Custer Channel Wing. Basically he formed a wing into a U shape around a pusher propeller to gain extra lift. He said that when he had the FAA inspector come out to certify it for flight testing the prototype he was told that it wouldn’t be certified until he put wings on it since there was no way an aircraft of that weight could fly based on their formulas. However, he’d been flying test machines for years without the wings, but that didn’t sway the inspector. Just like the bumblebee, a valid calculation was being used on an object it didn’t apply to. Unfortunately, the technology didn’t go anywhere and is relegated to history.

  119. I love the Custer Channel Wing. If I were to build a RC airplane from scratch, it would probably be a channel wing.

  120. Anthony’s story has some unexpectedly alarming implications for climate-change:

    Theresa Cole’s thesis, page 116: “The decreasing global annual mean atmospheric pressure trend shown in Figure 5.8 [and prominently posted here on WUWT] is expected with increasing global average temperatures.”

    Needless to say, the explanation given is incorrect. The observed pressure decrease [if it is not artifactual] implies not a temperature increase, but rather a atmospheric mass decrease.

    At least some explanations for such a mass decrease are sufficiently alarming as to be unpalatable to WUWT’s traditionally non-alarmist reading of the climate-change data:

    Alarming Explanation #1: Atmospheric mass is decreasing because the H2O content of the atmosphere is decreasing with increasing global temperature; the lessened cloud cover contributes to positive climate-change forcing.

    Alarming Explanation #2: Atmospheric mass is decreasing because the oxygen content of the atmosphere is decreasing, in consequence of global deforestation and/or suppression of oceanic photosynthesis with increasing acidification and/or water temperature.

    Needless to say, both possibilities tend to strengthen the cAGW position. So, WUWT?

  121. Andy Smith says,
    “If you increase the air density, yes you will certainly increase the lift but at the same time you will also increase the drag, meaning that that you probably have not gained a great deal. ”

    True but what about the other way? In a vacuum no drag but no lift either. Surely much depends on the power available in the creature?

  122. Perhaps UHI is a factor. If the temperature rises at a place due to human influences, that point will tend to be more thermic, ie attract heavier cooler air, and naturally will be at a slightly lower pressure. I am not a meteorologist, but in the southern hemisphere the local seabreezes tend north easterly on the eastern seaboard, and I have always assumed that happens because of pressure gradient and corialis effect.

    If so then this could be a method to correct UHI influences in the data record.

  123. i think i got things wrong and should have just stfu. typing first and thinking afterwords bad.
    moderators, do for me what i should have, plz.

    [REPLY: OK, you got it. Takes a big man uhhh.. person. -REP]

  124. So, if we now accept that 100Mya, there was an atmosphere with about 20% CO2 and say 5 Bar pressure, would plant and animal life have thrived under such conditions? Do we even know that these values were anywhere near accurate?

    This is out of touch with experimental data. Geological data – both models and measurements – show CO2 levels of about 5000-10000 (0.5-1 %) in the Cambrian and getting lower since then. 20% just 100 MYa is impossible.

  125. The scientific community is still stuck in this 19th century mindset of imagining that dinosaurs had to be slow, dim-witted, cold blooded and in every way inferior and less efficient than us hominids, the pinnacle of evolution.

    The psycology behind this in the 19th century was a little sinister. It was ideologically necessary to show evolution as a continuous improvement, from inferior to superior bodies and physiology. The late Steven Jay Gould has written lucidly to demolish this fallacy – the “quality” if you like of organisms by the late Cambrian was already no different to today. Gould´s premise of “contingency” is that the species that survived and continued did so largely by good luck in relation to changing climate and geography on earth.

    What made this “upward march” paradigm sinister in the 19th century was that it was extended to human races – in those non-PC days scientist spoke quite openly for instance about africans being racially inferior, it even became a science in its own right, us Caucasians were supposed to show a higher degree of neoteny (adult retention of embryonic/juvenile traits) than the bigger and more robust afros. What then arose was an embarrasing problem in that – by the same yardstick – the Chinese and Asians were superior (more neotenic) than us Europeans. (So the hypothesis was quietly shelved!) Anyway for the full story on this its best to read SJ Gould himself.

    But our need for dinosaurs to be lumbering slow and inferior is still deep rooted in modern society, the term “dinosaur” is used as a metaphor for something becoming dated and uncompetitive, in a business environment for example.

    Thus in this discussion of pterosaurs we have to make the air denser and give them more oxygen – in defiance of the geological record on the palaeo atmosphere. Give them a handicap;

    The extent to which the reality is the stark opposite to this popular idea is extreme to the point of shocking.

    In fact the Jurrasic Park films, for all their flaws, actually got it right in the sense that dinosaurs transported to our time quite likely would pose a mortal threat to all animal life larger than a rat or hedgehog.

    As has been pointed out above, birds are dinosaurs. It follows that dinosaurs are birds. OK some with knowledge of taxonomy will point to exceptions, but the relatedness to birds included one very important physiological factor: birds – and dinosaurs – had a lung breathing system about 10 times more efficient than our own. Yes – TEN TIMES.

    How and why is this? First, our lungs are tidal. The air comes in and goes out by the same trachea, bronchi and bronchioles down to the gas exchanging alveoli. Unfortunately – and sorry to disappoint the 19th century evolutionary supremicists – but this design is CRAP. The diffusion situation means that the O2 concentration gets lower and lower deeper into the lung and reaches its minimium where it is actually needed, at the gas exchanging alveolar sacs.

    Birds by contrast have lungs in which the air flows ONLY ONE WAY through the tubes. It does this by a complex system involving air spaces within the bones. But it means that air crosses the equivalent of gas exchanging alveolar surfaces at essentially atmospheric concentration. Engineers among you will appreciate the significance of this.

    This hugely more efficient bird breathing system is why they can fly. And it is also why pterosaurs could fly. (If not technically dinosaurs, they derived from the Triassic Therapsid line and thus probably had a similar physiology to the dinosaurs.) Recent research (published in Anatomical Record about 2-3 years ago) has shown that many signs of dinosaur anatomy confirm this avian type of lung system. this includes ribs all the way down the body (ever seen a bird with a 6-pack?) and thus a rigid torso. With the more efficient one-way breathing system, the lung does not need to inflate and deflate anything like as much as our tidal lungs. In birds there is only a small membrane at the back of the torso which moves in and out with breathing – this is where you stick your fingers in when you are gutting a bird.

    It is also why dinosaurs and pterosaurs had much superior cardiovascular efficiency to us – they would have quite literally run rings around us. And maybe gutted us and eaten us for Christmas dinner.

    And pterosaurs with their one-way breathing anatomy would have no difficulty in flying thank-you very much, no need for fictitious atmospheres.

  126. On the matter of flying reps, here is some comparative numbers from the modern R/C proxies with a “standard” wing, fuselage and some kind of empennage: 5-10 oz/sq.in of lifting surface floats like a leaf more or less. Your basic handlaunched flat-bottomed 2 channel glider. Soars like an eagle, flies like a pig. 10 15 oz/sq.in, nice performance range for aerobatic gliders, and high-dihedral powered trainers. Good power-off flight characteristics for gentle landings, not much drag compensation without power unless aerodynamically very clean. 15-25 oz/sq.in – high performance powered aircraft at the high end, slope soarers and clean aerobatic gliders at the low end.

  127. PTEROSAURS WERE NOT DINOSAURS.

    Sorry to shout, but it’s a schoolboy error (quite literally), painful to the palaeobiologist.

  128. MacCready’s Q. northropi “model” was not very realistic, and proved little.

    However, the model was not anatomically correct and embodied vertical and horizontal tail stabilizers that were lacking in pterosaurs. The weight distribution of the model was also different due to the longer tail of the model.

    Some Pterosaurs may have been competent walkers:

    Though traditionally depicted as ungainly and awkward when on the ground, the anatomy of at least some pterosaurs (particularly pterodactyloids) suggests that they were competent walkers and runners.

    http://en.wikipedia.org/wiki/Pterosaur#Flight

    Evidence of accretion argues that the mass of Earth must have been smaller in the remote past. Some combination of weaker gravity and heavier atmospheric pressure seems to be the simplest and most plausible explanation for pterosaur flight and dinosaur mobility.

  129. If you want something to cheer you up, have a read of “Causes and timing of biosphere extincions” By Franck et al, 2006.

    http://www.biogeosciences.net/3/85/2006/bg-3-85-2006.pdf

    Figs 4 and 5 above confirm that CO2 is gradually being removed from the atmosphere; Franck et al. conclude that CO2 starvation will be the eventual cause of extinction of life (first multicellular, then bacteria° in around 1 billion years time – not heat.

    The implications of this in regard to the CAGW hypothesis and human emissions of CO2 are too obvious to mention.

  130. A fan of *MORE* discourse says:
    June 2, 2012 at 2:18 pm
    “Alarming Explanation #1: Atmospheric mass is decreasing because the H2O content of the atmosphere is decreasing with increasing global temperature; the lessened cloud cover contributes to positive climate-change forcing.”

    I think you should read the alarmist bible, IPCC AR 4, again, especially the section about positive water vapor feedback, if they have mentioned that. (They should, as it’s essential to their alarmism)

    Then, read about Miskolczi’s theory.

  131. Not sure how to explain a 5 fold loss in atmospheric mass, even given the geologic time involved.

    But here are some additional considerations related to a five fold increase in atmospheric pressure: If the organism living in the atmosphere used hemoglobin to transport oxygen, it is likely that its physiology is at least similar to today’s mammals and reptiles.

    1. Breathing effort is a function of gas density. A five fold increase would require a very powerful respiratory system. Any evidence for that in the fossil record?

    2. O2 at partial pressures exceeding 1 to 2 Bar has been shown to be toxic to today’s organisms. It attacks and destroys enzymes and central nervous system [CNS] cells. A 5 Bar atmosphere with 21% O2 would require an entirely different CNS physiology for Jurassic reptiles. A higher percentage of atmospheric O2 only compounds the problem.

    3. Inert gasses and CO2 have demonstrated significant narcotic properties at any elevated partial pressures. CO2 is 25 times more soluble in lipids as N2 and is considerably more narcotic than the N2 that is responsible for nitrogen narcosis in SCUBA divers. 5 bars worth of elevated partial pressures would result in considerable narcotic effects unless Jurassic physiology was somehow very different than today’s organisms. The problem is compounded for air breathing marine organisms that would swim to any depth.

    Given the above physiology constraints of a denser atmosphere, I think there is a larger problem with a 5 Bar atmosphere and life as we understand it.

    With respect to Philip Foster’s comment/question on the relationship between lift and drag: Lift and Drag are linearly proportional to atmospheric density. They both increase or decrease proportionally with a change in density [at low airspeeds - we aren't concerned with high speed compressibility effects in pterodactyl flying]. What is gained by a density increase is the ability to generate the same lift at lower airspeeds [fly slower].

    So I vote with Philip, no significant aerodynamic benefit to having a denser atmosphere except slower takeoff and landing speeds. Perhaps useful depending on the reptile’s wing characteristics.

    http://wright.nasa.gov/airplane/lifteq.html

    http://wright.nasa.gov/airplane/drageq.html

  132. 1. I think the question of atmospheric pressure several hundred million years ago has nothing to do with the ~0.1% change measured on century scale.
    2. You should give some thought to how global annual mean atmospheric pressure is measured. It may have the same problems global annual mean atmospheric temperature has. That is, you can calculate annual means for an ever changing set of measurement points, distributed unequally on the surface, but a great many assumptions go into transforming it into a true mean.

  133. Andi, please convert the atm. PRESSURE loss into atm. VOLUME
    loss in ppmv and compare it to the 2 ppmv atmospheric gain by
    our man-made addition(emission) of CO2/GHG…..
    The present CO2-volume is soon reaching 400 ppm, we thus
    INCREASE the atmospheric pressure with the
    weight of man-made emissions!
    You talk about pressure/volume LOSS, whereas we have
    a man-made pressure GAIN with the volume of GHG emissions….
    Plus, CO2-emissions are heavier than air, also INCREASING
    the total atmospheric pressure…..The galance would be the
    total volume loss into space, being decomposed on top of the
    atmosphere by UV and solar wind, whith the wind pressure blowing
    the top off (2 recent posts on that….)
    JS

  134. In the article above it is written: “—- the current accepted mean value is around 1013.25 Mbar. So any warming observed over the past 90 or so years should be ruled out as causation – warm or cold the air weighs the same (within reason)” –

    First let me, if I may, start with the figure 1013.25 Mbar which looks like a very precise value but may not necessarily accurately reflect the weight of any air at the Earth’s surface. That is because 1013.25 is the international Altimeter setting for aircrafts flying on instrument settings in open air-space. – In short, in order to keep a precise altitude during instrument conditions (high traffic, high speeds – dense fog) an aircraft needs to have an Altimeter that can be accurate to two decimals. (Just ask Burt Rutan how long this has been the case – I can only guess it has been for at least half of the 90 years of warming mentioned above). –

    Then the last bit: “– warm or cold the air weighs the same (within reason)” –

    That statement is quite true as long as we weigh individual molecules/atoms, but the fact which is that as air warms it forms a pocket which increasingly occupies a larger space than does the air that remains cold(er), could also do with a mention. – By volume warm air is the larger and therefore lighter by volume.

    The surrounding colder air resist the warming air’s expansion at all points and the result is that the pressure inside the said pocket increases. A “warm air pocket” can – and often does – grow to become a High Pressure System. – However, also take into consideration, as the warm air expansion is resisted the colder air pressure must also rise albeit a lot less as any ‘outside area’ is always larger than the corresponding ‘inside area’. It is also worth noticing that The Troposphere occupies a lot more space (in the form of height) in the tropical than it does in the far northern/southern hemispheres.

    In the place where I live, the air pressure which – just a couple of days ago, in glorious Sunshine – hovered around 1025/ 1030 mbar has today dropped to 1002 mbar under a gray mass of rainclouds.

    Needless to say the saturation rate is higher today than what it was two days ago, therefore I feel justified in saying that the “saturated air column” pressing down on my roof today weighs more than did the unsaturated or dry air that was present earlier and that therefore atmospheric/barometric air pressure has got more to do with cloud formation than it has to do with the weight if the vertical air column.

    PS.
    Maybe the graph depicting an observed fall in global annual mean atmospheric pressure since 1916 (from NOAA as you believe) is unintentionally depicting an increase in cloud cover (and therefore also quite accurate global temperature fluctuations 1916 -2006).

  135. “Turning our attention for a moment to Earth’s twin, Venus…”

    I wish this misconception could be put to rest. The similarities are few, differences many.

    This false notion that helped get the entire CAGW scam rolling, along with an early, but mistaken belief that CO2 was responsible for the extremely high temperatures on Venus.

    I think Sagan trumped Velikovsky with that one, the latter having predicted the high temperatures on Venus, but who turned out to be “right for the wrong reasons.” Or so they say.

    After Hansen got wind of Sagan, he dropped dust, glommed onto CO2 as the heat devil on Venus, and turned his attention on Earth.

    Much of the early CAGW scare featured the specter of Venus looming in Earth’s future, and Hansen continues to deploy it.

    Rather than calling Venus “Earth’s Twin,” I’d suggest we use:

    Earth’s Fairy Godmother

  136. Rising atmospheric temperatures should increase the absolute humidity and therefore the mass of the atmosphere.

    The likely mechanism decreasing the mass of the atmosphere over this timescale, is decreased water droplets (clouds) caused by decreased aerosols/particulates.

    Its well documented that aerosols/particulates seed more persistent clouds.

  137. Hoser,
    Planes do not fly better in high humidity, nor is humid air more dense. Think about it, what are the molecular weights of O2, N2, CO2 and H2O ?

  138. Question that comes to mind: What do we not know about the pterosaurs? We don’t know if they could fly, or if they could glide, or if they had scales or feathers. We only know that they appear to resemble some of the birds that live today. Some of the birds that live today do not fly, nor glide. Some appear to use their wings to simply maintain their balance, or sometimes to help them swim. As further muddying of the water, what’s to say that the pterosaurs weren’t some sort of swimming animal?

    Therefore, though this subject provokes an interesting discussion, we really don’t know anything about pterosaurs except that they are all dead.

  139. bean says:
    June 2, 2012 at 3:43 pm

    “…1. Breathing effort is a function of gas density. A five fold increase would require a very powerful respiratory system. Any evidence for that in the fossil record?”
    =====================================================================
    This may be the least of our fallacies, but I can’t agree–the denser the air and the higher the O2 content the easier and slower the breathing. Rather the evolution of vertebrate cardiovascular and pulmonary systems suggests perpetual oxygen starvation. Critters living under 5 atmospheres with high O2 content (before trees evolved) would never have needed vascular systems, hearts, gills, hemoglobin, lungs, better hearts, blood cells with no nuclei, etc.

    It’s a mystery to me how anyone can take the diminishing gravity speculation any more seriously than Noah’s flood. Don’t you understand that if G decreased while the inertial properties of mass remained unchanged, all the orbits of planets and moons would be altered?

    I bet thousands of aero engineers have claimed bumblebees break the laws of aerodynamics, just like ceramic engineers claim glass flows over decades, and creationists claim evolution breaks the laws of thermodynamics. If aero engineers had their act together we might expect that one or two of them would tackle the superbird myth–the ubiquitous fairy tale that a peregrine falcon can stoop at 240mph.

    And what’s this nonsense about lunar tides sucking out the atmosphere? News to me.

    What interests me about the pterosaurs is their fragility which suggests a lack of strong winds where they flew. –AGF

  140. If the dunno sir atmosphere was five times as dense as today’s, wouldn’t those terrasaurs have to have five times as much horse; excuse me that’s T_Rex power to cope with the higher air resistance drag; and in that case, wouldn’t they be just too damned heavy to fly ?

  141. Edit note;
    “Deutrium” s/b Deuterium.
    ____
    The dinosaurtheory.com site derives a pressure of about 350 bar during the Mesozoic, with about 2/3 of land dinosaurs’ weight buoyed up by the air, permitting e.g. brachiosaurs to walk out of water, and to pump blood to elevated heads without chained hearts etc. Pterosaurs could fly with great agility, sufficient to hunt and feed themselves.

  142. juanslayton says:
    June 2, 2012 at 7:16 am

    I believe that water transport to the top of tall trees is attributed to leaf transpiration pulling a very narrow column of liquid from the ground. (As opposed to being pushed up by ambient atmospheric pressure–which would limit lift to approximate 32 feet.) I’m wondering how a much heavier atmosphere might affect this system. Would water transport change because of a change in transpiration? Could an entirely different system of transport evolve not based on capillarity tension? What effect might there be on maximum plant height?

    There ain’t no difference nohow between pulling and pushing. Much of the transport is due to capillary action, the affinity of water for the tube walls. Dip a cloth into water and watch it soak upwards!
    Increased pressure would of course increase the height water could be drawn up by pressure differences.

  143. @bean at 3:43 pm

    There is another important aspect of a denser atmosphere to flight. The Power it takes to stay aloft is a function air density, ie. Proportional to ρ^(-0.5) where ρ is air density.

    http://web.mit.edu/16.unified/www/SPRING/systems/Lab_Notes/airpower.pdf

    Eq. 16 shows that the energy expended to fly a distance is independent of density and directly proportional to weight.

    Eq. 17 shows that the Power = Energy/time, is inversely proportional to sqrt(density), and proportional to weight^(3/2)

    So for a 2 bar atmosphere, only needs 70% of the power as at 1 bar. 50% of the power at 4 bar than 1 bar.

    Can we assume that Max Power from an organism is no better than proportional to weight? Pmax proportional to W^(x) where 0 < x <= 1. For simplicity, lets assume x = 1. Double the weight, you can double the Max Power. Double the weight and you need 2^(3/2) = 2.83 times power at constant density to stay aloft. It’s a losing game to get bigger if density is constant. However, if you double the air density and double the weight, you can restore the Max Power balance.

    I conclude that the max weight of a flying organism is proportional to AirDensity^(1/(3-2x))
    If x = 1, then Max weight is proportion to air density.
    If x = 0.8, then Max weight is proportional to AirDensity^(0.71)

    Doubling the weight implies more wing area, too, but it seems like in Eq. 17 that a larger wind area S cancels out for little change in power. But as the paper says,

    However, it’s essential to realize that most of the variables and parameters in equations (16) and (18) are coupled in an actual design application, so the effect of changing one will have multiple side effects, with the net effect being nonobvious.

  144. “The Levenspiel et al 2000 paper is well worth a read…” HEY! Dr. Octave Levenspiel was my professor! Don Pettit was a classmate! Dr. Levenspiel could take any complex thing and turn it into a fun story, easy to understand. Yes, I’m an Oregon State Chemical Engineer. Woot!

  145. Janice says:
    June 2, 2012 at 7:51 pm
    Question that comes to mind: What do we not know about the pterosaurs? We don’t know if they could fly, or if they could glide, or if they had scales or feathers. We only know that they appear to resemble some of the birds that live today. Some of the birds that live today do not fly, nor glide. Some appear to use their wings to simply maintain their balance, or sometimes to help them swim. As further muddying of the water, what’s to say that the pterosaurs weren’t some sort of swimming animal?

    The only nonflying birds are ones that lost flight secondarily, except possibly the ratites. The bat-like membrane wings of the pterosaurs stretched between thin fingers would be no use whatsoever in the sea, these were no manta rays. The first thing you need to understand in biology is the unity of form and function, if something looks like it flew, it probably did fly.

    Or of course if they did not fly, then what purpose could these huge wing structure have played? Perhaps the pterosaurs had discovered morality, and used the large thin structures as clothing to conceal their genitals. Or maybe they had developed a taste for holidays on the beach, and evolved wings to be deployed as beach-umbrellas?

  146. Steve P says:
    June 2, 2012 at 3:40 pm
    MacCready’s Q. northropi “model” was not very realistic, and proved little.
    However, the model was not anatomically correct and embodied vertical and horizontal tail stabilizers that were lacking in pterosaurs. The weight distribution of the model was also different due to the longer tail of the model.

    An aircraft designer’s contributions to compensate for the lack of a computer light enough (and fast enough) to make the minute corrections necessary to keep it flying. Quetzalcoatlus was essentially a B-2 — no empennage meant it was highly unstable in all three axes. It had to make dozens of small corrections every minute it was in the air, either with its wings or head, in order to stay aloft.

    Unless, of course, it made a living by renting itself out as a beach umbrella…

  147. davidmhoffer says:
    June 2, 2012 at 10:23 am
    Besides, he built his model out of wood and all the fossils we’ve found so far were made out of rock…

    Okay, that’s it. No more popcorn for you until I get my keyboard cleaned off…

  148. phlogiston says:
    June 3, 2012 at 7:54 am
    Perhaps the pterosaurs had discovered morality, and used the large thin structures as clothing to conceal their genitals.

    That was actually my first thought when Steve P said that MacCready’s model was not anatomically correct…

  149. @ Stephen Rasey

    Touche’. Thinking in terms of energy vice power.

    Here’s a good paper on wing shapes at low reynolds numbers, also some discussion about power requirements. Still unsure about power requirements for soaring reptiles. Reaching minimum drag flying speed is the flight regime that requires the most power. Then power requirements aren’t as high, especially if they are “soaring designs”.

    http://www-scf.usc.edu/~tchklovs/Proposal.htm#_Toc110650543

  150. Bill Tuttle says:
    June 3, 2012 at 8:35 am

    …when Steve P said that MacCready’s model was not anatomically correct…

    Bill, that part came from Wikipedia. Not that I disagree, but at June 2, 2012 at 3:40 pm
    I said this:

    MacCready’s Q. northropi “model” was not very realistic, and proved little.

    Period. The part in italics in my original post at 3:40 pm came from Wikipedia and my formatting should have made that crystal clear. Apparently not.

    You also said that

    “Quetzalcoatlus was essentially a B-2.”

    I think that qualifies as a misleading oversimplification, at the very least, like Venus being Earth’s “twin.”

    You then went on to say:

    no empennage meant it was highly unstable in all three axes. It had to make dozens of small corrections every minute it was in the air, either with its wings or head, in order to stay aloft.

    Well the B-2 may require a computer to fly – not that it is alone – but the B-49 managed to fly pretty well without one. It was the development of the deep-chord monoplane wing that allowed these aircraft to fly, not the computer.

    At any rate, neither the B-49 nor the B-2 have a long neck extending forward of the wings. For that, you’d have to cite the B -70, but it didn’t have big, wide wings. It did have powerful engines however. With enough thrust (power-to-weight ratio greater than 1), even a brick can fly, but I wonder of Q. northropi perhaps tucked/folded its long neck against its breast ala Great Blue Heron when flying?

    At any rate, for the pterosaurs , all that’s really required for them to fly easily is a thicker/heavier/denser atmosphere than what we have today. They had all the special adaptations necessary for flight: long wings, hollow bones – pneumatic in some cases – specialized keel bone for flight muscle attachments, and specialized brain development for flight control.

    No flying bird today weighs much beyond about 40 lbs. Elephants and other pachyderms, while massive, are small compared to some marine creatures.

    Video of hippos moving while underwater is revealing, and entertaining. Who knew these seemingly clumsy, awkward beasts could move so gracefully while submerged?

  151. Phlogiston, looks like the pterosaurs may have been a lot like ducks. Ducks, if their wings are stretched all the way out, look a lot like a pterosaur, especially if you remove all the feathers. And even though ducks can fly, they are much more at ease simply floating around on shallow water and grubbing in the mud for food. Many wild ducks don’t fly much, using their wings to escape from danger by stretching them out to allow their little legs to work better for running (not really flying, but doing a very shallow glide). So I will agree that a pterosaur might be able to fly, but I would hedge on that by saying that it may never have felt the need to do so.

    http://www.citeulike.org/user/martydaniel/article/6090353

  152. Speculations on this subject should include an awareness that the diameter of the Earth itself during Pangaea was about 60% of today’s. The Earth has expanded since “antediluvian” times, whatever length of time ago those actually were.

    This can be proven for oneself by getting a couple of inflatable globes. Cut one of them up, and patch Africa into the Americas, etc, and you will see the collapse as you go back in time. You can see the corkscrew that happened in the Arctic. You notice the shapes of continental edges and how they tore open as –whatever it was– happened. You see why there are mountains as wrinkling of the crust was inevitable with the diameter change.

    I was introduced to this reality on a Young Earth Creationist website. This was supposedly the catastrophe that led to Noah’s Flood. But that explanation is far from the only one possible and is denied by some of the layers found in the Earth’s fossil record. It seems more likely that there have been repeated catastrophes that led to successive ages of life and fauna, or that something has been going on gradually for a long, long time, related to Wegener’s Plate Tectonics..

    —–

    Another relevant factor in understanding greatly different atmospheric pressure is the Gas Law equation PV =nRT, where P is pressure, V = volume, n=number of moles, T is the temperature in Kelvins or some other measure where absolute zero is zero on the scale, and R is the “gas constant,” a fudge factor that makes all the units come out right. It value will depend on what units you use to measure everything else. In the SI system of units, its value is 8.3 J per Kelvin per mole.

    Using this equation for an entire atmosphere is a bit problematic, for pressure will be different at different depths and so on. But it is still relevant.

    • I am of the same opinion: The diameter of the Earth grows
      because the gain in the Pacific is 20 cm/year and in the Atlantic
      is 10 cm/year, where the continent plates drift apart… It is falsely
      shown that the continental plates move downwards under
      the adjacent (in California for example) plate, maintaining the globes
      diameter…. but I am sure
      this is wrong….
      The ongoing globe expansion will also produce a atmospheric
      volume expansion
      with the atmospheric material thus thinning, thus less dense for
      flying……
      JS

  153. Quite a mix here–brilliant comments from Phlogiston, Chuckles, and others, combined with a medley of sheer quack science–growing earth, shrinking earth (gained a following before plate tectonics), diminishing G, Noah’s flood taken seriously with other Creationist nonsense. I wonder if meteor accretion exceeds hydrogen and helium loss.

    It seems to me that a wildly varying atmosphere would be as problematic to evolution as an unconstant G would be to cosmology. The distant galaxies appear to have the same gravity behavior as the near ones–none of them flying apart even when colliding–usually. Likewise an undependable atmosphere would be nearly as dangerous for life as a solar system which had not been mostly cleaned of collison debris. In a very thick atmosphere big animals could fall out of trees and off cliffs and not be hurt. Penguin like creatures could fly. Frogs would not need lungs, and amphibians might never have lost their ocean hegemony.

    Land vertebrates rely heavily on precise sensing of O2 and CO2 to control breathing–it seems unlikely that such highly tuned systems have survived a roller coaster of air pressure. As with climate, there must be negative feedback systems that keep air pressure and gas mix in check. Rain drops typically fall in air with no vertical wind component, and if fossil rain drops indicate similar atmospheres, that may be as good evidence as we get for a while. –AGF

  154. agfosterjr says:
    June 3, 2012 at 2:04 pm

    It seems to me that a wildly varying atmosphere…

    No one is making that argument.

  155. @agfosterjr The distant galaxies appear to have the same gravity behavior as the near ones–none of them flying apart even when colliding–usually

    While I do not accept that the gravitational constant is changing, nor that the Earth’s diameter has significantly increased in 2 billion years, I must point out that it is the “gravity behavior” of near and distant galaxies that has caused cosmologists to hypothesize otherwise unknown Dark Matter and Dark Energy.

  156. Sorry for coming in late, but I’ve been busy. The mathematician who posted up above is quite correct. The Earth (and all of the other planets) are constantly losing atmosphere by thermal outgassing — molecules that happen to bounce just right and end up with escape speed on a trajectory that takes them away from Earth. Lighter molecules are lost faster than heavier ones — hence little hydrogen or helium in the atmosphere, while O_2, O_3, and CO_2 last a fair bit longer.

    IIRC, the lost atmosphere is constantly being replenished by outgassing from the Earth’s crust and biological processes. But “constantly” should be taken with a grain of salt — the process very likely has large fluctuations associated with it as the crust turns over on time scales of tens to hundreds of millions of years, not decades. So I wouldn’t worry a lot about a short-term decreasing trend over the absolutely trivial period of humans’ ability to measure pressure in the first place. That’s almost certainly just noise on some (possibly trendless!) million-year timescale function.

    Besides, long before we reach 100,000 years, humans will either be able to manipulate and replenish the atmosphere with sheer engineering or we’ll likely be extinct anyway. At any rate, by then we will arguably no longer be “human”.

    rgb

  157. Andy Smith says:
    “If you increase the air density, yes you will certainly increase the lift but at the same time you will also increase the drag, meaning that that you probably have not gained a great deal. ”

    Perhaps, but I’m dubious. Water is denser than air, but all kinds of creatures not adapted to flight can nevertheless swim. Not just fish, but dogs, humans, and even elephants. Lacking further argument, this armchair philosopher finds it plausible that denser air makes easier flight.

  158. Janice says:
    June 3, 2012 at 11:38 am
    Phlogiston, looks like the pterosaurs may have been a lot like ducks. Ducks, if their wings are stretched all the way out, look a lot like a pterosaur, especially if you remove all the feathers. And even though ducks can fly, they are much more at ease simply floating around on shallow water and grubbing in the mud for food. Many wild ducks don’t fly much, using their wings to escape from danger by stretching them out to allow their little legs to work better for running (not really flying, but doing a very shallow glide). So I will agree that a pterosaur might be able to fly, but I would hedge on that by saying that it may never have felt the need to do so.

    The long bills of some pterosaurs do suggest an ecological niche similar to a pelican or cormorant (the set of animal / bird types and corresponding niches is broadly similar in dinosaur/pterosaur times a now). They would have needed quite a substantial waterproof feather plumage in order to have floated – do you know if there is any fossil evidence for feathered pterosaurs?

  159. mfo says:
    June 2, 2012 at 6:24 am
    There is a NASA project to obtain the first quantitative measurements of atmospheric pressure on the early Earth, from the Archean Eon >2.5 billion years ago:
    ———
    Now that’s what I like to see!

  160. juanslayton says:
    June 3, 2012 at 7:24 am

    Brian H: There ain’t no difference nohow between pulling and pushing.

    Ah, but there is. Take a look at

    http://sites.bio.indiana.edu/~hangarterlab/courses/b373/lecturenotes/water/waterintro.html

    Scroll down to the sections “Capillary Rise” and “Tensile Strength”. We can’t get water to the top of a 200 foot tree by capillarity or by suction (max lift c. 32 ft).

    I take it back. It’s the roots: they’re pushing water up the trunks, and forcing it to squirt out of the leaves.

  161. Steve P says:
    June 3, 2012 at 11:28 am
    @ me: I think that qualifies as a misleading oversimplification, at the very least, like Venus being Earth’s “twin.”

    Not *that* much of an oversimplification to compare Q. northropi to a B-2, considering the Northrop connection to both…

    You then went on to say: “no empennage meant it was highly unstable in all three axes. It had to make dozens of small corrections every minute it was in the air, either with its wings or head, in order to stay aloft.”
    Well the B-2 may require a computer to fly – not that it is alone – but the B-49 managed to fly pretty well without one. It was the development of the deep-chord monoplane wing that allowed these aircraft to fly, not the computer.

    The B-49′s four vertical stabilization fins (extending above and below the wing) served well enough to controll yaw stabilization.

    With enough thrust (power-to-weight ratio greater than 1), even a brick can fly

    Heh. That statement always produces red faces among my fixed-wing brethren.

    but I wonder of Q. northropi perhaps tucked/folded its long neck against its breast ala Great Blue Heron when flying?

    Could be — it appears to have been flexible enough to do so.

    At any rate, for the pterosaurs , all that’s really required for them to fly easily is a thicker/heavier/denser atmosphere than what we have today. They had all the special adaptations necessary for flight: long wings, hollow bones – pneumatic in some cases – specialized keel bone for flight muscle attachments, and specialized brain development for flight control.
    No flying bird today weighs much beyond about 40 lbs.

    No dispute there, actually, but the atmosphere would have to have remained fairly dense right up through the Miocene — Argentavis magnificens is estimated to have weighed at least 150 pounds.

  162. Amidst all this speculation about what extinct flyers could or couldn’t do I repeat, we have an extant bird which is almost universally credited with the ability to dive at 240mph (=386kph=107m/sec). So I ask, how thin would the air have to be for such a stoop to be possible? Maybe all our barometers are wrong. Or maybe Alerstam’s radar gun is right (85mph max). But I challenge any to find skeptical aerodynamic discussion of the claim. Why should we put any credence in dead bird aerodynamics when we can’t get the live ones right? –AGF

  163. agfosterjr says:
    June 3, 2012 at 2:04 pm

    Your question about equilibrium status of the atmosphere amd feedback was taken up by Robert Brown:

    Robert Brown says:
    June 3, 2012 at 10:13 pm

    It makes sense that the atmosphere isnt just running out from a static starting stock but instead is the result of an equilibrium.

    More on the avian and dinosaur lung arrangement can be found here:

    http://people.eku.edu/ritchisong/birdrespiration.html

    The special edition on dinosaurs in the journal Anatomical Record is available at palaeoblog here – the articles are all downloadable:

    http://palaeoblog.blogspot.be/2009/09/anatomical-record-special-issue-on.html

    Here is Emma Schachner et al 2009 on recent evidence for dinosaurs having avian lungs:

    http://onlinelibrary.wiley.com/doi/10.1002/ar.20989/pdf

    The basis for my “ten times more efficient claim” is this quote on page 1505:

    Respiration in Extant Birds
    Lung morphology. The avian respiratory tract is
    composed of two main components: the rigid gas
    exchanging bronchial lungs and the nonvascularized
    ventilatory air sacs (Duncker, 1972, 1974). The air sac
    system permits unidirectional airflow over the paleopulmonic
    parabronchi during both inspiration and expiration
    (Maina, 2005). This system, enabled by the rigid
    structure of the lung, provides birds with the most efficient
    respiratory apparatus of any air-breathing vertebrates
    (Maina, 2002). The rigidity of the avian lung and
    constant volume throughout the respiratory cycle provide
    the mechanical foundation for an enlargement of
    the oxygen exchange surfaces into a three-dimensional
    mesh network of blood capillaries 10 times larger than
    the gas exchange surfaces found in mammalian lungs
    (Duncker, 1974).

  164. Bill Tuttle says:
    June 4, 2012 at 4:50 am

    Bill, good post. Thanks for keeping a sense of humor intact, and also for raising the question of the Mesozoic bird-of-prey A. Magnificens, with its 70 kg mass and 7 meter wingspan.

    It’s interesting to talk about the airplanes, but I don’t think we should go too far with the analogy. Birds generate lift and thrust with their wings, while airplanes have separate parts for these tasks – wings for lift, engines for thrust.

    Birds also employ variable geometry in their flight – easy for them being a flexible, living organism, but not so easy for machines. I don’t think man has done very well trying to build machines that mimic flapping flight, at least not big ones… In recent decades, variable geometry has been applied primarily to the engines rather than the wings.

    But in a larger sense, the implications here are staggering, and I’m eagerly looking forward to Part II. As a student of life, I find WUWT serves as a virtual university, where I have the privilege of sitting in on the fascinating lectures of brilliant men as we all work to understand our dynamic planet.

  165. And to be precise, airplane wings do use variable geometry on leading and trailing edges, and other control surfaces like the rudder, but typically, the term variable-geometry is applied to aircraft such as the F-14 Tomcat, that have swing-wings. Also, it occurs to me that some modern fighters employ a third set of variable-angle wings forward of the cockpit.

    agfosterjr says:
    June 4, 2012 at 8:42 am

    Good question. I’ve had doubts myself that the Peregrine really attains that speed in a stoop, although it seems to be possible according to the Wiki article on terminal velocity. Falco peregrinus strikes with its talons clenched into a “fist” to deliver a blow – actually a kick – to the prey bird’s head, back, or wing at the bottom of its stoop, so I’d think that too much velocity might be dangerous for the Peregrine, and unnecessary. Golden Eagles are also said to attain speeds approaching 150 mph in a dive, but I’d like to see some precise data.

  166. Attempting to determine ambient air pressure based on fossil flyer anatomy and aerodynamics seems futile and unscientific. If by studying a dead bar goose you could determine how high it could fly (7 lbs at 21,000 feet), then you might be able to figure out how fast a peregrine falcon could dive (85mph), and you might set NASA, the Smithsonian, National Geographic, and the BBC straight (they all buy into the 240 mph stoop nonsense–at least NG used to). It seems the geese are not limited by aerodynamics but by oxygen deficit–the Himalayas rose up across their migration path and the fittest survived.

    Of course birds have no problem flying around the Dead Sea; accordingly on our present planet flight is obtained over altitudes that range through more than a doubling of pressure. Vance Tucker’s “ideal falcon” could dive at super speed in his mathematical world. In the real world it seems they don’t. Maybe ancient air was thicker and maybe it wasn’t, but the most feeble evidence is the aerodynamic–excepting rain drop fossils. –AGF

  167. I think the latest theory on Venus is that it is actually the result of two proto planets colliding some 500 million years ago. This also is theorized to have had the effect of moving Earth’s orbit further away from the Sun than it originally was. The theory coincides well with both the surface age of Venus, the strength of the Sun back then, the climate conditions of Earth at the time and after, and some other parameters.

    So, Venus is actually a really poor analog for Earth, especially if that’s true.

    We know we lose atmosphere to space though, and we know volcanism has slowed down (so less material being put back into the atmosphere), so seems highly likely that we did have a thicker atmosphere back then, which could provide more oxygen to such massive animals (even if the percent oxygen was the same, the density would have provided significantly more uptake by the lungs. Same with CO2 for plants), and allowed flight.

    These theories seem to fit the facts so far.

  168. Steve P says:
    June 4, 2012 at 8:59 am

    “…the Mesozoic bird-of-prey A. Magnificens”

    Oops.The giant bird-of-prey Aregentavus magnificens dates from the late Miocene – not the Mesozoic – or about 6 mya, but the class Birds arose during the Mesozoic, or about 160 mya, during the Jurassic.

    A. magnificens appears in artist’s renderings looking like a giant Golden Eagle. No bird that size could fly today on Earth.

  169. Steve P says:
    June 4, 2012 at 12:34 pm

    “No bird that size could fly today on Earth.”
    ==================================================================
    Some serious problems here:
    1) The weight of these birds is typically estimated by wing span, which is in turn estimated by the size of the tibiotarsi, assuming of course an atmosphere comparable to the present one.
    2) The thicker the atmosphere the smaller the wing area is necessary to provide adequate lift for a given weight.

    Accordingly the best ornithological evidence we might discover for a changing atmosphere would be an altered ratio of wing span to weight, which is of course difficult to determine from the partial and mangled fossil remains. Claims such as Steve P’s are based on a priori assumptions and circular reasoning: a thicker atmosphere should in fact lead to stubbier wings. –AGF

    • A couple of decades ago I read a fascinating book called “Why Big Fierce Animals are Rare” by Paul Colinvaux. The basic takeaway is that big fierce animals are rare because they sit atop the food chain and there just isn’t enough food to sustain that many large carnivores.

      When I think about the thundering herds of immense herbivores from the age of the dinosaurs & the huge scale of ancient sharks and T-Rex’s, it is plain there is something fundamentally different about the amount of food available at the bottom of the food pyramid. You probably had more CO2 & O2 and a thicker atmosphere creating a richer organic soup in the oceans and faster growing plants on the land, maybe the earth weighed less and spun faster so you had slightly less effective gravity, maybe there were areas of fertile shallow marshes and seas before the continents finished breaking up… Whatever the cause, there was clearly more food available all along the line back in the Jurassic.

      -
      (aside)
      I’m an artist. When I look at paintings of long dead animals, I’m frequently dismayed by the unlikely way the animal is arranged. Every time I come back to this thread, the Quetzalcoatlus illustration bugs me ’cause I think the way that bird is holding its neck just looks wrong. I can’t help but think it ought to be held more like the folded back position used by pelicans in flight.

  170. agfosterjr says:
    June 4, 2012 at 1:54 pm

    2) The thicker the atmosphere the smaller the wing area is necessary to provide
    adequate lift for a given weight…a thicker atmosphere should in fact lead to stubbier wings.

    s

    It think it depends on how the bird does business. Many small songbirds have rather short, rounded wings like Chickadees, while others have long rather narrow ones, like swallows. Chickadees don’t do much fly-catching, but swallows make their living that way, so they need different types of wings, all under the same atmospheric pressure. Based on that observation, I don’t know if your conjecture has any merit, or not.

    And I think you’ll look long and hard to find a flying creature with short, stubby wings, excluding the F-104, of course. True, Penguins are birds, and they have short stubby wings, but they are used for swimming, not flying. I think most marine creatures tend to have rather short, stubby fins, rather than long ones.

    The long, probably narrow chord wings and other specialized adaptations of the pterosaurs must have served some function. If not to fly, then what?

  171. A recent study about the variability of atmospheric pressure (a poster presented by students of the Natl Tech Univ of Athens at the EGU 2012): http://itia.ntua.gr/1208/

    Dear Dimitris,

    What a pleasure to see you post on WUWT! I discovered one of your papers quite by accident several years ago, and was most impressed. And I think your work on Hurst-Kolmogorov processes and climate is extremely compelling. I’m a physicist (who is currently dabbling only in climate science — random numbers and statistics and e.g. Monte Carlo simulations are more my line) and have worked with Langevin and Fokker-Planck (or more generally, Master equations) and appreciate the general idea better than most, and think there are very likely some very interesting e.g. Poincare cycles in high dimensional spaces that projectively become the stationary transitions you so beautifully describe (and that qualitatively fit the time series data!).

    I’m hoping to get more people on this list to become aware of your work. In particular you might want to communicate with Bob Tisdale, who has some Sea Surface Temperature (SST) data that could all by itself be a poster child for Hurst-Kolmogorov with El Nino being a possible driver of (some of) the transitions. But the data series are too short to be able to really differentiate pure stochastic from driven in some way.

    rgb

  172. Nikolov & Zeller speculated that the decline of the planetary temperature over the 60 million years since the PETM was caused by a 47% drop in atmosperic pressure.

    If they are right we should stop worrying about CO2 causing a “Runaway Greenhouse Effect” and start worrying about combating any further reduction in atmospheric pressure.

    De-sequestration anyone?

  173. The dinosaurs had a really great sense of humor. Hence there was a lot of levity, and not much gravity.

  174. RGB, thanks for the flattering comment. I have the feeling that a better connection of (nonlinear) dynamical systems and stochastics is needed. About difficulties in differentiating stochastic and deterministic components, you may wish to see my paper “A random walk on water”, http://itia.ntua.gr/923/

  175. Steve P says:
    June 4, 2012 at 9:54 am
    And to be precise, airplane wings do use variable geometry on leading and trailing edges, and other control surfaces like the rudder, but typically, the term variable-geometry is applied to aircraft such as the F-14 Tomcat, that have swing-wings. Also, it occurs to me that some modern fighters employ a third set of variable-angle wings forward of the cockpit.

    The term for that set of wing/control surface combination is “canard” — probably because the French claimed naming rights for aircraft parts (aileron, empennage, etc.) on the theory that it gives them more of a mystique than “fin” or “stuff that hangs off the rear of the fuselage.”

    The canard configuration got its name from someone who evidently thought a few of the early aircraft using them looked like ducks in flight.

  176. Also, thanks for the kind comment in http://wattsupwiththat.com/2012/06/02/what-can-we-learn-from-the-mauna-loa-co2-curve-2/#comment-1000735

    I first ran into the preprint of your hydrology paper where you show a roughly sinusoidal curve that is statistically analyzed at three different scales. That figure alone is sheer brilliance, and should be required “reading” for every single person involved in climate research. The entire IPCC political force should be required to sit down and have it explained to them, using simple words and speaking slowly and distinctly so they cannot possibly fail to understand. Then they should be made to understand that the entire thermometric era — and quite possibly the entire last millennium — is arguably still just “region A” in this figure, since the only meaningful variability trend visible in the ten-million year data is the punctuated decline over the last 3.5 million years, with what appears to be warm/cold phase oscillations associated with strange attractors (poincare cycles) in some at least 3 or 4 dimensional phase space, projected onto global temperature. Enormously nonlinear and chaotic, with unknown feedbacks and capable of synchronizing itself to weak quasi-periodic external forcings like those provided by the general planetary orbital variables (tilt, eccentricity and so on).

    Everything on top of this appears to be exotic noise — driven noise, to be sure, non-Markovian noise quite possibly, but resolving signal from the noise, causal trend from Taylor-series accident returns us once again to your figure.

    I finally got a few of the better physics people who post on the list to look at your Colorado State talk (which is brilliant and so very easy to understand). And I wasn’t kidding — look up a few of Bob Tisdale’s many posts on SSTs and take a gander at his data. If perfectly meshes with the Hurst-Kolmogorov model, IMO — punctuated transitions to locally stable (on a decadal scale) states, with a POSSIBLE weak bias in the direction of transition and the period (in SSTs, they appear to weakly synch with El Nino).

    Anyway, a pleasure (once again) to see you on WUWT. There are some very good discussions that take place on some of the threads, sometimes with halfway decent physics and statistics, along with a certain amount of (possibly understandable) ranting — not really terribly constructive except as an opportunity to vent against political solutions imposed by force to ameliorate a problem that has not been soundly demonstrated to exist. But focus on the science and math as sometimes it is quite good (and unlike the IPCC reports and RealClimate, a few of us try to police claims against the CAGW hypothesis that don’t hold water or are just bad science — we try to be critical of our own plausible beliefs and not just knee jerk oppose CO_2 mediated CAGW because we don’t like the idea of carbon taxes that even according to their political proponents WILL NOT WORK to significantly ameliorate the worst-case projected problem).

    rgb

  177. Demetris Koutsoyiannis says:
    June 5, 2012 at 12:31 am

    RGB, thanks for the flattering comment.

    You’re living proof that rumours of brilliant thinkers in Ancient Greece may have some basis in fact, despite the apparencies of recent history. .
    ;)

  178. Steve P says:
    June 4, 2012 at 3:57 pm

    “And I think you’ll look long and hard to find a flying creature with short, stubby wings, excluding the F-104, of course.”
    =========================================================================
    And I would maintain the reason is that we don’t have a dense atmosphere. If the atmosphere doubled in density a robin might take to soaring (and starve) or it might reduce its wingspan. And consider that the weaker the flyer, i.e., the lower the power to mass ratio, the longer the wingspan, as exhibited by the Gossamer Albatross.

    Ashby says:
    June 4, 2012 at 3:41 pm
    =======================================================================
    The biggest animal that ever lived is alive in the ocean today. –AGF

  179. agfosterjr says:
    June 5, 2012 at 7:22 am

    The biggest animal that ever lived is alive in the ocean today. –AGF

    Yes, marine animals can be much bigger than terrestrial ones because water is much more buoyant than air for floating bodies.

    Because of water’s buoyancy, enormous marine creatures can live today, but no terrestrial beast is bigger than a bull African Elephant, an animal that can neither run, nor jump, and weighs up to 10 tons. Out to sea, a Blue Whale can weigh up to about 200 tons.

    The design of terrestrial animals is different from the design of marine animals, and both differ from that of birds. To fly, birds need a relatively light-weight, streamlined body, wings to generate lift, a breastbone to attach the wing muscles, and hollow bones to reduce weight, to mention just some of their specialized adaptations for flight.

    Terrestrial animals, meanwhile, must support their own weight with the structure of their bones, and there are numerous ways to do that, some seemingly better than others, but all constrained by gravity and physics.

    Marine forms can become streamlined rather like a missile to reduce drag, because the buoyancy of water is providing most of the support for them, and that allows massive size.

    So how did 35 ton Supersaurus manage to get around on land when an elephant can only shuffle? Some dinosaurs are estimated to be even more massive, approaching 100 tons, or more.

    Similarly, no flying bird today weighs much more than c40 lbs., and the vast majority weigh much less.

    You also wrote about my no stubby wings comment:

    And I would maintain the reason is that we don’t have a dense atmosphere. If the atmosphere doubled in density a robin might take to soaring (and starve) or it might reduce its wingspan. And consider that the weaker the flyer, i.e., the lower the power to mass ratio, the longer the wingspan, as exhibited by the Gossamer Albatross.

    Or, the robin might just get a little bigger to take advantage of a denser atmosphere, but as you allow, an American Robin would have no reason to begin soaring, because there is no food up there for it, unless worms too someday sprout wings.

    An American Robin can see potential prey much better down on the ground, where it does most of its summertime hunting for smallish insects, and neither its wings nor its tail are shaped or adapted for soaring anyway.

    And that example illustrates the problem with hypothetical situations: there are too many unknowns, both known and unknown, along with the unwarranted assumptions. I work to base my arguments on empirical evidence, not theory.

    As far as I know, the only songbird to soar is the Common Raven, which species is also the largest and heaviest songbird, btw. Soaring is a strategy for big birds, not small ones. Birds with long, narrow wings like the Albatrosses use them to stay aloft for long periods, and to cover great distances as they feed. The general rule is the more aerial the bird, the longer its wings, and I wouldn’t be surprised if the same rule should apply to the Pterosaurs.

    Again, the design of the wing is a function of the bird’s way of making a living, and birds have many different ways of doing that. Similarly, the shape of a fighter’s wing is distinct from that of a transport because the two aircraft have different missions even though both fly in the same airspace.

    So, again, based on real-world examples, your conjecture about a direct wing-size-to-atmospheric-density relationship is refuted by modern birds, who have wings short and long, but all fly in the same sky.

    I don’t think we know nearly enough about how Pterosaurs made a living to object to the way their wings were conformed. There was something about their environment that prompted nature to design them that way. Perhaps early ones had shorter wings – isn’t that how evolution would work? – but most seemed to have had longish wings, and by no means were all of them large.

    @Bill Tuttle: Yeah; newer canards work better than some of the old ones.

  180. The biggest animal that ever lived is alive in the ocean today. –AGF

    Ah yes, but look how far down the food chain it eats! Krill?? Where’s the drama in that? Where are the 19′ high carnivores tromping around devouring bison? I suppose we’re now the keystone predator and have outcompeted any alternative predators…

  181. >>
    agfosterjr says:
    June 3, 2012 at 2:04 pm

    I wonder if meteor accretion exceeds hydrogen and helium loss.
    <<

    On page 73 of the book: “The World’s Greatest Book of Useless Information,” it reads:

    “The Earth gains about twenty to forty tons of weight each day due to meteors and other space debris landing on the surface. At that rate it would take 450,000 trillion years to double the mass of the planet.”

    If we assume an average rate of thirty tons per day, then in 100 million years the Earth’s mass would change by about 1/10^10. It’s a lot, but not enough to account for a significant change in surface gravity.

    Jim

  182. Steve P says:
    June 5, 2012 at 2:41 pm
    And that example illustrates the problem with hypothetical situations: there are too many unknowns, both known and unknown, along with the unwarranted assumptions. I work to base my arguments on empirical evidence, not theory.

    Steve P says:
    June 4, 2012 at 12:34 pm
    A. magnificens appears in artist’s renderings looking like a giant Golden Eagle. No bird that size could fly today on Earth.
    ===========================================================================
    Utterly incompatible claims. And I might as well ask, why were there no Jurassic marine animals as big as our whales? The best reason I can think of for large dinosaur size is their superior respiratory systems, not yet equaled by the mammalian.

    Why are bats nocturnal? I.e., why is there only a single species of mammal that flies by day (the fruit bat)? Because mammals can’t compete with birds, about 99% of which fly by day. Birds are superior in almost every way. Mammals were nocturnal while dinosaurs roamed; like birds, dinosaurs were probably diurnal, with poor night vision. After the dinos were gone mammals ventured out into daylight and got bigger. Of course a few birds specialized on hunting little mammals at night, and a few even compete with bats, gathering fruits and bugs at night. The oil bird in the equatorial western hemisphere even uses echo location.

    Your remarkable and unexplained claim that Argentavis magnificens could not fly today is in line with the whole discussion, which has appealed to both possible and outlandish speculation. We may safely assume gravity has not changed. We may also safely assume that the atmosphere has never been dense enough to appreciably “float” either land lubbers or flyers. We don’t know to what extent atmospheric mass and composition has varied, but we can place reasonable limits on max O2 because there have been forests since the Carboniferous–they did not spontaneously combust.

    Accordingly you seem to be claiming that A. mag. couldn’t fly today because air is too thin–that air was substantially denser 5mya. And your reasoning seems to be that…what? Its wings are too big? It was too heavy? I don’t know–you merely state it as an unsubstantiated article of faith, and then you say, “I work to base my arguments on empirical evidence, not theory.” When in fact the whole notion that big wings imply denser air is backwards: denser air entails greater lift per wing area.

    So I repeat and refine: until evidence of systematic modification of wing area to weight is identified within various functionally continuous flyer types, we have no ornithological or zoological flight evidence for atmospheric variability. Why might A mag have gone extinct? It happened when the Panama Strait appeared with the rising Cordillera. Winds changed and new predators appeared. Maybe the pumas were too much for A mag just as they were too much for the marsupial carnivores. If a puma caught an A mag without a breeze or a cliff nearby, it could not take off. So all we need is a puma than could climb better than the marsupial predators. Another possibility is a smaller invader able to reach its eggs. –AGF

  183. agfosterjr says:
    June 6, 2012 at 9:09 am

    Why are bats nocturnal?

    You’re all over the place with your arguments here, but these facts remain:

    Argentavis magnificens does not fly today, nor does any bird that massive. Try as you might, you can’t find one.

    You wrote:

    Utterly incompatible claims. And I might as well ask, why were there no Jurassic marine animals as big as our whales? The best reason I can think of for large dinosaur size is their superior respiratory systems, not yet equaled by the mammalian.

    Wiki:

    All cetaceans, including whales, dolphins and porpoises, are descendants of land-living mammals of the Artiodactyl order (even-toed ungulates). Both are related to the Indohyus (an extinct semi-aquatic deer-like ungulate) from which they split around 54 million years ago.[6][7] Primitive whales probably first took to the sea about 50 million years ago and became fully aquatic about 5–10 million years later.[8]

    Or about the time A. magnificens is thought to have flown.

    Birds arose much earlier, and so did Pterosaurs. I don’t understand the pace and permutations of evolution, and neither do you.

    It wasn’t until cetaceans became fully aquatic that they also became massive, because marine creatures can be much larger than terrestrial ones, and both can be much bigger than flying animals, because of a law of physics articulated in Archimedes’ Principle on Floating Bodies

  184. I said:

    Or about the time A. magnificens is thought to have flown.

    No, I was wrong about that, having misread 5-10 million years later as 5-10 million years ago. My flub

    A. magnificens dates from c6 mya not 40-45 mya

  185. Steve P says:
    June 6, 2012 at 10:43 am
    You’re all over the place with your arguments here, but these facts remain:

    Argentavis magnificens does not fly today, nor does any bird that massive. Try as you might, you can’t find one.
    =============================================================================
    So what? There’s nothing as big as a mammoth or mastadon either. And nothing as big as a brontosaurus. And nothing bigger than a whale. What’s your point? –AGF

  186. Looks like previous estimates for the weight of Dinosaurs may have been dramatically too high! From today’s LA Times “Dinosaurs weren’t as heavy as we thought, researchers find”:

    http://www.latimes.com/news/science/sciencenow/la-sci-sn-dinosaur-weight-20120606,0,6506496.story

    Quote:
    Estimating the weight of prehistoric animals by examining their fossilized skeletons is notoriously difficult. Estimates for the weight of larger species, such as dinosaurs, can vary by a factor of three or four. Now British researchers have developed a new way to estimate weight and conclude that our previous estimates are much too high: Dinosaurs were, in fact, much lighter than we thought.

    A team headed by biologist William I. Sellers of the University of Manchester used a laser scanner to compile a three-dimensional image of the skeletons of various animals, then calculated the minimum amount of skin that would be necessary to cover the skeleton. Using well-known estimates for the average density of tissue, they could then calculate the weight of the animal. When they applied this technique to animals whose weight was known, including reindeer, polar bears, giraffes and elephants, they consistently underestimated body mass by 21%, they reported in the journal Biology Letters.

    The team then went to Berlin’s Museum fur Naturkunde and scanned the nearly complete skeleton of the Berlin brachiosaurus, Giraffatitan brancai, one of the largest complete sauropod dinosaurs. Using their algorithm, they then concluded that the living animal weighed 23,200 kilograms (51,150 pounds). Previous estimates for the brachiosaurus mass had gone as high as 80 metric tons, or 176,000 pounds.

    “Our method provides a much more accurate measure and shows dinosaurs, while still huge, are not as big as previously thought,” Sellers said.

    —-

    Why didn’t they use flightless birds to calculate the weight vs. skeleton size? Might have ended up with an even lighter ratio…

    So the math WAS off, but the problem wasn’t gravity/atmosphere, it was bad estimates of mass!

  187. agfosterjr says:
    June 6, 2012 at 12:26 pm

    So what? There’s nothing as big as a mammoth or mastadon either. And nothing as big as a brontosaurus. And nothing bigger than a whale. What’s your point? –AGF

    My point is the part about Archimedes’ Principle:

    It wasn’t until cetaceans became fully aquatic that they also became massive, because marine creatures can be much larger than terrestrial ones, and both can be much bigger than flying animals, because of a law of physics articulated in Archimedes’ Principle on Floating Bodies.

    Simply put, water can support heavier creatures than air because it is much denser and inherently more buoyant. The whale for example, does not have to support itself with its bones, like an elephant does, so it can grow much bigger. There are limits to the amount of bones and muscle that can be used to support a creature on Earth, and let it get around. As I say, an elephant can only shuffle because of these limitations, and it can neither jump, nor run. Its size is its primary defense, and it is about as big as a terrestrial beast can be these days.

    Finally, big males of the flightless, terrestrial bird known as Ostriches can weigh well over 300 lbs., and flightless, aquatic Penguins over 75 lbs. Prehistoric Penguins were even bigger.

    But for flying birds these days, 40 lbs. is about it, and most are much, much lighter.

    Ashby says:
    June 6, 2012 at 1:03 pm

    So the math WAS off

    I’ll say. The numbers quoted in that story neither add up nor make sense. Did they mean they constantly overestimated by 21%?

    • I noticed that too, but on further reflection I think the editor had abbreviated the science writer’s prose into virtual incomprehensibility.

      But I assume the scientists first calibrated the program using known skeleton to mass ratios:

      Using well-known estimates for the average density of tissue, they could then calculate the weight of the animal. When they applied this technique to animals whose weight was known, including reindeer, polar bears, giraffes and elephants, they consistently underestimated body mass by 21%, they reported in the journal Biology Letters.

      If the program is consistently 21% low, then that’s useful info. Just increase the numbers by 20% and you are probably in the ball park.

      If you then apply it to dino skeletons and the numbers it spits out are off by 3-4 fold compared to existing estimates, then existing estimates are probably about 3x too high.

      The team then went to Berlin’s Museum fur Naturkunde and scanned the nearly complete skeleton of the Berlin brachiosaurus, Giraffatitan brancai, one of the largest complete sauropod dinosaurs. Using their algorithm, they then concluded that the living animal weighed 23,200 kilograms (51,150 pounds). Previous estimates for the brachiosaurus mass had gone as high as 80 metric tons, or 176,000 pounds.

      “Our method provides a much more accurate measure and shows dinosaurs, while still huge, are not as big as previously thought,” Sellers said.

      The article is ambiguous about whether the new weight estimates corrected for the 21% low algorithm, but I assume they corrected for that since they identified it prior to analysis of the dino skeletons. So, I think I understand what they were saying, but I agree the article is incoherent as published. We shouldn’t have to guess about something that central to the results being discussed.

  188. We’ve had fully aquatic marine animals for half a billion years, but none as big as our modern whales, toothed or baleen. The atmosphere has nothing to do with this. But what limits a bird’s size?

    Speculation that Argentavis magnificens was too big to take off without a breeze or fall is just that–speculation–but it’s possible. Bird size otherwise must take into account gigantism and dwarfism rules in general. Species trapped on islands sometimes grow big (like the Kodiak bear) and sometimes small (like extinct pygmy hippos and rhinos on Mediterranean islands). In the case of the bears their size increase may have to do with their ability to fish in the ocean, or it could have to due with sexual selection. In the case of the hippos it probably has to do with a more limited food supply: the bigger the animal, the more it eats, the more easily it starves. Small mammoths survived on Wrangel Island till less than 5000 years ago. Why were they small? They had a limited food supply and no predators, while on the mainland having a predator proof size outwieghed problems of limited food supply.

    We certainly don’t want to compare birds with whales, but we do want to compare whales with fish. And the blue whale is so big because of a plentiful and reliable supply of filter food. The bigger the mouth the more it can catch. Most sharks require warm water. Having higher metabolism than most fish isn’t enough to keep them warm when their gills constantly cool them; lung breathers have an advantage in this regard. But big mammals can also overheat. Size x activity spells heat exhaustion, so gigantism and speed aren’t typically combined in mammals as they were in dinos. The dino/bird respiratory system was also a cooling system, enabling them to be big AND fast.

    So what limits a bird’s or pterosaur’s size? Here are some initial considerations:
    1) Available niches–big birds can’t land on leafy trees and eat fruit; flying birds don’t land on the ground and eat bananas–flight is of little advantage for such a niche. Hence,
    2) The size of its prey–big flyers tend to be carnivorous.
    3) The efficiency of its respiratory/cooling system.
    4) The size and ferocity of its predators.

    At this point it’s worth noting that these avian experiments in size extremes have been largely limited to the New World where competition with advanced placentals has been restricted in time and area–hummingbirds inhabit only the western hemisphere, like condors and A. mag. And while the hummingbirds are the most energetic vertebrates extant, the soaring birds are the most efficient energy consumers among the flyers. For whatever reasons, larger birds are more energy efficient than smaller birds, but this is clearly necessitated by the limitations of feeding and digestion–a hummingbird consumes its own weight in nectar each day, and of course the nectar is easier to digest than meat. Soaring not only saves energy but prevents overheating. And while a hummingbird is always just a few hours away from starvation–it has to “hybernate” at night–a condor is always a few generations away from extinction. These are precarious niches.

    Accordingly, aerodynamic limitations constitute a part of many considerations controlling flight behavior and morphology. That a giant vulture or raptor living on the edge of existence went over that edge when its territory was invaded by North American fauna is hardly reason to suppose that the atmosphere was very different. –AGF

  189. The reduced surface gravity of the Phanerozoic per The Gravity Theory of Mass Extinction (www.dinoextinct.com) explains why the megafauna existed, among other things.

  190. It’s best to consider the various ideas each on its own merits, if any.

    agfosterjr says:
    June 7, 2012 at 9:03 am
    Good read.

    We’ve had fully aquatic marine animals for half a billion years, but none as big as our modern whales, toothed or baleen.

    It’s also true that we’ve had mammals scurrying around, diversifying, growing larger, evolving into a myriad of different forms since the extinction event 65 mya, but smart ones like H. sapiens appeared only within the last few hundred thousand years, or so.

    The modern Blue Whale appears to be the most massive animal ever, but even its great size doesn’t protect it from another mammalian denizen of the deep, blue sea and that is the Killer Whale, sometimes called Wolf of the Sea, but I think Lion of the Sea is better, even though Orcas are much larger than lions. In fact, Killer Whales are not a whole lot smaller than T Rex. They eat Great White Sharks for lunch.

    All that proves is what I said before: we don’t understand the pace or permutations of evolution but it does appear that endothermy – warm blood – confers significant evolutionary advantages.

    A few more thoughts:
    Big birds don’t land on trees to eat fruit, but they do land on big trees. Flying birds don’t land on the ground to eat bananas, but they do land on the ground to eat insects. Raptors also land on the ground to catch and eat prey they spot while sitting in those trees. When worms sprout wings, birds fly out to catch them, also from a perch. Even great fliers like Peregrine Falcons and Barn Swallows spend a surprising amount of time just sitting around, preening, singing, sunbathing, and doing what perched birds do.

    Finally, convergent evolution is found from one hemisphere to the next with the New and Old World vultures being a good example, and the Hummingbirds and Sunbirds being another.

    The maximum size reached by the New World Condor is very nearly matched by a couple of the Old Word Vultures such as the Cinereous Vulture.

    But I agree we really don’t know why A. magnificens no longer flies, any more than we know why all the megafauna of the Americas went extinct sometime in the relatively recent past.

    Maybe Andi Cockroft will help clear it up for us in Part II.

  191. And further one: a few birds are indeed bananivorous.

    And so the question is:

    If a banana falls in the forest, is it heard by a bird who’d be lured to eat it?

    Apparently, yes, there are really some banana-eating birds. Oddly enough, they’re sometimes called Banana Birds, and a few of these are familiar species.

    I’d read somewhere before that species known as “plantain eaters” actually didn’t eat bananas, but it turns out that other birds do, including some of our Orioles.

    One section of the genus Icterus has been named Bananivorus from the implied habit (of banana-eating) of the birds composing it; the type of this is the common orchard-oriole of the United States, Icterus spurius.

    http://www.wordnik.com/words/banana%20bird

    http://coo.fieldofscience.com/2008/04/banana-eating-birds.html

    Bugs or bananas, there’s a bird who’ll eat ‘em.

  192. True, a banana makes for nutritious food for lots of different critters, but they are native to South East Asia. So a bird that evolved in tandem with bananas would be found there. I think it’s safe to say there is no symbiotic relationship between bananas and birds–that is, bananas don’t depend on birds for reproduction. But I could be wrong. –AGF

  193. The problem with bigger things is a tricky one, how Chares realised when he agreed to build the Colossus of Rhodes.
    Legend say that he was approached to build a statue half the size, and after long discussions and preliminary calculations, when he finally came with the model and agreed the price, he was asked if he would build the statue double-size at double-price and he hastily agreed.
    The result was that he thus ruined himself and committed suicide after finishing the statue, not being able to pay his bills.
    Whatever the truth of the story is, the point is that double height is the square of base surface and the cube in volume for the same body. We have not only huge flying dinosaurs but also walking giants, giant fern, giant insects how could they exist? All because of denser air? Or gravity is variable?
    A weird theory says the Earth was smaller (the expanding Earth theory). Ok, I know it is weird, but let it be for a moment:

    It explains in an original way how the continents perfectly fit on a smaller Earth 1/1.7 size which would have only 50% gravity – which would perfectly allow for the dinosaurs to thrive and run and jump, the giant insects to fly and fern to grow to gigantic dimensions:

    http://www.dinox.org/index.html

    The Earth grew through material accretion and maybe through cosmic neutrons bombardment. BTW, did anybody made the calculation how much substance is contained in the neutron bombardment and how deep do they really penetrate the ground?
    Well I fear it has only the problem that the neutron count is much too low and the limited time since the existence of the Earth and universe are too short for the needed material accretion, or else life would be really interesting with many more meteors and a real neutron shower…
    Now I stop before fabulating too much. OK not before a last link, the dinos left an egg – a cosmic egg near Saturn:

    http://www.planetary.org/blogs/emily-lakdawalla/2012/05211206.html#ad-image-0

    • Lars….. the Earth must expand (like a baloon) and the
      expansion is loosening up the Earth’s crust….the continents
      thus drift all away and there is no place, where it is measured
      that a continent submerges under the other…. all expansion lines
      expand to the sides and no tectonic plate disappears by sliding under
      the neighboring plate….this is not weird but very clear….
      JS

  194. Lars P. says:
    June 12, 2012 at 1:07 pm

    OK, I’ll bite (no one else is reading this).

    But, but, what makes it grow? Why does all the new mass land in the ocean? Where did it land when there was no ocean? Where does it land now, or did it quit landing? Why doesn’t it land on the sun too? Or does it? If it does, why doesn’t the sun’s growing gravity draw us closer? And make us hotter? And make the year shorter? And the day longer? And burn our forests and calendars?

    Neutrons are the least of our problems. This makes climate scientists look like little Einsteins, and brings us skeptics into disrepute by association. Nobody with the tiniest shred of intelligence can take such a theory seriously. Here’s a small sample of quantitative evidence for a planet of stable mass:

    http://gsabulletin.gsapubs.org/content/82/4/1085.abstract:

    “Daily growth increments and monthly markings on Silurian and Devonian corals and brachiopods were counted using a maximum count method. Early and Middle Silurian fossils indicate that the number of days per year during these periods was 421 and 419, respectively; the number of days per year in the early Middle Devonian Period was 410. The number of days per month has decreased from 32.4 in the Early Silurian to 31.5 in the early Middle Devonian.”

    The earth slows down just a little, the moon moves out, the years and months grow longer–quite the opposite of what would happen if planetary and solar mass were growing. The earth isn’t flat, etc. –AGF

    • Mr. Foster: Accumulation of cosmic dust is indeed a bad
      idea…. but better is that the compressed Earth solid core
      is loosening up, releasing compressed gases (now found
      with the fracking drilling technology….etc) and this way, the Earth
      is expanding…thus Earth does not have to change its orbital
      parameters….also the axial revolutions can be as they want,
      this does not change the orbital flight around the Sun….
      JS

  195. Joachim Seifert says:
    June 12, 2012 at 4:17 pm

    JS, your explanation makes no sense: the gas cannot expand until it comes very near the surface. Gases are only compressible to the point that they reach their liquid or solid state density, which pressures are achieved at the deepest places of the ocean and about a mile down on the continents. So only the top mile could expand even a little, and of course there is no evidence for such high concentrations of gas (a mass majority?) even in the top layer. What little methane there is best explained as of organic origin.

    And in the context of the other pseudoscience in this thread, where increasing earth mass has been the theme rather than increasing volume, your theory makes for decreasing surface gravity (equal mass, more distant from center of gravity). At the same time this hypothetically decreasing density at great depth would greatly increase LOD, not just a little as through tidal friction.

    There’s a reason a planet’s atmosphere is on the outside rather than the inside. Being lighter, free gases float to the surface as soon as they can, very early in the processes of planetary formation (even in their solid states common gases are lighter than SiO2). Helium and radon continue to surface as the products of radioactive decay. Small amounts of hydrogen are freed as the result of chemical reactions, and escape to space with the helium. Methane formed beneath the surface as the product of fossilizing organic matter 2 or 3 hundred million years ago; most escaped but some is trapped under impermeable layers of sediment. If it were of inorganic origin it would have escaped with early accretion, billions of years ago. –AGF

  196. agfosterjr says:
    June 12, 2012 at 3:59 pm
    “But, but, what makes it grow? ”

    Well, you ruined the whole story with this question AGF and I was so proud of my little post. I should have said that I modelled it and my model proved it ok as only in the smaller world did the modelled dinos survive, in the bigger one they could not stand up.

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