Guest post by Ira Glickstein
Albert Einstein was a great theoretical physicist, with all the requisite mathematical tools. However, he rejected purely mathematical abstraction and resorted to physical analogy for his most basic insights. For example, he imagined a man in a closed elevator being transported to space far from any external mass and then subjected to accelerating speeds. That man could not tell the difference between gravity on Earth and acceleration in space, thus, concluded Einstein, gravity and acceleration are equivalent, which is the cornerstone of his theory of relativity. Einstein never fully bought into the mainstream interpretation of quantum mechanics that he and others have called quantum weirdness and spooky action at a distance.
So, if some Watts Up With That? readers have trouble accepting the atmospheric “greenhouse” effect because of the lack of a good physical analogy, you are in fine company.
For example, in the discussion following Willis Eschenbach’s excellent People Living in Glass Planets, a commenter “PJP”, challenged the atmospheric “greenhouse” effect:
“The incoming energy (from the sun) you express in w/m^2, lets simplify it even more and say that energy is delivered in truckloads. Lets say we get 2 truckloads per hour. … when we come to your semi-transparent shell [representing greenhouse gases (GHG) in the atmosphere], you are still getting two truckloads per hour, but you say that these two truckloads are delivered to both the earth and to the shell — that makes 4 truckloads/hr. Where did the extra two truckloads come from?”
In that thread, I posted a comment with an analogy of truckloads of orange juice, representing short-wave radiation from Sun to Earth, and truckloads of blueberry juice, representing longwave radiation between Earth and the Atmosphere and back out to Space. A later commenter, “davidmhoffer” said “Ira, That was a brilliant explanation. …”
This Post is a further elaboration of my physical analogy, using a pitching machine and yellow and purple balls in place of the truckfulls of juice.
Graphic 1 shows the initial conditions. The Sun is a ball pitching machine that, when we turn it on, will throw a steady stream of yellow balls towards the tray of a weight scale, which represents the Earth. The reading on the scale is analogized to “temperature” and, with the Sun turned off, reads “0” arbitrary units.
TURN ON THE “SUN”
Graphic 2 shows what happens when the Sun is turned on and there are no GHG in the Atmosphere. The stream of yellow balls impact the tray atop the weight scale and compress the springs within the well-damped scale until equilibrium is reached. The scale reads “1”. This is analogous to the temperature the Earth would reach in the absence of GHG.
The balls bounce off the tray and, for illustrative purposes, turn purple in color. This is my way of showing that Sun radiative energy is mostly in the “shortwave” visible and near-visible region (about 0.3μ to 1μ) and that radiative energy from the warmed Earth is mostly in the “longwave” infrared region (about 6μ to 20μ). The Greek letter “μ” (mu) stands for a unit of length called the “micron” which is a millionth of a meter.
Since, at this stage of my physical analogy, there are no GHG in the Atmosphere, the purple balls go off into Space where they are not heard from again. You can assume the balls simply “bounce” off like reflected light in a mirror, but, in the actual case, the energy in the visible and near-visible light from the Sun is absorbed and warms the Earth and then the Earth emits infrared radiation out towards Space. Although “bounce” is different from “absorb and re-emit” the net effect is the same in terms of energy transfer.
If we assume the balls and traytop are perfectly elastic, and if the well-damped scale does not move once the springs are compressed and equilibrium is reached, there is no work done to the weight scale. Therefore, Energy IN = Energy OUT. The purple balls going out to Space have the same amount of energy as the yellow balls that impacted the Earth.
ADD GHG TO THE “ATMOSPHERE”
Graphic 3 shows what happens when we introduce GHG into the Atmosphere. The yellow balls, representing shortwave radiation from the Sun to which GHG are transparent, whiz right through and impact the weight scale and push it down as before.
However, the purple balls, representing longwave radiation from the Earth, are intercepted by the Atmosphere. In my simplified physical analogy, the Atmosphere splits each purple ball in two, re-emiting one half-ball back towards the Earth and the other half-ball out to Space. Again, you can assume that half of the balls “bounce” off the Atmosphere back to Earth like reflected light from a half-silvered mirror and the other half pass through out towards Space. In the actual case, it is “absorb and re-emit half in each direction” but the net effect is the same in terms of energy transfer.
OK, here is the part where you should pay close attention. The purple half-balls that are re-emitted by the Atmosphere towards Earth impact the tray of the weight scale and press against the springs with about half the force of the original yellow balls. So, at this stage, when equilibrium is reached, the well-damped scale reads “1.5” arbitrary units.
But, we are not done yet. The purple half-balls are absorbed by the Earth, and re-emitted towards Space. Then they are re-absorbed by the Atmosphere and once again split into quarter-balls, half of which head back down to Earth and re-impact the weight scale. Now it reads “1.75”. As you can see, the purple balls continue to get split into ever smaller balls as they bounce back and forth and half head out to Space. The net effect on the weight scale is the sum of 1 (from the yellow balls) + 1/2 + 1/4 + 1/8 + 1/16 and so on (from the purple balls). That expression has a limit of “2”, which is approximately what the scale will read when equilibrium is reached.
Again, the well-damped scale does not move once the springs are compressed and equilibrium is reached, so there is no work done to the weight scale. Therefore, Energy IN = Energy OUT. The purple balls going out to Space have the same amount of energy as the yellow balls that impacted the Earth. But the “temperature” of the Earth, as analogized by the reading on the weight scale, has increased.
DOUBLE THE GHG IN THE “ATMOSPHERE”
Graphic 4 is the final step in my physical analogy. Let us double the GHG in the Atmosphere. (NOTE: I am assuming that the doubling includes ALL the GHG, most especially water vapor, and not simply CO2!) This is represented by putting a second layer of Atmosphere into the physical analogy.
The purple balls emitted towards Space by the first layer of the Atmosphere are intercepted by the second layer, where they are absorbed, and smaller balls are re-emited in each direction. The downward heading balls from the upper atmosphere are intercepted by the lower Atmosphere and half is re-emitted down towards the weight scale that represents Earth. Once again, they compress the springs in the weight scale increasing the reading a bit, and are re-emitted back up. The purple balls get halved and bounce around up and down between Earth and the two layers of the Atmosphere, further increasing the reading on the scale once equilibrium is reached.
Again, the well-damped scale does not move once the springs are compressed and equilibrium is reached, so there is no work done to the weight scale. Therefore, Energy IN = Energy OUT. The purple balls going out to Space have the same amount of energy as the yellow balls that impacted the Earth. But the “temperature” of the Earth, as analogized by the reading on the weight scale, has increased due to the doubling of GHG in the Atmosphere.
WHAT I LEFT OUT OF THE PHYSICAL ANALOGY
Any simplified analogy is, by its very nature, much less than the very complex situation it is meant to analogize. Here is some of what is left out:
- My purple balls are re-emitted in only two directions, either up or down. In the real world, longwave radiation is emitted in all directions, including sideways.
- My purple balls are all totally absorbed by the Atmosphere and re-emitted. In the real-world, a substantial amount of longwave radiation is re-emitted from the Earth and the Atmosphere in the 9μ to 12μ band where the Atmosphere is nearly-transparent. A substantial portion of the radiation from Earth and the Atmosphere thus passes through the Atmosphere to Space without interception.
- My physical analogy addresses only radiative energy transfer. In the real-world, energy transfer from the Sun to Earth and Earth to Space is purely radiative. However, the Earth transfers a considerable amount of energy to the Atmosphere via convection and conduction, in the form of winds, precipitation, thunderstorms, etc. These effects are absent from my analogy.
- I represent the Atmosphere as a single shell, when, in fact, it has many layers with lots of interaction between layers.
- I represent doubling of GHG as adding another shell, when, in fact, doubling of GHG, if it occured (and if it included not just CO2 but also a doubling of water vapor and other GHG) would increase the density of those gases in the Atmosphere and not necessarily increase its height significantly.
- In my analogy, all the energy from the Sun strikes and is absorbed by the Earth. In the real-world, up to a third of it is reflected back to Space from light-colored surfaces (albedo) such as snow, ice, clouds, and the white roof of Energy Secretary Chu’s home :^). If a moderately warmer Earth, due to increased GHG, evaporates more water vapor into the atmosphere, and if that causes more clouds to form, that could increase the Earth’s albedo to counteract a substantial portion of the additional warming.
I am sure WUWT readers will find other issues with my physical analogy. However, the point of this posting is to convince those WUWT readers, who, like Einstein, need a physical analogy before they will accept any mathematical abstraction, that the atmospheric “greenhouse” effect is indeed real, even though estimates of climate sensitivity to doubling of CO2 are most likely way over-estimated by the official climate Team. When I was an Electrical Engineering undergrad, I earned a well-deserved “D” in Fields and Waves because I could not create a physical analogy in my overly-anal mind of Maxwell’s equations or picture the “curl” or any of the other esoteric stuff in that course. Therefore, those WUWT readers who need a physical analogy are in great company – Einstein and Glickstein :^).
I plan to make additional postings in this series, addressing some implications of the 9μ to 12μ portion of the longwave radiation band where the Atmosphere is nearly-transparent, as well as other atmospheric “greenhouse” issues. I look forward to your comments!
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Alexander Feht says:
February 21, 2011 at 11:49 pm
Phil,
Links to designedly “friendly” sites prove nothing but the weakness of your position.
Whereas your position is backed by nothing just your unsupported assertion.
The Mauna Loa record and Keeling’s methods were criticized so much and for so long that it makes no sense for me to continue this argument.
Not by anyone who knows the subject, and the CO2 data does not rest on ML alone as has been pointed out to you.
You would excuse me if I find no pleasure in conversing with people who initially insult their opponent by assuming that he or she knows nothing, and then, realizing that they’ve blundered, scramble to justify their hasty and rude attitude by searching the Web for a couple of links that would agree with their unfounded statements.
I made no such assumption, I addressed your incorrect assertions, I didn’t need to search the web for any links. Your failure to address any of the points speaks volumes.
Nice post, but I think a better physical analogy for CO2’s atmospheric warming ability is as “a very thin, gaseous mirror.” There is no actual surface to this mirror (or to the “greenhouse”), there is only a thin gas which randomly reflects some small amounts of light in all directions equally, and lets the rest pass through. The end product is a diffusion of IR light which increases the residence time of this energy in the atmosphere. And in the midst of this, the whole process is controlled by a complex vapor-water-cycle that is far more powerful than the contribution CO2 makes.
Another remark that I want to post here is that despite the increases in GHG’s during the past 40 or 50 years there has not een any causal link that I could find between that increase and the actual warming of the planet.
Namely, if GHG’s were to blame for the warming noticed during the past 150 years, or even be partly responsible therefore, you would expect minimum temperatures to rise, in line with modern warming or even in line with the increase in maximum temperatures observed. What I find is exactly the opposite. e.g. minimum temps have declined or stayed the same.
see here:
http://www.letterdash.com/HenryP/assessment-of-global-warming-and-global-warming-caused-by-greenhouse-forcings-in-pretoria-south-africa
ergo. this post and this whole debate is a waste of time…
Unless somebody has other test results than I have?
To HenryP
I agree with you.
The Tmin data have the least amount of ‘atmospheric noise’ as well as ‘solar noise’ (and political ranting and raving noise!).
They are the clearest signals.
And all the Tmin data I seem to find, show stable or decreasing temps over the past 50 to 60 years.
Since I get named explicitly in this article, I suppose I really have to respond to it.
My basic issue is that you absolutely can not double count energy input.
There is one dominant source of energy to warm the Earth, and that is the sun.
It provides a relatively constant number of Joules of energy input to the Earth, and that alone is responsible for raising the temperature of the Earth.
It should also be remembered that heat transfer by radiation amounts to excitation of a molecule to a higher state of energy. When that molecule “relaxes” it emits a photon equal in energy to the state change.
That photon can ONLY excite another molecule if the molecule is at a lower energy state, AND it next highest state is equal to or less than the energy contained in the photon.
Since the energy that excited a CO2 or H2O molecule in the atmosphere originated from the Earth, and that Earth is likely warmer (at a higher energy state) than the photon, the photon will not cause any further excitation of molecules on the Earth’s surface, and hence increase its temperature.
In other words, heat transfer by radiation only works in one direction, from the hotter body to the cooler body. Never the other way around.
Example – shine as many 100W bulbs as you want at the Sun, but you will never increase its surface temperature that way.
One modification to the above though. If the warmer air moves (a long way) so that it is over an area much cooler than the area that caused its original warming, then some back-flow is possible (and likely).
However, also consider that warmer air will tend to convect upwards, taking it closer to the outer atmosphere from which outwards radiation takes place. Also, as it moves further from the surface of the Earth, there are many more molecules between it and the Earth which will intercept those photons.
But this is NOT new energy. It is energy that has already been accounted for and should NOT be re-counted.
Domenic says:
http://wattsupwiththat.com/2011/02/20/visualizing-the-greenhouse-effect-a-physical-analogy/#comment-604786
Thank you Domenic!
I did a similar investigation in La Paz, Bolivia (June & July from 1974).
I found exactly the same as in Pretoria.
I already mentioned Spain and Northern Ireland here as well:
http://www.letterdash.com/HenryP/more-carbon-dioxide-is-ok-ok
Put your results together with mine and we find: minimum temps have not been increasing in line with modern warming. The increases in GHG’s of the past decades do nothing whatsoever in keeping earth a bit warmer.
That is why I am saying: more carbon dioxide is good for the environment as it stimulates growth of greenery (photo-synthesis) and susequently also that of all animal life.
Professor Johnsons view of it all;
http://www.csc.kth.se/~cgjoh/blackbodyslayer.pdf
Frank Lee Meidere says:
February 22, 2011 at 12:14 am
Oliver Ramsay says:
February 21, 2011 at 10:25 pm
I appreciate the effort, Oliver, but I can drive faster or slower in any direction. I’m still not understanding why heat transference can only be in one direction.
———————————————-
Not at the same time, you can’t!
The more furiously that particles are charging around and crashing into one another, the more heat there is in that bunch of particles. That’s a description, not a cause and effect.
A colder thing radiates energy, not heat, to a hotter thing with nary a care. The hotter thing absorbs what it is sent, but it doesn’t become heat because it doesn’t result in the average frenetic motion of all those particles becoming more frenetic. (This was my car analogy; you can’t be both more frenetic and less frenetic at the same time) Two adjacent objects will happily radiate back and forth, but the hotter will radiate much more energetically than the cooler, such that the cooler can never heat the warmer by throwing photons at it, ‘cos they’ll just get thrown right back (or elsewhere) at a rate that is proportional to the fourth power of the temperature.
Radiation is not transfer of heat. It is transfer of energy. Heat is the kinetic energy of a volume of particles, not just one. At any moment, in a chaotic soup of particles colliding with one another, each one will have its own speed. The temperature is the average speed of all the particles.
The presence of the cooler object influences the rate at which the warmer body cools, just as the warmer body influences the rate of warming of the cooler body. However, the cooler body cannot make the warmer body warmer than it was before. In one’s imagination, it can make the warmer body warmer than it hypothetically would have been, in the absence of the cooler body.
One scenario describes a physical process, the other an imaginary state of affairs, which is initially helpful in visualizing but later distracts.
Imho, the CO2 backradiation story is the weaving of the “warmer than it otherwise would have been” into what actually happens, with a concomitant creation of energy “out of thin air”, if you’ll forgive me.
“”””” Fred Souder says:
February 21, 2011 at 6:01 pm
George Smith,
Yes, there is such a thing as radiative heat transfer. Just like convective heat transfer, and like conductive heat transfer. It is not a term used loosely. It is what heats up Earth. It can be calculated. I am not getting why you say that it doesn’t exist. I understand everything else you wrote in your brief explanation of electromagnetic waves. Maybe I am using the vocabulary loosely? “””””
Well Fred, that is precisely the problem, you ARE using the vocabulary loosely. And I say that not in any critical or derogatory manner.
One of the unfortunate things about the study of science (any science; not just Physics) is that we have many words which have perfectly ordinary every day common lay usage; but those words MAY also have a very specific and NOT substitutable scientific technical meaning. And misuse of terms with specific scientific meaning, will simply convey false impressions.
A good example, is the word “Brightness” when referring to some source of light; but also used in referring to things that aren’t at all visible (like an infra-red, or even a microwave source.) Particle accelerator engineers and scientists talk about the “brightness” of their particle sources.
It turns out that Photometry is one of the most screwee up areas of physics, and an easy one to miscommunicate in. A lay person, might reasonable say that “The sun is very bright today”; or perhaps, “my desk top isn’t nearly as bright as I would like” “I need to get a brighter lamp to illuminate my desk more brightly.”
To the scientist, some of those usages of the word bright or brightness, are not even measured in the same units; so they clearly can’t be referring to the same things. So we DECRY the use of the word bright or brightness, when talking about light sources (or IR ones) in a scientific context.
So we can more pedantically say that the sun has a high “Radiance” or a high “(radiant) Intensity”; which are energy related terms; or photometrically, we would say it has a high “luminance” or a high “(luminous) Intensity” Those are quite different terms with different units. Radiance (luminace) is measured in Watts per square metre, per steradian (lumens per square metre, per steradian). Radiant (luminous) Intensity, is simply Watts per steradian (lumens per steradian); from an assumed point source. With light that’s a fancy term for candlepower.
We can also talk about Watts (lumens) per metre squared which would be Radiant (luminous) emittance.
When it gets down to the desk surface, it is still Watts (lumens) per square metre, but we now call it “Irradiance (illuminance).
So back to your “RADIATIVE HEAT TRANSFER”.
Now there isn’t any (well much) MATTER between the sun, and the earth; so there is no mechanism by which “Heat” can be transferred fromt he sun to the earth or vice versa, since “Heat” is a property of real physical matter; not of photons which are also elecromagnetic waves.
ENERGY however CAN be transported from the sun to the earth, and also the other way, by means of EM RADIATION, which is either an EM wave, or a stream of photons; your choice. The transport is of ENERGY, not of HEAT.
That energy could be subsequently converted into heat by some mechanism that absorbs the energy; but it doesn’t have to be. for example, if the radiant energy from the sun is in an appropriate wavelength range, it can be absorbed by some semiconducting material and converted into an electric current, instead of being converted directly into heat.
The critical issue, is that the photons; or the elctromagnetic waves can go any darn place they fancy; although they can be absorbed if they encounter matter; but they can transport across empty space (vaccuum) from a very cold place to a very hot place with impunity; including travelling from Vostok Station to the surface of the sun. EM fields or photons do not even know what Temperature is; that is a property of real physical matter; made up from atoms of some of the 92 (naturally)known elements. Sans atoms; there can be no heat.
It would help if people used “heat energy”, when referring to heat as if it was a noun, whereas some of us prefer to think of heat as a process, so it is a verb, meaning to raise the kinetic energy of random motion of atoms, and molecules.
And when I said that “Skeptics” get branded as “ignorant fools”, that was NOT my sentiment; that was the perception of the AGW crowd. And that is why I try to get the community here to understand the disticntion between “radiant energy”, and “heat energy”
The transport of the latter is restricted by the second law of thermodynamics; the former is not; which is why I also said that photons and electromagnetic fields are not part of thermodynamics.
We do know that EM theory reuires that any (material) body that is at a Temperature above absolute zero can radiate a thermal EM spectrum of radiant energy. In a closed isothermal cavity, that is in thermal equilibrium, there will be a well understood density of electromagnetic radiation (energy), whose source of energy, is whatever maintains the Surface Temperature of that cavity. The radiation itself is quite oblivious to the Temperature of the cavity walls.
Suppose for the sake of discussion, that there is ONE point on the inside of that surface, that is one degree C lower in temperature than every other point on the surface. That point must also be radiating EM radiation, just slightly lower in radiant emittance, than the rest of the cavity wall; and that wall is totally absorbing everywhere.
What on earth happens to the photons emitted from our colder spot; if as some suggest, they can go nowhere else, since everywhere else is at a higher Temeprature ?
Well fortunately those photons, have no idea whatsoever what the wall temperature is so they simply cross the cavity and get absorbed wherever they land. How easy is that to understand.
And skeptics and lay folks need to understand the difference, and the difference in the technical terminology; if they wish to avoid that “ignorant fools” label the AGW crowd wants to brand them with. I’m just trying to help folks understand.
As I skim through the replies and questions Ira sparked, I sometimes scratch my head at the number of questions that are asked but are actually answered in the article, the slew of criticisms on points that the analogy was clearly never designed for, and arguments about cold things not being able to heat warm things, one that I see coming up in almost every thread over and over and over, plus a few others.
1. The physical model isn’t designed to explain how CO2 interacts in the atmosphere over all. The model was designed to illustrate one single characteristic of CO2, that being how it reacts with long wave radiation in the context of the “greenhouse effect”. It does a pretty good job of that. Expecting it also explain thermal quenching, convection, etc is silly. It wasn’t a model of the atmosphere that was proposed, it was a model of how CO2 interacts with long wave, and that’s it. Its like building a model of a car to test in a wind tunnel. It tells you nothing about the car’s horsepower, and it wasn’t supposed to.
2. This cold things can’t send heat to warm things argument never seems to end. The amount of heat any given object radiates is well known and easily determined. The caculus to arrive at the final equations is complex, but the equations themselves are easily understood by anyone with high school math. Here’s a couple of decent explanations:
http://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_law
http://www.egglescliffe.org.uk/physics/astronomy/blackbody/bbody.html
The point being that the temperature of the surroundings has NOTHING to do with the calculation. Any body emmits heat or energy flux as photons, and those photons travel at the speed of light until they hit something. The photons neither know nor care if what they are hitting is warmer or colder than where they came from. The amount of heat radiated by the warm body is much higher than the amount of heat radiated by the cold body, so obviously if there are no other factors, the warm body cools and the cold body warms. But remove the cold body, and the photons it was emitting that were being absorbed by the warm body go away with it. So the warm body is still cooling, but it has no off setting photons from the cold body, so it cools faster. What did the early settlers use to insulate their houses in the depths of winter? Answer: SNOW!
3. Why don’t we use CO2 to heat greenhouses or insulate houses if it does what is claimed? I love this question because of all the ridiculous answers it generates arguing over what it would or would not do. The answer is in part that greenhouses heat up because the prevent heat loss via convection, but that still leaves why not use CO2 for other applications to retain heat? The answer is because CO2 is a pretty lousy insulator and there’s tons of materials on the market that do a far better job in a far smaller form factor, and are practical to install and maintain. Trying to compare what a few inches of CO2 could do for a building compared to thousands of meters of atmosphere is just silly.
That must be why double stars disappear. They keep heating each other up until they get so hot they just explode.
Amazing. Utterly amazing.
Glickstein’s explanation of the “greenhouse effect” is nothing more than the “ballgame” version of the simplistic notion that radiation streams affect the temperature of all matter–gaseous, liquid, or solid–in the same way that they would a blackbody. And it perpetuates the rampant confusion between local radiative intensity and thermal energy transfer. It is only in space that the two can be equated.
What such pseudophysical, radiation-only explanations totally miss is differential thermalization of various substances through all the other means of thermal energy transfer: conduction, convection, and–most importantly on a largely oceanic planet–evaporation. Scores of careful energy transfer eperiments around the globe have repeatedly shown that moist convection is the principal means by which the base of the atmosphere is directly heated. Without it, the near-surface air could never become nearly co-thermal with the surface, because all the noncondensing GHGs taken together lack the thermal mass to accomplish that. It is through these neglected mechanisms that a nearly null-net radiative exchange between surface and the bulk constituents of the atmosphere, including clouds, is maintained. The intensity of that exhange should not be confused with energy transfer rates, which are a separate matter.
The “ballgame” analogy nevertheless can be made semi-realistic for those who lack deeper physical comprehension. Think of a pitching machine that flings balls at a backstop that forcefully bounces them back to a bevy of inept fielders with a collective .500 fielding average. They are weak-armed to boot and can only roll balls back toward the backstop. There stands the noted hitter, “Mighty” Joe Aqua, who picks up the returned balls at the backstop and hits them into the outfield, well beyond the infielders’ reach. The outfielders delight in throwing the balls into the bleachers and beyond. There is no infinite loop of returned balls that would double (as in the binomial series) the number of balls reaching the backstop. There’s only the increase indicative of the fielding average.
Oliver Ramsay, your explanation needs a few clarifications…
“A colder thing radiates energy, not heat, to a hotter thing with nary a care. The hotter thing absorbs what it is sent, but it doesn’t become heat because it doesn’t result in the average frenetic motion of all those particles becoming more frenetic.”
Radiation will register as a temperature increase if the radiation is within the absorption spectrum of the other body (colder or hotter, doesn’t make a difference). That’s how a microwave heats food, and how the sun heats the earth. The radiation results in more frenetic motion of the bonds within individual molecules (stretching, rocking, scissoring). Unless the molecule exists in a vacuum, that bond motion will result in the molecule pushing against neighboring molecules. The molecules then move in relation to each other – a temperature increase.
“The temperature is the average speed of all the particles.”
Almost, but not quite. Temp is the average kinetic energy – that’s velocity times mass. Given clusters of 100 atoms each of iron and hydrogen, the temperature of the iron cluster will be much higher than the hydrogen cluster if all atoms have the same average velocity. It takes more energy to move a higher mass to a given speed. Think of how much you would have to speed up iron atoms to get them moving as fast as hydrogen atoms are at room temperature – you’d have to vaporize the iron.
@davidmhoffer says: February 22, 2011 at 11:36 am
In an idle moment I foolishly returned to this thread. Ira Glickstein PhD’s protegé wants the last word, apparently.
‘What did the early settlers use to insulate their houses in the depths of winter? Answer: SNOW!’
So all the photons streaming into the house from the cold snow kept the house warm? Mmm. Food for thought, there, davidmhoffer.
– The early settlers didn’t know what Professsor Planck knew about the relationship of the energy levels of photons and the temperature of the body emitting them. Ira Glickstein PhD doesn’t seem to know this either – at least it plays no role in his rubber ball and kitchen scale model, which you so admire.
– Snow is cold, though. It is not capable of raising the temperature of any object above its own temperature. If you don’t generate heat in your snow covered house it will quite quickly get to snow temperature. Use snow as an insulator, or to keep the wind from whistling between the logs, but forget the energy it is radiating. It’s only useful if you are colder than snow.
‘The physical model isn’t designed to explain how CO2 interacts in the atmosphere over all. The model was designed to illustrate one single characteristic of CO2, that being how it reacts with long wave radiation in the context of the “greenhouse effect”. It does a pretty good job of that.’
No it doesn’t. Ira Glickstein PhD’s model IS bonkers, and I don’t understand a word of this defence of it. You cannot use the laws of motion as an analogy for the laws of thermodynamics. You cannot use a scale measuring – er… what? momentum? work? general bounciness? – for temperature. You cannot just sum impacts together as an analogy for increasing temperature, or heat, or… whatever.
I note with a sinking heart that he is planning a sequel. More overcooked graphics and ridiculous analogies, I bet.
Nobody argues against the fact that some trivial increase of atmospheric CO2 has been, indeed, taking place during the last few decades. It is very minor, compared even to the most recent historically recorded swings of the same parameter.
The most important point is that this CO2 increase is not correlated with the temperature changes in any way; that is, there is no “greenhouse effect.” None. Nothing to worry about, nothing to discuss.
It is also important to remember that this increase is negligible, compared to drastic changes of CO2 concentration in the atmosphere, as measured during the 19th and 20th centuries. The proponents of the AGW hypothesis, including the authors of all IPCC papers, are inexplicably (or understandably, depending on your point of view) ignoring this fact.
On the long-term, geological scale, the amount of CO2 in Earth’s atmosphere was almost always much higher than today.
The veracity of Mauna Loa record is a secondary issue of little importance. Willis Eschenbach, whose opinion I respect, even published an article on WUWT, few months ago, defending the Mauna Loa record.
However, I remain a skeptic. The Keeling’s curve is simply too smooth, too artificial, compared to most other CO2 data, to be real. Something is wrong there, something is being done with the equipment, or with the calibration methods, or simply with the representation of acquired data, to produce the desired curve. I am not a specialist in calibration of Siemens gas analyzers but some specialists, including Knorr, made the same observation.
Finally, when I am told that Mauna Loa record is confirmed by the measurements made on several other stations around the globe, I cannot help but keep in mind that all these stations are staffed by people carefully chosen to walk the green party line, and all these data are prepared and published, almost exclusively, by the green hoax zealots.
There is no hope for any objectivity in this field. Too much money, too many careers, too huge a corruption of people and information are involved for me to trust anything or anybody. I only trust (to some extent) my own eyes and brain, comparing what other people are saying, trying to separate the husk from the grain, and to adjust opinions by taking into account the self-interest of opinion-makers.
I am sure that time will prove me right, as it has on many other occasions. Meanwhile, as CO2 concentration gets a bit higher every month, global temperatures are dropping precipitously. This warms my heart but costs more and more in heating expenses.
Steve says:
February 22, 2011 at 12:41 pm
Oliver Ramsay, your explanation needs a few clarifications…
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Thanks Steve,
I certainly take your point “velocity X mass”.
My contention was that there would not be thermalization arising from vibrational excitement if the incoming radiation were less than the outgoing, as would be the case where the other body is cooler.
Now, I know nothing about magnetrons, but I assume that the filament is at a higher temperature than the food it heats. The sun is hotter than planet Earth, albeit somewhat cooler than planet Gore.
davidmhoffer says:
February 22, 2011 at 11:36 am
… “The point being that the temperature of the surroundings has NOTHING to do with the calculation. Any body emmits heat or energy flux as photons, and those photons travel at the speed of light until they hit something.” …
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Hi David,
Well, humm. I’m going to have a hard time explaining this to you so bear with me, I have thought much on why these people could possibly think the way they do and the only thing I keep coming up with has to do with what Feynman showed so very clearly with little simple cartoon drawings like Ira has drawn above. See this link:
http://vega.org.uk/video/subseries/8
You only have to absorb the first and a bit into the second lecture to see what I am about to say.
It gets into the statistical amplitude at any given point in space being the possibility of a photon being found at a that point. He gives a number of examples, reflection and gratings, explaining to the audience just how photons can possibly cancel to where there is no photons at all at some places and the amplitude is zero so the probability is zero. His imaginary scintillators are recording absolutely no photons where clearly there should be photons found there for the whole surface is being illuminated. I sure hope you don’t think IR is somehow different that SW in its purest sense.
Kind of like taking a large hollow perfect sphere, perfectly smooth and it the same temperature everywhere, what is the amplitude calculated by his quantum electrodynamics at any point within. I really don’t know, no, I think zero. Clearly there would be at any given point inside the sphere all frequencies, all polarizations and all directions. Do all amplitudes cancel like in the problem he was having with the infinities?
If you look at this one way then yes, there would be no photons within the sphere at all, all canceling as in reflection where there is absolutely no photons. If you believe there is no way photons can cancel, that is, there is no place in that sphere where the amplitude is zero then you are visualizing as you stated above that in your words “the temperature of the surroundings has NOTHING to do with the calculation”
I tend to lean on Feynman’s side. There is cancellation but I don’t have the facilities, programs and books with the equations to prove it to you. So, I see why there is two sides to that argument.
Now if you ever tries to measure within that sphere you could not for any equipment or probe would destroy the symmetry and cast an infinite number of shadows on the opposite side. Then I think you would see you imagine, photons everywhere within!
Whoops… number of misspells above so please ignore.
to Alexander Feht
I’ve been studying Keeling in detail. And I am rapidly coming to the conclusion that Keeling knew for quite a while that CO2 was not causing temperature rises, and could not cause temperature rises. He had to be aware of the data from Amundsen-Scott that showed no rise in temperature while an increase in CO2 was recorded. The Antarctic is the most pristine site in the world to take baseline data. And he knew it….I found evidence that he knew of its pristine nature. The south pole is much better than Mauna Loa. But, when funding wound down, he probably chose Mauna Loa to focus on because its a much nicer place for him to live and hang around rather than the South Pole.
From: http://www.aip.org/history/climate/Kfunds.htm
“The survey’s logistics, like its instruments, depended on things that happened to be available for unrelated purposes. One lynchpin would be a weather observatory built in 1956 atop the volcanic peak Mauna Loa in Hawaii. Rising above the lower atmosphere and surrounded by thousands of miles of clean ocean, it was one of the best sites on Earth to measure undisturbed air. Funding for the Mauna Loa Observatory was split between the U.S. Weather Bureau and the National Bureau of Standards. It was also reported that “The Armed Forces are keenly interested in some of the projects at Mauna Loa” thanks to concerns with high-altitude equipment and monitoring satellites.(9) The military accordingly provided help for road-building and the like.
Another key station would be in the pristine Antarctic, where scientific work depended wholly on military assistance. It was almost a parable, the coldest of Cold War science. The U.S. Navy and other services, intent on developing expertise that would prepare them for warfare under any circumstances, would gladly pick up some credit along the way by giving scientists heroic logistical support. This was only one of many ways that the Navy and other armed services, by funding work connected with their military missions, provided essential support for research that would turn out to tell something about climate change. ”
“When Keeling set up his recording spectrophotometers at these stations, they proved to be worth their cost. Spikes in the record on the strip charts pointed to CO2 contamination blowing past from volcanic vents on Mauna Loa, and from machinery in Antarctica. Stalking such problems with a meticulous attention to detail that verged on the obsessive, Keeling managed to extract a remarkably accurate and consistent baseline number for the level of CO2 in the atmosphere. In late 1958, his first full year of Antarctic data hinted that a rise had actually been detected.”
That website
http://www.aip.org/history/climate/index.htm
although run by someone who does believe in AGW, is very rich in historical detail of how this whole fiasco came about.
David, one more thing. If you go ahead and watch lecture three and four, it gets into the couplings in his diagrams. That is another reason I think no photons within the sphere. For at every interaction there is a coupling cost (loss of energy) that occurs and it seems on the top that if you were always having photons passing back and forth in reality then there would be a constant coupling loss of energy occurring and that does not seem real to me. In a nutshell *that* is why I think no photons within. Of course the coupling is the fine structure constant.
Oliver Ramsay “Thanks Steve, I certainly take your point “velocity X mass”. My contention was that there would not be thermalization arising from vibrational excitement if the incoming radiation were less than the outgoing, as would be the case where the other body is cooler.”
Well there would be thermalization (that has a specific definition in thermodynamics, btw), but I get your meaning. As you pointed out, radiation from a cooler object will slow the rate of cooling of the hot object, not increase the temperature of the hot object above it’s initial temperature.
A ball of steel that is half a degree away from molten in a 30 degree room won’t get to it’s melting point if you move it into a 300 degree room. The room is still the cooler object, so the steel ball cools. The only difference is that it will cool slower as it is cools to a “room temperature” of 300 degrees instead of 30 degrees. The room does transfer energy to the ball, but nothing in comparison to the original energy content of the ball.
Eureka!! – The proof of “back radiation” as a heat-engine, is that The Sun has lasted for some 4.5 to 5 billion years – It is obvious, even to a dumb-scull like me that back radiation from the planets, moons and other bodies floating around in the solar system is keeping The Sun much warmer than it otherwise would be. –
Oh no, no, no I thought for a moment I had it there but then I suddenly remembered the “Ice-core graphs” and they show that, in the past when both CO2 concentration and Earth’s temperature are at max. peak (and back radiation both from CO2 and Water Vapour may also therefore very well be at maximum) the Earth usually chooses to return to glaciations.
Oh well, I had better a look for “The Hot Spot”- I suppose.
Fred Souter: Say you have a regular camera that takes photos in the visible light range (shortwave radiation). You take a photo of the Sun with that camera, and that is proof that shortwave radiation from the Sun arrived on Earth. No controversy here. Right?
OK, now you get a camera that takes photos ONLY in far infrared light (longwave radiation). It has absolutely no sensitivity to light in the visible range. I worked on aircraft systems that had what is called a Forward Looking IR (FLIR) camera. You may have seen video from such a camera showing how, in absolute darkness, the people in the airplane can see things of higher and lower temperatures. For example, if you are looking at a moving truck at night, the engine compartment and the tailpipe and the tires will look white in the image and the rest of the truck will look gray or black. If it is daytime, with a camera of that type, you can distinguish between a truck that has its engine running now or recently had it running and a similar truck that has been parked for a while and has cooled down.
If you are in space, far from Earth, and you point that FLIR camera at the Earth, in daytime or nightime it will show the warmer parts of the Earth in white or light gray and the cooler parts in dark gray. It will show space around the Earth in black because there is no longwave radiation coming from empty space. OK so far?
Now, take that FLIR camera near the Sun and point it at the Earth. Will you be able to distinguish the Earth from the space around it? YES. The Earth will be a lighter shade, in contrast to the space around and behind it. That is proof that the longwave radiation from the Earth has reached to the Sun and some of it will impact into the Sun and, ever so slightly, warm it.
That shows that the Earth, which is a lot cooler than the Sun, emits longwave radiation into space, some of which falls onto the much hotter Sun, warming it a tiny bit, even as the Sun emits shortwave radiation into space, some of which falls onto the cooler Earth, warming it considerably.
If that example is not convincing, imagine (as an earlier commenter did) that you and I are in a water fight and you are spraying me with water from a fire hose. I am spraying you with water from a garden hose that happens to have blue dye in it. No doubt, I will get a lot wetter than you, but … BUT, you will get some of my blue water on you, will you not?
When scientists say that radiation goes from the hotter to the cooler object, they are talking about the NET transfer of heat energy. The Sun transfers a lot more energy to the Earth than the Earth does to the Sun, so the NET transfer is from Sun to Earth. However, just as some the blue water from my small hose hits you, and much more water from your fire hose hits me, the NET transfer of water is from you to me – but you get some of my blue water. Right?
During the morning rush hour, 100,000 cars come into the city and 10,000 go out of it. The NET flow is 90,000 cars into the city. However, as anyone who cares to look will see, there is a flow in both directions, both into and out of the city.
“No, your coat will NOT radiate heat back to your body. It only radiates to objects cooler than itself. Again, this is a basic concept of Thermodynamics. So far, we have found no examples in the universe to refute this law.”
Your wording is a bastardization of the second law. Radiation and heat are different types of energy transfers, for one, so “radiate heat” is just a muddy term.
Unless your coat is at absolute zero it is radiating energy to everything around it. Odds would be extremely high that it absorbs more heat from the environment than it emits, though.