A couple of days ago WUWT carried a story, talking about intense cold in Antarctica, carbon dioxide, and the icecap of Mars. This one passage stirred up a significant debate:
According to Weather Underground, Vostok, Antarctica is forecast to reach -113F on Friday. That is four degrees below the freezing point of CO2 and would cause dry (CO2) ice to freeze directly out of the air.
It seemed (at the time) a reasonable statement. The freezing point of CO2 is -109.3 degrees Fahrenheit (-78.5 degrees C). There’s been mentions of this supposed phenomenon of CO2 freezing out of the air before on other blogs and websites. One of the best examples was even an entry in the website “ask a scientist” where the question of CO2 freezing out of the air was posed, and the answer from an Argonne National Laboratory scientist seemed to indicate that CO2 could indeed precipitate as a solid from the air if the temperature was low enough at Earth’s south polar ice cap, specifically at Vostok Station, which holds the record for the lowest surface temperature recorded on Earth at −89.2°C (−128.6°F)
Certainly, at least some of the carbon dioxide in the atmosphere at the poles does freeze out during the winter. However, there is not enough frozen out to accumulate to any extent at the present.
David R. Cook
Atmospheric Research Section
Environmental Research Division
Argonne National Laboratory
So, it seemed possible. But as WUWT commenters soon pointed out, temperature is only part of the equation needed to deposit CO2 as a solid from the free atmosphere at that temperature.
Soon we were discussing gas laws, phase diagrams, and partial pressures. The debate mainly centered on whether or not this phase diagram for carbon dioxide applied to 1 atmosphere of pressure of pure CO2 versus simply 1 atmosphere of pressure independent of the purity of the gas.
The author of the post, Steven Goddard wrote in comments:
The phase diagram shows unambiguously that the equilibrium state of CO2 at one atmosphere at 113F is solid. The freezing point of CO2 is -109F at 1 atmosphere.
The PDF referenced doesn’t translate well to the blog size format, but this less detailed phase diagram for CO2 does fit and was mentioned in comments also:
Since many of us know from experience that with ice, be it water ice or CO2 (dry) ice, that a phase change can occur directly from solid to gas (sublimation). It seemed reasonable to conclude that the reverse could be possible, going from a gas to a solid as long as the temperature was below the “triple point” of CO2 as well as the freezing point at 1ATM.
The freezing point/sublimation point of CO2 at 1ATM is at -78.5C (-109.3F). In the situation described in the forecast for Vostok station, the temperature was forecast to reach below the freezing point for CO2 at -80.5 C (-113F ). It seemed reasonable then to concludes that CO2 would freeze right out of the air, much like frost does from water vapor. Plus we had a statement from a scientist at a National Laboratory saying it was possible also. What’s not to like?
One small detail: partial pressure.
The concentration of CO2 in the free atmosphere is very small. Thus the partial pressure of CO2 in the atmosphere is about 0.0004 atmospheres. But wait there’s more. Vostok station is at a high elevation, 3288 meters above sea level (10,787 feet) and the atmosphere is thinner. Thus the partial pressure of CO2 is even lower.
Commenter George E. Smith summed it up pretty well with this paragraph:
At -78.5 deg C (-109F), that equilibrium occurs at a partial pressure of CO2 of 760 mm Hg, one atmosphere. Below that pressure, there isn’t enough abundance of CO2 molecules in the vapor phase for collisions with the solid surface to occur at a fast enough rate to make up for the ones that escaped; so the solid CO2; dry ice, will continue to sublimate.
Basically, there are so few CO2 molecules in the free atmosphere, sublimation rules over deposition as a solid. Yes some CO2 may deposit on a surface at at -80.5 C (-113F ), but it would quickly sublimate back into the free atmosphere, and thus accumulation would not occur.
Meanwhile WUWT reader Ric Werme had written to Dr. David Cook of Argonne National Lab to ask about his original opinion he wrote for “ask a scientist” web site. Ric reports he responded with this:
Ric,
You are correct. In my attempts at being simplistic I made a mistake in my answer to “Freezing CO2″ on the Ask-A-Scientist page. -57 C is the boiling point of CO2. The freezing point of CO2 at atmospheric pressure is -78.5 C (-109.3 F). If the temperature reaches -113 F at Vostok, Antarctica, some carbon dioxide might freeze out of the air, assuming that the carbon dioxide vapor pressure drops to its saturation vapor pressure.
The vapor pressure must reach the saturation vapor pressure for dew or frost to form. This happens at the dew point or frost point temperature, which is dependent on atmospheric pressure and the absolute amount of vapor in the air. As atmospheric temperature increases, the dew/frost point temperature increases. As atmospheric pressure increases, the vapor pressure increases. At very low temperatures, the dew/frost point temperature is very low.
When the temperature of the surface (whether grass or a car window) is below freezing, frost will usually form instead of dew, although water can be super-cooled and not produce dew, fog, or clouds in some cases. Surfaces on the Earth cool off sooner than the air, so dew/frost will normally form on them before fog (water or ice) forms in the air.
The temperature being at “freezing” or below does not imply that frost will form on surfaces or in the air. The vapor pressure must be high enough (saturation vapor pressure) and the temperature low enough (the frost point temperature) for frost to form.
So it seems, Dr. Cook (and our own Steve Goddard) made the basic and simple error of not taking vapor pressure into account. Given our human experience with the everyday freezing of water, we don’t often think about it. I didn’t catch it either initially, nor did some WUWT commenters.
It does demonstrate though, how little CO2 there is in our atmosphere, we can’t even precipitate it to solid under any natural condition of earth.
But, even with the debate apparently settled, the CO2 freezing question was still all in the realm of opinions and phase diagrams. Some people really wanted to see some empirical proof. Some thoughts on experiments were tossed about.
Enter WUWT reader Dr. Thomas Thatcher of the University of Rochester who had not only an idea for an experiment, but the means with which to carry it out. He had a lab freezer which would “maintains -80˚C (-112˚F) in my lab, and it can be set as low as -86˚C (-122˚F).”.
He proposed that he could use that freezer to do a test with dry ice:
The argument, as far as I can tell, is that at the atmospheric partial pressure of CO2, dry ice at -113F will sublimate faster than it forms (which may be different than how a pure CO2 atmosphere would behave). I am in a position to test this, as described above.
…
Based on the arguments presented here, the two postulated outcomes are,
1) significant loss of mass, as the sublimation rate exceeds the deposition rate
2) no change, or negligible gain in mass.
(I suspect that any gain in mass will evaporate on the short walk from the freezer to the balance.)
It’s admittedly an imperfect experiment. But I expect the outcome will be rather obvious; the dry ice will be gone in the morning. We’ll see.
He conducted his experiment overnight between Thursday and Friday, and writes:
The freezer is a VWR brand ultralow temperature upright freezer, similar to models shown here.
http://www.vwrsp.com/catalog/product/index.cgi?catalog_number=14230-120&inE=1&highlight=14230-120
It is set to -86C, the temperature typically rises 1-3C when opened, and recovers in about 30 minutes. (Factory temperature calibration was NIST-traceable but it has not been recalibrated since it was installed here.) The samples were loaded at 4:30 pm and removed at 9:30 am, so the freezer will have been largely undisturbed during that time.
The interior is mostly filled with stainless steel racks that hold cardboard boxes for storing biological samples. I placed the test samples in two boxes on the bottom shelf at the rear of the freezer, the coldest zone and closest to the temperature probe.
One sample was placed in an open box with extra holes cut to allow air circulation. The other sample was placed in small zip top plastic bag inside a cardboard box. The samples were weighed by difference before being placed in the freezer and after removal in the morning. Additional weighings were taken to estimate the amount of sublimation during the weighing procedure and the amount of water that might condense on the boxes, but these amounts proved insignificant next to the overall results.
The samples were placed in the freezer at 4:30pm (reading -82C) and removed at 10:00am (reading -83C).
Open container, start weight 36.5g dry ice, end weight 0g, amount sublimated 100%.
Zip-top bag, start weight 27.6g dry ice, end weight 25.3g, amount sublimated 8.3%
Proving, I think, that CO2 will freeze and remain frozen at below -78.5C if the partial pressure of CO2 is near 1 ATM, but the CO2 will rapidly sublimate is the partial pressure of CO2 is near atmospheric normal.
And he concludes:
Bottom line, 40g of dry ice placed in an open container at -82C completely sublimated overnight, while 27g of dry ice placed in a zip top bag retained 90% of its mass. This proves two things, first, that the temperature of the freezer did not exceed -78.5C for any appreciable period of time, and second that yes indeed, the partial pressure of CO2 is the key to the problem.
Best of all, he sent photos of the experiment he conducted:
Thanks to everyone who participated in the debate, including Ric Werme for his correspondence help and especially Tom Thatcher for conducting the experiment and taking photos.
We all learned something, we had a little fun, some online yelling occurred, and some egos were bruised. Overall though it was worthwhile that this myth of “CO2 snow at Vostok station” was finally put to rest.
Anthony, it’s really heart-warming and encouraging to see this sort of interaction… rather than just assertions of “our results are robust!” I learn an awful lot on this blog…. even the trolls force me to think…. but now that dhogaza is banned (and justifiably so!) I’m prognosticating that Flanagan will be next and I’m volunteering to help hold him down while Jeez [SNIP!] him.
Seriously, the willingness of people here to check out and test what they don’t know or what doesn’t sound right is important. The word is “empiricism”, the second or third most important element in science.
😉
“Overall though it was worthwhile that this myth of “CO2 snow at Vostok station” was finally put to rest.”
What did the previous article make about predictions?
Good work. And really interesting – the initial question was very appealing and I certainly learned a lot from it.
I hope there were no bruises – we are all here to learn.
for example, one of the things I liked about Loehle’s work on his 2000 year reconstruction is the way he accepted criticism of his initial efforts. Then revised his work. Isn’t that how science is supposed to be?
Great experiment.
Science at its best: a genuine question, some ideas kicked around, then an experiment. So simple that everyone can understand.
Thanks.
Thank you for this post. I was worried about the original post but (as with my own moments of weak science) this issue seems to have set about thoroughly redeeming itself and becoming an instructive lesson instead.
My heart warms to this cool episode.
Should have said “as I endeavour to do with my own moments of weak science”
Hehe, read the first comment in the original post. Vapor pressure wins.
REPLY: Yup and good for you for pointing it out first. – Anthony
Actually, I had that same thought in a posting to this very site over a year ago and mused about CO2 freezing out. Followed up the post about 10 minutes later with … vapor pressure.
What IS interesting, though, is to see blobs of liquid CO2 in the ocean emitting from undersea volcanoes at great depth!
Wow, that is just great stuff, thanks to Mr. Watts and all the participating people.
Wow! Impressive work. 🙂 And interresting.
Wonderful work on this post. Thanks to Dr. Thatcher for the experiment so we can see with our own eyes. And thanks to the yellers. I have always felt that sometimes yelling helps, especially when there is something to yell about. And we are all wiser for the yelling — along with the experiment.
Anthony, I am only receiving the fourth photo of five.
Yes, but what do the climate models say?
REPLY: You mean the refrigerator climate models? 😉 – Anthony
Well, well well. REAL science in action! Superb!
We don’t get that on the climate alarmist websites. Debate, leading to experiments leading to a real answer derived from actual empirical evidence and observation. What a refreshing change.
The closest some other website would have come to this would have been a computer simulation designed to show a thick layer of solid CO2, thus PROVING the theory and anyone who disagreed would be labelled an evil denier.
Well done home science experiment, if your home has a really cold freezer. Looking at the phase diagram and extrapolating it looks like you would need to get down to -160°C (-250°F) or so to deposit solid CO2.
Mars has a CO2 pressure of about 0.006 Atm. and forms solid Ice at about -125°C (-193°F) which is inline with the phase diagram above. Source
http://marsprogram.jpl.nasa.gov/msp98/lander/science.html
and
http://en.wikipedia.org/wiki/Atmosphere_of_Mars
Yes, but what do the models say?
Good job!
How does this work in Mars
“When the southern cap was largest, the mean daily pressure observed by Viking Lander 1 was as low as 6.8 millibars; at other times of the year it was as high as 9.0 millibars. The pressures at the Viking Lander 2 site were 7.3 and 10.8 millibars. In comparison, the average pressure of the Earth is 1000 millibars.”
“The average recorded temperature on Mars is -63° C (-81° F) with a maximum temperature of 20° C (68° F) and a minimum of -140° C (-220° F).”
http://www.solarviews.com/eng/mars.htm
“The six most common components of the atmosphere are:
•Carbon Dioxide (CO2): 95.32%
•Nitrogen (N2): 2.7%
•Argon (Ar): 1.6%
•Oxygen (O2): 0.13%
•Water (H2O): 0.03%
•Neon (Ne): 0.00025 % ”
Possibly more CO2 in Mar’s atmosphere than in Earths atmosphere.
The five pictures from Dr. Thomas Thatcher are not appearing. The links are broken. — John M Reynolds
I doubt that we would have seen this result by relying on CO2 temperature models.
It high lights the difference between the alarmists and the skeptics.
Skeptics create an experiment. Warmists make a model.
(Warmists also have a tendency to denigrate actual data, when they aren’t falsifying it.)
Hey, science can be fun when you don’t have to be paid to do it!
A question – in your text above you say:
“Since many of us know from experience that with ice, be it water ice or CO2 (dry) ice, that a phase change can occur directly from solid to gas (sublimation).”
Now, I’ve never bothered to pursue this, but my chem profs back in the ’60s used to insist that water never sublimated. That while vapour production looked like sublimation, there was actually a 3 point phase change from ice >water>vapor, and there wasn’t in fact a true two-point change to gaseous phase directly from solid state. Maybe some active physical chemists can update me.
So as a result of what has transpired here will CO2 ever “snow” out of the atmosphere and if it does what is the approximate temperature at which this will happen?
Many thanks
Sandy
REPLY: about -140C, but it may be such a thin powder that it is unobservable, since there is so little CO2 in the atmosphere.
– Anthony
(big sigh) Thank you. I have learned a bit more of our world.
It’s refreshing to see science and the scientific method in action, isn’t it? Good job!
Thank you, Dr. Thatcher. Once again the adage is proved: One experiment is worth a thousand expert opinions. 8^)
Now, I’m really curious. I’m not sure how, but I once created dry ice accidentally while I was testing a device in a small environmental test chamber. The chamber used a tank of compressed CO2 like consumable refrigerant to lower the temp in the chamber. I was trying to get the temp down to -55F but after an hour, I couldn’t get it much below -5C. There was an access hole in the back of the chamber for routing cables and wires to the device that was supposed to be plugged with foam (which I forgot to do).
I opened the door to the chamber (~2 cubic ft. cavity) and it was completely filled with CO2 “snow”. I wheeled the cart-mounted chamber over to a stainless steel slop sink in the lab and scooped the ice into the sink. The sink started to make cracking noises and I thought it might actually crack so I turned on the cold water. Thick CO2 vapor poured over the sides and covered the floor of the entire lab. Yeah everybody thought it was cool (in more ways than one).
Because of the open access port, I’m sure there was a lot of water in the snow and maybe that’s what was trapping the CO2 gas, moreso than the presence of frozen CO2.
Brilliant !!
You just solved the phantom SWPC/NOAA sunpot issue.
The spots yesterday that nobody imaged or drew but were counted (06-12-2009) sublimated before they could exist.
The spot of 06-10-2009 likewise sublimated after it was draws so that it could not be imaged.
Problem solved.
Throw them out.
open and shut in 72 hours.
wow.
the power of the internet.
Well done. Once again, WUWT lives up to its well-deserved title of Best Science Blog.
Very interesting discussion and explanation. It took me a long time to get a good handle on partial pressure in my nuclear power training, but, now that I’m retired, that nuclear “learning” is still good for something other than giving me a gut feeling that there is something — Q = mc∆T — entirely wrong with AGW theory.
May I add this? When “freezing point” is mentioned (or indeed “condensation point”, boiling point” and so on) you have to ask “under what conditions?”. For CO2, the quoted freezing point refers to atmospheric pressure and – the crucial point – pure CO2. It so happens that you can also use information extracted from the phase diagram to calculate the frost point for CO2 at atmospheric pressure even when CO2 is not pure, but is dissolved in air (in answer to someone’s enquiry in the earlier thread, air is, technically, a solution of O2, N2 ….). Or, to be precise, when CO2 is dissolved in dry air. In wet air, there is the potential for the complication of CO2 and H2O frosting together, as a “hydrate” or “clathrate” – which was one of the most interesting points raised in the earlier thread. You can’t check that possibility in any simple way from the phase diagram for CO2 alone – you’d need some measurements done on that very problem, preferably summarised into a suitable phase diagram.
It’s worth realising that saying “It so happens that you can also use information..” rather disguises the fact that experimental measurement has revealed that “It so happens that …” – strictly, you can’t tell just by hand-waving or assertion, someone had to make the measurements. All this is elementary stuff for, say, chemical engineers or many physical chemists. But many other scientists may never need to understand the issue in a whole career.
One last point – understanding of this “elementary stuff” has been backed by a century’s worth of theory and experiment. That knowledge is therefore infinitely more secure than knowledge about “climate science”, whose proponents are necessarily limited to observations and modelling – you can’t do controlled experiments on the climate. For that reason alone – and there are plenty of others – I find find the global warmmongers’ lack of a sense of proportion, and lack of due humility about their claims, an offence to the spirit of science.
Wonderful!
That is how science should be done.
An ounce of experimental fact outweighs a ton of arm waving.
But it IS enough to worry brass monkeys.
Always good to learn. Thanks to everyone involved.
Bye,
TMTisFree
Well done, and well said.
Anybody else have the pictures *not* show up (unless specifically clicking on each one)?
.
.
Well done everyone here who participated in the debate-surely this was science in action, whereby a hypotheses was tested and found wanting.
No mention of Phil, who I think made some very valuable points -a little less snark would go a long way Phil, your comments are always interesting and to be respected, but so are those of others. A triumph for the scientific process. The hockey stick next to be demolished on line? (again)
Tonyb
REPLY: Phil. did indeed make some valuable contributions, but behaved very badly. Note that I also didn’t mention “crosspatch” in the article, although he was actually the very first to identify the issue. Since this article may be cited as a reference in the future when the question arises, I felt it appropriate to only mention contributions to solving the issue from people that use their real name. Science is not advanced anonymously, peer review journals do not accept anonymously submitted letters/papers with snark attached, why should we?
That, and I don’t believe in rewarding bad behavior. There was too much labeling of people by some commenters, and it was entirely unprofessional and unnecessary. We really don’t do anyone any favors when we revert to this level while trying to educate and enlighten online. – Anthony
Ric, George, Phil, Steve, David, Thomas, Anthony…..
I am thrilled to bits for this education. It swept off over 50 years of dust, added a lot of new material and had me brushing up on Boyle, Gay-Lussac, Avogadro, Henry, Boltzmann, phase rule, ….. and the honour of feeling part of a society of giant intellects that let others like me make my little offerings at will. And this is just one of the kaleidoscope of topics from solar physics to ocean chemistry and currents, biology, and expansion of my own geological and engineering field. This is got to be the future of education when this medium can inspire an old dog like me.
If C02 is heavier than air, what affect will this have on its “freezing out” of the atmosphere as snow?
The sign on the wall of the Metrology/Calibration lab I worked in:
ONE TEST IS WORTH A THOUSAND EXPERT OPINIONS
Thanks, Dr. Thatcher.
I really hate phase diagrams. Geologists have to suffer through endless phase diagrams in school, supposedly explaining why one obscure mineral appears before another in a rock, only to never use them again.
Glad to see they are of limited use in atmospheric science as well.
Elliptically related topic: Regarding CO2 in ice cores at Vostok: Since some 3500m of ice built up raising the altitude as it did so, is there any indication that the CO2 content sytematically declined as one ascends the record? Was there any sign that the gas at higher pressures down below caused microfracturing and outgassing of the cores?
OT http://www.wrh.noaa.gov/pdt/
Go quickly to the above site and check out the @Apple logo in the infrared over Oregon. I screen captured it when it was really good.
“If C02 is heavier than air, what affect will this have on its “freezing out” of the atmosphere as snow?” Essentially none. The individual CO2 molecules are heavier than N2 and O2 but the molecules collide with other so frequently that for most purposes you can treat the air as having uniform composition.
Yes – an excellent debate. Thanks to Stephen Goddard for the original post as well. He posed a very good question and one which not many of us knew the answer to – me for one.
It was also good to see real science in action.
I missed the fun. Must have been arguing someplace else:).
I was intrigued that in the other thread
http://wattsupwiththat.com/2009/06/09/co2-condensation-in-antarctica-at-113f/
Phil. (00:20:45) :
look at the phase diagram of CO2!
That is four degrees below the freezing point of CO2 and would cause dry (CO2) ice to freeze directly out of the air.
This would only occur in an atmosphere entirely composed of CO2, i.e. a volume fraction of 1.0 not 385ppm. At a vapor pressure of ~1000ppm the sublimation point is approximately -135ºC
One in a thousand will not be shaking hands with a second one to start making snow. Pity. I had that image of ice crystallizing out of clear air, like pixie dust, as sometimes happens when it is very cold and very humid. I suppose it means that the kinetic energy is so low that the gravitational one sticks that molecule on the surface, and then another one from the 1/1000 comes etc etc.
Mars is in a better position and gets CO2 snow.
from the wikipedia article on Mars:
Mars’s mean surface pressure equals the pressure found 35 km above the Earth’s surface. This is less than 1% of the surface pressure on Earth (101.3 kPa). The scale height of the atmosphere, about 11 km, is higher than Earth’s (6 km) due to the lower gravity. Mars’ gravity is only about 38% of the surface gravity on Earth.
The atmosphere on Mars consists of 95% carbon dioxide, 3% nitrogen, 1.6% argon, and contains traces of oxygen and water.[5]
Okay, let me get this straight. You had a hypothesis, tested it, found it not to be true, and so abandoned your hypothesis. What the hell kind of scientist are you?
Hi,
We have just added your latest post “Results: Lab experiment regarding CO2 “snow” in Antarctica at -113°F (-80.5°C) – not possible” to our Directory of Science . You can check the inclusion of the post here . We are delighted to invite you to submit all your future posts to the directory and get a huge base of visitors to your website.
Warm Regards
Scienz.info Team
http://www.scienz.info
jmrSudbury (04:28:31) :
The five pictures from Dr. Thomas Thatcher are not appearing. The links are broken. — John M Reynolds
Check your firewall settings. I couldn’t see them either until I turned off ad blocking. Something about the URL got the pictures labeled as ads.
The photos are not showing due to an error in coding. The closing virgule, “/” in the image markup needs a space before it.
cheers,
gary
the partial pressure of CO2 is the key to the problem.
Yes – it seems that both sides of the debate on AGW seem to have forgotten some basics from high school chemistry. Good on you guys for admitting the error. Everybody makes mistakes after all to err is human.
The people who frighten me most are those who are never wrong and won’t admit it.
Incidentally, have Steig et Al come forward and retracted their Nature paper (for their nonsensical inversion of temperature data that turned cooling into warming)?
@Doug W (06:21:37) :
“I really hate phase diagrams. Geologists have to suffer through endless phase diagrams in school, supposedly explaining why one obscure mineral appears before another in a rock, only to never use them again.”
What!? Who doesn’t like phase diagrams! There was no suffering from this geologist when I was learning about phase diagrams (except for when I was trying to construct them). But I use them all the time now days.
This is awesome! EXACTLY how science SHOULD be done!
I had originally replied in the original thread to Crosspatch and posted the quotes from David R. Cook from the “Ask A Scientist” site link that he had provided. It is wonderful to see things like this emerge from an true and honest vetting process.
To Crosspatch: Your original “Uhm, no. Vapor pressure and all of that.” comment turns out to be right on! Congratulations!
This was fun!!! Let’s do it again!
Also, I am sorry I missed most all of the fun and games from the original thread on this subject (work and all that). I am simply astounded by the enormous volume of truly intelligent and resourceful individuals that frequent and contribute to this blog. A heartfelt salute goes out to all! 🙂
Got to jump on the bandwagon a wonderful resolution to the question of CO2 snowclear easy to understand for this layman and easy to relate to others even without visual aids. JG
Mr. Wizard, let’s do more experiments.
What is this? Some kind of science blog?
And that, kiddies, is why frost doesn’t always form on daddy’s car windows — except when he’s running late to work and all the windows are frosted over with a thick coating — but that’s another ‘law’.
As my favorite robot Johnny #5 used to say with great excitement “Data!”
I sure love this site for all that it does so well.
What kind of effect would CO2 precipitating out of the air have on ice core data ?
“ONE TEST IS WORTH A THOUSAND EXPERT OPINIONS”
Sorry, NO. You only need one perosn who understands what the data means. We are not talking about the effect of a wide range of random variables here. This is basic physical chemistry data at the level of 1st year undergraduate.
I honestly cannot see why the refrigerator experiment proves anything more than the phase diagram. The phase diagram merely presents the results of a large number of such experiments done under far better controlled conditions.
As a physical chemist all my working life the answer was all there in the phase diagram and needed no extra work. Even if the fridge experiment went the other way it would merely mean that the experimental design failed.
“I really hate phase diagrams.”
I don’t – they are wonderful things! The value of phase diagrams is that they often are on a log scale and allow the results of a huge range of variation to be summarised on a simple diagram. The main thing to remember is that they generally deal with equilibrium conditions. It says nothing about how fast equilibrium is reached.
Jolly good knock about stuff, though!
Now, if we could only apply this sort of rational debate to AGW theory.
Just a thought!
Can we debunk the whole ‘CO2 will cause runaway global warming’ with a simple experiment – say, by putting sealed bags of different concentrations of CO2 into an oven and see what happens?
Sorry – I’m just a geologist. To paraphrase the late great Jack Eddy: I like rocks.
and another big thank you from a lurker on this site; though I did briefly ask a question on this one !
Thank you to all; now to find out how to get this to the Head of Science at the kids’ school so he can show them just what SCIENCE is all about.
I propose a home experiment to show how CO2 levels can be the result of global warming rather than the cause. I know the science blogs talk a lot about the solubility of CO2 in the ocean as a function of temperature; this just brings the concept home.
1. Go to the refrigerator, take out and open two cans of soda.
2, Pour a little out of each can into glasses to verify that both have the same levels of CO2 while cold.
3. Put one of the open cans back in the refrigerator and leave the other on the kitchen table.
4. Wait six hours.
5. Pour a little of each can into glasses and note the level of fizz in each.
6. Note that the can that was on the kitchen table lost more dissolved CO2 than the can from the refrigerator.
7. Theorize whether the extra CO2 from the can on the table kept the kitchen warm, or whether the warm kitchen caused more CO2 to come out of solution.
Please don’t try this experiment with beer. The result would be the same but it would be… well just wrong.
I’ve been watching this (and the earlier thread) with great interest. This is what chemical engineers do routinely – work with chemicals (including CO2) and their phase changes (of all types, but more frequently liquid to vapor and the reverse) – and at various pressures. We deal with systems ranging from high vacuums up to many thousands of pounds pressure.
Partial pressures are important. Some commenter (I don’t recall which) got it right by asking why is there dew or frost some mornings and not others, when the air temperature is the same.
I don’t expect those who are not chemical engineers to fully grasp all of this, but I do expect the climate-modeling scientists to understand and follow the basics of physics. That they do not is apparent, and that is of grave concern in the ongoing debate over Global Warming via climate models.
I believe I have fixed the photo issues (due to adware blocking) by copying them to the local server rather than referencing them at the Picasa web where Tom stored them
If not here is a direct link to the album:
http://picasaweb.google.com/thatcher131/WUWTDryIceSublimationExperiment#5346510294789862818
– Anthony
It’s gratifying to see so many people getting involved in this question and it’s also great that it resulted in an experiment that everyone agrees on. Let’s not go too far though and imply that the CO2 phase diagram and other “models” can’t be useful. It did, after all, “predict” the right result.
If Anthony reflects a bit about dew point, I would wager even he might admit to at least a little bit of chagrin at having missed the analogy early on.
But there is an important point to be made about complexity and the limits of models. Some of the discussions in the previous thread raised important questions that the simple “model” of the phase diagram couldn’t address. (Effect of water ice, locally high concentrations of CO2, etc.)
Here, in my view, is the important lesson: Models aren’t worthless, but many of them work the best under equilibrium conditions and under scales of observations closest to those under which they were developed and tested. Paul Coppin’s (04:47:36) question about water’s sublimation is a case in point. If you simply look at the phase diagram of water, you dismiss the question out of hand. But I seem to recall a similar “sidebar” discussion by one of my profs along the same line. As I vaguely recall, something about “walking” along the phase diagram at a microscopic level related to locally high concentrations of water vapor. I’m not saying that’s what happens, it just that you can’t dismiss it out of hand with a simple phase diagram.
And here’s where there is an important distinction between the CO2 phase diagram and climate models (which I think is the underlying current here). The farther you get from equilibrium, the farther you get from the relevant scale at which models were developed, and the more moving parts you have in a system (the more dynamic it is), the harder to model and the less “certain” the predictions.
Also, once again I think dearime (05:32:20) has a good point. Our understanding of phase diagrams for simple systems comes only after centuries of replication and thorough vetting by the scientific community. It wasn’t there when Guy-Lussac et al were first doing their stuff. Not to elevate or denigrate climate scientists to too high or too low a level, but their understanding of climate is about on par with Ben Franklin’s understanding of gas laws before the theories and experiments all came together decades later.
In fact, not to stretch an analogy too far, but as much as a genius a Franklin was, would it have made any sense for him to have crafted the country’s energy policy from 1780-1880 on the sole basis that he was the electricity expert of his day?
Dr. Thomas Thatcher
Thanks so much.
Katlab (06:51:11) :
Okay, let me get this straight. You had a hypothesis, tested it, found it not to be true, and so abandoned your hypothesis. What the hell kind of scientist are you?
Too funny!
dearieme:
Thank you for the explanation.
Gary Pearse:
This is a little out of my field but the whole measurement of CO2 bubbles in the the Vostok core has always bothered me. Has anyone developed the CO2/H20 phase change diagrams at these temperatures? Although certainly pure CO2 snow cannot exist at these temperatures, the water snow will have significant CO2 included. We know that rain absorbs CO2 and the equilibrium states at normal temperatures are well known.
I am also very suspect about how cores could be brought up from great pressures without lots of fractures and migrations and exchanges into the surrounding ice. I’d like to see a comparison of the CO2 content of the melted ice to the bubbles. I suspect there was a lot of data processing to get those neatly correlated CO2/air temperature results.
All I saw were some pictures Anthony! Before we draw any final conclusions I think the funding of that scientist in question should be questioned! Has the guy who did this experiment ever published in a peer reviewed journal?
….
Wait, he showed me his data, he explained his method CLEARLY. I could, if were skeptical, repeat his experiment.
Imagine, if our good scientist had published the results in Nature. In that publication a scientists Steig could claim results without providing a clear description of the methods.
It seems that Dr. Cook still has some misconceptions:
The vapor pressure must reach the saturation vapor pressure for dew or frost to form.
True.
This happens at the dew point or frost point temperature, which is dependent on atmospheric pressure
No, only on the partial (“vapor”) pressure. But, is there a small effect on the CO2 partial pressure if atmospheric pressure changes?
and the absolute amount of vapor in the air.
Yes, assuming he means partial pressure.
As atmospheric temperature increases, the dew/frost point temperature increases.
No, it remains the same. If the temperature of the dry ice doesn’t change, the partial pressure of CO2 is unchanged.
As atmospheric pressure increases, the vapor pressure increases.
No, it remains the same, so long as the temperature of the frozen CO2 stays constant.
At very low temperatures, the dew/frost point temperature is very low.
Yes, the CO2 will freeze out, and the frost point cannot be significantly higher than the air temperature.
Benjamin P. (07:48:56) :
What!? Who doesn’t like phase diagrams! There was no suffering from this geologist when I was learning about phase diagrams (except for when I was trying to construct them). But I use them all the time now days.
Ha! Right! And the 3D ones? Those still give me bad dreams.
rephelan :
I don’t see why I would be next. I think I behave quite peacefully. Moreover, I was right about the CO2 deposition :0)
KBK (10:00:08) :
Careful.
Take a look at the diagram on this page.
http://webwormcpt.blogspot.com/2008/08/air-dew-point-conversion-chart.html
If you take a given volume of air with a given water content and compress it (raise its pressure), the dew point does indeed change. If there is no condensation, the partial pressure of water will increase, but not the mole fraction. Meterologically at a single location, it’s not a big deal, but if you’re pumping air around or dealing with large changes in altitude (and hence air pressure), it’s important to recognize.
I too have followed this topic with interest: I was surprised that no mention of the analogous situation of solubility was made. A sparingly soluble salt, calcium carbonate, say, will dissolve (in water) to such an extent as to saturate the solvent with calcium ions and carbonate ions (neglecting the subsequent acid-base reactions of carbonate with water) IF IT CAN. If sufficient solvent is present such that the saturation concentration (of either ion) is not reached, all of the salt will dissolve (eventually). Temperature, of course, quantitatively affects what that saturation limit is.
As long as the atmosphere above CO2(s) is not saturated with CO2(g) (at that temperature) – particularly difficult given atmospheric replenishment due to wind or thermal gradients – any solid CO2 formed will continue to sublime. The experiment described here showed this nicely.
Thank you Anthony and Dr. Thatcher. This is what science is supposed to be about. Formulate a hypothesis. Design an experiment where one variable is changed and the rest controlled. Develop check questions and the means to test them (i.e. the plastic bag). Collect data. Analyze the data. Report the experimental procedure and the results so that others can replicate the experiment.
Good job!
–Mike Ramsey
If the temperature of the dry ice doesn’t change, the partial pressure of CO2 is unchanged.
That should read “vapor”, not “partial”, pressure. I am also having problems keeping them straight!
Only had time to glance at the first post but great outcome.
Best Science Blog – by a long way!
Maurice Garoutte (08:51:42) :
I propose a home experiment to show how CO2 levels can be the result of global warming rather than the cause. I know the science blogs talk a lot about the solubility of CO2 in the ocean as a function of temperature; this just brings the concept home.
1. Go to the refrigerator, take out and open two cans of soda.
2, Pour a little out of each can into glasses to verify that both have the same levels of CO2 while cold.
3. Put one of the open cans back in the refrigerator and leave the other on the kitchen table.
4. Wait six hours.
5. Pour a little of each can into glasses and note the level of fizz in each.
6. Note that the can that was on the kitchen table lost more dissolved CO2 than the can from the refrigerator.
7. Theorize whether the extra CO2 from the can on the table kept the kitchen warm, or whether the warm kitchen caused more CO2 to come out of solution.
Please don’t try this experiment with beer. The result would be the same but it would be… well just wrong.
TERRIFIC.
Wish Ms. Jackson at the EPA had conducted this experiment before designating CO2 a “dangerous pollutant”, with all that portends.
@ John M
Our comments crossed in moderation. I did mispeak.
Thanks for your clarification – that answers my other question. The partial pressure of CO2 goes up with the partial pressure of N2, etc. So increasing the overall pressure raises the temperature where the partial pressure is in equilibrium with the vapor pressure, i.e. the frost point.
The effect is small, but if the atmosphere cools, the pressure at ground level rises, and so does the frost point, a little. Right?
>>>•Carbon Dioxide (CO2): 95.32%
>>>Possibly more CO2 in Mar’s atmosphere than in Earths atmosphere.
We’re not going to have a runaway warming on Mars, are we?
.
I’m probably a kook, but I love phase diagrams.
neill (11:09:43) :
“Wish Ms. Jackson at the EPA had conducted this experiment before designating CO2 a “dangerous pollutant”, with all that portends.”
I wish Ms. Jackson could be prosecuted for fraud in calling CO2 a dangerous pollutant, but I’m sure her defense in court would be that you can’t use an english dictionary to define “pollutant.”
Experiment? In a global warming context, my heavens, that is so…..so….so
so Scientific!
The ignomy. How will you ever live it down?
Ive got a question. Given that carbon has such a love for sharing itself, how much of the ‘melted’ dry ice went into the air as Co2 and how much of it was left as a residue on the racks and floor of the freezer? I have worked with a few productions that used masses of dry ice, the result was white powdery stuff everywhere the fog bank went. Granted we caused the effect by dunking dry ice into hot water so it could be a water/ice residual… just wondering.
KBK (11:13:01)
Now you’re going to get me to go all weaselly on you. Will the pressure be lower? Yes…”all other things being equal.”
Of course, all other things are never equal. (I’ll try not to use “on the other hand”.)
In this case, the system is not a closed one, and will respond to everything else that’s going on, including winds and air currents. More importantly though, it will respond to neighboring air pressure and the effect of temperature drop on the local air pressure will be swamped out by the response imposed by the sea of surrounding air.
But let’s say for the sake of argument that we can treat a “chunk” of air of constant volume near the ground in isolation from the rest of the atmosphere. If the temperature drops from 0 °C to -5 °C (32 °F to 23 °F, or more importantly, 273.15 K to 268.15 K, which is the temperature scale that counts here), that would correspond to a drop in pressure of 0.018 atm (1-268.15/273.15) or about a quarter of a psi.
Based on the dew point conversion chart I linked to earlier, I would estimate that the change in dew point from that type of pressure change would be less than a tenth of a degree F. Note again, that’s a distinct upper limit with the unnatural constraint that the chunk of air is independent of its surroundings. (I think we’re starting to get to the difference between reading a phase diagram and modeling the climate.)
Hope that helps.
This experiment is about weather, not climate.
So, is there anything here that can help us with the various Ice Core data. ALL of them, well, except for the scatter plot that I belive Beck and Jaworaski published, look suspiciously like a plot of depth vs CO2. A the temperatures and pressures encountered, what would happen to air trapped in snow as the depth and pressure increases? I’ve not seen this explained anywhere on the web, and I’ve looked.
REPLY: Phil. did indeed make some valuable contributions, but behaved very badly.
Really, how?
That, and I don’t believe in rewarding bad behavior. There was too much labeling of people by some commenters, and it was entirely unprofessional and unnecessary. We really don’t do anyone any favors when we revert to this level while trying to educate and enlighten online. – Anthony
By implication here and directly elsewhere you have accused me of ‘labelling people’, I did not do so.
By the way Anthony you said “If it turns out the statement is wrong, and some empirical proof can be presented, I’ll retract and/or amend the article.”, however the offending statement is still there.
Good job. I would like to point out that, while this may be a basic chemistry lesson, climate studies cover so many disciplines of science (meteorology, geology, paleontology, astronomy, chemistry, biology, and many more) that few, if any, of us will have even basic mastery of all of them. Many times a scientist in one field will have need of expertise in another field, and we should not be impatient with having to explain some basic concepts. An expert in solar magnetic fields may have little need for knowing the details of phase diagrams.
The fact that a reproducible experiment can put us all on the same page must not be underestimated. I have seen arguments on other sites by some who were clueless as to what even constituted an experiment – up to and including the belief that the output of computer models was the same as experimental results. In one instance someone posited that a CO2-warming experiment wasn’t needed because the models predicted there wouldn’t be a measurable temperature change in that situation, oblivious to the possibility that the model might be wrong (and a temperature change WOULD be detected) and what the implications of that would be. Models may help us determine what questions we may want to research, but they are not science.
I don’t expect those who are not chemical engineers to fully grasp all of this, but I do expect the climate-modeling scientists to understand and follow the basics of physics. That they do not is apparent, and that is of grave concern in the ongoing debate over Global Warming via climate models.
This is simply high school chemistry not rocket science – there is very little to grasp it is very elementary stuff. People are lazy that’s all – so they make assumptions, make comments and don’t bother checking. I find it embarrassing that some people would think this is akin to rocket science.
They used to teach this in Grade 11 in Canada and even I can remember Dalton’s, Charles and Boyle’s Laws. Please let’s not make a mountain out of basic stuff.
FWIW: I think it would be more interesting to add a post to explain to lay people why the Sky is Blue and why Sunsets are Red. Lord Rayleigh was a pretty sharp fellow along with Charles and co.
I suppose what I’m interested, in, is “the behavior of atmospheric gases at arctic temperatures and increasing pressures in a semi-permeable substrate.”
@Alan Bates:
True, as long as you grasp the importance of partial pressure in the phase diagrams, what I did was not really an “experiment” as much as it was a demonstration. In fact, I added the zip-top bag when I realized that filling the bag with CO2 should preserve the dry ice. Still, it took me several passes through the comments to finally “get it”, and I hope that there is value in a simple demonstration with pictures.
@Skeptic Tank, if you open a container of liquid CO2 (under pressure, of course) to normal atmospheric temperature, some of it will boil away to CO2 gas. It takes heat to do that (the heat of vaporization) which is pulled out of the remaining liquid so that some of it will solidify. It will all, of course, sublimate eventually.
@pkatt, probably water ice. In our lab we also have large dewars of liquid nitrogen (-196C, I think). When we draw off the liquid nitrogen, frost forms on the steel transfer hose. I would expect that as long as that hose gets below -140C, some of the frost will be CO2. The problem is that most of it will be water ice and it will be difficult to measure the CO2 fraction without special equipment.
REPLY: about -140C, but it may be such a thin powder that it is unobservable, since there is so little CO2 in the atmosphere.
– Anthony
Thanks Anthony,
so as my comment in the earlier thread, it was a question of at what temperature it happens not that it can’t happen. It is unlikely to get that cold even in the deepest ice age?
M White (04:18:56) :
(and Ralph Ellis)
“Possibly more CO2 in Mars’s atmosphere than in Earths atmosphere.”
Lots more. If you assume 6millibar surface pressure on Mars(it can go up to more than 10mB) and the partial pressure of CO2 on Earth is 0.6mB you get a factor of 10. But because the surface gravity on Mars is 0.38g there must be 2.63 times as many molecules to create any given pressure. So depending on the pressure at the Martian surface there is 26 to 44 times as much CO2 over every square meter on the Martian surface as there is on Earth.
Clearly Mars must be sweltering!(just kidding)
Seriously, in Mars we have a nice natural laboratory to explore the consequences of lots of CO2 in the atmosphere without a lot of confounding factors. The numbers I’ve found indicate that the warming effect of the CO2 on Mars is 5 to 10deg C. I don’t know whether this is just a poor estimate with wide error bands or meant to describe differences at different locations. Note that compared to Earth, Mars has almost the same length of day, almost the same axial tilt, has a year about twice as long and receives half the insolation at the top of the atmosphere.
Also conveniently, the CO2 levels vary during the Martian year by a factor of nearly 1.7. Can anybody tease out the effects of the changing CO2 levels on the surface temperature of Mars? There’s got to be at least a scientific paper in this if not a PhD.
The facebook script that I use (Facebook provided) for reposting WUWT stories does not seem to work on this post. Something must have changed in the data format.
Here is the script (saved as a bookmark in Firefox):
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Atmospheric pressure really isn’t the issue. The issue is how much CO2 is in the atmosphere. An easier way of thinking about it is to pretend that CO2 is water. If we pretend CO2 is water than Earth’s atmosphere is very “dry”. It has extremely little CO2. Mars has a very “wet” atmosphere or a lot of CO2 by proportion to the total gasses.
Now what happens to regular water ice in an extremely cold by extremely dry environment? It evaporates. We see that in the “dry valleys” in Antarctica. The air is so dry that the ice evaporates without going through the liquid phase.
The same thing is happening with CO2. In terms of CO2, the earth’s atmosphere is extremely “dry” and frozen CO2 would evaporate even if the temperature were well below the freezing point of CO2. The experiment that had the dry ice in a bag in effect created an atmosphere very “humid” in CO2 and so the ice did not evaporate.
I believe that is the easiest way to put it into terms most people can understand.
Jeremy (13:42:45) :
Too many of us were victims of “relevance” in the 60’s and 70’s. World History? Irrelevant. Classical Languages? Irrelevant. French, Spanish and German? They all speak English. Irrelevant. Philosophy? Irrelevant, this is the 20th Century, Man! Science? Nothing left to learn, they’re just tying off loose ends. Irrelevant. Learning to think for yourself? Don’t you want to fit in? Irrelevant.
Unfortunately, this CO2 episode on this blog has really lowered the value of the whole blog. Steven Goddard made a wrong statement about the basic CO2 chemistry and physics. It would have been much better if he admitted his error straightaway, rather than trying to prove his (wrong) point with more and more bizarre posts.
I understand that he is a regular contributor to this blog, but did you really have to create a “scientific experiment” to save his face as if there was any doubt about the CO2 phase diagram? Equally well, you could have made an experiment to check if water really freezes at 0 C or if water boils at 100 C.
As somebody already said above, this is really basic stuff, my 14 year old daughter is doing similar demonstrations (not scientific experiments) at school.
WUWT is my favorite blog. I am skeptic about everything unless I see the real data. There is a lot of good information on this blog. However, in my opinion more background check is needed before CO2 freezing kind of stuff is published.
The fact that we have another post about CO2 behaving just the way hundreds of scientists have shown many years ago (and school children in proper educational systems are demonstrating every day), is lowering the credibility of this site.
Anthony, you are doing a great job with this site, please do not give any more ammunition to the AGW side with these “let’s measure the water boiling point again” posts.
Sincerely,
Jari
I can see it now; GE/NBC get the contract to build giant co2 assist scrubbers at both poles.
Flanagan (10:17:33) :
rephelan :
I don’t see why I would be next. I think I behave quite peacefully. Moreover, I was right about the CO2 deposition :0)
I actually expected Anthony or Charles to snip my post, but since they didn’t, let me explain. You are a polite troll, but a troll nonetheless and you contribute almost nothing to the discussion here. Your serial references to that French blog? Tamino, Stoat and even RC are more informative. I still retain enough French to deduce that much. You post references to charts that are not self explanatory and expect the rest if us to say OOHHH!!!!. You cited a social science paper on the effect of non-ideological information’s impact on perceptions of global warming….(sorry, I can’t find the reference right now, but I did download it) and incorrectly….. no, deliberately misrepresented, the results to suggest that AGW advocates were more intelligent than denialists. The number of times I’ve said to myself “maybe the little bugger has something this time….” I’m tired of searching out obfuscation and dishonesty. Get honest, or if Anthony decides to hold a vote on who gets snipped first…..Tsai-jian, ben-dahn.
Yeah, hate to say this guys but this is a downer… I have to say that the science on this is fairly established… However I applaud the fact that someone went through the trouble to experiment, simply because science is established does not mean that real world experimentation is not warranted or smiled on when it is done.
Tom Thatcher (13:56:18) :
@pkatt, probably water ice. In our lab we also have large dewars of liquid nitrogen (-196C, I think). When we draw off the liquid nitrogen, frost forms on the steel transfer hose. I would expect that as long as that hose gets below -140C, some of the frost will be CO2. The problem is that most of it will be water ice and it will be difficult to measure the CO2 fraction without special equipment.
Boiling Point of nitrogen @ 1 atm: -320.5°F. Definitely could be some frozen CO2 there. We were also taught in the navy that the “water” on the hose was a no-no. It’s actually liquid oxygen (boiling point of -297.3°F). We used the LN2 for freeze seals on pipes that could not be isolated.
Andy
Somewhere way back up in the middle of the 100+ comments, I think it was Anthony who made an oblique reference to comparing the results of cooling water to cooling of CO2, since we are all familiar with dew and frost forming from water as the temperature drops. Recall, if you will, that the dew point is where, sort of by definition, the water vapor content is maximum (100%), and can’t go any higher. Since CO2 content is less than 0.01%, the comparison fails. Frost point comparison suffers the same fate. All just another way of illustrating that the partial pressure is the controlling factor.
What country are you in? My experience in the US is that nothing like what you describe (proper educational system) is taught in our schools any longer. So I take exception to your dismissal of the experiment as unnecessary, since no social science, fine arts or other non-science graduates understand the concept of partial pressure, and as illustrated here, apparently many science graduates missed that lesson also.
Squidly (08:06:36) :
Aughh! Please, not soon. That was rather stressful, especially since I thought we had settled the issue in February. One good thing, this article will be easier to find.
Hmm. Let me save that February link here.
http://wattsupwiththat.com/2009/02/04/snow-job-in-antarctica-digging-out-the-data-source/
KBK (10:00:08) :
> It seems that Dr. Cook still has some misconceptions
Yeah, the first paragraph especially suffers from not realizing how little CO2 we’re talking about. I sent a reply to explain that a bit better (and referred to 140F where I should’ve said -140C) so I didn’t clear things up very well.
If he had participated in the debate here I think he would have worded the first paragraph more clearly, but the big thing is he readily admitted his mistake. Not all scientists in this sordid field would do that.
I figure I can “appeal to authority” and reference his “Ric, You are correct” for all future debates here. 🙂
Here we have an example of real science taking place. Hypotheses were formed; theoretical calculations were made; experiments were devised and executed; reality was better understood; and not one dime of government money was expended! Let’s have more science!
Hu McCulloch on Climate Audit, date December 19 2008.
(It’s so good to see that Climat Audit and WUWT combine and cooperate so well).
57
reply and
paste link Hu McCulloch:
December 19th, 2008 at 7:07 pm
Re Geoff Sherrington, #47,
Is it relevant that a block of dry ice has a surface temperature of -109.3 degrees Fahrenheit (-78.5 degrees C)? (Wiki). Dry ice is solid carbon dioxide.
In the Antarctic, Vostok is recorded a a lowest -129°F (-89°C) on July 21, 1983.
That bothered me too, since it would seem that it would snow CO2 on a cold day in Vostok, perhaps skewing the ice core CO2 readings.
But in fact, the -78.5 °C temperature only applies when the partial pressure of CO2 is 1 atmosphere. When there is only .00028 or .00038 atmosphere of CO2, the freezing temperature is much, much lower.
Jeremy (13:42:45) :
On one hand, I fully agree with you, it is just high school chemistry and physics. Several people posted notes that the answer was in the phase diagram and left shaking their heads at the controversy.
When you get right down to it, Tom’s experiment merely qualitatively verified two points on the phase diagram and that pahse diagram is clearly “settled science.”
On the other hand, the CO2 frost idea is a concept that people had trouble wrapping their heads around. Heck, I had trouble myself in February until I came up with my frost on the windshield analogy, whereupon it became “crystal clear” (sorry).
Ultimately, the debate served as a teaching experience for a diverse audience ranging from people who hadn’t been exposed to all this, people who had but forgotten most of it, several who were quite familiar with it, and a few who should have been but weren’t. More people know about phase diagrams today then they did a week ago. This blog has made the world a better place this week. Cool.
Ric Werme,
Well said. Science is also about teaching. Jack Eddy certainly thought it was a worthwhile part of science. Also our own much loved Leif must feel that it is worth his time to help those of us, like me, who are science-challenged. Thanks to all who through questions, information, explanations, experiments and challenges make this a place of learning and joy.
Mike
I knew that we didnt have CO2 snow at the poles but I didn’t know why so I was looking for phase diagram specifics and even the simple diagram above is just what I needed. Notice at -120 C the pressure can be much lower,(Mars?) and at -150 it can be very low. The shape of the curve down there was important because it explains solid CO2 existing in various places in the solar system and why we see the stuff forming on our liquid Nitrogen lines.
I think what some of the people jumping all over Steve etc. are missing is these examples. I knew that atmospheric pressure affected boiling point but that partial pressure should have been the thing controlling solid-gas equilibrium. But I also knew there were conditions where solid CO2 could form that at first glance are not that wildly different than the Antarctic, but 40 or 50 C is a pretty big difference.
Are phase diagrams based on theory or observation? A telling point may be that the latter is true.
[wry]
It’s quite obvious that Dr. Thomas Thatcher is in the employ of “Big Oil” due to the raw material composition of the plastic bag.
Sorry folks, but the U.N. has plans to stop this sort of science…
Achim Steiner, UN Under-Secretary-General and UN Environment Program Executive Director would now like to have a word with Dr. Thomas Thatcher specifically about his plastic bags. The U.N. of course cannot allow such experiments to be done in the future as that would allow “unfair” competition with computer models.
The U.N. would also argue that such models do not use plastic bags and are thus “environmentally superior.” Oh, also please ignore:
http://wattsupwiththat.com/2009/01/21/meet-deep-black-the-met-office-supercarbon-footprint-climate-computer/#more-5216
[/wry]
@Ric Werme (19:38:46) :
“When you get right down to it, Tom’s experiment merely qualitatively verified two points on the phase diagram and that pahse diagram is clearly “settled science.” “
Ric, you are so right that CO2 “snow” is all in the phase diagram. That level of science is absolutely settled.
That is why I, and the other chemical engineers with whom I work and otherwise associate, know for a fact that there is zero correlation between CO2 in the atmosphere, and global air temperatures.
Just as the CO2 phase diagram is solid science, so too are the principles of cause-and-effect for process control. Engineers take one look at the steadily rising CO2 levels, and the global air temperatures that sometimes rise, sometimes fall, and sometimes stay fairly constant, and know instantly that AGW is all very Bad Science (BS).
What Anthony has shown on WUWT regarding negative water vapor feedback seals the deal.
“crosspatch (15:39:41) :
Atmospheric pressure really isn’t the issue. The issue is how much CO2 is in the atmosphere. An easier way of thinking about it is to pretend that CO2 is water. If we pretend CO2 is water than Earth’s atmosphere is very “dry”. It has extremely little CO2. Mars has a very “wet” atmosphere or a lot of CO2 by proportion to the total gasses.”
Excellent very simple very clear. Thank you
Jari (15:50:44) :
I hope to have definitive answer on that soon. It’s taking a while to get my refrigerator up the side of Mount Everest.
I believe I was the first to suggest an experiment. After about 100 posts of argy bargy which didn’t look like it was going to settle anything.
As the drag racers say ” when the clutch drops, the bs stops”.
I’ll run the results past my software guy tomorrow.
rephelan: please don’t call a troll anyone who doesn’t share your vision! As I said, I was right about the CO2 thing from the beginning, and the link I give to the French site is about the NCEP/NCAR reanalysis which is in my sense a pretty cool global temperature indicator.
About the study linking level of education to climate skepticism, it’s not my fault, I didn’t do the survey myself you know. You also forgot to mention my never-ending references to the Mercer paper of 1978 on antarctic ice shelves :0)
And I also (some time ago) gave rather unknown references to papers showing a direct, satellite-based measurement of the greenhouse effect when a “debate” was raging about the fact it was a “hoax”.
Flanagan,
Let’s cut to the chase, shall we? Do you believe that a rise in CO2 will cause runaway global warming and climate catastrophe? And if so, exactly where do you think this tipping point will occur?
“Are phase diagrams based on theory or observation?” Oh, better yet, they are based on controlled experiments, backed up by well established theory, principally Gibbs’ Phase Rule.
Things happen so fast on this site that most issues are resolved before I think to comment. But I may have something to contribute as follows.
An equilibrium vapour pressure occurs when the condensation rate equals the evaporation rate. If there is insufficient material all of it will evaporate before this pressure, a partial pressure, is reached. The equilibrium points define the lines on the P-T phase diagram. There is no unique condensation point except for the triple point, which is the point where solid, liquid, and gas are in equilibrium. The important relationship for vapour pressure , whether gas-solid or gas-liquid, can be derived from the Clausius-Clapeyron equation as
P = Po exp(-L/RT)
where L is the molar latent heat, R is the gas constant, and Po is a characteristic pressure. This is not an exact relationship but gives you the basic idea of the P-T dependence.
The melting of a solid to liquid is more complicated. There is still a pressure dependence, but it is the pressure exerted on the solid externally.
Boiling is a non-equilibrium phenomenon. Eventually all the liquid will evaporate as the external atmosphere will not be close to the required partial pressure of the vapour concerned.
To understand the dependence on the total atmospheric pressure of all gases, consider the physical process of boiling. Inside the liquid a bubble of gas has nucleated at an impurity, usually at the bottom of the container (pot or beaker). The bubble contains only the vapour of the liquid concerned, but it will only be stable or grow in size if the internal vapour pressure is equal to or greater than the local hydrostatic pressure, which in turn is equal to the total external atmospheric pressure plus the effect of the liquid depth (usually small). This is why the boiling point depends on atmospheric pressure and why quoted condensation temperatures are referenced to one standard atmosphere. The internal, bubble, vapour pressure is still given by the Clausius-Clapeyron equation. There is a similar process for sublimation, but it is easier to describe boiling.
I hope that this is a useful contribution, but if not I had fun writing it. Some what off topic, but it would be nice if you had a printer format option, as some topics deserve to be read at leisure. Cheers.
William:
Simply highlight the text or article of interest, copy and paste to Wordpad or almost any word processing program and print. Read at leisure.
Flanagan (02:58:27) :
“….About the study linking level of education to climate skepticism, it’s not my fault, I didn’t do the survey myself you know….”
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Sheesh. Even when denying you are any kind of a troll, you still can’t resist indulging in trollish behavior. Your statement above certainly implies that the paper I referred to
How Citizens Integrate Information without Ideological Cues: Local Weather and Americans’ Beliefs about Global Warming by Patrick J. Egan and Megan Mullin
Said what you claimed for it. Let’s check the record. On April 30th in the Mad Dogs and Englishmen thread you wrote:
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Flanagan (14:08:29) :
By the way, another intersting study
http://politics.as.nyu.edu/docs/IO/4819/egan_mullin.pdf
people tend to belief in global warming as a function of their local temperature. In cold and temperate places, those supporting global waming are the ones with the highest level of education, whose opinion is relatively constant whatever the local temperatures.
I made some snarkish comment about getting some integrity and your defender Tom P challenged me on that. I then submitted on May 2 a more detailed response, as follows:
Tom P (02:40:34) :
rephelan,
I don’t know why you are questioning Flanagan’s integrity. The lower plot of figure 6 in the Egan and Mullin paper shows precisely what he states:
“…people tend to belief in global warming as a function of their local temperature. In cold and temperate places, those supporting global waming are the ones with the highest level of education, whose opinion is relatively constant whatever the local temperatures.”
Perhaps I was too hasty in criticizing Flanagan’s integrity. There is an equal probability that neither you nor Flanagan can interpret a graph. The paper itself was concerned with the influence of non-ideological information on perceptions of global warming. The non-ideological information in question was the local weather. The chart referenced showed that the weather, either hotter or colder, had almost no effect on changing the perceptions of the more educated and had the greatest effect on changing the perceptions of the least educated. The chart does NOT show that more educated people believe in global warming and less educated do not. The authors own legend for that graph should have given you a clue:
“Figures show predicted probabilities of agreeing there is evidence for global warming when local temperature is much hotter than normal (at the 95th percentile, or 14.7°F above normal) and much cooler than normal (at the 5th percentile, 4.3°F below normal).”
The conclusion of the paper, as presented in the abstract, was:
“Our results suggest that when politically relevant information is conveyed without ideological cues, political sophistication may prohibit the integration of this information into political beliefs regardless of the direction of one’s predispositions. “
The bottom line is that whether you are an alarmist or denialist, political sophistication (defined by the authors as either high education or ideological commitment to a party) tends to leave your position on AGW unmoved in the face of your perception of the weather.
Whether Flanagan has an integrity issue or literacy issue, neither choice looks particularly good for Flanagan….
===============================================
Neither you nor Tom P followed up on that and today you are still implying that your interpretation of the paper was correct. You are a troll not because you disagree with me, rather you are a troll because your presentations are dishonest. I can’t speak to anything you may have gotten correct or were accurate about because I simply haven’t seen them. I for one, will not be bothering to check out anything you suggest. Your credibility is nil.
Paul Coppin (04:47:36) : “Now, I’ve never bothered to pursue this, but my chem profs back in the ’60s used to insist that water never sublimated. That while vapour production looked like sublimation, there was actually a 3 point phase change from ice >water>vapor, and there wasn’t in fact a true two-point change to gaseous phase directly from solid state. Maybe some active physical chemists can update me.”
I used to live in Denver. Some mornings, all the accumulated snow would suddenly be gone, even though the temperatures had been below 32°F overnight. I always assumed the snöw had sublimated. Hmm. Maybe not. Any opinions based on theory?
Smokey: sorry, but this is not the topic at all… I wouldn’t like to be accused of trolling!
rephelan: though you are also widely digressing I thought I could simply copy and paste the rest of the sentence you mention from the abstract:
“In this study, we identify one piece of information that is devoid of ideological content and to which Americans are exposed at random—their local weather—and show that it leads a significant share of the public to reassess its beliefs about the evidence for global warming. This effect is much stronger for the less educated and those with weak partisan ties, and virtually non‐existent for the most educated and most partisan citizens.”
and further in the text (yes, usually people read the entire text)
“By matching geocoded survey data to local weather records, we find a significant relationship between local weather and beliefs about global warming.”
“Is there solid evidence that the average temperature on earth has been getting warmer over the past few decades, or not?” Americans’ responses to this question were largely in the affirmative: […] 74% of respondents agreed that the earth is getting warmer.”
which, combined with
“Local weather affects those with the least education significantly but those with the most education not at all”
and the result of Figure 5b showing that 0% of post-graduate people are influenced by the local weather leads to, in any sense, self-evident conclusions.
Flanagan,
You seem to be missing rephelan’s point. He agrees the article was linking lack of education with the influence weather has on people’s perceptions. What he doesn’t agree with is your original comment that people with lower education seem to be skeptics.
Indeed, based on your premise, I guess we can conclude something about Al Gore and his gang opening the windows to let in the heat during Hansen’s famous 1988 testimony.
Who were the “lower educated” that Gore and his cronies were trying to influence?
Flanagan, you insist you are not a troll and then cherry pick your way through a few quotes from a 33 page paper and misrepresent completely what it had to say. Anyone can do that. At the bottom of page 16 of the PDF it also says
“… but when temperatures are hotter than usual, the least educated become those most likely to agree that there is evidence for climate change.”
to cite that phrase out of context would also be a gross misrepresentation of the paper. That would be the behavior of a troll and that is exactly what you have been doing. To repeat: the paper said nothing, I repeat, nothing about the relative intelligence of alarmists vs. deniers. What it addressed was the conditions under which perceptions of global warming changed in the face of perceptions about the weather.
Simple syllogism:
Trolls cherry pick quotes, misrepresent conclusions, obfuscate and argue ad infinitum;
Flanagan cherry picks quotes, misrepresents conclusions, obfuscates and argues ad infinitum;
Therefore…..
For anyone interested in reaching their own conclusions, the paper by Egan and Mullin can be downloaded here (the link is, by the way, courtesy of flanagan):
http://politics.as.nyu.edu/docs/IO/4819/egan_mullin.pdf
please weigh in. Does it make any conclusions about the relative intelligence of warmers or deniers?
Re: Paul Coppin
Water can/does sublimate, but not under any natural terrestrial conditions. See following link for details. http://encarta.msn.com/media_461541579/phase_diagram_for_water.html
Mike
And yet we are told that comets are frozen balls of water ice and CO2 ice in the Vacuum Of Space… (Just what IS the partial pressure of CO2 in a hard vacuum?…)
So, while I think the issue of pure CO2 freezing out has been settled, I think the issue of “CO2 Clathrate Snow” is still a bit, er, open…
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WGF-472SWX0-4Y&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=583e769d0c26987de7ad7805b5945f98
Is not about CO2, they used oxygen, but has this little gem in it:
Oxygen clathrate hydrate which was used as a model substance for other clathrate hydrates with highly volatile guest species was formed from microporous vapor-deposited amorphous solid water prepared at 77 K, and from O2 enclosed in the pores during heating and sintering of the amorphous deposit up to ≈120 K, with “external” O2 pressures during the sintering and gas enclosure process of 10, 100, 200, and ≈ 1700 mbar. Clathrate hydrate formation occurred between ≈170 and 210 K as seen by X-ray diffraction. If was stabilized by layers of ice and decomposed completely on heating at a rate of 10 K min− only between 240 and 250 K, which is much higher than anticipated from dissociation pressure/temperature curves.
Notice we have pressures as low as 10 mbar and formation as high as 210 Kelvin for O2 clathrate in water… Last time I looked oxygen had a boiling point of about 90K and a critical point 154K 5.4 Mpa so having it form a “solid” in a Clathrate at 210K is, um, “interesting” …
Other interesting bits are in:
http://www.sciencemag.org/cgi/content/abstract/254/5031/548
http://ppeppd07.chemeng.ntua.gr/manuscripts/366.pdf
You can get a great deal of interesting reading with a google search such as for “clathrate formation elevated temperature CO2 -methane”.
At the end of a bunch of hours of wandering I’m left with these conclusions:
1) We don’t have a good handle on clathrate formation nor decomposition.
2) Decomposition is not always symmetric with composition.
3) Clathrates do screwy things to the temperature of deposition of species.
4) It is related to a physical crystalline cage capture of each atom or molecule, not so much to physical properties of the bulk materials (i.e. the degree of fit and atomic charges / attractions inside the “cage” relative to the trapped species matter most.
5) Small “contaminants” can alter things a great deal, including contaminants such as salt and biological / organic materials.
6) It’s going to be incredibly hard to figure this out without an actual on the ground test with the specific mix of “stuff” at the pole in the polar air.
7) The low CO2 statistic for the south polar air is, um, “interesting”…
This abstract looked really interesting:
http://pubs.acs.org/doi/abs/10.1021/je034260i
Where the google “tease” had:
Measurements were taken up to the point of clathrate formation. …. They measured only the isotherm at the critical temperature of CO2 up to 10 MPa. …
and the abstract:
Density data of the water + carbon dioxide system were determined using a calibrated vibrating tube mass flow meter with a uncertainty below 0.15%. Measurements were performed in the pressure and temperature regimes (1 to 30) MPa and (284 to 332) K, respectively. The water-rich phase density showed a pronounced dependence on pressure and temperature whereas the CO2-rich phase density did not change from the pure density within the measuring uncertainty. A regression function was developed which describes the experimental data in the range studied.
But the article was paywalled and I don’t have enough “credentials” for whatever they think are deserving minds… (and / or I’m just too damn cheap… 😉
Even the wiki article
http://en.wikipedia.org/wiki/Carbon_dioxide_clathrate
is slightly helpful (though dismissive of CO2 clathrates on the surface of the planet) with statements like:
Carbon dioxide hydrate is a Type I gas clathrate (Sloan 1998). However, there has been some experimental evidence for the development of a metastable Type II phase at temperature near the ice melting point (Fleyfel and Devlin 1990, Staykova et al. 2003).
The article might be this one buried in the references:
Fleyfel, F. and Devlin, J. P. (1990) Carbon Dioxide Clathrate Hydrate Epitaxial Growth: Spectroscopic Evidence for Formation of the Simple Type-II CO2 Hydrate. J. Phys. Chem. 95, pp. 3811-3815
And it has these bits of temperatures for dissociation and pressures for decomposition, but not both together and not for formation. Sigh.
Later on in 1894, Villard deduced the hydrate composition as CO2·6H2O. Three years later, he published the hydrate dissociation curve in the range 267 K to 283 K (Villard 1897). Tamman & Krige (1925) measured the hydrate decomposition curve from 253 K down to 230 K and Frost & Deaton (1946) determined the dissociation pressure between 273 and 283 K. Takenouchi & Kennedy (1965) measured the decomposition curve from 45 bars up to 2 kbar (4.5 to 200 MPa). For the first time the CO2 hydrate was classified as a Type I clathrate by von Stackelberg & Muller (1954).
What’s a budding Kitchen Scientist to do… I go do the test at the south pole myself if I had the money. I’d do it in the kitchen if I had a super freezer. Just chasing the papers is getting tedious…
At any rate, I can smell an interesting effect going on here in a temperature regime that is not within the normal intuitive range of people and involving surface and crystallization chemistry that is way outside the ken of most folks (and many / most chemists…). I’m certain there is something of importance inside this box; I just can see how to get the darned thing open… 8-}
Don’t know nuthin about clathrates or CO2 sublimation, but the ice cubes I froze in my ice trays last October were a lot smaller when I decided I needed some in April.
rephelan (08:44:46) :
uhhh… in my diatribe above, please replace “intelligence” with “level of education”. The paper did not use “intelligence”.
Jeremy (13:42:45) : They used to teach this in Grade 11 in Canada and even I can remember Dalton’s, Charles and Boyle’s Laws. Please let’s not make a mountain out of basic stuff.
I got it in Grade 10 IIRC of my hick farm home town of 40 years ago… but from inspection of my kids homework while “helping them” it looked like the present High School Chemistry was, er, very lacking in critical thinking skills and heavy on memorizing how to do equilibrium calculations… (In other words “Don’t think about what’s going on, just follow the formulas you have been taught”…
I asked the teacher on “open house night” what he did to make chemistry interesting, did they have any fun “hands on chemistry”. He looked at me blankly. I gave a couple of examples I remembered from my (Excellent) chemistry teacher. His response was, with a deeply derisive tone of voice, “Oh, you mean demonstrations. Not much.” He clearly felt that actually doing chemistry was meaningless when compared with the ability to play with word problem sets. This was in a well laid out chemistry room with sinks and gas outlets at each station. A brief inspection showed a fair amount of dust and dry/aged hard water deposits (i.e. not much actual use in a very long time…)
Frankly, my kids would have learned more chemistry in the kitchen with common household items in a long weekend than they actually learned in high school. (I did teach them some this way). THAT is why most of the folks “doing the science” today (and almost everyone who is NOT a trained scientist, IMHO) have this so horridly backwards. They have spent a young lifetime being taught that “science” is a word game, that actual experiments are “demonstrations”, and that computer models can give you the right answer to things much more quickly than you can find it yourself… Oh, and don’t think. Just do the formulas as you have been taught.
It is a special person who can rise above that and move against that tide.
George M (19:16:50) :
William Sears (11:54:01) :
but it would be nice if you had a printer format option, as some topics deserve to be read at leisure.
William:
Simply highlight the text or article of interest, copy and paste to Wordpad or almost any word processing program and print. Read at leisure.
Maybe it’s a Mac thing… but when I want to save a piece to read later, I just choose “print” in the “file” dropdown menu and when presented my options choose “save as pdf”. Then I have a PDF file I can read or print whenever.
rephelan (08:44:46) : please weigh in. Does it make any conclusions about the relative intelligence of warmers or deniers?
I don’t see anything about relative intelligence, but it does seem to support my bald assertion from extensive personal observation that the very intelligent are more likely to believe their own BS even in the presence of physical evidence to the contrary.
One can most easily see this manifest at places like Mensa gatherings where there is always someone or other arguing for a completely whacky favorite belief despite all the world around them to see… It is common enough that I think it may be a general property of the over educated and highly intelligent: They just have a harder time getting a grip on reality, here and now.
Nope. I offer no proof. It’s just an early stage observation of 40+ years running total.
BTW, this “rule” has stood me in good stead for a very long time. I first started by applying it to my own BS quotient (about 35 years ago). Part of my “keeping a tidy mind” process. I do a “reality check” on things whenever possible. Computer programs especially (where we used the phrase “reality check” in a more formal sense as part of the jargon in my group of programmers.)
And that, boys and girls, is why I trust the “local weather” (from all over the planet) far more than I will ever trust any computer generated anomaly map from anyone. And why I would put actual experimental results rather close to first in my list of important attributes of science…
So my “vote” on Flanigan would be: Yes, he’s a troll. But a polite and a relatively harmless one who sometimes (accidentally?) can cause an interesting discussion to follow, while the worst of his trollishness just creates easy “softball” points to get warmed up on while having First Coffee. So I’d vote for not tossing him. Even a broken clock can get you thinking about how to make a good clock…
http://chiefio.wordpress.com/2009/06/13/making-an-english-foot/
has a couple of links to some interesting science done while making pendulum clocks very stable. Including using both iron and brass parts in the pendulum so as they differentially expand they cancel out the thermal expansion error in pendulum length…
E.M.Smith (13:11:58) : I’m certain there is something of importance inside this box; I just can see how to get the darned thing open… 8-}
That was supposed to be “I just can’t see”…
Mike (12:22:57) :
How so? Is it possible that you’ve missed the whole point of the partial pressure discussion?
According to this source
, the vapor pressure of ice at -10 C is 1.95 torr, or about 0.0026. So any atmospheric conditions drier than that (i.e. less than 100% relative humidity) should make the conditions right for sublimation.
Should be “0.0026 atm”.
When the suggestion arose that someone should do an experiment to resolve the argument between competing theories, somebody else (forget who but it’s in the record) pointed out that these phase diagrams are the result of a whole bunch of experimental evidence that has already been collected.
In the majority of cases, I believe that is true; but not necessarily always.
It is my understanding that such things as phase diagrams, solubility products and the like can actually be calculated from theoretical considerations; generally quantum theory in nature.
For example the whole issue of atomic structure and electron orbitals, came about because of theoretical attempts to explaing the spectral lines of the Hydrogen atom, and subsequently other atoms.
The Balmer series and Paschen series and other accoutrements of atomic spectra led to the Bohr atom, and ultimately the theory of orbitals. All of this suddenly elevated chemistry from; “mix a dash of this with a pinch of that and you get a whiff of that other thing. Suddenly (well actually after a whole lot of hard work by many), it became possible to predict the outcome of the pinch/dash experiemnts, with surprising accuracy.
In “The Constitution of Binary Alloys”, a standard reference text (now unavailable), the phase diagrams of many binary inorganic systems are chronicled. They range from the simplest gold/silver phase diagram, where the two components are completely soluble in each other in any possible mixture, to that terror of all metallurgical studies; the Iron Carbon phase diagram; better known as the “steel” diagram.
I have no idea how it is possible to unravel the iron carnon binary phase diagram, with all its intermediate compounds and multiple paths. How experimentalists did experiments to unlock those secrets is just beyond my imagination; yet the outcome is key to monerd structural engineering.
Somehwere in the iron/carbon binary phase diagram is the key to why the Titanic sank; something to do with very low carbon (iron) rivets, instead of the steel rivets that the designers called for; which were apaprently unavailable in sufficient quantities to build the ship.
In the cold waters of icebergia Atlantis; those low carbon rivets turned to s***, and popped their heads off.
But apparently it is possible to compute these phase diagrams from fundamental physics and chemistry; well chemistry is just applied physics anyway. Fortunately such studeis are beyond my pay scale, so I am glad that there are those who do understand that.
I used to teach the atomic physics stuff at a freshman level; but much of that is long gone to the vaporous universe of senility or Alzheimers or just time elapse. I know that the s/p/d/f labels assigned to electron energy levels. or at least their quantum numbers, used to have some appearance meaning to spectroscopists. s stood forr sharb, and d for diffuse, as the resulting spectral lines had those appearanceas. Can’t remember what the other two stand for; but I guess if we need four bases for DNA assembly it is reasonable to have four different quantum number labels, regardless of how they originally came to be.
Try to get some modern egg-head Quantum physicist to explain where s/p/d/f came from; and they probably didn’t even know there ever was such a job title as “spectroscopist”.
I once wanted to be one; more than I wanted to be a fireman.
So yest the CO2 phase diagram was already the work of much experimental verification; and most of us don’t have the means or the patience to do all those experiments; so we thank those who constructed the phase diagram; so we don’t have to do the experiment; But Dr Thatcher’s simple overnighter lab demonstration, is a simple way to save thousands of words. Too bad you can’t do that with a stick in the sandy beach though.
George
E M Smith
I like Flanagan and Joel Shore and RW and Phil, and others who do not sing from the same song sheet as the rest of us. It is good to have a (mostly) civilised discussion with people you will never agree with-and who will never agree with you- and who sometimes make good and thought provoking points.
Tonyb
TonyB (16:32:34) :
E M Smith
I like […] who do not sing from the same song sheet as the rest of us.
I agree. Without sand, no pearls…
EM Smith
Did you get my email? Your last post on directions on how to contact you were rather cryptic to someone like me who studiously avoids the crosswords we have in every UK newspaper. If you did get it, can you do a quick ‘return’ and I will send you the information promised.
Tonyb .
“”” E.M.Smith (14:50:18) :
rephelan (08:44:46) : please weigh in. Does it make any conclusions about the relative intelligence of warmers or deniers?
I don’t see anything about relative intelligence, but it does seem to support my bald assertion from extensive personal observation that the very intelligent are more likely to believe their own BS even in the presence of physical evidence to the contrary.
One can most easily see this manifest at places like Mensa gatherings where there is always someone or other arguing for a completely whacky favorite belief despite all the world around them to see… “””
Well in colloquial Mexican, “Mensa” refers to a crazy lady; not to a club for self annointed air heads. Oh I know the name is supposed to relate to a “table”, but remember in Mexican Spanish, that a table is “mesa” not mensa” which as I have said is a crazy lady; well it’s a different Latin root you see, and all the ladies know why it means a crazy lady.
As I explained to Ric when we corresponded, we attempt to keep our explanations simple in Ask-A-Scientist. As I continued to do so in my response to Ric, I didn’t indicate that my statements were to be considered in the context of a constant volume assumption.
So, my re-posting of my reply to Ric onto Ask-A-Scientist will again be modified to try to better clarify that situation.
I’m only too happy for people to point out the mistakes that we scientists make. Indeed we do make mistakes, which is why we go through a peer review process when we seek to publish our scientific results. Even so, we still find errors in peer reviewed publications. As the group that I work in once found, an error can propagate into further publications based on an earlier mistake. On one such occasion, we published a paper to show how three authors had made further errors based on an initial published error. We must be constantly vigilant in looking for and reporting on such situations.
E.M.Smith (14:50:18) :
All in all, I think the crowd here is pretty intelligent – because discussions sound like Mensa meetings. (At least those where the people not interested in climate have fled someplace else. 😉 )