Tuesday, March 20, 2018

Dear Judge Alsup: Putting on the Pressure

Some may recall that at the end of the first episode, the Spectroscopic Basis,  Eli asked why the CO2 IR absorption spectrum at atmospheric pressure


Was different from that at 1/1000 th of an atmosphere



The answer lies in the second letter to the judge, the Quantum Interlude, where Eli discussed how the interaction of light with molecules is really an interaction with the charges, the electrons and nuclei, and how that interaction can be decomposed into a series of multipole moments, the dominant one being the electric dipole, an asymmetry in the distribution of charges.  Higher moments, like the quadrupole and shudder, octapole, only become important when the dipole is zero because the molecule is cylindrically symmetric as is the case for N2 and O2.

Comparing the two spectra above, bunnies notice that the baseline has lifted in the first, and if they look real close or blow the figure up, they would see that the absorption lines are wider.

Now those out there who have taken General Chemistry, or even maybe General Physics, can go get a drink while Eli goes on.  Turns out that the electrons and nuclei in one molecule or atom can interact with the electrons and nuclei in nearby ones and move the charge around.  If we are dealing with molecules that have a dipole moment a picture of what is happening would look like this.






But we need not restrict molecular interactions to only dipole-dipole forces, but can also include the interaction between a dipole and a molecule that has zero dipole moment.  In that case, the dipole can interact with the electrons on the dipoleless molecule and shove them around so that there is an induced dipole moment.  That is what is happening with the CO2 molecules in the first spectrum.  Collisions with N2 or O2 molecules induce a dipole on the N2 and O2 molecules, which then interact via the electric field with each other.  This spreads out the spectrum of the CO2 that we observe.

The symmetric N2 and O2 molecules are no longer so symmetric.  They can interact with IR light in the regions near their vibrational frequency via the induced electric dipole moment, but wait, there is more.  When two molecules with zero electric dipole collide, their electrons and nuclei can also rearrange (as a practical matter it takes a lot less energy in the collision to shove the electrons about than the nuclei, and a lot easier to move the outermost or valance electrons about.








So, let's take a look at what these collision induced dipole moments do to the absorption spectrum of N2 over 10 km at 70% N2.  The fuzz is the quadrupole absorption that was shown in the first letter to the judge.




O2, because of it's position at lower frequencies where the 300 K black body spectrum is more intense is perhaps more interesting


and we might better compare it's absorption spectrum with ozone (O3) and methane (CH4) which occur roughly at the same place in the spectrum at their measured mixing ratios in the atmosphere.  Even so, the effects of methane and ozone on the absorption are relatively small.


The upper scale shows the absorption coefficients of the molecular lines without boadening.

As a final (well semi-final) point, a Rabett could look for the absorption of O2 in the observed high resolution spectrum from the FIRST balloon ~60 km up


A definite maybe.

Now Eli did say semifinal.  Turns out there is a paper by Höpfner, Milz,Buehler,Orphal, and Stiller  from the Karlsruhr Institute of Technology that goes through the numbers.  They find
The effect of collision-induced absorption by molecularoxygen (O2) and nitrogen (N2) on the outgoing longwaveradiation (OLR) of the Earth’s atmosphere has been quantified. We have found that on global average under clear-sky conditions the OLR is reduced due to O2 by 0.11 W/m2 and due to N2 by 0.17 W/m2. Together this amounts to 15% of the OLR-reduction caused by CH4 at present atmospheric concentrations. Over Antarctica the combined effect of O2 and N2 increases on average to about 38% of CH4 with single values reaching up to 80%. This is explained by less interference of H2O spectral bands on the absorption features of O2 and N2 for dry atmospheric conditions.

An important point in interpreting these results (Eli's and the KIT group) is that while the concentration of CO2 in the atmosphere has changed from 280 to 410 ppm (see Keeling, Charles) in the last 150 years or more and the concentration of CH4 has more than doubled, the concentration of O2 has changed by a few ppm (see Keeling, Ralph), and N2 bugger all.  The small absorptions of O2 and N2 have remained constant only changing really in very deep time.

Eli has written to Dr. Hoepfner about a few questions but has not yet received a reply.

22 comments:

Jan Galkowski said...

Placed links to this very fine series at my related About page.

Jeffrey Davis said...

If understanding this is necessary for the proper settlement of this case and issue, we're doomed. If the judge is sincere, the complexity can create doubt. If he's bent, it will create cover.

Jan Galkowski said...

I think such answers being read into the record of a case is a tremendous idea. They then can be referenced in litigation later.

Hank Roberts said...

So let me see if my 5th grader brain is getting this.

Absorbtion of the electric field energy of a photon depends on how well the absorbing molecule's electrical dipole happens to be lined up. Because we know a horizontal sending antenna produces a horizontal field, and a vertical antenna produces a vertical field, and the receiving antenna works best when aligned the same way.

So since the molecules are randomly oriented, some of them are always available to absorb energy from the photons -- and there are so many molecules that any given photon is going to interact with a compatibly oriented molecule over a short distance ("mean free path")

And the reason that photons get emitted by greenhouse gases is the GHGs get 'wound up' by collecting energy from collisions until their bond has accumulated one photon's worth of energy which then goes "sproing" and emits that photon -- and does so in a random direction

Now I get handwavey here: is the photon emitted in a direction that depends on which way the GHG molecule happens to be oriented?

Or is there some magic happening that when the GHG molecule's bond sproings, that energy goes out in a photon emitted in a random direction unrelated to the orientation of the originating molecule at the time? Because quantum, or something?

I was smarter when I was five.

But I'd still have asked my old question -- isn't there some way to align all the GHG molecules to aim those outgoing photons?
HAARP antenna to line them up in the stratosphere? Like the Martians do to keep their planet cool?
https://www.google.com/search?q=mars+atmosphere+laser

EliRabett said...

Well Hank, given enough lasers you can excite the ones that are aligned with the photons,

https://aip.scitation.org/doi/abs/10.1063/1.481612

and here is an interesting review of ways to grab onto them little buggers.

https://arxiv.org/pdf/1306.0912.pdf

The only point Eli would comment on is that because the vibrational and rotational states are quantized, the excitation occurs in a jump in a single collision and the orientation of the collision partners tends to be controlling (as well as the available energy from the collision). For example, collisions along the cylindrical axis of a diatomic are more effective for vibrational excitation, while collisions perpendicular to the axis are more effective for rotational excitation as you would expect

EliRabett said...

Thanks Jan

Russell Seitz said...

Guess who has alredy called on Judge Alsup to volunteer his tutorial services ?

http://vvattsupwiththat.blogspot.com/2018/03/in-zero-dimensions-not-many-pinheads.html

David B Benson said...

Eli, off topic but this chemistry question came up elsewhere.

What happens to a very hot, say 650 °C, mixture of graphite, finely ground, and sulfur dioxide? There is no air to speak of but enough breeze to produce a uniform mixture.

In particular, does the oxygen prefer the carbon so that carbon dioxide forms?

EliRabett said...

David, Mostly CO2 and elemental sulfur bound to the graphite. There is a literature on this you can find using Google Scholar as it has been proposed for scrubbing SO2 from emissions of coal plants.

Eli suspects that if you had some water vapor in the mix some of it would go to sulfurous acid and eventually sulfuric.

Gingerbaker said...

Are you going to condense/simplify all these results down so that a judge who has little scientific background can understand them?

David B Benson said...

Aha! Thank you very much, Eli.

lifeisthermal said...

So, to sum it up, we have a good amount of data and theories that explains the data, which all shows clearly that atmospheric gases at low temperatures causes the planet to emit less heat for various reasons. Increasing the ratio of some gases, reduces heat emission even more.

Now, heat emission is independently related to the temperature, or the energy density, of the emitting body. So reduced heat emission is a definite sign of reduced temperature of the body. Unless there is a reflective or conductive barrier which reduces heat transfer leading to reduced heat absorption in the surroundings.

Reduced heat emission from a cold layer of gas which is heated by a solid concentric heat source, is a definite sign of dropping temperature of the gas. Dropping temperature of the gas, is a definite sign of increased rate of heat transfer from the heat source. Increased rate of heat transfer from the heat source is inevitably coupled to increased rate of heat absorption in the cold gas. Increased rate of heat absorption in the surroundings of a heat source is what you want to avoid if the aim is to retain heat in the heat source.
So, reduction of heat emission by cold gases in the atmosphere, where there are no reflective or conductive barriers, is a definite sign of increased cooling of the heat source by these gases.

This is what thermodynamics says about heat sources which heats cold gases. It is pretty clear that you say the opposite, that less emission of heat, and increased absorption of heat, in surroundings which decreases in temperature, causes increasing power of the heat source.

Could you please give us a reference showing the experimental data which confirms that dropping temperature of a cold gas causes increasing heat emission from a heat source.

Explain how the gh-effect can work in opposite way to the laws of thermodynamics, where only work can transfer energy from low temperature to high temperature.

Please avoid blankets, pumps, hot cars, greenhouses, thermal insulation (which works by reflective and conductive barriers) etc.

We have working physical laws and theories for cold gas and heat sources, use them. They don't include quantum details of molecules, because quantum physics is not used for bulk properties like temperature.

It should not be hard, if the gh-effect is true, to find support in experimental data for a claim that less heat emission of a gas causes more heat emission from the heat source.

Can a cold gas make it's heat source increase in power by dropping in temperature, even though proven physics say the opposite?

lifeisthermal said...

Forget the quantum details of photons and their interaction with molecules if you are trying to understand temperatures and heat flow through a system. It doesn't apply to bulk properties.

In the context of temperature the electric field energy of photons is transferred and absorbed according to potentials determined by differences in temperatures. Heat flows only from high to low, heat is defined as the energy in transfer from high to low T. Any transfer of energy in opposite direction must be work, says the second law.

On the quantum level, whatever happens, it will obey the heat flow or the work done.

So, unless gh-gases do work that transfer energy to the surface, there is no gh-effect. Because gh-gases have a much lower temperature than the surface.

Now we will probably see claims about how cold air is a blanket, a pump, a sweater, a car in the sun or maybe a magic unicorn.

Keep in mind that cold air is not those things, and the gh-theory is a religion which is used to grab your money and to make you feel guilty for being a human being. Always remember that what cold air does to your body, it also does to the earth surface.

Jan Galkowski said...

@lifeisthermal,

This is a serious discussion, and you are acting like a troll. This is not my blog, but a comment like

``... and the gh-theory is a religion which is used to grab your money and to make you feel guilty for being a human being.''

would get you banned from mine, permanently.

Oale said...

Dr.Prof.Jan. Mr.Rabbett has a habit of housing some idiocy in the comments' section. Usually it's easy to spot and at the first sight the best is just to note the current nick of the blog's resident science denier and talk past him. He regularly shows he doesn't understand science so there's no harm talking science. By now I've probably used all the space allotted to this explanation so I'll stop.

Jan Galkowski said...

@Oale,

Thanks. Your advice is wise.

And, BTW, it's neither "Dr" nor "Prof" for me.

snarkrates said...

lifeisthermal says, "Forget the quantum details of photons and their interaction with molecules if you are trying to understand temperatures and heat flow through a system. It doesn't apply to bulk properties."

And that, right there is why we know we are utterly justified in ignoring anything this ignoramus spews. It is not just wrong, it goes beyond "not even wrong," surpassing even reagent grade purity bullshit.

Mr. thermal would have us believe that quantum mechanics is unimportant in molecular energetics. Mssrs. Planck, Einstein, and every other physicist or chemist since 1920 would disagree.

lifeisthermal said...

snarkrates:

"Mr. thermal would have us believe that quantum mechanics is unimportant in molecular energetics. Mssrs. Planck, Einstein, and every other physicist or chemist since 1920 would disagree."

Is that really what I said? Could you please quote me on that?

What I said was: quantum physics doesn´t apply to macroscopic bulk properties. Temperature is a bulk property, it isn´t defined by quantum physics. Now you have the chance to learn. Pay attention.

Thermodynamics deal with the nature of heat flow, temperature and forces. It is a science entirely built on observation. Basically, people stared at hot things for a long time in labs, taking notes, and building theories on those notes. The result is the laws of thermodynamics, which no sane person questions. Thermodynamics gave birth to the theory of blackbody radiation, which led to the quantum theory. You see, quantum theory is a branch of thermodynamics. It is the microscopic details of temperature and heat. Without thermodynamics, there would be no quantum theory.

Quote where I wrote that quantum physics is important. Or, be honest, and quote me on what I really wrote.

Are you trying to say that quantum physics isn´t ruled by the laws of thermodynamics?

Come on, attack me with blankets.

lifeisthermal said...

Blogger Jan Galkowski said...
@lifeisthermal,

"This is a serious discussion, and you are acting like a troll. This is not my blog, but a comment like
``... and the gh-theory is a religion which is used to grab your money and to make you feel guilty for being a human being.''
would get you banned from mine, permanently."

Yeah, I know. You blanket people like the chinese style of internet. It´s called censorship. I also have a blog, and I publish every comment, even if I don´t agree or like it. Only assholes censor information and discussion.

I actually respect the hell out of Eli for letting me play with you here, once in a while.

Don´t worry, I won´t visit your blog. If I did, I would start every comment with:

"Dear mr. Blanket Man"

And little girls like you can´t handle that.

lifeisthermal said...

@mr Snarkblanket:

I wrote:

"Quote where I wrote that quantum physics is important. Or, be honest, and quote me on what I really wrote."

What I meant was:

"Quote where I wrote that quantum physics is UN-important. Or, be honest, and quote me on what I really wrote."

lifeisthermal said...

@mr. Oale-blanket

you said:

"Dr.Prof.Jan. Mr.Rabbett has a habit of housing some idiocy in the comments' section. Usually it's easy to spot and at the first sight the best is just to note the current nick of the blog's resident science denier and talk past him. He regularly shows he doesn't understand science so there's no harm talking science. By now I've probably used all the space allotted to this explanation so I'll stop."

You write about denial. Let´s take a look at the second law:

"Heat cannot spontaneously flow from cold regions to hot regions without external work being performed on the system"

https://en.wikipedia.org/wiki/Second_law_of_thermodynamics

It specifically says, that transfer of heat(energy) from cold to hot, can only be work done on the system.

You are a greenhouse-blanket-man, trying to defend the greenhouse-theory. Your theory says that energy is transferred to the surface from cold air, but not as work. That is a violation of the second law.

Per definition you are denying a physical law. That makes you a denier of physics.

Was your post about yourself, a denier of physics being housed in this comment-section?

Then, you must talk past yourself?

How does that work?

Do you use blankets for that?

EliRabett said...

Eli even (thanks to Izen) has a video explaining how you left something out of your statement of the second law.

https://youtu.be/DFC3DOEyoz0

What you left out is the sun which is an external source of energy and space which is a very cold heat sink. Both tend to be noticeable.

The interchange of energy between the surface and the atmosphere is a steady state situation not a true equilibrium (Hey you left that out too!)

While the net flow of thermal energy is from the surface to the atmosphere, the presence of the absorbing and emitting atmosphere retards the cooling of the surface and to maintain the steady state, with an equal rejection of the income solar energy to space the surface heats up.