Where can I find the gas phase spectrum of Methane

Norm Why

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Oct 30, 2021, 12:47:54 AM10/30/21

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The IR spectrum here:

https://webbook.nist.gov/cgi/cbook.cgi?ID=C74828&Type=IR-SPEC&Index=1#IR-SPEC

Notice: Except where noted, spectra from this collection were measured on
dispersive instruments, often in carefully selected solvents, and hence may
differ in detail from measurements on FTIR instruments or in other chemical
environments. More information on the manner in which spectra in this
collection were collected can be found here.

Notice: Concentration

is bizarre.

I have never believed the alarmists claims about cow farts, etc. Alarmists
claims are always wrong.

Is Methane black!!!???

Norm Why

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Oct 30, 2021, 12:57:52 AM10/30/21

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Methane has no permanent dipole moment and it is symmetrical. I would think
it is no more a greenhouse gas than Helium. Is Helium a greenhouse gas? Is
Helium black?

Norm Why

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Oct 30, 2021, 1:07:46 AM10/30/21

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This appears to be the IR Spectra of pure liquid Methane. Morons want to
scare us and control the world.

Norm Why

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Oct 30, 2021, 1:43:18 AM10/30/21

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Bloomberg Green: The Dangers of Methane Gas
https://www.youtube.com/watch?v=b5VDMyYPyfs

Is a propaganda site.
the following comment was implanted there and it was immediately removed.

https://webbook.nist.gov/cgi/cbook.cgi?Scan=cob8873&Type=IR

is IR spectrum of pure cold liquid methane with all its isotopomers; CH3D,
CH2D2,CHD3, CD4. CH4 methane is in the middle. CH4 a symmetric molecule has
no permanent dipole moment and has no IR spectrum.

Once again it is shown morons are in charge of the planet.

Be prepared to be inundated with propaganda from criminal fraudsters.

Martin Brown

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Oct 30, 2021, 4:15:28 AM10/30/21

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Moron! A comparison of your intellect with two short planks would be
insulting to the planks. All polyatomics with 3 or more atoms are
potential GHGs irrespective of whether they have a dipole moment or not.

Think about the vibrational degrees of freedom and you might see why.

Helium is monatomic and plays no part as a GHG and so is argon which
makes up nearly 1% of the Earth's atmosphere.

Nitrogen and oxygen are so tightly bonded together that their
vibrational frequencies are way beyond thermal IR bands on Earth.

CO2 and H2O are the canonical simplest common greenhouse gasses. They
have several vibrational modes with frequencies in the right ballpark.

Any polyatomic gas has resonant frequencies that are in the right range
to absorb (and emit) thermal band IR on the Earth.

The most extreme GHG and also one of the most stable is SF6 which has
been considered as a possibility for terraforming Mars. It is used in
electrical switchgear and ultra high voltage accelerators.

https://www.forbes.com/sites/thebakersinstitute/2021/03/25/sf6-the-little-gas-that-could-make-global-warming-worse/?sh=3dac86c022ad

--
Regards,
Martin Brown

mrou...@shaw.ca

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Oct 30, 2021, 10:55:16 AM10/30/21

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On Saturday, October 30, 2021 at 2:15:28 AM UTC-6, Martin Brown wrote:

> Nitrogen and oxygen are so tightly bonded together that their
> vibrational frequencies are way beyond thermal IR bands on Earth.

Minor correction: Actually, the real reason that nitrogen and oxygen don't absorb in the IR is that they have a dipole moment of zero, and that can't change as they vibrate because of their very simple symmetry. The selection rule for IR-active modes is that the dipole moment has to change during a vibration.

To the people asking questions about whether methane is black: irrelevant. You can't see in the infrared, so you can't judge IR absorption by looking. Put it another way: the atmosphere is transparent in the visible range, and yet the surface of the Earth is much warmer than it would be without our atmosphere. So the visible color of atmospheric gases clearly can't play a role in the greenhouse effect.

If I may be permitted to editorialize for a moment, I would say that what we are seeing here is the heart of the problem. The people who are most convinced that global warming is a hoax are those people least able to explain the physics behind it. I have yet to meet a person with these views who can give a reasonable account of the planet's heat balance. It's not extremely complicated. I teach it to my first-year students. It's also not completely trivial. There are lots of great resources out there, notably this one from the American Chemical Society (since this is sci.chem): https://www.acs.org/content/acs/en/climatescience.html. Learn, then maybe you can ask sensible questions.