Will CO2 absorb photon in all directions?

In the bending vibration mode you have these two relatively massive Oxygen atoms either side of this piddly carbon atom. You tend to think of the Oxygen atoms being waved about but in reality it is the carbon in a bungee being vibrated up and down so to speak. How can those bonds take the strain with out snapping?
Can the whole of one IR photon go into a single atom or is it spread over multiple as BillyT seemed to suggest? I can't see how the arrangement of multiple molecules can work, but then I have my doubts about it all going into the one molecule of CO2 as well.

Has anyone looked into the physics of this?

 

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Greenhouse Gases:

"Carbon dioxide () is one of the greenhouse gases. It consists of one carbon atom with an oxygen atom bonded to each side. When its atoms are bonded tightly together, the carbon dioxide molecule can absorb infrared radiation and the molecule starts to vibrate. Eventually, the vibrating molecule will emit the radiation again, and it will likely be absorbed by yet another greenhouse gas molecule. This absorption-emission-absorption cycle serves to keep the heat near the surface, effectively insulating the surface from the cold of space."

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I do not understand your question.

1. You give an example where you claim that mass conservation law is not valid?
2. You give an example where you claim that energy conservation law is not valid?

3. Something else?

 

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Well thanks for responding. Look at that animation again. It is showing two IR hitting the CO2 in parallel. There is only 1 IR photon interacting with a single CO2 at any one time. Since it is one on one the energy transfer must be through the Carbon atom (you shake the middle part to make the side weights bend in this fashion. Pick up a long stick hold it in the middle and shake it, it can resonate if you pulse it at the right frequency.)

Also note there are the two Oxygen atoms being pushed downward and no upward Movement of the Carbon to balance it.
If both were pushed downward like that the Carbon would follow the oxygen downward and there would be a motion established in the direction of the momentum in the IR photon, but the photon has only a certain amount of momentum but heaps of energy. So to conserve both the momentum and the energy what is the action on the CO2?

So it was rather an ill formed animation in some ways.
Emil - put this thread on your saved subscription list. I'll get back to it in a week or so. Just a bit pressed for time this week sorry.

 

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The average number of electrons near the carbon atom is less than its normal 6 when in the linear molecule O--C--O and of course higher than 8 near the oxygen atoms of the molecule. Thus in the middle of the molecule there is a net positive charge and at each end, a net negative charge. I.e. something like:

(--)...(++++)...(--) is the electrical charge distribution of the molecule. As the molecule is neutral the electric field it is in can apply no net force to the molecule as a whole. - Its center of mass is NOT accelerated, but the bonds can be stretched, as the force on the + & - parts is in opposite directions causing excitation of its natural resonances.

If it is not hit by some other molecule to de-excite it without radiation, it will soon radiate tha stored excitation energy, which will be essentially the same as the energy that excited it.

 

OK Billy T I don't have a problem with your distribution of electrical charges. [Note I am only talking of bending vibration here, I fully appreciate the alignment would be different to get a stretching effect.]

But test yourself on this? I would imagine there would need to be a minimum distance between the molecule and the photon, so to get the sort of bending effect it would be logical to say the photon passes over/under/near the Carbon atom. If it was nearer one end the bending motion is less likely to occur.

So how intimate does the ray and the molecule need to be?

I can see how this flapping motion could take in some of the Energy. Do you think it is a partial transfer or the whole package.
If the photon is absorbed entirely what happens to the linear momentum of the photon?

 

For an atom the electrons are in "shells" that can hold only the pauli exclusion principle limts For example in ground state hydrogen their is one electron in the n = 1 shell as only one proton. if two protons (He atom) there are two electrons in the n=1, Obying the Pauli principle as one is spin up and the other spin down. These are "s" electrons, (called that for historical reason that their spectra is always that of a singlet, In atoms later in the periodic table the ground state has these same two of He in the n=1 but can have n = 2 (or higher) In the n = 2 shell you can have up to two s electrons and 6 "p" (the Ps can have three projections of their angular moment each with a spin up or down - why there can be up to 6 + 2 = 8 is why second row of periodic table has 8 elements, etc.

This is too confused for me to follow so I just note energy levels are defined by the molecule or atom - have nothing to due with EM waves, but the energy of the EM wave must equal the difference between energy levles to interact with the isolated matter. Dense matter is different.

Heat and temperature are not defined for single atoms - they a based on the random distribution of velocities of a collection of many molecule interacting by collisions.

 

Thanks again Billy T for trying to clear that up.
What Only Me was referring to was your implication that as the IR photon went past one CO2 molecule it could partially loose some of its energy and then proceed onto another or was it like it is transferring to multiple molecules all at once.
He was of the opinion it is an all or nothing event. Photon is totally absorbed or it isn't, not partially off-loading of the energy.
I think that was in the 2nd post you made on this thread that you said something like this. What did you really mean? Is the photon only interacting with one molecule at once?

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[you were more than likely saying just something about the size of the wavelength but we might have understood that as affecting more than 1 molecule at once because of its length and speed.]
#35 #38 were misunderstood.

 

This clears up what seemed confusing earlier..., that portion of your earlier post in red above, suggested some combined electron field. I was trying to understand your statements, more than myself being uncertain of what the generally accepted model was.

This is not entirely accurate, while to understand, I guess you could say define heat, we need more than one molecule or atom. However, there are a number of atoms that do not generally form multi-atom molecules, for which heat remains relevant and descriptive. The fact that to measure heat we need a group of atoms or molecules, does not exclude individual atoms or molecules from being affected by, rafiating or transmitting heat. Every photon emitted by "an" atom has an intrinsic heat potential.

 

Same as if a bb fried from gun hits and enters an apple on a tree. - the target gains that momentum.

I think I must stop trying to help as you both are wanting to understand in classical terms, things which are not classical. Much of the wave vs particle discussion of photons is due to this same human bias. Photons are photons, they do what photons do - often not things people can feel warm and fuzzy about.

 

No heat and temperature relate to the DISTRIBUTION OF RANDOM VELOCITIES of a large number of particles, atoms or molecules. A single atom that radiates emits energy, not heat.

The kinetic energy a CO2 molecule is zero in one reference frame and positive but different in all others. The temperture of a collection is the same in all reference frames.

The electric field of an electon, in the frame in which the electon is at rest is spherical falling off as inverse r squared. Being spherical it makes no force on the elctron, All the electrical force acting on the electron come from some other source of E-field (which could be another electron or proton)

The E-field of an electron viewed from a frame in which it is moving is not spherical and in fact there is a magnetic field due to that electron - why wire carrying many moving electrons, i.e. a current, produces a magnetic field.

 

I don't want you to stop helping but let's try and sort this out.
BB vs Apple - apple goes nowhere so ultimately (remains on the tree) the momentum is transfered to the Earth and the Earth transfers it to the moon!

You know I am trying to find out the reason the winds on the planets covered in GHG are strongly prograde.
I then believe the winds affect the speed that the planets rotate. So from the minor most impact of the momentum addition to the Carbon dioxide I feel it was the beginning of a wind that spins the planet.

 

They are caused by differential heating at equator and the poles but not prograde all over the earth (or any other planet). I will quickly explain why winds are both pro and anti grade on planets that spin with simple numerical case:

The air mass over the equator is traveling at about 1000mph, as it must go around with the Earth´s tangential speed. If it warms it will rise and move more towards the north to replace the more northern air flowing south along the surface which replaces it at the equator.

If the Earth were not spinning then the surface winds would come out of the North (for Northern Hemisphere) and higher winds would go due north. This is what they try even with the actual earth, but that air mass which was at the equator surface is still traveling eastward at say 900 mph when at Spain´s latitude (surface drag slowed it some from 1000 mph)

The ground´s tangential speed toward the east at Spain is only about 500 mph. So the 900mph air motion high up is a wind (out of the west) at about 400 mph. Wind is the difference between ground speed to the east (1000mph at equator and zero at poles) and the air mass speed. Up high this difference can be sevaral hundred mph ("jet streams") but at the surface friction keeps it say ~50 mph or less usually.

Now lets consider the colder air that was near surface over spain as in flows towards the equator. It was travelin at 500mph and remembers that speed to some extent as it goes to the equator´s 1000mph speed. I.e. if it were not down low, it would have ~500 mph wind to the WEST - but it is down low so near the equator the winds are anti-prograde. Columbus did not know why, he just knew as all sailor did that the "trade winds" blow WEST are anti- prograde. Why he first sailed south to off the African coast before turing west to get help from the trade winds. This is also why Huricanes move form off African coast to wards Cuba, etc.

You need to become educated, about what is well known before making up nonsese that claims winds are prograde - at least get the facts straight - this is all well known - why I asked you to read about Coreolis effect. The gulf stream makes a clockwise circulation if viewed form space for the same reason, but the south bound leg off of cosat of Spain etc. is on the ocean floor as when near Iceland etc. the water got cold and sank with its higher than local water salt content. (salter as when on surface near equator there was more evaporation)

 

Hi Billy T - All what you've said applies directly to the Earth, which is a place I don't consider as a "planet covered by GHG". It has a moderate amount of atmosphere only.
Have you studied the winds on Venus and on Jupiter? Are the same effects as apparent on them? From what I understand the winds on these two planets are rotating faster than the planet by far. Something the coreolis effect can't account for.
But let's not rush it. Let's just make sure we understand how the greenhouse gas picks up energy and momentum from a photon first.

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I'll quickly C&P a section out of Wikipedia on the Atmosphere of Venus

http://en.wikipedia.org/wiki/Atmosphere_of_Venus

Now I don't have anyone teaching me other than what I can discover on the internet but that clearly tells me the winds on Venus are spinning faster than the whole/any part of the planet. And I use the word prograde to mean in the same direction as the planet spins, which is also true of Venus.

Years ago I saw a study that showed that if all the air movements on Earth are added up there is a small prograde net wind on Earth as well, but I could not find any reference to it recently.

 

Hi Rbb1.

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I don't know if this is anything, but some time back I hypothesized about the reason for such super-rotation of atmospheric layers.I came up with the idea that the intial 'dynamo' of the early molten planet would slowly lose effect as its rotation energy was bled off into the atmospheric layers where the PRESSURES were great and possible 'conductive/plasma' states were present that 'coupled' the planet body rotation energy to the atmospheric rotation of high-pressure 'superfluidic' and/or 'superconductive' layers which are thereby 'sped up' towards super-rotation speeds as the planet's interior 'dynamo' rotation was bled off and the planet's rotation slowed to what is observed today. The pressures on Jupiter et al AND on venus may produce fluidic/conductive effects which may couple and draw energy of rotation from the central 'dynamo' until the planet's rotation slows to a crawl?

Naturally, such phenomena is not likely on planets like Earth where the atmospheric pressures/densities/properties may not trigger such effects/outcomes. Our Earth's rotation has been slowed by gravitational coupling with The Moon rather than with any high-pressure atmospheric states involving superfluidic/superconductive coupling' possibilities with the internal 'dynamo'.

That's all I have to offer you on your conundrum, Rbb1. I haven't had the chance yet to follow through on my hypothesis. Maybe someday when time is more plentiful, hey!

Cheers and good luck with your own endeavours, Rbb1.

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The winds would only move as fast as the dynamo and that's about the same speed as the Earth is turning now.

What would be interesting would be to show it is the other way around, the winds and their static charges generating the current that drives the dynamo. But that would be a long shot.

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Welcome back Robittybob1

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Im sorry but I can not give a clear answer. I don't know.
Maybe it's a wave, and passes through the dioxide molecule, giving a very small portion of its energy? (Carbon dioxide absorbs infrared light little, but a lot of ultraviolet light.)

The temperature of an ideal monatomic gas is related to the average kinetic energy of its atoms.

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Looking at the planet with strongest wind Neptune:
Very strong fast winds high up so the net effect is at a guess prograde too! Westward, or westerly is prograde.

http://en.wikipedia.org/wiki/Neptune

 

Emil - you know that wave idea is a good one. UV light would cause ionization but IR will add energy to the molecule making it vibrate and adding momentum. This energy and vibration is passed on to other molecules in the atmosphere. Too many will cause trouble. - Climate change.

 

Winds on Saturn Now they have worked out how fast the planet spins winds are blowing both ways but from what I can gather the wind to the East (prograde) are still the fastest. But the gases are not true GHG just mainly Hydrogen and Helium.

http://news.sciencemag.org/sciencenow/2009/07/30-02.html