Will CO2 absorb photon in all directions?

[Billy T]

rearranging that equation M = E/C^2
Now the higher frequency IR photon that CO2 absorbed 2349 Hz and frequency times Plack's Constant gives photon energy
2349 Hz * 6.63E-34 = 1.56E-30Joules
dividing that by C^2 you are going to get a mass increase (1/(9*10^16)* 1.56E-30) kg.
The mass increase is small and could account for the momentum and the energy but not the physics of the GHG using the energy as heat not mass.

I have no idea what you are trying to do here (and doubt you do either) Note that 2349 Hz is not even a high pitch audio note - lower frequency than the highest audio notes of the piano!

 

[Billy T]

... So the momentum always speeds up the interacted particle, never slowing it down. ...

False. Whether or not the absorber speeds up or slows down depends upon if the photon was red or blue shifted for that absorber - typically a 50/50 chance, unless you have formed a beam of particle to be the absorbers and then directed it towards the light source. In that case they ALL would be slowed down very slightly by an absorption.

I can´t keep correcting your error as must get back to doing taxes so will Just note for innocent readers that a high percentage of your statements are false as you have very little understanding of what you post about. (You have learned some form my corrections so, it I had more time, I think your undrstanding would improve.)

 

[Billy T]

Thanks for reminding about that experiment. Were the results accepted and peer reviewed. I like it. ...

No it was a standard experiment in a physic lab where I got my Ph.D. Most Ph.D, candidates did it.

 

[Robittybob1]

I have no idea what you are trying to do here (and doubt you do either) Note that 2349 Hz is not even a high pitch audio note - lower frequency than the highest audio notes of the piano!

Have I made a serious mistake in the frequency? That could be right for no one has been checking the maths, the number came from the internet but was it the "wave number" not the frequency?

I've got all the math on an excel sheet so if there is a correction it will be easy to adjust the values.
I'll be back!

Thanks Billy T - I have done it wrong I've confused wave number with frequency - i'll have to reassess the figures.
http://www.wag.caltech.edu/home/jang/genchem/infrared.htm

"Infrared radiation at 2349 (4.26 um) excites this particular vibration. The symmetric stretch is not infrared active, and so this vibration is not observed in the infrared spectrum of CO2. The two equal-energy bending vibrations in CO2 (C and D in Figure 4) are identical except that one bending mode is in the plane of the paper, and one is out of the plane. Infrared radiation at 667 (15.00 um) excites these vibrations. "

wavenumber =frequency/speed of light

Energy of Photon = Plancks Constant * speed of light * wavenumber

We can convert this to Hz by multiplying by the speed of light which is 2.99792458 x 10^10 cm s-1

I might get some more realistic numbers for energy and momentum now!
PS: Some much more realistic figures are showing up now. Thanks Billy T.

 

[Robittybob1]

Here's how that message from James R related to a question I asked: From http://www.sciforums.com/showpost.php?p=2918980&postcount=693 Gravity never zero thread.

OnlyMe
#693

“ Originally Posted by hansda
In Einstein's paper , he corelated light energy with change in kinetic energy of a mass .

I dont think if particle photon has any kinetic energy because photon's energy depends upon its wavelength/frequency (its rest mass is zero.) .

So, i think he meant non-zero atomic-mass ; which has kinetic energy . ”

I believe you are mistaken, take a look at this discussion of the subject, The Concept of Mass, where Lev Okun does a pretty good job of discussing the issue surrounding the equation E = mc^2 and it's history.

Robittybob1
Registered Senior User (1,885 posts)
03-25-12, 02:09 AM #694

“ Originally Posted by OnlyMe
I believe you are mistaken, take a look at this discussion of the subject, The Concept of Mass, where Lev Okun does a pretty good job of discussing the issue surrounding the equation E = mc^2 and it's history. ”

One thought that came out of reading that paper was that Einstein had no problem that the energy in a photo took away mass from its source.
So I was thinking does that mean an electron in its ground state is less massive than a free electron.
I have not tried to research this yet, so please no hostile responses please.

James R
Yes, it does mean that. Or, more precisely, the atom-with-bound-electron is lighter than the equivalent atom (minus one electron) plus one free electron.

 

[Robittybob1]

I have no idea what you are trying to do here (and doubt you do either) Note that 2349 Hz is not even a high pitch audio note - lower frequency than the highest audio notes of the piano!

Now Billy or someone could you check the figures please.
If a photon has Wave number = wn = 2349 cm-1 Its calculated frequency = 7.05E+13 Hz (Based on est. c = speed of light = 3.00E+08 m/sec = 3.00E+10 cm/sec (you have to use this one as wavenumber in cm-1)
use formula f= wn*c
Planck's constant = h = 6.63E-34 )

This Photon has energy = 4.67E-20 Joules (E= hf; f for frequency)

Photon has linear momentum = p = 1.56E-28 kgm/sec (p = E/c) which will impart an increase in velocity of the Carbon Dioxide molecule 2.13E-03 m/sec if the CO2 was stationary to start with. Using formula v = p/mass.
Mass of CO2 = mass = 7.31E-26 kg

 

[Robittybob1]

Now if the full energy of the photon was converted to mass
E = M * C^2
Rearranging that equation M = E/C^2
Now the higher frequency IR photon that CO2 absorbed 2349 wavenumber or 7.05E+13 Hz and we know that the frequency times Plack's Constant gives photon energy
7.05E+13 Hz * 6.63E-34 = 4.67E-20 Joules
dividing that by C^2 you are going to get a mass increase (1/(9*10^16)* 4.67E-20) kg. = 5.19E-37 kg

The mass increase (5.19E-37 kg) is small and yet could account for the momentum and the energy but not the physics of the GHG using the energy as heat not mass. (Even though in a closed system even heat is mass, but hot mass is different than cold mass)

 

[Robittybob1]

Now Billy or someone could you check the figures please.
If a photon has Wave number = wn = 2349 cm-1 Its calculated frequency = 7.05E+13 Hz (Based on est. c = speed of light = 3.00E+08 m/sec = 3.00E+10 cm/sec (you have to use this one as wavenumber in cm-1)
use formula f= wn*c
Planck's constant = h = 6.63E-34 )

This Photon has energy = 4.67E-20 Joules (E= hf; f for frequency)

Photon has linear momentum = p = 1.56E-28 kgm/sec (p = E/c) which will impart an increase in velocity of the Carbon Dioxide molecule 2.13E-03 m/sec if the CO2 was stationary to start with. Using formula v = p/mass.
Mass of CO2 = mass = 7.31E-26 kg

Now an interesting feature was noted today in that as the velocity increases every time the photon strikes the CO2 molecule there is a constant momentum change MV, since the mass is not going up significantly the change in Velocity component of the momentum stays the same. But to get that same velocity change as determined by momentun conservation the amount of photon energy climbs to cause that change in momentum, as velocity takes energy.
Since kinetic energy is related to 1/2 m v^2 and as the V gets larger the V^2 is exponentially larger.
At the speed of light (or slightly before it) the energy required to provide additional velocity for the momentum conservation uses up all the energy in the photon. Beyond that speed (of light?) no further momentum transfer can happen hence no further velocity increase is possible.Is this the reason something can't be made to go faster than the speed of light?

 

[Billy T]

Congratulations You are reading and learning. Your post 246 is fully correct (I mainly checked ideas and orders of magnitudes but only the division etc in my head to one place.) Post 247 has no errors too, but I think your reason for doing it may be a little flawed.

You do not convert all the photon energy into mass by absorbing it. Part of its energy is stored as energy in the excited state of the absorber; however, that absorber does have an increase in it massenergy. I don´t have time to think carefully about it now but suspect that the total massenergy of the absorber photon system is conserved. I.e. after the photon no longer exists and the absorber is in an excited state, the massenergy is still the same.

Now an interesting feature was noted today in that as the velocity increases every time the photon strikes the CO2 molecule there is a constant momentum change MV, since the mass is not going up significantly the change in Velocity component of the momentum stays the same. But to get that same velocity change as determined by momentun conservation the amount of photon energy climbs {required} to cause that change in momentum, as velocity takes energy.
Since kinetic energy is related to 1/2 m v^2 and as the V gets larger the V^2 is exponentially {quadratically} larger.

At the speed of light (or slightly before it) the energy required to provide additional velocity for the momentum conservation uses up all the energy in the photon. Beyond that speed (of light?) no further momentum transfer can happen hence no further velocity increase is possible.Is this the reason something can't be made to go faster than the speed of light?

{better terms inserted in your text}
First the tiny velocity increment with CO2 gas (like in the atmosphere) by absorbing 2349 cm-1 photon is 50/50 likely to be down instead of up; however, it will soon be an even smaller decrease in the average velocity of the air due to the momentum change being shaired with the O2 & N2 molecules. I.e. in the limb with gas moving towards the sun the air speed will be very very very slightly less.

Secondly, even if you had a beam of photons with 2345 cm-1 shining on a single CO2 molecule in deep space (no collisions) you could eventually drive it to very high speed as each time the absorbed energy is radiated away, it gives a recoil velocity increment to the CO2 that randomly directed. However as the CO2 speed up it sees the photon with less energy as they are red shifted for it. To keep driving it to higher speeds your photon beam must have photons which leave the source with ever shorter wavelenghts than 2349 cm-1 photons have.

Put some consideration of the red shift effect into your thought process then you will have a better understanding of why you can not drive the CO2 molecule faster than speed of light even when your beam is emitting / made of gamma rays!

 

[Robittybob1]

Thank you Billy for looking at the figures. I was still a bit unsure if I had some of it right as the frequency seemed lower than I expected but this is the first time for ages that I have had to work with these equations and IR photons.
As I was saying my last post was that it was the Excel sheet that was coming up with the limit in velocity it was showing up in the figures and it blew me away. OK I was aware that unless the CO2 had a way of off loading its vibrational energy it probably was in no state to absorb even the 2nd photon of the same wavelength, so I knew the situation was completely wrong, but the amount of mass-energy of the photon that had to be used to provide the mandatory momentum change just kept on increasing until the Co2 was moving close to the speed of light. I knew there would be complications of how the CO2 would react to the light and I would, as you say, have to provide it with Blue shift light make it work in real life.
I was also wondering if the increasing mass-energy of the momentum would at some stage affect the inertial mass of the CO2 as the velocity went up.

But the formulas showed up a limit just below the speed light without having to tweak the weight. Which is odd because the photons velocity never came into.
So it was sayingto me "you can't get the atom to travel faster than the speed of light because the photon hasn't got enough energy to change the molecule's momentum" rather than just reading and saying it "nothing can go faster than the speed of light" without giving the reason.

 

[Robittybob1]

False. Whether or not the absorber speeds up or slows down depends upon if the photon was red or blue shifted for that absorber - typically a 50/50 chance, unless you have formed a beam of particle to be the absorbers and then directed it towards the light source. In that case they ALL would be slowed down very slightly by an absorption.

I can´t keep correcting your error as must get back to doing taxes so will Just note for innocent readers that a high percentage of your statements are false as you have very little understanding of what you post about. (You have learned some form my corrections so, it I had more time, I think your undrstanding would improve.)

Note Billy this is the purpose of this thread, may even be the purpose of my life, my contribution to science, will be to solve this issue once and for all. Who's right you or me?

 

[Robittybob1]

Note Billy this is the purpose of this thread, may even be the purpose of my life, my contribution to science, will be to solve this issue once and for all. Who's right you or me?

Just like above it wasn't I who worked out that a molecule could not be accelerated faster than the speed of light using photons but the formulas themselves for there comes a time when the photons don't have enough energy to change the momentum at the extreme velocities.

Now I think the same or reversed principle will apply to an interaction of a photon and a particle that is moving with a "subtantial " reversed momentum vector. (ie the light and the particle are moving in substantially in opposite directions.)
Now it was previously established (in one of these discussions) that it is the relative motion of the source and the receiver (A-B) that determines whether light will be blue shifted or not.

Red shift when the relative positions of A-B are getting further apart, and blue shift when A-B positions are getting closer.
In the Pound Rebka experiment it was shown that gravitationally blue shifted photons had more energy and were able to do something the others were not.
So we tend to think of all blue shifted photons as being more energetic but are they really?
What experiment showed that blue shifting because the receiver is moving has the same "energising" ability?

The other issue that is even harder to put into words is the time warp effect of the reverse motion interaction. %???%! As I said it is hard to put into words. I can sort of picture it but it will take time to say it.
But let's first see if blue shift photon have more "go"!

 

[Robittybob1]

It is going to take time to answer this question. Some of what I read seems to suggest that since the observer is moving toward the light aspects of length contraction and time dilation come into it. Just the things I didn't want for relativity discussions go on forever. Looking at the basics, the energy package in the photon was something that happen way back in the Sun say, and then while traveling out of the Sun's gravity it would have red shifted and a little blue shift coming in toward the planet but the photon is definitely not "restored" from the Gravitational Red Shift it has endured.

So what effect does the motion of the observer have on the photon? (By observer I mean the molecule that will absorb it.)
All agree that it will appear "motion induced" Doppler shifted but writers differ so far as to the effect on its energy content. - So the jury is out.

 

[Robittybob1]

http://en.mimi.hu/astronomy/red_shift.html
for a definition of motion induce redshift.
"red shift Motion-induced change in the wavelength of light emitted from a source moving away from us. The relative recessional motion causes the wave to have an observed wavelength longer (and hence redder) than it would if it were not moving."
>>> http://lifeng.lamost.org/courses/astrotoday/CHAISSON/GLOSSARY/GLOSS_R.HTM

 

[Robittybob1]

This thread on PhysicsForum really emphasises the confusion. -do they come to an answer?
Photon Energy when Doppler Shifted!

http://www.physicsforums.com/showthread.php?t=71433

 

[OnlyMe]

This thread on PhysicsForum really emphasises the confusion. -do they come to an answer?
Photon Energy when Doppler Shifted!

http://www.physicsforums.com/showthread.php?t=71433

I did not follow the whole tread through. A lot going on today.

One thing to keep in mind is that for the kind of red shifting that I believe Billy was referring to, it was an artifact of the absorbing atoms motion. In that case the photon energy remains constant, while the momentum involved in the meeting of a photon and an atom, has components contributed by both the atom and the photon.

I am not entirely clear on the detail but I think part of what Billy was saying is that the red/blue shift was a function of the atoms momentum, rather than the photons. If the atom is moving toward to photon there is a greater total momentum than if it is moving away. Both the atom and photon contribute to this.

 

[Robittybob1]

I did not follow the whole tread through. A lot going on today.

One thing to keep in mind is that for the kind of red shifting that I believe Billy was referring to, it was an artifact of the absorbing atoms motion. In that case the photon energy remains constant, while the momentum involved in the meeting of a photon and an atom, has components contributed by both the atom and the photon.

I am not entirely clear on the detail but I think part of what Billy was saying is that the red/blue shift was a function of the atoms momentum, rather than the photons. If the atom is moving toward to photon there is a greater total momentum than if it is moving away. Both the atom and photon contribute to this.

When you find time this link http://www.newtonphysics.on.ca/einstein/chapter8.html
Einstein's Theory of Relativity
versus
Classical Mechanics
by Paul Marmet
Chapter Eight The Doppler Effect.


Gives far the best concept and explanation so far, and it links in well with what you have just said. The formulas it uses we should be able to enter them in and see what effect we get from the Doppler shifts in the planet's limbs.

 

[OnlyMe]

When you find time this link http://www.newtonphysics.on.ca/einstein/chapter8.html
Einstein's Theory of Relativity
versus
Classical Mechanics
by Paul Marmet
Chapter Eight The Doppler Effect.


Gives far the best concept and explanation so far, and it links in well with what you have just said. The formulas it uses we should be able to enter them in and see what effect we get from the Doppler shifts in the planet's limbs.

I took a quick look over the link and in the first section the following jumped out,

We do not believe that any kind of energy can ever be lost whatever the circumstances are. If this were possible, energy would be created from nothing when an emitter moves toward an observer because of the Doppler effect. ​

What came to mind was the Cynamical Casimir effect, where a mirror moving relativistically through the zero point fluctuations of vacuum energy, could change a virtual photon into a reflected real photon. Would seem to create energy from nothing. There was a paper a while back, Observation of the Dynamical Casimir Effect in a Superconducting Circuit that seems to support the prediction. Though I have to admit I am not qualified to say one way or the other. I am still trying to digest parts of the paper.

The point being that there may be some more fundamental connection between what we call empty space, the ZPF of vacuum energy and both energy and mass, than we can currently define.

Doesn't really have much to do with your objective, just a randomly associated tid bit that came to mind.

 

[Robittybob1]

I took a quick look over the link and in the first section the following jumped out,

We do not believe that any kind of energy can ever be lost whatever the circumstances are. If this were possible, energy would be created from nothing when an emitter moves toward an observer because of the Doppler effect. ​

What came to mind was the Cynamical Casimir effect, where a mirror moving relativistically through the zero point fluctuations of vacuum energy, could change a virtual photon into a reflected real photon. Would seem to create energy from nothing. There was a paper a while back, Observation of the Dynamical Casimir Effect in a Superconducting Circuit that seems to support the prediction. Though I have to admit I am not qualified to say one way or the other. I am still trying to digest parts of the paper.

The point being that there may be some more fundamental connection between what we call empty space, the ZPF of vacuum energy and both energy and mass, than we can currently define.

Doesn't really have much to do with your objective, just a randomly associated tid bit that came to mind.

Me too! With these virtual particles when they appear they were matched by their opposites so its like production of a 1 and a minus 1 but still adding to nothing.

But that paper on the Doppler Effect demonstrates how the energy is taken up in the recoil of the atom so it is similar to what I had been working with.
So in the moving frame a potential high energy photon is split between the energy of recoil and the resultant photon energy. (i.e. the total energy stays the same.)

Whether that supports my theory in the OP or not I haven't got my mind around that yet.

 

[Robittybob1]

On both sides:
On both sides of a planet like Venus which is covered in CO2 gas and has a super rotating prograde wind.
On both sides the photons striking and adding energy and momentum to the CO2 will have the same frequency, momentum and energy in the frame of the CO2 molecule, for that is the physical fact that only a photon of that frequency will vibrate the CO2.
(The only reason they are the same WRT the CO2 is that one is blueshifted and the other redshifted. But we will cover this later.)

On the side that moves toward the Sun:
A low energy photon leaving the Sun is blueshifted WRT the CO2.
So during the interaction some of the energy and momentum comes from the motion of the CO2. The CO2 slows on photon absorption due to conservation of momentum.

On the side that moves away from the Sun:
A higher energy photon leaving the Sun is redshifted WRT the CO2.
So during the interaction all of the energy and momentum comes from the photon and not the CO2. The CO2 speeds up on photon absorption due to conservation of momentum.

So on the balance it looks quite even, but it isn't in fact for in the frame of the planet it is the high energy photons adding their momentum and energy to the "away side", and only low energy photons on the "towards side".
Therefore I would propose that there is a net prograde acceleration of the atmosphere due to the energy and momentum imbalance.
It is imbalanced because the blueshifted side borrows momentum from the molecule whereas on the redshifted side this momentum is gifted to the molecule (for want of better terminology).

Please let me know if there is a problem in the logic of this.

So here I have conceded to a change, contrary to what I said in the OP, I now agree that molecules and photons do not require a common direction for absorption to occur. But due to the different motion induced Doppler effects the planet still has more kinetic energy and momentum added to one side than the other.