Recent content by suibhne

Tandem78 Thanks very much, that's a big help all I need now is some paper for my printer many thanks.

Yes I fully understand the Kinetic Theory of Gases and I have no wish to intrude on your query any further.

I think that the black body cavity theory developed by classical Physics from considerations of solids and relatively high temperatures does not completely explain gases or even very high temperatures. See the "ultraviolet catastrophe". Its a perfectly good question. How does an isolated...

How does N2 gas radiate at say temperatures below 280K when its spectra shows no available lines-what is the mechanism ?

The same question interests me; for instance integrals answer is the usual response but if you have a gas, say N2 with no apparent means of radiating at 280K or below how does it radiate?

The sceptical science website despite its name is a site that supports the theory of AGW. Carrot Eater I would guess from his reply works in a professional capacity in Climatology and certainly is a believer in the consensus view. Thank you for directing me to your source- a very expensive book.

I was asking much the same question on scepticalscience website. The thread was "Is CO2 a pollutant" I used my same user name suibhne. A dialog open up between my self and "carrot- eater" and in his second reply gave this latest information on use of Stephan Boltzman Equation.

I have since been told that the Stephan Boltzman equation is not used in more recent methods dealing with heat transfer situations concerning gases. The current method apparently takes account of the wavelength dependency and quantum nature involved to give a more realistic base to the calculation.

Since I do not work in the industry I do not have acess to study the effective ways of dealing with gases mixed or otherwise. I would guess that in the case of CO2, excitation of thermal bands then by collision with say H2O would allow more permitted IR bands. For a pure sample of CO2 gas then...

A CO2 molecule has two significant quantised infra red bands. I still find it difficult to understand why some people think it is appropriate to use Stephan Boltzman equation in this situation for an isolated molecule at STP.

Thanks Conway any chance of putting me in the direction of answer as to the probability of photon energy changing to KE verses simply re-radiating

Thanks turin,gokul and conway for your helpful replies. I gather from what you are saying is that for a gas like CO2 at STP then being subjected to a strong beam of infra red radiation for however long will not result in itself in an increase in any molecules translational KE. That is the...

Its common knowledge that infra red radiation heats up an absorbing solid surface. That is,the em radiation energy is converted into translational KE of the particles of the solid. What happens in the case of an isolated CO2 molecules absorption? Can the EM energy be converted into increased...

CFDFEAGURU Thanks for the reply will follow the lines you suggest.

Homework Statement The Stephan Boltzman Law used in black body cavity situations is sometimes used when dealing with gases, is this a valid use of the equation? Homework Equations H=AekT^4 H is heat current in radiation A is the area e is the emissivity k the Stephan Boltzman...