Quote:
Originally Posted by sjastro
The answer is no.
Quantum mechanics states that the time for an energy transistion to occur such as an electron moving back to it's ground state is related to the energy difference between the excited and ground state. The larger the difference the faster the time for the transistions to occur.
Since a gas can undergoe various transistions at different energy levels none of the transistions occur simultaneously.
A spectrum is simply a record or snapshot of these transistions over a particular exposure time.
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Ok. Got it - that's at the atomic scale of things. I think I was thinking of a 'cloud of gas' scale - one part of the cloud could be in the emission state another part of the same cloud could be in the absorption state ? (ie: different temperatures in the cloud).
Quote:
Originally Posted by sjastro
The intensity of the peaks in either an IR absorption spectrum or IR emission spectrum relates to the concentration of the functional group causing the peak. Unfortunately this is not an absolute value.
By taking two IR spectra at different time intervals, any variations in the peaks allows one to calculate the emission rate of material from a comet.
As seen in the Japanese paper this is not a straightforward process.  |
Yep. I noticed that they calculate the amount of gas, (in molecules), by integrating the area under the peaks, over the timeframe during which they occur. This seems to be the answer to Alex's question of how they calculate the volume of gases instantaneously expelled .. and by doing this at different times, they can take the differences and work out how long it'll take for the nucleus to sublimate completely.
Also, for emissions: if the external energy (doing the excitation) has regular (or irregular) fluctuations (in terms of frequency), would the discharge emission frequencies also fluctuate ? Ie: higher frequency lines would appear and disappear ? -This being due to the amount of energy being delivered, being proportional to frequency of the excitation ? (Ie: the power/frequency distribution function).
Cheers