- #1
Karl Coryat
- 104
- 3
- TL;DR Summary
- Wondering if entropy has anything to do with the smallest systems seeking low-energy states.
I realize that nothing causes an excited atom to emit a photon, and that it's a random process. But someone was asking me about why energized systems in general tend to lose their energy to the environment and move toward equilibrium. I mentioned that an inflated balloon, given a hole, will tend to deflate, and I gave the thermodynamic explanation which ultimately invokes statistical mechanics. Plenty of other macroscopic processes, even gravity, have thermodynamic, emergent explanations, at least in some theories.
What about on the atomic level? Is a system of an atom plus an emitted photon considered higher-entropy than the atom when excited? One could say that there are many more configurations of atom + photon than there are of an excited atom alone.
Basically, I want to learn how small a system can be and still have a "macrostate" for the purpose of considering a statistical, entropic explanation. Surely an ensemble of excited atoms, decaying exponentially, meets the description...but just one?
To be clear, again, I'm not looking to explain the particular emission, just why an excited atom tends in that direction.
(Note: A similar question was asked here a long time ago, but I find the answer unsatisfying. https://www.physicsforums.com/threads/a-thermodynamic-approach-to-spontaneous-emission.75515/ )
Thank you!
What about on the atomic level? Is a system of an atom plus an emitted photon considered higher-entropy than the atom when excited? One could say that there are many more configurations of atom + photon than there are of an excited atom alone.
Basically, I want to learn how small a system can be and still have a "macrostate" for the purpose of considering a statistical, entropic explanation. Surely an ensemble of excited atoms, decaying exponentially, meets the description...but just one?
To be clear, again, I'm not looking to explain the particular emission, just why an excited atom tends in that direction.
(Note: A similar question was asked here a long time ago, but I find the answer unsatisfying. https://www.physicsforums.com/threads/a-thermodynamic-approach-to-spontaneous-emission.75515/ )
Thank you!