It is surprisingly difficult to find a short sweet list of subatomic interactions where photons are released. Every link google gives on the subject has to give an entire explanation of quantum mechanics dumbed down in layman’s terms first before giving any sort of answer related to the title of the article/whatever. Hell, even laymen would find the terms to be too simple.
Basically, what I want to know is:
Are electrons the only particle that can release a photon?
I am 99% sure they aren’t, but someone is telling me that photons are only released by the interactions of an electron. I’m almost positive that photons are also released during interactions like a proton and anti-proton annihilating each other, and at least a dozen other interactions, but I want a credible source giving me some straight answers, and not one that has to give 10 paragraphs of analogies like they’re talking to a 5 year old.
Can anyone help me out?
Also, when two protons get close to each other and repel one another because they both have a positive charge, did this repulsion have to be mediated by a photon?
I don’t know how I missed this thread… sorry about that.
The most common creation of a photon is by the orbital reduction of an electron. The energy that is released comes from the energy that was stored between the electron and the nucleus. But as you point out, that is certainly not the only means.
One problem that you are going to have trying to straighten out this subject is that a photon isn’t really defined very well. In QM, a photon is merely a small amount of radiant energy of interest, a “virtual particle/photon”, not quite the same as what you think of as a discreet photon. Just about every subatomic interaction releases a photon of one sort or another, thus creating an increase in entropy.
A photon is actually merely a “bundle of free energy”. The other descriptors that tend to go along with that create ontology problems regarding sizing, frequency, and energy content. Unfortunately, I can’t point you to a good authoritative description of today’s idea of what a photon really is or how one is created. And my personal understanding of physics doesn’t allow for such loosely defined entities.
Basically anything that creates high frequency radio type radiation, creates “photons” (depending on who is explaining it at the time).
The thought that “photons mediate” is strictly a QM ontology. I disagree with their ontology for a variety of reasons, but when it comes to the repulsion effect of like charges, they hardly ever speak of their photons. In reality, there is no physical thing involved that could justly be called a “photon” in such reactions. The protons appear to repel merely because they are causing each other to “migrate” in the opposite direction. There is no actual “force” involved, no “pushing”. Each proton merely blocks the other from being able to remain in its location. The explanation for that is very involved, but there is no actual interaction between the two entities. Each proton merely seeks the lower field strength (which is always in the opposite direction of the other proton). Neither is aware of the other at any time. The momentum involved merely returns as the resultant momentum of the two particles.
I like your last paragraph; the super-positioning of the two particles “repelling” each other does not allow for them to get any closer, and the phenomenon of electromagnetic repulsion occurs. On the macroscopic scale, this same process causes gravity. Space is the collection of particle super-positioning; there is no true location, only relations to other stuff.
I’ve also thought of gravity like this: the quantum foam which makes up the background of space is literally pushed out of the way by the matter propagating through it, since two things (the particle and the foam) can not occupy the same precise location simultaneously, literally warping space-time in the process.