[raducu]

How can two photons collide? Aren't photons force carriers/bosons?

[eigenhombre]

Yes, photons are bosons / force carriers, but they interact with charged particles, and in this case produce e+ e- pairs via this Feynman diagram [1]. By rotating the diagram in spacetime, you get different known interactions: pair production (this topic), pair annihilation (same diagram running the other way in time), and, if memory serves, Compton scattering.

[1] https://en.wikipedia.org/wiki/Two-photon_physics#/media/File...

[bee_rider]

"Rotate the diagram in spacetime" would make for some top-tier technobabble (not expressing doubt that it is a real thing, just wow, it sounds so cool).

[coldtea]

Well, "rotating the diagram in spacetime" is also exactly what you do when you move your hands while holding the printout of a diagram...

(In this case though it's about rotating what's shown in the diagram, that is the interactions pictured, not the diagram itself :-))

[vanderZwan]

This is as deliciously anti-climactic as finding out what "non-Euclidean space" means after hearing it a lot in Cthulu-like horror settings

[raducu]

Ok, so high enough energy photons fluctuating to other particle/antiparticles and then being able to interact with other high enough photons is an explanation I'm willing to settle for, because I thought that multiple bosons can occupy the same space, thus they were not able to interact with each other, by the "boson" definition.

It's still blows my mind that a photon could do that -- turn into a particle-antiparticle pair, the pair then quickly gets annihilated and turns back into the same photon and continues in the exact same direction and form the initial photon was travelling.

But if this process is real, does it mean that high energy photons travel slower than low energy photons?

Because low energy photons could not transform into particles that have mass, while higher energy photons could and thus spend just a liiiiiiitle bit more time as massive particles that can't travel at the speed of light.

[dr_dshiv]

So, can photons interact and produce matter without particles to interact with?

[BizarroLand]

One of the consequences of E=MC^2 is that there is a strong implication that energy can be converted directly into energy and vice versa.

Photons, although mass-less, have energy and can therefore be converted into matter under some circumstances.

[adamc]

I think you mean "directly into matter".

[BizarroLand]

Yes. Thank you!

Apparently my well intentioned ramblings can be directly converted into brain farts.

[api]

I’ve always understood photons as being “stuff” in it’s all energy no mass state.

What is “stuff” as all matter no energy?

[BizarroLand]

Probably any matter at absolute 0 would qualify? I think otherwise all mass has some excess of energy in it, I could be wrong.

Alternatively, possibly dark matter would qualify, although I am not sure either as we haven't even proven that it exists.

[BizarroLand]

Wait, no, I was wrong. Matter and Energy are the same thing. Only nothing has no energy or matter.