Thread: How do scientists prove that light lives billions of years?

How do scientists prove that light lives billions of years?

not sure if it's ever been proven as in mathematical proof, but is there any reason to assume otherwise ?

after all, if the initial assumption is that light does not decay (unless it's absorbed, obviously), and all calculations based on that assumption give sensible results, the Occam's razor says that there is no need for alternative assumptions

We can never prove anything in science, only disprove it. However, as marnix says, all the observations and all the theory suggest and confirm that light lasts unless interacting with matter.

Originally Posted by Attiyah Zahdeh

How do scientists prove that light lives billions of years?

They never have "proved" anything of the kind. Light is not alive.

mind you, it's an interesting thought, decaying light, it's just that there's no evidence for it

Let me then pose another question on this matter...

If time does not pass for a photon, why does it decay? Shouldn't the photon be eternally in the state that it is?

why does it decay

Well, it doesn't. According to current theory (the standard model), photons are a fundamental particle, that is, it cannot be reduced to constituent parts. It is the ultimate final stage of all energy as far as I know. For example in a matter-antimatter annihilation the mass is converted directly into pure energy according to E=mC², which manifests as photons.

Sorry, I posed my question incorrectly. What I meant to ask was: "why is it absorbed by electrons”.
If time doesn’t pass for them, then there shouldn’t be a “time before”, neither a “time after”…