If a photon does not experience time and exists in its full trajectory at a given instant, how does it “perceive” a body moving to cut its path?

Question

OK maybe ELI12 would do.

In: Physics

Answer 1

Don’t take the analogy and GR thought experiment of the photon not “experiencing time” too far. Photons don’t experience _anything_, they don’t. An object moving at the speed of light can still run into something, quite obviously. It still moves from point A to point B, and that takes a very finite amount of time.

IF you were a photon moving at the speed of light, you’d perceive the rest of the universe passing by in an instant because of the exponential nature of the Lotentz curve which dictates the effect of time dilation on a moving object. However, you’re not, and you don’t, and you can’t, and massless photons aren’t conscious.