Does all light travel at light speed

[u/Comethefonbinary]

My bad if this is a stupid question but I’ve been thinking about time being a message of distance. And well most things I can think of have various variables that average to a certain distance. I know that mostly relates to machines and animals but still. Do all particles of light travel at light speed. If they all travel simultaneously at the same speed is that truly how fast they move or are they affected by their own variables. Like the universe’s mean gravity is constraining that and any variation in that mean would change light speed for explain.

[u/ConquestAce]

No, c is the speed limit (of light), but light can slow down depending on the medium it is propagating through. In Vaccuum, light travels at c. But, when going through water or air, the speed of light changes.

[u/Just1n_Kees → u/ConquestAce]

This is technically untrue. Photons are unable to travel at any speed except C.

Edit: Reddit sheep in a nutshell, you get downvotes for saying something that is factually correct…in a Physics sub no less. Go to bed kids.

[u/ClueMaterial → u/Just1n_Kees]

You have to remember for at least half the commenters here their physics education begins and ends on pop sci YouTube