If light doesn’t experience time, how does it have a limited speed?
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We don’t know. We have no idea why the speed of light (the speed of causality really) is what it is. We are pretty certain our physical law would work just as well no matter what the speed of light is, but things might seem different if we were in that world, especially if lightspeed was “everyday speed” slow.
What we do know is that this speed limit is the only speed massless particles (without rest mass) can travel, and that at that speed, time doesn’t pass. It’s as if the speed of causality/speed of light is a combination of movement in space and time – move faster through space, you move slower through time, and when you’ve reached the speed limit, there’s no more time left to move through.
It is impossible to say anything meaningful about what light experiences. We’re the ones observing the speed of light, not the light itself.
Even without special relativity speed can only be measured by someone else, from your own point of view you’re always stationary.
Because everything moves through spacetime at the speed of light and photons are a bit of a special case. Right now sitting there reading this, you’re moving at the speed of light. It’s just all in the time direction, so instead of perceiving it as motion in meters per second, you perceive it as moving through time at one second per second. For a photon experiencing no time, it must have all of it’s motion in space and travels at the speed of light.
The speed that light travels is basically the “refresh rate” of the universe. It’s not that light itself is limited by some kind of speed limit. It’s simply the speed at which ANY information is passed along inside the universe. It’s like cosmic download speed that can’t be exceeded. Anything that happens in one part of the universe requires X amount of time to transmit that information to another part of the universe.
Your question doesn’t really make sense. When we talk about experiencing time, or speed, we need to clarify relative to what. Light, or anything moving at c, doesn’t have a valid reference frame making this comparison impossible.
Light moves at the speed of causality. This is the fastest speed something can move and affect something else. So light, like everything else, is limited by the speed of causality but since it has 0 mass it moves at the speed of causality which we generally just call the speed of light.
Edit: Typo
There is no such statement of “limited speed” ever made.
The correct and more baffling statement is that it has a constant speed in reference to the observer. Or in other words, the speed seems to be the same in all directions, no matter if you are already moving or not.
It is as if reality becomes non linear with movement.
Because we’re not measuring the speed of light from the viewpoint of the light itself, but from an outside observer.
Life, the Universe, and Everything happens at the speed of Reality. We used to call it the speed of light, but now we realize it’s really the “Speed of Reality.” Nothing happens faster than that. We’re not sure why, it might just be the fabric of the universe, for which we have some nifty equations you can learn about when you’re older than 5.
I think it’s easier to think of it this way: for some reason the universe has a speed limit, nothing can move faster than it. So light is just moving at the maximum speed the rules of our universe allow.
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