# How can light travel at speed of light? [duplicate]

I am well aware that the speed of light is a universal constant at which nothing but light can travel.

But why? Why can even light travel at such a speed?

Our maths tell us that anything with rest mass takes infinite energy to reach speed of light, so do we just mean that light is the lightest of all things and it can reach speed of light with negligible energy?

Why isn't the speed constant which appears not only as speed of light, but various other places like GR etc something even more than speed of light?

Why can light reach the speed of light?

I think my question was highly misinterpreted, my question has nothing to do with mass of light. My question is why is the speed limit that appears universally equal to speed of light, why isn't even light allowed to reach the universal speed limit?

Yes after that I did ask, the reason for light reaching the highest possible speed. Whether it is it's unusually less mass(mass-less) or something else.

So to summarize my question is : 1. Why anything at all can reach the top speed limit, why is even light permitted to reach the top speed limit? 2. Why light can reach the top speed? (Only this part is related to the question whose duplicate my question is marked)

• Note that (1) any other massless particle must also travel at $c$ and (2) that light does not "reach" $c$, it simply has that speed. – dmckee --- ex-moderator kitten Sep 2 '14 at 2:23
• Note dmckee's comment that photon's don't reach the speed of light, it always has that speed. – Kyle Kanos Sep 3 '14 at 14:02
• I think "reach" was a poor choice of word on my front, I did not at all meant reaching "c" as in from 0 to "c" I meant just having a certain speed. – Rijul Gupta Sep 3 '14 at 14:05
• This is still a duplicate, just of another question. (I've linked the most helpful answer, in my opinion) – ACuriousMind Sep 3 '14 at 15:04