Question

why light is the fastest thing in universe

Answer 1

The best way to think about it is; there is a speed (C) that is the fastest speed and, by the way, light goes that fast. There’s nothing special about light, it’s just a useful way of describing C (“the speed of light”). Photons are just another podunk massless particle, whipping around the universe as fast as fast can be.
Historically, the derivation of the strange properties of C (relativity) relies on a pretty straight forward piece of Einsteinian logic, based in part on an understanding of light.

1) All the laws of physics work the same, whether you’re moving or not. There is no experiment that can tell you whether or not you’re moving.

2) Light is an electromagnetic wave, and the velocity of these waves can be derived from Maxwell’s laws.

3) Maxwell’s laws, like all physical laws, are independent of how fast you’re moving.

Answer 2

hi mate,

Tachyons is the fastest thing in the universe are hypothetical particles that travel faster than light.

I hope it helps you.