Why/how is light the fastest thing in the universe and nothing else can be faster?

Question

Why have we ruled out the possibility of finding something faster when we’ve only scratched the surface of space exploration and understanding?

In: 144

Answer 1

Actually, it’s not like there can not be a thing faster than light.
This is an additional assumption on top of an Einstein General Relativity theory.
That theory (that so far we have no evidence to think it’s not correct), does put a limit of a speed that any object with a mass can reach.
In simplification, the faster an object goes, the more energy it’s need to accelerate it further, and the light speed is a limit, where You will need infinite energy to achieve that speed.
But the value of the limit (~300k m/s) is not coming from the theory, theory only says there is “some” limit, actual value comes from real world measurements.

For the same reason, objects that don’t have a mass (like photons, that are the “light particles”), have to travel with this speed all the time.

But, interesting fact now, the theory didn’t exclude objects with speed greater than a limit (light speed), we just don’t observe such things in our world, so we make an additional assumption for the Einstein Theory that those objects faster than light doesn’t exist.
And if those objects exist, they have to obey the same limit, but from “opposite side”, I mean, in that case, slowing down the object will require energy, and slowing it to a speed of light, will require infinite energy.

And also very important things to know is if we do not exclude those objects, their existence will have huge impact on how we understand world and modern physic.
Because of the space-time nature, and how it behaves, those objects have to break the Causation Law. Basically, it will be looked like those objects travel back in time in a sense, so for them the result comes first, and the cause of that result comes later, in reverse order compared to all objects that travel with a lower speed of light.

If You interested in a topic, I recommend to watch Andrzej Dragan series about General Relativity:
[https://www.youtube.com/@relaTVty/playlists](https://www.youtube.com/@relaTVty/playlists)
It’s pretty ELI5, for a such difficult subject like General Relativity.