In the grand body of the universe and even our own solar system the speed of light is incredibly slow on the cosmic scale. Why does it have this speed limit ? It is theoretically possible to go faster than light ? Or is light just the fastest thing we have observed thus far ?
In: 1092
In ELI5 terms:
* Light has no mass. Imagine hitting a ball with a baseball with a fixed strength. If it’s a bowling ball, it won’t move much. If it’s a baseball ball, it’ll move some far away. If it’s a golf ball (lighter, smaller), it’ll move much farther. So the lighter it is, the further it goes. How far does it go if it has 0 weight? That’s light, the 0-weight ball that you hit.
* But it doesn’t go at infinite speed. In space (vacuum), it looks pretty empty but it’s still not empty. There’s what is called “vacuum energy”, think of it as a very, very light version of air. Only, it doesn’t have resistance in the classic sense, it doesn’t “slow down over time” the ball, but it’s still the key to understand this.
* So the light speed can be calculated through two variables that are intrinsically related to this “vacuum energy”, the electric constant ε_0 and the magnetic constant μ_0. They are like how dense air is, but for space. It’s a constant through the galaxy, and it determines the fixed speed of light.
Latest Answers