Eli5: Why does light travel so fast?
In: 130
If you push on something, it starts to move, right?
If you push on it 2x as hard, it starts to move 2x as fast, right? *Wrong*.
In essence, we’ve learned the thing only travels something like 1.99999999x as fast, somehow energy is going missing.
Using Einstein’s math, we learned the missing energy is somehow getting “absorbed” by the object and getting turned into mass, meaning the object doesn’t get pushed as easily as it did a moment ago, which is why it only goes 1.9999x now, not 2.
Extending this math out, and this bit gets confusing, we learn that since objects get “heavier” the faster they move, and also that they get “heavier” faster than they accelerate, if that made sense to you, it means that an object gets heavier faster than you can accelerate it, ultimately you can’t push an object any faster. It would take literally an infinite amount of energy to push the object even one teensy bit faster. So that becomes a Galactic Speed Limit, and that speed is a massive number so we just call it “C” for short.
Now all of the above only applies to physical objects, objects with Mass. No object with mass can ever travel at speed C, or faster, C is the limit.
Light though, in this context, light is pure energy and does not have mass, so it is uniquely capable of traveling at exactly C. Even light can’t go beyond C, but it can travel at C.
So it’s less accurate to call C “the speed of light” and more accurate to call it “the maximum speed possible, which only light is capable of traveling”. It’s sort of a chicken vs the egg thing.
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