Eli5: Why does light travel so fast?
In: 130
[Everything](https://i.stack.imgur.com/4xBUV.gif) moves though spacetime at c, that is the speed of causality. It’s just that all the massive things(electrons, protons, people, planets etc) move some in direction of time, light moves only in spatial directions and doesn’t experience time. That’s why a photon can just continue going from big bang up until the heat death of the universe, it can’t decay, because it doesn’t even move in time direction.
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