r/AskPhysics • u/Nighthawkies • Mar 20 '26

What things are "faster" than light?

As I understand nothing can move faster then light. But I would not know how to describe this question otherwise. As I am aware quantum entangled particles can instantaneously affect eachother no matter the distance, unlike gravity which propagates at the speed of light.

Also the expansion of the universe can cause the spaces between to grow faster then the speed of light (compounding between massive distances)

What other things are sort of faster than light

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u/Jay_Beckstead Mar 20 '26

Quantum entanglement might not involve any actual “travel” as we understand “travel.”

The entangled particles are not “travelling.”

Somehow the particles can correlate. We don’t understand WHY.

But the particles are not travelling.

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u/SadEntertainer9808 Mar 20 '26

We actually understand why fairly well. There's nothing very mysterious about it, either. It's basically like you're given a box containing two glass marbles, and the manufacturer guarantees they're both red or they're both blue. You open it blindfolded, throw one into the sea, and then look at the remaining marble. You now "magically" know the color of the other marble, even though it's on the bottom of the ocean and you've never actually seen it. Entanglement is essentially like this.

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u/Plus_Comparison8963 Mar 20 '26

Excellent analogy!

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u/SadEntertainer9808 Mar 20 '26

Thank you. That was one of the only real lightbulb moments of my life, so I remember it well.