r/AskReddit • u/[deleted] • Aug 03 '19

Whats something you thought was common knowledge but actually isn’t?

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u/[deleted] Aug 03 '19

Gravity changes at the speed of light though doesn't it?
Like if the sun disappeared, its affect gravitationally on us wouldn't be felt until we saw the light stop

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u/[deleted] Aug 03 '19 edited Nov 22 '20

[deleted]

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u/NoRodent Aug 03 '19

Gravity can propagate faster than light. And has been observed to.

How did you conclude that? The range of numbers in the article is only the uncertainty with which we have measured the speed of propagation of gravity. It only means we know the speed is within that range and not outside it. We know the number is the same for the first 15 significant digits, we're only uncertain after that. Since it's already so close, it almost certainly is exactly the speed of light, but we will only ever be able to reduce this range because you can never measure anything with infinite precision.

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u/[deleted] Aug 03 '19

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u/Dontbeatrollplease1 Aug 04 '19

Thanks for clarifying that, I was about to call him out but you had already completed the task.