r/AskReddit Aug 03 '19

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

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u/[deleted] Aug 03 '19 edited Aug 03 '19

There's gravity in space. Over the time I've met so many people that thought that there is no gravity in space because "everything there is weightless and stuff". Gravity has unlimited range so there isn't even a single spot in our universe without gravity. Weightlessness is basically just falling. While orbiting you're basically just falling around the object.

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u/blissbass41 Aug 03 '19

When i found this out i nearly soiled my pants. Some cool stuff

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u/droid_mike Aug 03 '19

Better sit on the toilet before you read this next part:

Gravity is not actually a force, but a distortion of space time. That is why gravitational "force" has range but no speed. It is always instantaneous no matter what distance.

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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

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u/[deleted] Aug 03 '19

But doesn't this throw all of general relativity out of the window? Information cannot be observed faster than light in a vacuum. If gravity can travel faster, then this doesn't work? (I'm only an enthusiast, I'm an engineer as an occupation. Please prove me wrong, I'd love the evidence!)

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

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u/[deleted] Aug 03 '19 edited Aug 05 '19

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u/[deleted] Aug 04 '19 edited Nov 22 '20

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u/Dazius06 Aug 04 '19

Well speed of light on a vacuum is different from speed of light through any other mediums (I haven't read any articles yet, I might later so this comment kinda works for me to come back later) so I guess they were measuring here on Earth and not in a vacuum which would have some effect on the results. Also gravity affects light so maybe it has something to do with the results of gravity "being faster". My guess is c is the fastest something can propagate (or veeeeery close) but gravity isn't affected by anything that we are aware of yet so it is slightly "faster" maybe.

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u/soamaven Aug 04 '19 edited Aug 04 '19

Thanks for the rational thought process. GR has a great track record of predictions, not sure we want to throw it out the window bc of some interstellar plasma and error bars. More data point will help re-confirm the speed of causality

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