Is “Now”, for me, mathematically the same as “Now” for people on the other side of the world?

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I have only a very vague awareness of the idea of relativity but I’m aware that there’s a concept that people in orbit experience less time than those on the planet due to gravity, in some way.

Does this mean that the idea of “now”, as in a moment that is right now, is marginally different for people in other places? Are they experiencing a moment that is in my objective future/past, in a mathematical sense?

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Anonymous 0 Comments

Mathematics does not describe reality so it’s not really a mathematics question. It gives you tools to examine and predict reality, but does not tell you what reality is.

“Now” doesn’t really mean much aside of your own typically consistent’ish perception of time. You can’t, in any manner whatsoever, instantly tell anyone else that now is your now, not even theoretically, as the speed of light limits your ability to convey such information.

You also can not possibly know what’s happening somewhere else right now. You could make predictions, sometimes very good ones, but still, it’s just predictions.

But if you do apply some math, you can create a consistent understanding with others about when something happened to you, albeit how long ago it was in your perception might still be different than in someone else’s perception. E.g. to you something might have happened 5 hours ago and to them it was 10 hours ago.

The concept of “now” is not really something that physics defines, so.. No, you can’t say we all experience a now now.

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