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?

In: Physics

25 Answers

Anonymous 0 Comments

Your motion relative to the CMB is probably the most important factor in what “now” is. I base this on my degree in theoretical physics from the university of Youtube.

Edit: Hat tip PBS Space Time

Anonymous 0 Comments

Colonel Sandurz: Now. You’re looking at now, sir. Everything that happens now, is happening now.
Dark Helmet: What happened to then?
Colonel Sandurz: We passed then.
Dark Helmet: When?
Colonel Sandurz: Just now. We’re at now now.
Dark Helmet: Go back to then.
Colonel Sandurz: When?
Dark Helmet: Now.
Colonel Sandurz: Now?
Dark Helmet: Now.
Colonel Sandurz: I can’t.
Dark Helmet: Why?
Colonel Sandurz: We missed it.
Dark Helmet: When?
Colonel Sandurz: Just now.
Dark Helmet: When will then be now?
Colonel Sandurz: Soon.
Dark Helmet: How soon?

Anonymous 0 Comments

Yes, except relativity.

If you define your ‘now’ loosely to fit within speed of light delays, then it is. You and the person on the other side of the earth will agree to the current time within 0.043 seconds, which is the time it takes light to travel one earth diameter. If you want more than that, then Einstein’s General and Special Relativity come into play, which state that each ‘reference frame’ has its own definition of ‘now’

Anonymous 0 Comments

Nope, the brain has processing time, and we all live in the past. Read/write on your brain is weirder than you think as well, and it’s trash at remembering things correctly

Anonymous 0 Comments

The idea of “now” for you, ‘mathematically’ (logically) is different from the idea of “now” for someone on the other side of the room. It isn’t much more noticeable for someone on the other side of the world than that. It depends more on *how fast they/you are moving* than your relative physical position, but it is *still* negligible until your/their relative velocity increases to a substantial fraction of the speed of light. And anyone circling around the center of the Earth farther away is necessarily traveling faster than someone who is doing so closer to that center point. This is why people reference astronauts, although the actual difference is mere seconds accumulated over days, weeks, and months. Since they travel through space faster than you do, they travel slower through time, so technically they are in your past (what would be your past if you were in their present/presence) and you are in their future (likewise), but are also experiencing the same present we do (just from a different perspective), so those terms aren’t a good way to think about it.