4 ms·

I believe (from my limited knowledge from Interstellar) that it’s the opposite: higher gravity environments move slower relative to lower gravity environments,

I believe (from my limited knowledge from Interstellar) that it’s the opposite: higher gravity environments move slower relative to lower gravity environments, which enabled the “go down to high gravity planet for a couple hours and come back and it’s ten years later” plot point in the movie. So if you’re in intergalactic space, time is actually passing very quickly in the higher gravity environment of a galaxy. But a person’s experience should always be the same, no matter what reference they are in. They will perceive time as passing at the same rate in all environments, but it will be different from people in other environments. Caveat: IANA physicist, and this is not physics advice.

umvi 6y ago
I don't think that is quite right. If you travelled near the speed of light and then slowed down again it would look (from your perspective) like you jumped 10 years into the future. So high gravity environments "moving slower" shouldn't result in a jump to the future upon exit. Instead I think what is happening is that massive objects actually stretch the fabric of spacetime somehow so that the closer you are to the object, the slower you travel through both space and time. And the more massive the object, the more stretched space and time become as you get closer to it. Hence if you go near a very massive object, from an outside observer it looks like you are frozen in time because time is so stretched it takes forever for you to move through it. As you mentioned though, from any given frame of reference time will always feel the same. 1 second will always feel like 1 second.
- vecter 6y ago
  > the slower you travel through both space and time No. You are always traveling at a constant velocity through spacetime. [0] Spacetime: https://en.wikipedia.org/wiki/Spacetime https://en.wikipedia.org/wiki/Spacetime
  - umvi 6y ago
    Ok then in that case I think of it as massive objects tend to compress space the closer you get to them. So though your velocity is constant, you are travelling through more space the closer you get to a massive object (since the space is now compressed) which means you are travelling through less time (in order to maintain same velocity).
kubanczyk 6y ago
> So if you’re in intergalactic space, time is actually passing very quickly in the higher gravity environment of a galaxy. Not "very". Look up the actual equation, it's a really easy one. AFAIR for a standard stellar black hole, you'd need to be within meters from the event horizon to get any substantial time difference. Thus the implication that Interstellar's Gargantua was an SMBH, i.e. probably the center of it's galaxy.

umvi 6y ago

I don't think that is quite right. If you travelled near the speed of light and then slowed down again it would look (from your perspective) like you jumped 10 years into the future. So high gravity environments "moving slower" shouldn't result in a jump to the future upon exit. Instead I think what is happening is that massive objects actually stretch the fabric of spacetime somehow so that the closer you are to the object, the slower you travel through both space and time. And the more massive the object, the more stretched space and time become as you get closer to it. Hence if you go near a very massive object, from an outside observer it looks like you are frozen in time because time is so stretched it takes forever for you to move through it. As you mentioned though, from any given frame of reference time will always feel the same. 1 second will always feel like 1 second.

vecter 6y ago
> the slower you travel through both space and time No. You are always traveling at a constant velocity through spacetime. [0] Spacetime: https://en.wikipedia.org/wiki/Spacetime https://en.wikipedia.org/wiki/Spacetime
- umvi 6y ago
  Ok then in that case I think of it as massive objects tend to compress space the closer you get to them. So though your velocity is constant, you are travelling through more space the closer you get to a massive object (since the space is now compressed) which means you are travelling through less time (in order to maintain same velocity).

kubanczyk 6y ago

> So if you’re in intergalactic space, time is actually passing very quickly in the higher gravity environment of a galaxy. Not "very". Look up the actual equation, it's a really easy one. AFAIR for a standard stellar black hole, you'd need to be within meters from the event horizon to get any substantial time difference. Thus the implication that Interstellar's Gargantua was an SMBH, i.e. probably the center of it's galaxy.