4 ms·

It seemed that the pulse jumped for about an hour. Obviously this happened thousands of years ago, but would that be a literal hour? How much time is lost/ben

It seemed that the pulse jumped for about an hour. Obviously this happened thousands of years ago, but would that be a literal hour? How much time is lost/bent in transit?

Sir_Cmpwn 7y ago
Over the years of asking these kinds of questions myself, I've come to realize that this line of questioning betrays a fundamental lack of understanding of spacetime. Time is relative. From our perspective it might have happened a thousand years ago, but from alpha cen's perspective it happened at a slightly different time. There is no universal clock. Even the order in which events take place depends on your reference frame. So, it just happened, and the light took about 26,700 years to reach us, assuming nothing happened to it on the way (which is a bad assumption, even just because there's a lot of stuff between here and there, but especially considering it originated from a severely warped spacetime).
delecti 7y ago
We're moving around it, but we aren't moving very fast (relative to c), and our relative distance from it isn't changing much. The duration shouldn't be much different despite the distance.
- dooglius 7y ago
  Wouldn't time dialation around the black hole be very extreme? As in, from the perspective of just outside the black hole where the flare presumably started, it would have lasted only a very brief amount of time.
  - deleted 7y ago
    [deleted]
  - Retric 7y ago
    Bright long lasting events like this are extremely unlikely to occur every close to the event horizon. https://en.m.wikipedia.org/wiki/Innermost_stable_circular_orbit https://en.m.wikipedia.org/wiki/Innermost_stable_circular_or...
- rattray 7y ago
  > The duration shouldn't be much different Does that mean, same duration within nanoseconds? milliseconds? seconds? minutes?
  - delecti 7y ago
    It doesn't sound like you're asking in good faith, but I'll answer anyway. It was "a couple hours", so without doing too much more math than that, it was probably the same duration here and there within "a couple minutes". I'm more than comfortable calling that the "same" duration in conversational terms, but I would expect it's not the same duration within nanoseconds, as we're accelerating relative to Sgr.A* (rotationally).
    - rattray 7y ago
      I was asking of curiosity – thank you for sating it! I'm not familiar with spacetime, and was curious for a sense of scale here. A couple of minutes difference sounds quite significant to me (though I agree I'd conversationally call it "about the same").
      - delecti 7y ago
        My mistake, it just sounded confrontational. But yes, space is way more enormous than most people (including myself) can wrap their head around. Spacetime warping is also hard to really get, I understand it conceptually but I can't really picture it. Things moving less than about 15% of the speed of light experience less than 1% time dilation, and for comparison, we're moving around the center of the galaxy at 0.2% of the speed of light. One of the wildest things to me is that GPS satellites have to compensate for time moving slightly slower because they're moving so fast around the earth, and also time moving slightly faster because they're further from the gravity of earth.
- krasin 7y ago
  That makes an assumption that the flare was unidirectional. If it's a beam, it could be that Earth was in the beam for an hour, but its duration is anything (like, 1M years)
  - toxicFork 7y ago
    This is something awesome to consider. Perhaps we only passed through the beam. Perhaps the beam itself was rotating.
  - SiempreViernes 7y ago
    The beam would have to be godlike collimated to make any of the relevant velocities enough to take us trough it in a few hours. Things that far away just don't move fast.
deleted 7y ago
[deleted]

It seemed that the pulse jumped for about an hour. Obviously this happened thousands of years ago, but would that be a literal hour? How much time is lost/bent in transit?

Sir_Cmpwn 7y ago

Over the years of asking these kinds of questions myself, I've come to realize that this line of questioning betrays a fundamental lack of understanding of spacetime. Time is relative. From our perspective it might have happened a thousand years ago, but from alpha cen's perspective it happened at a slightly different time. There is no universal clock. Even the order in which events take place depends on your reference frame. So, it just happened, and the light took about 26,700 years to reach us, assuming nothing happened to it on the way (which is a bad assumption, even just because there's a lot of stuff between here and there, but especially considering it originated from a severely warped spacetime).

delecti 7y ago

We're moving around it, but we aren't moving very fast (relative to c), and our relative distance from it isn't changing much. The duration shouldn't be much different despite the distance.

dooglius 7y ago
Wouldn't time dialation around the black hole be very extreme? As in, from the perspective of just outside the black hole where the flare presumably started, it would have lasted only a very brief amount of time.
- deleted 7y ago
  [deleted]
- Retric 7y ago
  Bright long lasting events like this are extremely unlikely to occur every close to the event horizon. https://en.m.wikipedia.org/wiki/Innermost_stable_circular_orbit https://en.m.wikipedia.org/wiki/Innermost_stable_circular_or...
rattray 7y ago
> The duration shouldn't be much different Does that mean, same duration within nanoseconds? milliseconds? seconds? minutes?
- delecti 7y ago
  It doesn't sound like you're asking in good faith, but I'll answer anyway. It was "a couple hours", so without doing too much more math than that, it was probably the same duration here and there within "a couple minutes". I'm more than comfortable calling that the "same" duration in conversational terms, but I would expect it's not the same duration within nanoseconds, as we're accelerating relative to Sgr.A* (rotationally).
  - rattray 7y ago
    I was asking of curiosity – thank you for sating it! I'm not familiar with spacetime, and was curious for a sense of scale here. A couple of minutes difference sounds quite significant to me (though I agree I'd conversationally call it "about the same").
    - delecti 7y ago
      My mistake, it just sounded confrontational. But yes, space is way more enormous than most people (including myself) can wrap their head around. Spacetime warping is also hard to really get, I understand it conceptually but I can't really picture it. Things moving less than about 15% of the speed of light experience less than 1% time dilation, and for comparison, we're moving around the center of the galaxy at 0.2% of the speed of light. One of the wildest things to me is that GPS satellites have to compensate for time moving slightly slower because they're moving so fast around the earth, and also time moving slightly faster because they're further from the gravity of earth.
krasin 7y ago
That makes an assumption that the flare was unidirectional. If it's a beam, it could be that Earth was in the beam for an hour, but its duration is anything (like, 1M years)
- toxicFork 7y ago
  This is something awesome to consider. Perhaps we only passed through the beam. Perhaps the beam itself was rotating.
- SiempreViernes 7y ago
  The beam would have to be godlike collimated to make any of the relevant velocities enough to take us trough it in a few hours. Things that far away just don't move fast.

deleted 7y ago

[deleted]