4 ms·

Anyone else finds the "real time" attribute hilarious in the context of these cosmic events ?

by NVHacker 2y ago

tekla 2y ago
No because light-speed is the speed of causality. It is by all definitions, real time
- mulhoon 2y ago
  You’ve just blown my mind.
  - yesbabyyes 2y ago
    Another mind-blowing perspective is from that of a single photon; since time slows when approaching c, from its perspective it's eternal, and, since distance shrinks when approaching c, from its perspective it's also omnipresent.
    - d1sxeyes 2y ago
      Well, it's not exactly eternal, it's that time is not passing for that photon. It's also (as far as I can tell) only correct to say that distances shrink as speed increases when you're talking about massive objects. A photon would not experience space contraction in any meaningful way.
    - ImHereToVote 2y ago
      By eternal you mean the photon will "experience" being a phonon when it's absorbed by matter?
- EncomLab 2y ago
  You are conflating reference frames - it determines causality in your local reference frame but not in any other reference frame. The concept of "real time" - like all time - is entirely relative to the reference frame you are using.
  - wruza 2y ago
    Correct, there's no global timeline, so it's not clear what "just" 300M years ago even means. Some RFs seen it already, and some will never see it. But in ours it happened in Jun 2024. It's 300M light years away, not ago.
    - mfranc42 2y ago
      But there is a global timeline. The age of the universe itself. It happened when the universe was roughly 300M years younger. Somebody might say the universe was created a year ago if they traveled through it extremely close to the speed of light. But we know how fast we travel by measuring redshift/blueshift of the cosmic microwave background and it's definitely far from any relativistic speed. There must be some effect of gravity, but that is also within a rounding error. So, I'd say we are much closer to the "truth" than somebody who travels through the universe a few percent of the speed of light or "lives" right next to the supermassive black hole. Whether something we will never see exists or happens is a philosophical question akin to "if a tree falls in the forest..."
      - mr_toad 2y ago
        But a distant observer could also make the same measurement of the CMW background and see themselves at rest. And yet we could be moving away from either other at relativistic velocities, due to the expansion of the universe. Due to this relative motion we will see different ordering of events at different locations, despite both being at rest relative to the CMW background, so we can’t really say there is a global timeline. The thing is that the CMW background isn’t global, we don’t see the same background as a distant observer. CMW photons that are passing us now will take time to reach a distant observer, and vice versa.
    - JamesHist 2y ago
      There is a global timeline. It is distorted, just like space.
BearOso 2y ago
At the center of the black hole, time has relatively stopped with respect to us. So, yes.
onetimeuse92304 2y ago
It is not hilarious, it is actually the correct use of the term. Otherwise, you would have to contend with the fact that "real time" does not exist at all, as information about any event has to necessarily take time to travel to reach you. So no "real time" coverage of anything -- the information always takes time to travel the distance. What is not a correct understanding of how time works is claiming that it happened some thousands of years ago. No, from our reference frame it happened now. It is meaningless to say that it happened thousands of years ago because it happened thousands of years ago in some other, arbitrary reference frame.
- yoav 2y ago
  You’re using reference frames incorrectly. It didn’t happen in real time, but they did observe in it real time. One is a measurement of the event and one is a measurement of when the photons reached us.
  - baq 2y ago
    we saw it happening in real time from here. does it even matter here that elsewhere sees it at a different time?
  - anyonecancode 2y ago
    This is why any faster-than-light travel must either be impossible or mean that that traveling backwards in time is possible. I point my telescope at a planet four light years away (I have super advanced telescope that can see these details), and use a worm-hole or other plot device to teleport instantly to that spot. Where do I arrive -- at what I observed, or at some point in empty space because I've just arrived at where that planet was four years ago? If the former, I must somehow have traveled back in time by four years to arrive at the spot I had observed. If the latter, I suppose we could instead say our destination is where we calculate the planet will be four years from now. Except that my travel time was instantaneous, so again either I've arrived too early and need to wait around for four years, or I jumped 4 years into the future (at which point that's not really FTL travel, just kind of stepping outside of time into some nether state for four years).
bamboozled 2y ago
Yeah, it's old news.
deleted 2y ago
[deleted]
insane_dreamer 2y ago
"as it unfolded" would be more accurate than "real time" Technically, one can argue that "real time" is relative to the time frame in which we observe something, but that's not how we generally use "real time", but rather we use it to define an event that is observed at the same moment (or very close to) the moment in which it occurs, such as a match broadcast live on TV (though there is some delay).
wruza 2y ago
We say that it happened in the past, using our wall clock ideas. But you can't rush there and look back to "see dinosaurs", so it's at least as correct to say that it happens in real time. This is an event, registering now in our reference frame. Nothing else provided.

Anyone else finds the "real time" attribute hilarious in the context of these cosmic events ?

tekla 2y ago

No because light-speed is the speed of causality. It is by all definitions, real time

mulhoon 2y ago
You’ve just blown my mind.
- yesbabyyes 2y ago
  Another mind-blowing perspective is from that of a single photon; since time slows when approaching c, from its perspective it's eternal, and, since distance shrinks when approaching c, from its perspective it's also omnipresent.
  - d1sxeyes 2y ago
    Well, it's not exactly eternal, it's that time is not passing for that photon. It's also (as far as I can tell) only correct to say that distances shrink as speed increases when you're talking about massive objects. A photon would not experience space contraction in any meaningful way.
  - ImHereToVote 2y ago
    By eternal you mean the photon will "experience" being a phonon when it's absorbed by matter?
EncomLab 2y ago
You are conflating reference frames - it determines causality in your local reference frame but not in any other reference frame. The concept of "real time" - like all time - is entirely relative to the reference frame you are using.
- wruza 2y ago
  Correct, there's no global timeline, so it's not clear what "just" 300M years ago even means. Some RFs seen it already, and some will never see it. But in ours it happened in Jun 2024. It's 300M light years away, not ago.
  - mfranc42 2y ago
    But there is a global timeline. The age of the universe itself. It happened when the universe was roughly 300M years younger. Somebody might say the universe was created a year ago if they traveled through it extremely close to the speed of light. But we know how fast we travel by measuring redshift/blueshift of the cosmic microwave background and it's definitely far from any relativistic speed. There must be some effect of gravity, but that is also within a rounding error. So, I'd say we are much closer to the "truth" than somebody who travels through the universe a few percent of the speed of light or "lives" right next to the supermassive black hole. Whether something we will never see exists or happens is a philosophical question akin to "if a tree falls in the forest..."
    - mr_toad 2y ago
      But a distant observer could also make the same measurement of the CMW background and see themselves at rest. And yet we could be moving away from either other at relativistic velocities, due to the expansion of the universe. Due to this relative motion we will see different ordering of events at different locations, despite both being at rest relative to the CMW background, so we can’t really say there is a global timeline. The thing is that the CMW background isn’t global, we don’t see the same background as a distant observer. CMW photons that are passing us now will take time to reach a distant observer, and vice versa.
  - JamesHist 2y ago
    There is a global timeline. It is distorted, just like space.

BearOso 2y ago

At the center of the black hole, time has relatively stopped with respect to us. So, yes.

onetimeuse92304 2y ago

It is not hilarious, it is actually the correct use of the term. Otherwise, you would have to contend with the fact that "real time" does not exist at all, as information about any event has to necessarily take time to travel to reach you. So no "real time" coverage of anything -- the information always takes time to travel the distance. What is not a correct understanding of how time works is claiming that it happened some thousands of years ago. No, from our reference frame it happened now. It is meaningless to say that it happened thousands of years ago because it happened thousands of years ago in some other, arbitrary reference frame.

yoav 2y ago
You’re using reference frames incorrectly. It didn’t happen in real time, but they did observe in it real time. One is a measurement of the event and one is a measurement of when the photons reached us.
- baq 2y ago
  we saw it happening in real time from here. does it even matter here that elsewhere sees it at a different time?
- anyonecancode 2y ago
  This is why any faster-than-light travel must either be impossible or mean that that traveling backwards in time is possible. I point my telescope at a planet four light years away (I have super advanced telescope that can see these details), and use a worm-hole or other plot device to teleport instantly to that spot. Where do I arrive -- at what I observed, or at some point in empty space because I've just arrived at where that planet was four years ago? If the former, I must somehow have traveled back in time by four years to arrive at the spot I had observed. If the latter, I suppose we could instead say our destination is where we calculate the planet will be four years from now. Except that my travel time was instantaneous, so again either I've arrived too early and need to wait around for four years, or I jumped 4 years into the future (at which point that's not really FTL travel, just kind of stepping outside of time into some nether state for four years).

bamboozled 2y ago

Yeah, it's old news.

deleted 2y ago

[deleted]

insane_dreamer 2y ago

"as it unfolded" would be more accurate than "real time" Technically, one can argue that "real time" is relative to the time frame in which we observe something, but that's not how we generally use "real time", but rather we use it to define an event that is observed at the same moment (or very close to) the moment in which it occurs, such as a match broadcast live on TV (though there is some delay).

wruza 2y ago

We say that it happened in the past, using our wall clock ideas. But you can't rush there and look back to "see dinosaurs", so it's at least as correct to say that it happens in real time. This is an event, registering now in our reference frame. Nothing else provided.