4 ms·

From a philosophical point of view, an event happens at the point when observed by an observer. For us, Humans on earth, this supernova happens now and not 120

by tegeek 5y ago

From a philosophical point of view, an event happens at the point when observed by an observer. For us, Humans on earth, this supernova happens now and not 120 million years ago.

LegitShady 5y ago
I think even philosophy can withstand knowing the speed of light and incorporating it into the framework of 'when things happened' so that it agrees with our understanding of the universe instead of not.
awb 5y ago
I don’t think that’s right. If a tree falls in a forest and we stumbled upon it today, I don’t think philosophy says that the tree fell today. I think it says we found a fallen tree today. The supernova didn’t happen today, we found evidence of it today.
- CamperBob2 5y ago
  Minkowski spacetime confuses matters, though. From the point of view of the photon we observe, no time elapses between its emission at the location being observed and its arrival at the telescope image sensor. It's as if the photon were born in exactly the right place and time to be observed by us, at that very instant. So what we see is arguably happening in real time, regardless of distance.
  - deleted 5y ago
    [deleted]
  - andreareina 5y ago
    Ehh. The measurement is happening in real time but we have well-defined ways to say when the event happened, and that's 120MY ago (given the reference frame where Earth is motionless).
    - mr_mitm 5y ago
      Depends on what you mean by "real time". If by "real time" you mean "the spacetime interval between the event 'supernova explodes' and 'explosion observed on earth' is lightlike (or null)", then we witnessed it in real time. I can't think of any other definition that is observer independent. I also argue that it is not well-defined, as the time span depends on the observer, as you say. Did it happen 120MY ago or 1MY ago? Both can be true for different observers, and none is privileged over the other.
      - CamperBob2 5y ago
        Did it happen 120MY ago or 1MY ago? Both can be true for different observers, and none is privileged over the other. Great way to put it.
- spindle 5y ago
  > I don’t think philosophy says I'm a professional philosopher, and I and 100% of my colleagues agree with you.
BurningFrog 5y ago
There are many philosophical points if view thought.
- analog31 5y ago
  Indeed, and some of them are inertial reference frames. ;-)
asxd 5y ago
Say you were immortal and witnessed a supernova from a million light-years away. Eventually, after another million years have passed, you meet another immortal who happened to be right next to the supernova when it happened. When talking to this other immortal, would you refer to the event as happening two million years ago (when you witnessed it), or three million years ago (when the other immortal witnessed it)?

by tegeek 5y ago

From a philosophical point of view, an event happens at the point when observed by an observer. For us, Humans on earth, this supernova happens now and not 120 million years ago.

LegitShady 5y ago

I think even philosophy can withstand knowing the speed of light and incorporating it into the framework of 'when things happened' so that it agrees with our understanding of the universe instead of not.

awb 5y ago

I don’t think that’s right. If a tree falls in a forest and we stumbled upon it today, I don’t think philosophy says that the tree fell today. I think it says we found a fallen tree today. The supernova didn’t happen today, we found evidence of it today.

CamperBob2 5y ago
Minkowski spacetime confuses matters, though. From the point of view of the photon we observe, no time elapses between its emission at the location being observed and its arrival at the telescope image sensor. It's as if the photon were born in exactly the right place and time to be observed by us, at that very instant. So what we see is arguably happening in real time, regardless of distance.
- deleted 5y ago
  [deleted]
- andreareina 5y ago
  Ehh. The measurement is happening in real time but we have well-defined ways to say when the event happened, and that's 120MY ago (given the reference frame where Earth is motionless).
  - mr_mitm 5y ago
    Depends on what you mean by "real time". If by "real time" you mean "the spacetime interval between the event 'supernova explodes' and 'explosion observed on earth' is lightlike (or null)", then we witnessed it in real time. I can't think of any other definition that is observer independent. I also argue that it is not well-defined, as the time span depends on the observer, as you say. Did it happen 120MY ago or 1MY ago? Both can be true for different observers, and none is privileged over the other.
    - CamperBob2 5y ago
      Did it happen 120MY ago or 1MY ago? Both can be true for different observers, and none is privileged over the other. Great way to put it.
spindle 5y ago
> I don’t think philosophy says I'm a professional philosopher, and I and 100% of my colleagues agree with you.

BurningFrog 5y ago

There are many philosophical points if view thought.

analog31 5y ago
Indeed, and some of them are inertial reference frames. ;-)

asxd 5y ago

Say you were immortal and witnessed a supernova from a million light-years away. Eventually, after another million years have passed, you meet another immortal who happened to be right next to the supernova when it happened. When talking to this other immortal, would you refer to the event as happening two million years ago (when you witnessed it), or three million years ago (when the other immortal witnessed it)?