5 ms·

Or had collided in the year 222 :)

cyberferret 10y ago
This is the "time travel" aspect of astronomy that I find extremely fascinating. I was just talking to my young sons the other day as we were watching the sunset that we are seeing something that happened 8 minutes ago. Cool to see them trying to get their young brains around this concept...
- daveguy 10y ago
  The sunset you were seeing didn't happen 8 minutes ago. Sunsets are an interaction of the sun with your perspective position on earth and line of sight. The sunset was happening right then -- the light that was involved in the sunset had been emitted from the sun 8 minutes ago. The last blip of the light you saw disappear over the horizon was a view of a corner of the sun from 8 minutes ago, but the sunset was happening essentially at that moment. </pedantic>
  - troels 10y ago
    You're missing an opening tag.
    - Nuzzerino 10y ago
      Its similar to this, where typically no opening tag is provided. https://www.google.com/amp/s/madfileformatscience.garymcgath.com/2011/12/07/sarcasm-tag/amp/?client=ms-android-verizon https://www.google.com/amp/s/madfileformatscience.garymcgath...
itsbits 10y ago
considering it is thousands of light years off us, it's probably like before humans exists..
- cyberferret 10y ago
  Approximately 1800 light years away, therefore he is right, if it collided in our year 222AD (well within existence of humanity), then it would appear in our skies in 2022 (ish).
Achshar 10y ago
Since speed of light is the defaco speed of everything and hence reality itself, it's for all intents and purposes yet to happen even if technically it's already happened. That's kinda how relativity works, if it hasn't happened for us, it hasn't really happened.
- euyyn 10y ago
  > Since speed of light is the defacto speed of everything and hence reality itself This is false, and so is the rest of that reasoning.
  - Achshar 10y ago
    In what sense? If we can't reach some specific space/time coordinate, it's for all intents and purposes unreachable.
    - euyyn 10y ago
      Well, the speed of light isn't the speed of anything with mass. The rest is only indirectly connected to that. The collision did already happen, from our frame of reference. Its light arriving to us will be just a confirmation. From some other frame of reference (one moving very fast in the line that joins Earth and the collision), it might not have happened yet.

This is the "time travel" aspect of astronomy that I find extremely fascinating. I was just talking to my young sons the other day as we were watching the sunset that we are seeing something that happened 8 minutes ago. Cool to see them trying to get their young brains around this concept...

daveguy 10y ago
The sunset you were seeing didn't happen 8 minutes ago. Sunsets are an interaction of the sun with your perspective position on earth and line of sight. The sunset was happening right then -- the light that was involved in the sunset had been emitted from the sun 8 minutes ago. The last blip of the light you saw disappear over the horizon was a view of a corner of the sun from 8 minutes ago, but the sunset was happening essentially at that moment. </pedantic>
- troels 10y ago
  You're missing an opening tag.
  - Nuzzerino 10y ago
    Its similar to this, where typically no opening tag is provided. https://www.google.com/amp/s/madfileformatscience.garymcgath.com/2011/12/07/sarcasm-tag/amp/?client=ms-android-verizon https://www.google.com/amp/s/madfileformatscience.garymcgath...

itsbits 10y ago

considering it is thousands of light years off us, it's probably like before humans exists..

cyberferret 10y ago
Approximately 1800 light years away, therefore he is right, if it collided in our year 222AD (well within existence of humanity), then it would appear in our skies in 2022 (ish).

Achshar 10y ago

Since speed of light is the defaco speed of everything and hence reality itself, it's for all intents and purposes yet to happen even if technically it's already happened. That's kinda how relativity works, if it hasn't happened for us, it hasn't really happened.

euyyn 10y ago
> Since speed of light is the defacto speed of everything and hence reality itself This is false, and so is the rest of that reasoning.
- Achshar 10y ago
  In what sense? If we can't reach some specific space/time coordinate, it's for all intents and purposes unreachable.
  - euyyn 10y ago
    Well, the speed of light isn't the speed of anything with mass. The rest is only indirectly connected to that. The collision did already happen, from our frame of reference. Its light arriving to us will be just a confirmation. From some other frame of reference (one moving very fast in the line that joins Earth and the collision), it might not have happened yet.