- #1
Rob Haskell
- 11
- 0
Greetings - We speak of astronomical objects as being x number of light years away, which is also a statement about the age of the data. So our knowledge of M83, for example, is about 15 million years old, etc, etc. I'm just wondering why there never seems to be any attempt to move this information forward to the current state of the universe. Presumably we could? Since the universe is expanding, what does it really mean to say that M83 is 15 million ly away? At what point in time was this true? Is it true now? Or is this quandary already built into the calculation? Stated another way: just because the light left M83 15 million years ago, it does not mean that M83 is still in that same location. Of course, it is isn't. So... where is it, and how distant? Or maybe I've got this all mixed up...
Cheers,
Cheers,