Factoring 'Time' into Astronomic Observations
April 9, 2006 11:17 PM Subscribe
AskMeFi Physics folk: How do astronomers account for the temporal distinctiveness of their galactic subjects in their calculations?
I understand that observations of the red shift of quasars delinates a speed increase in the expansion of the universe - yet my brain explodes when I try to understand how the enormous expanse of time
is factored into these models.
posted by 0bvious to science & nature (12 answers total)
The hardest concepts for me to conceive are ones that factor the enormous AGE of the universe into their workings. I understand that by observing quasar red shift and comparing it to the shift of 'nearby' galaxies astronomers have determined that universe expansion is actually increasing. Surely though the fact that these quasar entities exist 'back in time' alters the nature of the data streaming from them? The photons of light astronomers gather in their observations have not just travelled great distances of space, but also great expanses of time, yet when the light was first emitted from these 'distant' objects their distinction in space was not as great as it is now (i.e. when the universe was smaller) a weird conflict indeed... This is where I reach the event horizon of my understanding.
Why doesn't the time aspect completely alter the nature of evidence gathered? Working with data that comes from billions of years hence must make calculations incredibly obscure.
In what ways is this temporality a help and a hinderance? How are the factors of time, space and motion / change plotted to form the model?