"eyelessgame" wrote in message
om...
"John Honan" wrote in message
...
Taking the current position and structure of say, the Andromeda Galaxy,
attempt to create a forecasted image of what it actually looks like at
the
moment in terms of its structure, and what its 'real' position in the
sky is
(how that has changed over the course of 2 million years)

Again, not much. It's a hundred thousand light years across, but the
stars in it only move at hundreds of miles per second, whereas light
travels at almost two hundred thousand miles per second. So it
doesn't change much at the scale we're talking about.


You're right. I did some rough calculations today basing the speed of light
on 300,000Km/s, and the speed of the stars moving at 100km/s, the diameter
of Andromeda is 200,000 light years, and Amdromeda is 2,000,000 light years
away from us.

In the course of 2,000,000 years, a star in Andromeda will only have moved
1/300th of the way across the galaxy. (As you pointed out, not much change
at the scale we're talking about)

Thanks for the feedback.

John.