This morning the teachers were talking about the way that the universe expanding, and what we see as galaxies move away from us. A standard analogy is to think about baking a loaf of bread with raisins. As the bread bakes, and rises, each raisin moves away from each other since the bread expands.
check out http://hyperphysics.phy-astr.gsu.edu/ for a more full explanation.
I saw the video below some time ago, I think it helps to see this idea of expansion a little more clearly (you can stop watching at 11:25).
No comments