We have known for some time that the universe is expanding, and that its expansion is accelerating. But how do we know that? We'll show you how Edwin Hubble revealed that the universe is getting away from us.
One of the biggest shocks, when studying science history, is much our view of the universe has changed in the last century. Less than a hundred years ago, brilliant and educated astronomers were still debating whether or not the Milky Way made up the entire universe. A decade after that, we still sure that the universe was at a steady state. Then we thought it was expanding, but would eventually collapse or slow to a standstill. Now we see that the universe is undergoing ever accelerating expansion. But how did astronomers look out at a sea of bright dots and come to these conclusions?