How to Measure the Expansion of the Universe

There's no edge to the universe even from our vantage point or any vantage point. So you can't just kind of like look out in one direction and see how far apart the edges of the universe are. What we have to do since there isn't like a ruler laid out for us is we have to find rulers. And so those are the basic ideas is to like try to put down some measuring points where we can look back in time and see how things have changed.