From candles to ladders: how astronomers measure very large distances in the universe
From candles to ladders: how astronomers measure very large distances in the universe How do we know the universe is expanding? Your high school trigonometry is involved in the process. Ever wondered how scientists know the distance to planets, stars, galaxies? Or even better, how to measure the universe’s size and its expansion? Well, they certainly don’t have a giant ruler, but they have other tools — including “candles” and “ladders”. The Parallax and 1 parsec = 3.26 light-ye...
Source: zmescience.com