Episode 206 - The Beginning of Time

In the 1920s there was an astronomical event known as the Great Debate about the structure of the universe. The debate ended pretty inconclusively and didn't really settle the question. A measurement taken by Edwin Hubble in 1924, he found a star in the Andromeda Nebula that he could measure the distance to. Later, it was discovered that the Andromeda Galaxy is around two and a half million light years away.