Background 7

Now I would like to pause and give you an idea of an amateur astronomer’s view of the universe before Hubble’s discovery in 1923. Pretend for a moment that you are this astronomer. You look up into the night sky and you see a bunch of dots. You can look at them with your telescope and you can measure the distance to some of them by measuring their stellar parallax (basically what you did in your geometry class when you measured the height of a building by the length of its shadow and the time of day) When you see how far away most of the stars are you find that they all fall within a certain range. So you conclude this is how big your neighborhood is. What lies outside this neighborhood? Maybe other, stars maybe not. All you know is that you can’t see them. They named our neighborhood (aka all the stars you can see) the milky way. There are some weird looking things, blobs and oblong shapes, but they are all pretty fuzzy and you don’t know much about them. There was this one guy named Charles Messier composed a list of all the fuzzy blobs so that you didn’t have to worry about them. Life was good.