Look up at night -- not from Cleveland (or any other city for that matter). We see a faint band of light overhead: the Milky Way
Using a telescope, the Milky Way can be
(Milky Way from KPNO)
Let's "unwrap" the sky and make a map. What do we see?
Mellinger's Milky Way Panorama page. There's a newer,
beautifully interactive version as well.
Immanuel Kant proposes that the Galaxy
is a disk of stars (including our Sun)
1785: Wiliam Herschel uses star count data to map the Milky Way. He assumes: