Astronomers

2. /helped create the OBAFGKM classification and classified about 350,000 stars
4. /proposed the Special Theory of Relativity and to extend this theory made the General Theory of Relativity
6. /the man who discovered Uranus
8. /classified the type of stars by relating their color to their absolute brightness.
11. /made the star magnitude scale (still used today)
12. / Wrote about how the light from the Moon is reflection from the sun

1. /these two guys discovered the cosmic microwave radiation stemming from the Big Bang
3. /the guy to be burned at the stake
5. /proved the Earth is spherical
7. /measured the circumference of the Earth by using geometry
9. /played a crucial role in establishing the field of extra-galactic astronomy, was also the first to show the universe was expanding
10. /the first to suggest the Sun was the center of the Universe