- sunspots are cooler than the surrounding solar envelope by about 2000K
- sunspots are associated with magnetic fields (via Zeeman splitting)
- some planetary nebula are actually outside the milky way galaxy, including M31 (Andromeda galaxy)
- most other galaxies are receding from ours at a rate proportional to their distance, indicating that at some time in the past the universe was much hotter and denser
All fairly amazing things! From 1908 until 1948 it had the largest telescopes in the world. And as any astronomer can tell you, the number of discoveries is proportional to the size of the telescope. And, to some extent, the skill of the astronomer.
At length it was time to rewind the climb, dodging bitey flies, lizards, a small blue rodent, and a few errant deer until, within site of the carpark I removed my shoes and walked the last mile or so barefoot. Then back home, shower, dinner, and out to a movie with friends.
Legs are STILL not sore, but at least the rest of me was pretty tired. Photos are here: https://picasaweb.google.com/CaseyHandmer/MtWilson
And a video of waterfalls from Yosemite is here: http://www.youtube.com/watch?v=HlRZdrZHH6o