ASTRONOMY 1021 September 21 , 2010
Astronomy – Lecture 2
DISTANCES, SIZES AND TIME IN THE UNIVERSE…
The Big Picture:
o Look at the “Big Picture” of the Universe.
What is the Solar System, the Milky Way, The Local Group, Galaxy Cluster?
How big are things, how far apart? How and where does Earth fit in?
What sort of timescales are appropriate?
o We won’t really explain how we know all that—we’ll save that for the remaining lectures.
Setting the stage for the rest of the course.
o Be able to estimate and visualize sizes and distances in the Earth-Moon-Sun system and beyond
using scale models.
o Express astronomical distances using light tr