2. There was no "before" the beginning of our universe, because once upon a time there was no time. * John D. Barrow
I don't pretend to understand the Universe--it's a great deal bigger than I am. * Thomas Carlyle
A universe that came from nothing in the big bang will disappear into nothing at the big crunch. Its glorious few zillion years of existence not even a memory. * Paul Davies
Anyone informed that the universe is expanding and contracting in pulsations of eighty billion years has a right to ask, "What's in it for me?" * Peter De Vries Nothing puzzles me more than the time and space; and yet nothing troubles me less. * Charles Lamb
Quotes

3. Milky Way Galaxy

5. The Milky Way Galaxy: Vital Statistics
Diameter - 100,000 light years
Thickness (Nucleus) - 20,000 light years
Thickness (Disc) - 2,000 light years
Number of Stars - 200,000,000,000
Age - 15,000,000,000 years

10. The Halo

11. The Disk

12. The Core

14. Elliptical Galaxies 1/3 of all galaxies
Giant Ellipticals are the size of our galaxy but are rare
Dwarf Ellipticals are more common (6000 light yrs across)
Riesen-E

15. Spiral Galaxies
Largest fraction of galaxies
Andromeda

16. Barred Spiral Galaxy
NGC-1365

17. Irregulars
Large Magellanic Cloud

18. Galaxies form groups or Clusters
Coma Cluster

22. IMPORTANT
Milky Way Data
Galaxy Classification
Galaxy Clusters

23. NEXT TIME:
SPECIAL THEORY