Astronomy and Cosmology

3713 topics in this forum

1. How can the universe be infinite in size? 1 2 3

   By Airbrush, December 17, 2012
   • 52 replies
   • 8.2k views
   • 
   • Spyman
   • January 14, 2013

2. Curvature of universe

   By NaxAlpha, January 12, 2013
   • 3 replies
   • 1.2k views
   • 
   • elfmotat
   • January 12, 2013

3. Why are early objects so massive?

   By DarkStar8, January 8, 2013
   • 2 replies
   • 866 views
   • 
   • Arch2008
   • January 9, 2013

4. How can the Universe not be infinite in size?

   By Selectrick, January 4, 2013
   • 2 replies
   • 833 views
   • 
   • imatfaal
   • January 7, 2013

5. Do all stars have "Oort Clouds" ??

   By Widdekind, June 2, 2010
   • 16 replies
   • 15.2k views
   • 
   • JohnStu
   • January 6, 2013

6. Universe expansion 1 2 3 4

   By justinater22, December 3, 2012
   • 91 replies
   • 12.9k views
   • 
   • swansont
   • January 4, 2013

7. Apparent lack of expansion of the universe

   By Jdizz, December 31, 2012
   • 1 reply
   • 1.7k views
   • 
   • swansont
   • December 31, 2012

8. More Kepler Missions?

   By Airbrush, December 29, 2012
   • 0 replies
   • 818 views
   • 
   • Airbrush
   • December 29, 2012

9. If the Earth stopped spinning, would half the world..

   By InNeedOfHelp, December 28, 2012
   • 2 replies
   • 969 views
   • 
   • Bill Angel
   • December 28, 2012

10. Expanding Space Questions

    By Jeremy Mallin, December 26, 2012
    • 6 replies
    • 1.8k views
    • 
    • StringJunky
    • December 27, 2012

11. How did planets end up orbiting the sun?

    By Arjun Artro, December 7, 2012
    • 16 replies
    • 5.3k views
    • 
    • ox1111
    • December 23, 2012

12. Long space journeys; Solar radiation shielding

    By 25Hz, December 4, 2012
    • 6 replies
    • 1.8k views
    • 
    • mr.spaceman
    • December 22, 2012

13. explaining Jet Brightness / Power relation ?

    By Widdekind, December 17, 2012
    • 0 replies
    • 2.4k views
    • 
    • Widdekind
    • December 17, 2012

14. Octopole and Quadrupole planes w.r.t. CMBR?

    By cohen990, December 13, 2012
    • 1 reply
    • 903 views
    • 
    • ajb
    • December 15, 2012

15. Detecting rotation speed of Galaxies

    By mr.spaceman, December 14, 2012
    • 2 replies
    • 1.3k views
    • 
    • mr.spaceman
    • December 14, 2012

16. Looking for references

    By justinater22, December 5, 2012
    • 2 replies
    • 1.1k views
    • 
    • elnetrino
    • December 12, 2012

17. cosmic density perturbations grow with time ?

    By Widdekind, December 11, 2012
    • 0 replies
    • 720 views
    • 
    • Widdekind
    • December 11, 2012

18. Cosmic Recombination occurred when ?

    By Widdekind, November 24, 2012
    • 3 replies
    • 1.7k views
    • 
    • Widdekind
    • December 11, 2012

19. Is this one way to make a planet?

    By alpha2cen, December 7, 2012
    • 10 replies
    • 1.7k views
    • 
    • ACG52
    • December 8, 2012

20. What if Cosmic Structure ceased expanding?

    By Widdekind, December 1, 2012
    • 2 replies
    • 1.3k views
    • 
    • Widdekind
    • December 7, 2012

21. a couple questions about stars

    By brandoncotten, December 5, 2012
    • 14 replies
    • 2.6k views
    • 
    • mathematic
    • December 5, 2012

22. What exactly is Gravity? 1 2

    By Arjun Artro, November 30, 2012
    • 27 replies
    • 5k views
    • 
    • juanrga
    • December 5, 2012

23. Shape of the universe

    By FunkyAce07, August 12, 2012
    • 15 replies
    • 5k views
    • 
    • justinater22
    • December 5, 2012

24. Trying to understand Primordial Black holes

    By justinater22, December 2, 2012
    • 7 replies
    • 1.5k views
    • 
    • justinater22
    • December 4, 2012

25. Black holes and spin

    By Moontanman, November 28, 2012
    • 3 replies
    • 1.7k views
    • 
    • Airbrush
    • December 4, 2012