Astronomy and Cosmology

3686 topics in this forum

1. Universe is 156 billion LY across

   By Realitycheck, March 2, 2008
   • 12 replies
   • 1.5k views
   • 
   • jackson33
   • March 13, 2008

2. Universe Maps

   By eaknarak, November 5, 2011
   • 1 reply
   • 951 views
   • 
   • granpa
   • November 6, 2011

3. Universe mass?

   By alpha2cen, December 28, 2010
   • 7 replies
   • 1.3k views
   • 
   • alpha2cen
   • January 4, 2011

4. Universe Might be Bigger and Older than Expected

   By darkangel199, August 7, 2006
   • 7 replies
   • 1.6k views
   • 
   • Martin
   • August 11, 2006

5. Universe originally Solid Mass?

   By mustang292, March 20, 2005
   • 1 reply
   • 787 views
   • 
   • Ophiolite
   • March 20, 2005

6. universe using faces to kill shock

   By iwasbitten, June 30, 2012
   • 1 reply
   • 1.4k views
   • 
   • Klaynos
   • June 30, 2012

7. Universe--A Moment in Time

   By B. John Jones, June 23, 2016
   • 5 replies
   • 1.1k views
   • 
   • swansont
   • June 23, 2016

8. Universe, past, probable inference, Arch's argument

   By Martin, August 26, 2008
   • 6 replies
   • 1.3k views
   • 
   • Arch2008
   • August 28, 2008

9. Universes Density

   By ShaneJ, June 5, 2013
   • 1 reply
   • 967 views
   • 
   • Royston
   • June 6, 2013

10. Universes Not With Different Versions, But Locations

    By jhcrue, December 19, 2014
    • 6 replies
    • 1.3k views
    • 
    • Phi for All
    • October 14, 2015

11. Universes outside the universe

    By barbie.=^.^=, April 13, 2008
    • 19 replies
    • 2.6k views
    • 
    • Arch2008
    • July 3, 2008

12. univgeometry

    By infoseeker, January 6, 2005
    • 7 replies
    • 1.2k views
    • 
    • infoseeker
    • January 7, 2005

13. Unknown Spectral Lines in Sunlight

    By EdEarl, March 19, 2015
    • 18 replies
    • 2.2k views
    • 
    • John Cuthber
    • March 19, 2015

14. Unruh Radiation

    By Quetzalcoatl, November 4, 2015
    • 7 replies
    • 1.6k views
    • 
    • Quetzalcoatl
    • November 10, 2015

15. Unusual surface feature on dwarf planet Pluto

    By instigator, September 8, 2011
    • 6 replies
    • 1.8k views
    • 
    • Realitycheck
    • September 13, 2011

16. Upper limit on star mass

    By luc, February 4, 2005
    • 3 replies
    • 1.2k views
    • 
    • Martin
    • February 6, 2005

17. Ursa Major

    By us.2u, December 8, 2004
    • 4 replies
    • 998 views
    • 
    • us.2u
    • December 8, 2004

18. us satellites outnumber the rest!

    By chitrangda, September 24, 2006
    • 12 replies
    • 1.6k views
    • 
    • Klaynos
    • October 1, 2006

19. Usable Energy After Big Crunch

    By LucidDreamer, October 7, 2005
    • 1 reply
    • 810 views
    • 
    • Xyph
    • October 7, 2005

20. use earth as Gravity-Wave detector ??

    By Widdekind, September 27, 2012
    • 3 replies
    • 903 views
    • 
    • Widdekind
    • September 28, 2012

21. Use of time dilation by advanced alien civilization

    By Nerexis, July 20, 2016
    • 3 replies
    • 1.3k views
    • 
    • swansont
    • July 21, 2016

22. Using Kepler's laws to find out various things about binary star systems

    By QuantumPerihelion, January 24, 2017
    • 5 replies
    • 1.2k views
    • 
    • Janus
    • January 25, 2017

23. Utilizing Gravity for Space Travel

    By kenel, July 20, 2002
    • 17 replies
    • 2.8k views
    • 
    • Klaynos
    • November 16, 2008

24. Vacumm and Sound

    By Guest Suzz, March 6, 2004
    • 8 replies
    • 1.7k views
    • 
    • Fluent in Lies
    • March 29, 2004

25. Vacuum decay theory questions

    By Bmpbmp1975, February 18, 2020
    • 15 replies
    • 1.2k views
    • 
    • Phi for All
    • February 18, 2020