Astronomy and Cosmology

3705 topics in this forum

1. Where Does Space End? It Must End Somewhere! 1 2 3 4 41

   By Edisonian, October 6, 2004
   • 1k replies
   • 344.6k views
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   • hypervalent_iodine
   • November 24, 2016

2. A question about spacetravel

   By Kriss3d, November 21, 2016
   • 5 replies
   • 1.3k views
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   • Kriss3d
   • November 22, 2016

3. Riddle me this...

   By Butch, November 17, 2016
   • 10 replies
   • 1.6k views
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   • imatfaal
   • November 20, 2016

4. Strange Stars

   By DrmDoc, November 17, 2016
   • 6 replies
   • 1.1k views
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   • Mordred
   • November 18, 2016

5. Help with entropy, arrow of time & things created from the vacuum

   By Jmanm, November 16, 2016
   • 8 replies
   • 1.6k views
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   • Mordred
   • November 17, 2016

6. Theoretically, could the universe have a center? 1 2

   By Sandro, October 13, 2016
   • 31 replies
   • 3.3k views
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   • Strange
   • November 17, 2016

7. Martian Aurora: to see or not to see?

   By GeeKay, November 16, 2016
   • 1 reply
   • 1k views
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   • Butch
   • November 17, 2016

8. how close a fit to LambdaCDM?

   By substitutematerials, October 30, 2016
   • 9 replies
   • 2.1k views
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   • Mordred
   • November 9, 2016

9. I need a 3D map of the universe out to 400 ly...suggestions?

   By rrw4rusty, October 31, 2016
   • 4 replies
   • 1.8k views
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   • Sensei
   • November 3, 2016

10. Astrospheres: the missing catalog and a proposal to make one

    By Jayson, October 30, 2016
    • 10 replies
    • 1.6k views
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    • Jayson
    • October 30, 2016

11. The rotation curve problem

    By Muser, October 26, 2016
    • 1 reply
    • 1.1k views
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    • swansont
    • October 26, 2016

12. we are in early stage of big bang ,,and there would be a black whole in center of universe

    By qasimchef, October 22, 2016
    • 5 replies
    • 1.4k views
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    • Phi for All
    • October 23, 2016

13. why there is no water om moon if,,,, it is aftermath of collision between earth and theia

    By qasimchef, October 22, 2016
    • 2 replies
    • 884 views
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    • Ophiolite
    • October 22, 2016

14. Could we detect an intrinsic change in the flow of time? 1 2

    By substitutematerials, October 17, 2016
    • 37 replies
    • 3k views
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    • koti
    • October 21, 2016

15. Anti-Space 1 2

    By æτhεr φ, August 11, 2010
    • 30 replies
    • 13.9k views
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    • swansont
    • October 21, 2016

16. New universe? (split from could the universe have a center)

    By geordief, October 14, 2016
    • 13 replies
    • 1.4k views
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    • geordief
    • October 18, 2016

17. The expanding Universe 1 2

    By Gian, September 7, 2016
    • 30 replies
    • 4.1k views
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    • Ivanov2000
    • October 10, 2016

18. Why You Can't See Stars on the Moon ?

    By Captain Silver, October 8, 2016
    • 3 replies
    • 1k views
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    • Strange
    • October 9, 2016

19. Gravity Waves

    By Ivanov2000, October 7, 2016
    • 8 replies
    • 1.6k views
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    • Mordred
    • October 9, 2016

20. Gravity Hypothesis

    By Raxsus, July 25, 2016
    • 7 replies
    • 1.6k views
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    • Ivanov2000
    • October 7, 2016

21. High energy gamma ray "magic" project

    By fred2014, October 3, 2016
    • 2 replies
    • 1.2k views
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    • fred2014
    • October 4, 2016

22. 1 gram solar sail project

    By fred2014, September 26, 2016
    • 7 replies
    • 1.5k views
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    • fred2014
    • October 3, 2016

23. Why don't you see stars in NASA space pics. of Earth?

    By ulrichburke, September 29, 2016
    • 6 replies
    • 1.1k views
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    • StringJunky
    • October 2, 2016

24. Arguable definition for the beginning of the universe?

    By Genecks, September 28, 2016
    • 2 replies
    • 1.1k views
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    • ajb
    • September 29, 2016

25. Nature of a straight line in curved space

    By Atom Man, September 24, 2016
    • 2 replies
    • 959 views
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    • pavelcherepan
    • September 29, 2016