Astronomy and Cosmology

3689 topics in this forum

1. Spacecraft Depressurization question

   By Guest MetroCognit, September 6, 2004
   • 15 replies
   • 5.1k views
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   • swansont
   • September 9, 2004

2. James Webb Telescope and L2 Orbit Question 1 2 3

   By exchemist, December 30, 2021
   • 55 replies
   • 5.1k views
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   • Airbrush
   • February 10, 2022

3. Is there such thing as infinite speed? 1 2

   By needimprovement, September 30, 2010
   • 26 replies
   • 5.1k views
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   • newworldphysics
   • November 1, 2010

4. Entropy and the Big Bang 1 2

   By theIndigoVervet, June 19, 2011
   • 34 replies
   • 5.1k views
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   • pantheory
   • July 11, 2011

5. Near Earth Asteroid Moon Hit...what would happen?

   By RichF, July 2, 2006
   • 8 replies
   • 5.1k views
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   • RichF
   • July 9, 2006

6. Time can't exist without matter (mass) and motion 1 2

   By Lakshya, October 26, 2007
   • 42 replies
   • 5.1k views
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   • Eric 5
   • December 24, 2007

7. Does Gravity reduce Entropy ?

   By Widdekind, August 9, 2010
   • 12 replies
   • 5k views
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   • Widdekind
   • December 3, 2010

8. Similarities and differences between the Universe and Black Holes. 1 2

   By Mr Skeptic, June 9, 2010
   • 34 replies
   • 5k views
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   • xxSilverPhinxx
   • July 12, 2011

9. This speculative SpaceX timeline reveals roughly when, where, and how Elon Musk plans to colonise Mars 1 2 3

   By beecee, October 15, 2018
   • 53 replies
   • 5k views
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   • beecee
   • October 24, 2018

10. my Moon Pictures. 1 2

    By YT2095, October 12, 2008
    • 25 replies
    • 5k views
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    • Syntho-sis
    • June 9, 2009

11. Big Bang and only 14 billion years? 1 2

    By Jiggerj, February 15, 2012
    • 40 replies
    • 5k views
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    • Phi for All
    • February 19, 2012

12. Universe always expands??? 1 2

    By Pradeepkumar, August 13, 2008
    • 40 replies
    • 4.9k views
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    • Martin
    • September 2, 2008

13. What is constant alpha? 1 2

    By ccwebb, February 17, 2014
    • 29 replies
    • 4.9k views
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    • Strange
    • February 25, 2014

14. New mass creation 1 2

    By David Levy, February 20, 2016
    • 40 replies
    • 4.9k views
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    • David Levy
    • February 27, 2016

15. A way to simulate gravity perfectly in the space station 1 2

    By Hypercube, April 28, 2008
    • 39 replies
    • 4.9k views
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    • Joegocal
    • June 8, 2008

16. How did planets end up orbiting the sun?

    By Arjun Artro, December 7, 2012
    • 16 replies
    • 4.9k views
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    • ox1111
    • December 23, 2012

17. What elements, minerals, or just molecules do star forming ' MOLECULAR GAS CLOUDS' contain , as they start a Star Birth? 1 2

    By Mike Smith Cosmos, November 17, 2015
    • 42 replies
    • 4.9k views
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    • Mike Smith Cosmos
    • November 30, 2015

18. Center of the Universe? 1 2

    By blike, July 19, 2002
    • 41 replies
    • 4.9k views
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    • Martin
    • June 16, 2004

19. Is nuclear fusion powering the sun technically just a theory?

    By Fanghur, October 31, 2009
    • 15 replies
    • 4.9k views
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    • bascule
    • November 2, 2009

20. Antimatter 1 2

    By ydoaPs, August 23, 2004
    • 42 replies
    • 4.9k views
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    • Edisonian
    • September 29, 2004

21. Quibbles with the balloon analogy

    By michel123456, January 8, 2010
    • 22 replies
    • 4.9k views
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    • J.C.MacSwell
    • May 28, 2010

22. How are super-massive stars formed?

    By EWyatt, April 14, 2012
    • 22 replies
    • 4.8k views
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    • a_lexios
    • August 14, 2013

23. end of a neutron stars life?

    By space noob, May 19, 2012
    • 3 replies
    • 4.8k views
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    • insane_alien
    • May 20, 2012

24. How awesome are Black Holes?? 1 2

    By Mastermold, February 1, 2003
    • 40 replies
    • 4.8k views
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    • Radical Edward
    • April 17, 2003

25. Dark Matter (Anti-Matter) 1 2

    By RedShift1121, May 3, 2011
    • 27 replies
    • 4.8k views
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    • Spyman
    • May 18, 2011