Astronomy and Cosmology

3591 topics in this forum

1. Cosmological redshift, thought experiment

   By Genady, January 16
   • 18 replies
   • 330 views
   • 
   • MigL
   • January 18

2. Is it easy to shade the Earth for cooling? 1 2

   By Kevin_Hall, January 6
   • 26 replies
   • 707 views
   • 
   • mistermack
   • January 8

3. Start of time ?

   By Genady, January 4
   • 9 replies
   • 346 views
   • 
   • Markus Hanke
   • January 6

4. Rocket fuel

   By Kevin_Hall, January 4
   • 8 replies
   • 351 views
   • 
   • Ken Fabian
   • January 6

5. What is the mechanism for SPACE EXPANSION ?

   By Marius, January 2
   • 15 replies
   • 566 views
   • 
   • Phi for All
   • January 5

6. Does space have mass ? If not, how does it accelerate ?

   By Marius, January 4
   • 20 replies
   • 449 views
   • 
   • swansont
   • January 5

7. "Our space is curved" 1 2

   By Genady, January 2
   • 33 replies
   • 659 views
   • 
   • Genady
   • January 3

8. The Universe's First Molecule Found:

   By beecee, January 3
   • 4 replies
   • 232 views
   • 
   • exchemist
   • January 3

9. What is the mechanism for the BIG BANG ?

   By Marius, January 3
   • 13 replies
   • 357 views
   • 
   • Ghideon
   • January 3

10. Happy New Year, astronauts!

    By Kevin_Hall, December 31, 2021
    • 0 replies
    • 168 views
    • 
    • Kevin_Hall
    • December 31, 2021

11. Dark Matter:

    By beecee, December 18, 2021
    • 6 replies
    • 362 views
    • 
    • MigL
    • December 23, 2021

12. Could the real size of the universe be infinite? 1 2 3

    By Strange Me, July 7, 2021
    • 71 replies
    • 3.1k views
    • 
    • skydelph
    • December 8, 2021

13. Do black holes have a centre?

    By geordief, December 2, 2021
    • 22 replies
    • 596 views
    • 
    • MigL
    • December 8, 2021

14. Naturally occurring elements heavier than U ?

    By Airbrush, November 12, 2021
    • 6 replies
    • 896 views
    • 
    • skydelph
    • December 3, 2021

15. If the sun were to go red giant wouldn't it cause all planets to move as well?

    By inbreeding, September 14, 2021
    • 9 replies
    • 577 views
    • 
    • Kevin_Hall
    • December 3, 2021

16. Atmosphere of Venus (split from An absolutely bonkers plan to give Mars an artificial magnetosphere)

    By Bufofrog, November 22, 2021
    • 6 replies
    • 337 views
    • 
    • swansont
    • November 23, 2021

17. Gravity wells determine orbital plane? 1 2

    By DeckerdSmeckerd, November 18, 2021
    • 35 replies
    • 1k views
    • 
    • Ghideon
    • November 22, 2021

18. Alone again?

    By geordief, November 21, 2021
    • 8 replies
    • 369 views
    • 
    • geordief
    • November 22, 2021

19. Oumuamua - mathematical question

    By DeckerdSmeckerd, November 14, 2021
    • 22 replies
    • 600 views
    • 
    • DeckerdSmeckerd
    • November 16, 2021

20. Some (Interested Layman's) "What if?"-Questions Regarding Neutron Stars

    By Godot, November 10, 2021
    • 10 replies
    • 475 views
    • 
    • beecee
    • November 13, 2021

21. What is correct calculation for Moon's brightness?

    By Jurassic Park, August 23, 2021
    • 5 replies
    • 520 views
    • 
    • Solon
    • November 12, 2021

22. Augmented Solar Sail. Would this work?

    By mistermack, October 31, 2021
    • 12 replies
    • 577 views
    • 
    • mistermack
    • November 8, 2021

23. Universal expansion and Black Hole Growth:

    By beecee, November 3, 2021
    • 1 reply
    • 317 views
    • 
    • beecee
    • November 4, 2021

24. Travelling faster than light

    By FindingMeaning, October 29, 2021
    • 1 reply
    • 244 views
    • 
    • swansont
    • October 29, 2021

25. ISS space station orbit – calculation discrepancy

    By ravell, October 25, 2021
    • 0 replies
    • 210 views
    • 
    • ravell
    • October 25, 2021