ask a physicist

[freyar]

Could Sigil (a small torus-shaped universe with gravity pulling toward the "walls" of the universe) exist with those physical laws? Can it be modeled mathematically?

Generally speaking, general relativity allows any sort of universe you want, but the trick is that you have to figure out what sort of matter/energy distribution would give that shape to the universe. I'm not sure that a toroidal universe like Sigil (with a boundary) is something that can easily be made with normal matter, but we've talked a lot about wormholes and warp drive spacetimes that require exotic matter/energy anyway.

 

[Scott DeWar]

A funny thing

Its me . . . . .again. This time it is not a question. This time it is a funny thing i saw on a web comic. "Eye candy ffor Christmas" If you will.

http://xkcd.com/1621/

Enjoy, laugh, even chastise me if you need. Bet enjoy the day regardless!

 

[tomBitonti]

Successful detection of gravity waves!

This just in:

Science Magazine: Gravitational waves, Einstein’s ripples in spacetime, spotted for first time

http://www.sciencemag.org/news/2016...nstein-s-ripples-spacetime-spotted-first-time

Washington Post: Cosmic breakthrough: Physicists detect gravitational waves from violent black-hole merger

https://www.washingtonpost.com/news...ational-waves-from-violent-black-hole-merger/

Haven't had a chance to read either article yet.

Cheers!
TomB

 

[freyar]

This just in:

Science Magazine: Gravitational waves, Einstein’s ripples in spacetime, spotted for first time

http://www.sciencemag.org/news/2016...nstein-s-ripples-spacetime-spotted-first-time

Washington Post: Cosmic breakthrough: Physicists detect gravitational waves from violent black-hole merger

https://www.washingtonpost.com/news...ational-waves-from-violent-black-hole-merger/

Haven't had a chance to read either article yet.

Cheers!
TomB

Yes! Very big news, though the press is missing that we've observed gravitational waves indirectly for a long time. Still, extremely exciting and long anticipated!! I noticed you have a thread in the Misc Geek Talk forum, so I'll discuss there mostly.