Gravity doughnut may solve time travel problem

  • #1
Ivan Seeking
Staff Emeritus
Science Advisor
Gold Member
8,010
1,010
"Gravity doughnut" may solve time travel problem

One of the major difficulties of traveling backwards in time has just been solved, according to an Israeli theoretical physicist. And the solution, he says, is doughnut-shaped...

...This is where Amos Ori from Technion, the Israel Institute of Technology in Haifa, comes in. He says that according to Einstein's theories, space can be twisted enough to create a local gravity field that looks like a doughnut of some arbitrary size. The gravitational field lines circle around the outside of this doughnut, so that space and time are both tightly curved back on themselves. Crucially, this does away with the need for any hypothetical exotic matter. [continued]
http://www.nature.com/news/2005/050711/full/050711-4.html
 

Answers and Replies

  • #2
George Jones
Staff Emeritus
Science Advisor
Gold Member
7,599
1,477
The arXiv version is here.

Regards,
George
 
  • #3
Chronos
Science Advisor
Gold Member
11,435
747
Ori is captivated by the concept of self-interacting gravitational fields, which I do not find very interesting. It's the sort of unobserved 'ultraviolet catastrophe' that signals an incomplete theory.
 
  • #4
pervect
Staff Emeritus
Science Advisor
Insights Author
10,178
1,342
This is still interesting, because according to the author it does get around Hawking's chronology protection result (Phys. Rev. D46 (1992) 603).
 

Suggested for: Gravity doughnut may solve time travel problem

Replies
10
Views
188
  • Last Post
Replies
12
Views
406
  • Last Post
Replies
2
Views
314
Replies
95
Views
3K
Replies
3
Views
497
  • Last Post
Replies
19
Views
1K
  • Last Post
Replies
7
Views
696
Replies
8
Views
450
  • Last Post
Replies
15
Views
1K
  • Last Post
Replies
10
Views
684
Top