The Naked Scientists

The Naked Scientists Forum

Author Topic: Is it true that light can orbit a black hole?  (Read 1355 times)

Offline Merccooper

  • Jr. Member
  • **
  • Posts: 11
    • View Profile
Is it true that light can orbit a black hole?
« on: 24/02/2015 16:22:10 »
I read that light can orbit a black hole just outside the event horizon. Is this true?
If it is true and light orbits for a long enough time, would you be able to look behind you and see yourself in the past?


 

Offline PmbPhy

  • Neilep Level Member
  • ******
  • Posts: 2760
  • Thanked: 38 times
    • View Profile
Re: Is it true that light can orbit a black hole?
« Reply #1 on: 24/02/2015 17:09:04 »
Quote from: Merccooper
I read that light can orbit a black hole just outside the event horizon. Is this true?
Yes.

Quote from: Merccooper
If it is true and light orbits for a long enough time, would you be able to look behind you and see yourself in the past?
Yes
 

Offline Merccooper

  • Jr. Member
  • **
  • Posts: 11
    • View Profile
Re: Is it true that light can orbit a black hole?
« Reply #2 on: 24/02/2015 17:32:01 »
Cool, thanks.

So another thought along those line, if I were (in this situation) to shine two lasers parallel to each other, they would continue around black hole (around the event horizon) and return back to me still parallel?
 

Offline yor_on

  • Naked Science Forum GOD!
  • *******
  • Posts: 11978
  • Thanked: 4 times
  • (Ah, yes:) *a table is always good to hide under*
    • View Profile
Re: Is it true that light can orbit a black hole?
« Reply #3 on: 24/02/2015 17:35:45 »
That must be a very specific solution. I would expect non linearities to break it up. But mathematics in some ways can ignore time, and a universe acting inside it.
 

Offline yor_on

  • Naked Science Forum GOD!
  • *******
  • Posts: 11978
  • Thanked: 4 times
  • (Ah, yes:) *a table is always good to hide under*
    • View Profile
Re: Is it true that light can orbit a black hole?
« Reply #4 on: 24/02/2015 17:40:04 »
please link me to it.
 

Offline PmbPhy

  • Neilep Level Member
  • ******
  • Posts: 2760
  • Thanked: 38 times
    • View Profile
Re: Is it true that light can orbit a black hole?
« Reply #5 on: 24/02/2015 17:40:15 »
Cool, thanks.

So another thought along those line, if I were (in this situation) to shine two lasers parallel to each other, they would continue around black hole (around the event horizon) and return back to me still parallel?
Not exactly parallel, no. Only approximately so.
 

The Naked Scientists Forum

Re: Is it true that light can orbit a black hole?
« Reply #5 on: 24/02/2015 17:40:15 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums