2y ago

Scientists confirm that the first black hole ever imaged is actually spinning

www.engadget.com

Scientists confirm that the first black hole ever imaged is actually spinning::The first black hole humanity has ever imaged has also provided us with what researchers are calling "unequivocal evidence" that black holes spin.

41 comments

The title kind of misses the point: of course it spins; it would be remarkable if it didn’t.
The really interesting bit is how relativistic frame dragging is causing its spin axis to precess.
(Also, the illustration conflicts with the description: it shows the whole accretion disk wobbling instead of just the jets.)
- Does the black hole spin? Or does the stuff outside the black hole spin? 🤔
  
  The black hole and the stuff outside it constitute a single system, and within that system, angular momentum is conserved. So as objects cross the event horizon, their angular momentum is transferred to the black hole.
  
  Isn’t most everything spinning? Seems like having zero angular momentum would be rare and remarkable. I’m not even sure how exactly to define zero momentum in terms of reference frames.
  
  If you're asking that then you first need to ask what the distinction between the two is. and further does it even make sense for one to spin and not the other
  
  Yes.
  
  It's in space and everything is relative, how do we know *everything else" isn't just spinning around the black hole? 🤔
- Can you ELI5 relativistic frame dragging and process?
  
  Frame dragging is when matter drags spacetime along with it. Roughly think of a the wake of a boat disturbing other things in the water.
  The misalignment of the black holes axis of spin, and the axis of the accretion disk is causing interesting frame dragging effects.
I guess the next questions would be
How fast? Really fast? Does this question even make sense?
What does this say about the inside of the event horizon? Does it say anything? Is this black hole leaking real information?
Is black hole spin quantized like quantum spin? Is it spin-up or spin-down?
- Quantum Physics “spin” has nothing to do with actual spinning. It’s just a weirdly named property of particles.
  
  I've always thought that they should have just named the properties something like P1, P2, etc. So there's no connotation.
  
  I thought "spinning" was meant rather literally in this case and not in some quantum sense
I thought we already knew they spun, given the incredible amount of angular momentum in their accretion disks. Seems like a "duh" thing to prove with image data that the physics data already implied.
- I thought so as well but the article says the spin doesn't match the accretion disc, I'm not sure if that's s significant aspect of the discovery possibly? I'm not well versed in relativity to be honest
  Edit: forgive me, someone below said pretty much this
  
  What’s an accretion disc?
I mean the majority of black holes spin... It's kinda fundamental to their existance as most things in the universe have motion and when you super compress those things into a black hole, that motion has to go somewhere.
That's really cool! It must have been hard to take that incredibly low res picture, and extract this much information out of!
I came here to be excited but the comments seem grumpy and I don’t know any what of the words mean that people are using.
Is there any reason to have ever believed that they didn't spin?
- Not really. But it's always good to get confirmation of our theories. And it's usually even more exiting to find an error in a well established theory.
  And then you've got to consider that at least mathematically a black hole doesn't have any volume, so what could actually spin in something that's infinitely small? This more or less confirms that this is bullshit.
This is a confirmation that was needed to accurately calculate the size of the black holes right?
Plug time:
Can’t wait for Anton on YouTube (Link ) to upload somethin about this.
Man explains things so nicely and so well. Always somethin interesting and it’s less time spent doom scrolling or listening to people yell at each other in comments
- Here is an alternative Piped link(s):
  Link
  Piped is a privacy-respecting open-source alternative frontend to YouTube.
  I'm open-source; check me out at GitHub.
Yeah cool but how many rpm
Good video covering black hole spinning in the film Interstellar:
https://youtu.be/Z4oy6mnkyW4
- Here is an alternative Piped link(s):
  https://youtu.be/Z4oy6mnkyW4
  Piped is a privacy-respecting open-source alternative frontend to YouTube.
  I'm open-source; check me out at GitHub.
It's actually Goku gathering energy for a spirit bomb

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