this post was submitted on 28 Sep 2023
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336
Scientists confirm that the first black hole ever imaged is actually spinning (www.engadget.com)
submitted 1 year ago by [email protected] to c/[email protected]
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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.

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[–] [email protected] 12 points 1 year ago* (last edited 1 year ago) (2 children)

For one thing, the size and shape of the event horizon change depending on the black hole’s spin.

[–] [email protected] 3 points 1 year ago (1 children)

What would happen if one were to stop spinning? Could one even stop spinning?

[–] [email protected] 6 points 1 year ago

Yes—it’s called the Penrose process.

[–] [email protected] 1 points 1 year ago (1 children)

I see. Thank you. So, you can use light to infer the mass, and then the volume information to infer the spin? Easy enough.

[–] [email protected] 3 points 1 year ago* (last edited 1 year ago)

That would be a general method, if we were close enough to observe the shape of the event horizon (which we aren’t).

The article is describing another way, which only works in this case because the black hole is precessing so extremely that the changing axis of rotation is frame-dragging the polar jets along with it.