Can we determine the rotation speed of a black hole?

AI Thread Summary
Calculating the rotation speed of a black hole is challenging due to the inability to observe phenomena inside the event horizon. Theoretical models, such as those involving Kerr black holes, suggest that rotation is linked to conservation of angular momentum. Some theories propose using light emitted from a black hole's surroundings, particularly in x-ray binaries, to estimate its spin. However, skepticism remains regarding the effectiveness of current methods to accurately derive a black hole's intrinsic spin. Overall, while there are promising approaches, definitive measurements of black hole rotation speed remain elusive.
cosmicpencil
Messages
25
Reaction score
0
Is it possible to calculate the rotation speed of a black hole? Idid not find anything on this on google.

thanks
 
Astronomy news on Phys.org
A Kerr black hole has a theoretical rotation component due to conservation of angular momentum. It cannot be measured directly as we cannot observe anything occurring inside the event horizon. I doubt it's meaningful to talk about rotataion with respect to the event horizon. For discussion, see
http://science.howstuffworks.com/black-hole.htm/printable
 
I heard in class of a theorie that would use the light emmited from the black hole surroundings to calculate the rotation speed, anyone familiar with these theories?
thanks
 
I heard about that. In an x-ray binary in which a black hole is believed to be the compact object, it has been suggested that the strength of an ultrasoft x-ray component is directly related to the black hole's spin.
Check out section 8.2 of the following:
http://arjournals.annualreviews.org/doi/abs/10.1146/annurev.astro.44.051905.092532
 
Good link, maria, but, I am unconvinced the authors have derived an effective way to derive the intrinsic spin of a black hole.
 
thank you for this link.
 

Thread 'Potential biosignature found in Mars rock'

Publication: Redox-driven mineral and organic associations in Jezero Crater, Mars Article: NASA Says Mars Rover Discovered Potential Biosignature Last Year Press conference The ~100 authors don't find a good way this could have formed without life, but also can't rule it out. Now that they have shared their findings with the larger community someone else might find an explanation - or maybe it was actually made by life.
View full post »

Thread 'Does it make sense to build new radio telescopes?'

TL;DR Summary: In 3 years, the Square Kilometre Array (SKA) telescope (or rather, a system of telescopes) should be put into operation. In case of failure to detect alien signals, it will further expand the radius of the so-called silence (or rather, radio silence) of the Universe. Is there any sense in this or is blissful ignorance better? In 3 years, the Square Kilometre Array (SKA) telescope (or rather, a system of telescopes) should be put into operation. In case of failure to detect...
View full post »

Thread 'Our Beautiful Universe - Photos and Videos'

This thread is dedicated to the beauty and awesomeness of our Universe. If you feel like it, please share video clips and photos (or nice animations) of space and objects in space in this thread. Your posts, clips and photos may by all means include scientific information; that does not make it less beautiful to me (n.b. the posts must of course comply with the PF guidelines, i.e. regarding science, only mainstream science is allowed, fringe/pseudoscience is not allowed). n.b. I start this...
View full post »

Similar threads

B Confusion regarding black hole spin
Replies
40
Views
3K
B Black hole equivalence
Replies
20
Views
2K
B What is the actual shape of black holes?
Replies
4
Views
2K
I Can there be slowly-falling accretion disks in black holes?
Replies
11
Views
2K
B I Need Help on Understanding Some Basic Astrophysics / Sand Clock Universe
Replies
5
Views
2K
Stargazing Dark matter and its effect on the orbit of stars
Replies
13
Views
3K
I Early Universe massive Black Holes question
Replies
10
Views
2K
I The initial density of an object and its compression into a black hole
Replies
17
Views
4K
B Circumgalactic Black hole imaged by the Hubble Space Telescope
Replies
1
Views
2K
B Ultramassive Black Hole (UMB), 30 billion solar masses?
Replies
4
Views
2K

Hot Threads

Recent Insights

Back
Top