Rewinding a black hole - Can a spinning black hole become a star?

In summary: It is still a singularity, just with different properties.In summary, the conversation discusses the possibility of a spinning black hole becoming a star under certain conditions and explores the idea of winding up something into a black hole. It also touches on the concept of spinning objects having more gravity and the effects of natural processes on a black hole's spin. Ultimately, it is concluded that a black hole cannot revert back to being a star once it has reached singularity.
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"Rewinding" a black hole - Can a spinning black hole become a star?

I couldn't fit all the important prerequisites and context in the title, so I'll set up the thought experiment here. Some of these assumptions are also questions, and might be easily refuted, thus answering the main question with a "no".

Prerequisites:
1. We have a black hole that barely satisfies the Schwarzschild radius by the increase in gravity from the spinning mass/energy. Is this possible? Maybe the typical evolution of stars makes this an impossibility. I may have the idea of "spinning object = more gravity" all wrong or maybe it doesn't apply to "singularities" and relativistic entities. I understand that the chances of a stellar object satisfying these possibly tiny tolerances and circumstances might be astronomically low, but good thing we're dealing with astronomical numbers :D I'm looking for "possible", not "probable".

2. Through natural processes (mass/energy gain/loss, Hawking radiation?), the spinning of the black hole slows down to the point that it doesn't satisfy the Schwarzschild radius. Imagine there's a line drawn based on how fast the object is spinning. Spinning fast enough pushes us over the line and we have a black hole. Slowing down to under the line gives us "something else". I'm seeing a delicate balance of mass and spin here that has to be just right. Again, maybe this isn't possible :/

Question:
Is this possible? Will the black hole revert from being a singularity and become a star again (neutron?), explode like a supernova, oscillate between visible/invisible, or become something entirely different?

We could also look at this from the other perspective, and ask if it's possible to wind something up into becoming a black hole. From what I've researched this seems to be more unlikely, similar to what happens when matter builds up on a white dwarf and results in a nova, making it impossible to gain enough mass.

I couldn't find this question being asked anywhere and thought it was worth throwing out there. Thanks for the input!
 
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  • #2
1. We have a black hole that barely satisfies the Schwarzschild radius by the increase in gravity from the spinning mass/energy
Spinning black holes don't follow the Schwarzschild solution, they can be described with the Kerr metric.
"spinning object = more gravity"
This is not true. The mass of the black hole is just determined by its total energy content. Sure, a rotating star has a bit more energy than a non-rotating star, but that effect is not significant and stars have a broad range of masses anyway.

I understand that the chances of a stellar object satisfying these possibly tiny tolerances and circumstances might be astronomically low
Which tolerances or circumstances?

2. Through natural processes (mass/energy gain/loss, Hawking radiation?), the spinning of the black hole slows down to the point that it doesn't satisfy the Schwarzschild radius.
That does not make sense.

Will the black hole revert from being a singularity
No.
 

1. What is a black hole?

A black hole is a region in space where the gravitational pull is so strong that nothing, not even light, can escape from it. This happens when a massive star dies and collapses under its own weight, creating a singularity with infinite density and zero volume.

2. Can a black hole be rewound?

Technically, no. Once a black hole is formed, it cannot be reversed or rewound. However, there are theories and hypothetical scenarios in which the effects of a black hole can be altered, such as Hawking radiation or merging with another black hole.

3. What does it mean to rewind a black hole?

To rewind a black hole means to reverse the process of its formation and turn it back into a star. This would require reversing the collapse of matter and restoring the star's original state, which is currently not possible with our current understanding of physics.

4. Can a spinning black hole become a star?

No, a spinning black hole cannot become a star. This is because the spinning motion is a result of the black hole's singularity and cannot be reversed. However, a spinning black hole can merge with another spinning black hole and result in a larger, more massive black hole.

5. Is it possible for a black hole to turn into a star again?

Theoretically, yes. If a black hole were to lose enough mass through Hawking radiation, it could eventually reach a point where its gravity is no longer strong enough to hold itself together, causing it to explode in a supernova and potentially form a new star. However, this is currently only a hypothesis and has never been observed in reality.

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