# Thread: Entering a rotating black hole

1. ## Entering a rotating black hole

The other night my friend told me that it was possible to enter the singularity of a rotating black hole, which seemed totally nuts to me.

I looked it up, and I found several articles that said that new mathematical models show that it would be possible to enter a singularity and emerge in another galaxy if you found the perfect path into a large enough black hole that was rotating in just the right way, but they were all short on details and any more complex research I did was too math heavy for me to make heads or tails of.

Is anyone able to explain how this concept works to me, preferably in layman's terms?

I just don't get how:

A: Why tidal shredding wouldn't occur at some point, even if it is only microscopic distance from the singularity itself.
B: How an object with finite size could enter a 1 dimensional point at all, let alone intact.
C: Why you would emerge in a different galaxy specifically.

Thanks!

2. ## Re: Entering a rotating black hole

Originally Posted by Talakeal
The other night my friend told me that it was possible to enter the singularity of a rotating black hole, which seemed totally nuts to me.

I looked it up, and I found several articles that said that new mathematical models show that it would be possible to enter a singularity and emerge in another galaxy if you found the perfect path into a large enough black hole that was rotating in just the right way, but they were all short on details and any more complex research I did was too math heavy for me to make heads or tails of.

Is anyone able to explain how this concept works to me, preferably in layman's terms?

I just don't get how:

A: Why tidal shredding wouldn't occur at some point, even if it is only microscopic distance from the singularity itself.
Tidal shredding would occur if you got close enough. That's why it has to be fricking HUGE.

B: How an object with finite size could enter a 1 dimensional point at all, let alone intact.
The trick is that the singularity of a rotating black hole is a ring, so if it's big enough, and has enough rotational energy, something could theoretically go through it without getting near the singularity.

C: Why you would emerge in a different galaxy specifically.
I don't think that's proven, though something odd might well happen.

Thanks!
You're welcome.

3. ## Re: Entering a rotating black hole

Originally Posted by halfeye
The trick is that the singularity of a rotating black hole is a ring, so if it's big enough, and has enough rotational energy, something could theoretically go through it without getting near the singularity
Cool, thank you.

Is there any way you could elaborate more on this?

I thought the whole point of a singularity was that it was a single point with mass, and therefore infinite density. Isn't a singularity with size and shape a contradiction?

4. ## Re: Entering a rotating black hole

Originally Posted by Talakeal
Cool, thank you.

Is there any way you could elaborate more on this?

I thought the whole point of a singularity was that it was a single point with mass, and therefore infinite density. Isn't a singularity with size and shape a contradiction?
A circle-shaped line still wouldn't have any volume. And it could sort of get shaped by an interplay between really strong gravity and really strong centrifugal force.

That being said, I think there is some maths behind the possibility of wormholes forming from donut shaped black holes, but that's usually the sort of maths that assumes extra dimensions and interprets strange rather freely. (Which is something entirely different than the math being wrong. It just leaves us with the question whether our universe is right for the math.) The idea that you could make a wormhole this way, or in fact any way, is far more speculative than the relatively solid concept of creating a ring shaped object by spinning a mass fast enough.

5. ## Re: Entering a rotating black hole

Originally Posted by Lvl 2 Expert
A circle-shaped line still wouldn't have any volume. And it could sort of get shaped by an interplay between really strong gravity and really strong centrifugal force.

That being said, I think there is some maths behind the possibility of wormholes forming from donut shaped black holes, but that's usually the sort of maths that assumes extra dimensions and interprets strange rather freely. (Which is something entirely different than the math being wrong. It just leaves us with the question whether our universe is right for the math.) The idea that you could make a wormhole this way, or in fact any way, is far more speculative than the relatively solid concept of creating a ring shaped object by spinning a mass fast enough.
Cool. That makes a lot more sense.

Still having trouble picturing actually making contract with the singularity though. Or do you skip that step and just jump through the middle like a hoop?

6. ## Re: Entering a rotating black hole

Originally Posted by Talakeal
Cool. That makes a lot more sense.

Still having trouble picturing actually making contract with the singularity though. Or do you skip that step and just jump through the middle like a hoop?
I think jumping through the hoop is exactly the idea.

7. ## Re: Entering a rotating black hole

The issue actually comes in two separate parts.

First, some maths say that if you jump into any black hole, they might be connected to other universes. The problem with most of them is that once you jump in you're on a collision course with the singularity, which means that tidal forces will tear you apart and then you'll eventually fall into nature's divide by zero error. So you can maybe see something, but you're not able to communicate with the outside world and you'll be destroyed in the not too distant future. Obviously this is less than ideal.

Then as mentioned, if the black hole is spinning in just the right way, the singularity can be a ring instead of a point. If that's the case, you may be able to fall through the hoop instead. This is just a way to do the above and not die, although it's very tentatively theoretical right now.

Relevant wiki link, if you want the idea without too much math.

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