(This is aimed at the astrophysicists amongst us - expect confusion to follow ;p)

I was watching a program just now on black holes and about the kerfuffle that singularities cause with their gravitional mass. The problem as they put forward is that the centrepoint of the singularity would essentially have a radius of zero, which means it'd have an infinitedensity which is patently erroneous.


However, if I'm not mistaken, as you approach the centre of a black hole, time effectively slows down amirite? (If I'm wrong then what follows is fallicious and should be scrunched up and burned immediatly):



When a black hole is generated you had a starting amount of mass was imploded. At a certain point the collective mass became such that the escape velocity exceeded the speed of light and the event horizon formed; at this moment it became impossible for mass to actually enter the centrepoint of the singularity because it was proposed that space is stretchedfaster than light around the centrepoint .

Matter falling into the hole is pulled towards it at increasingly astronomical speeds (to within a fraction of the speed of light), yet at the same time, space is pulled into the center faster than the speed of light. As a result, mass falling towards the black hole can never actually *reach* the singularity in any finite timespan.

As a result, there would be a shell of incredibly dense matter that makes up most the mass of the black hole and encompasses any new mass entering it, while the "centre" of the black hole would initially have a reasonable radius and as mass piles up around it, eventually pulls the mass in the centre out towards the edges of the shell; so the centrepoint of the singularity would not have any amount of gravity at the r=0 point and it'd be physically impossible for the divide by zero problem. In essence, a singularity woudl not be a point, but a shell with a non-zero radius.



I may of course be totally wrong, but it seems to me that there is something fundamentally wrong about the logic of the singularity =p

I'm surprised I understood all of that. O_o
Love the theory, I'll convey it to one of my astrophysicist buddies, to see what he thinks.

A singularity in physics is an object with a nonzero or negative mass, but that takes up no space whatsoever. It has an infinite density, not an infinite gravity by the way.

Hmm, something about you, Okk, makes me think that you don't have any astrophysics buddies. And even if they were well endowed with physics, it is likely that they already knew this.

Great thread, by the way.

Why would an object of infinite density not have infinite gravity?

But, yes, black holes have infinite density, not gravity.

In fact, infinity in the standard particle physics model is one of the reasons that string theory was developed.

Haxorzunited14 wrote:Hmm, something about you, Okk, makes me think that you don't have any astrophysics buddies. And even if they were well endowed with physics, it is likely that they already knew this.

Great thread, by the way.

When I say "astrophysics buddies", I mean a funny Jew who took an astrophysics class or two.
Didn't want to sound crude.

Well, you did.

I sincerely doubt he has ever taken an astrophysics class.

If he has, then he would certianly be well endowed with ordinary physics as well. Which I also doubt.

Don't be such a negative nancy.

GrandEnder wrote:Why would an object of infinite density not have infinite gravity?

It would in principle, but you need to remember the division is between a finite amount of mass and a zero amount of radius. On paper it would create an infinite gravitional field but it's a self evident mathematical error because the result cannot be greater than the sum total of gravitional mass placed into it.

It's a divide by zero error basiclly.

Ryuujin wrote:

GrandEnder wrote:Why would an object of infinite density not have infinite gravity?

It would in principle, but you need to remember the division is between a finite amount of mass and a zero amount of radius. On paper it would create an infinite gravitional field but it's a self evident mathematical error because the result cannot be greater than the sum total of gravitional mass placed into it.

It's a divide by zero error basiclly.

your right
so true,so true

Not to downplay the severity of dividing a non zero amount of mass by a zero volume...




...that sort've thing'd be a lot more common if maths on paper had total correlation to reality

So, could/does dividing by zero open a black hole randomly in the universe, or is that just 4chan humor?

okknaggs88 wrote:So, could/does dividing by zero open a black hole randomly in the universe, or is that just 4chan humor?

If Einstein was right about general relativity, then yes, black holes really do divide by zero 4chan style. In practice though it's probably a maths errorasi said earlier.

But no, dividing by zero is not a big deal in normal day to day living...

OR IS IT


Edit: Stupid link won't post. Short and sweet is that a US naval vessel once suffered a total systems failiure due to a divide by zero error in it's computer systems =p - but we're getting off topic now.

You know, my "friends" consider me as a nerd cause i gte more than 1 A.... they should see you guys