A black hole with a simple soul

[Gian]

Theoretical physicists always proclaim portentously that the singularity at the centre of a black hole "is where our laws of nature break down" which sounds to me like another way of saying "we don't know the answer."

But as no physical process is ever absolutely instantaneous (I think,) surely the collapsing matter gets smaller and smaller while slowed down by ever increasing density so it never quite gets to the singularity and the process continues to infinity.

Eg if you keep dividing 1 by 2 you'll never get to zero.

Cheerz

GIAN🙂

(I've no science qualifications beyond gcse maths n physics grade C, so pls be gentle with me.)

[beecee]

1 minute ago, Gian said:

Theoretical physicists always proclaim portentously that the singularity at the centre of a black hole "is where our laws of nature break down" which sounds to me like another way of saying "we don't know the answer."

But as no physical process is ever absolutely instantaneous (I think,) surely the collapsing matter gets smaller and smaller while slowed down by ever increasing density so it never quite gets to the singularity and the process continues to infinity.

Eg if you keep dividing 1 by 2 you'll never get to zero.

Cheerz

GIAN🙂

(I've no science qualifications beyond gcse maths n physics grade C, so pls be gentle with me.)

The singularity at the core of a BH is where our laws and GR break down, no question about that. But most physicists reject the singularity as defined by infinite spacetime curvature and density.

What we can reasonably expect is that which GR tells us...that is once the Schwarzchild radius is reach, further collapse is compulsory. Which means that most of the BH [ignoring in falling matter/energy] we can say is just critically curved spacetime, at least up to the quantum/Planck level where our singularity resides, and where our knowledge stops. Rejecting the singularity of infinite spacetime curvature and density, would mean a surface of sorts, in an unknown state, at or below that quantum/Planck level.

[swansont]

 

10 minutes ago, Gian said:

Theoretical physicists always proclaim portentously that the singularity at the centre of a black hole "is where our laws of nature break down" which sounds to me like another way of saying "we don't know the answer."

Yes. We don't have knowledge of the laws of physics at that scale. We don't know the answer.

10 minutes ago, Gian said:

But as no physical process is ever absolutely instantaneous (I think,) surely the collapsing matter gets smaller and smaller while slowed down by ever increasing density so it never quite gets to the singularity and the process continues to infinity.

Why does it have to happen instantaneously? That's not the only option.

 

 

[Gian]

On 7/6/2021 at 12:03 PM, swansont said:

 

Yes. We don't have knowledge of the laws of physics at that scale. We don't know the answer.

Why does it have to happen instantaneously? That's not the only option.

 

 

Well because I was given the impression that the singularity does not and cannot have any dimensions; the singularity is 0x0x0mm. 

Yes it's not instantaneous, but I thought that because of the gravity involved, it wouldn't take that long to reach 0x0x0mm. 

But given these forces, I guess it never quite gets there. 

I read somewhere that eventually black holes will evaporate away, although I've no idea how

[Genady]

Nothing slows down free fall. A matter falling into a black hole will change its shape, becoming "spaghettified." Anyway, it reaches singularity very fast. For example, in the supermassive black hole in the center of the Milky Way it will be a matter of seconds.

[beecee]

13 minutes ago, Gian said:

Well because I was given the impression that the singularity does not and cannot have any dimensions; the singularity is 0x0x0mm. 

Yes it's not instantaneous, but I thought that because of the gravity involved, it wouldn't take that long to reach 0x0x0mm. 

But given these forces, I guess it never quite gets there. 

I read somewhere that eventually black holes will evaporate away, although I've no idea how

Most physicists reject the singularity as defined by infinite spacetime curvature and density, or your 0x0x0. As GR fails us at the Planck/quantum level, it could be said that the gravitationally collapsed mass resides at the Planck volume, which is 4.22 x 10^-105 cubic meters.(https://www.quora.com/How-big-is-a-Planck-volume#:~:text=Short answer%3A It is not,all — it is an infinitesimally&text=Not that it makes much,3)πℓ 1.7710 m) So a surface of sorts should lay at that level.

 

[MigL]

On 7/6/2021 at 6:50 AM, Gian said:

the singularity at the centre of a black hole "is where our laws of nature break down"

No, the 'laws of nature' are perfectly fine, even at the center of a BH.
What 'breaks down' is our mathematical model, our ability to describe those 'laws of nature'.

GR is the model that breaks down, at those scales and mass/energy levels, but keep in mind that we also describe the concept of infinities using a mathematical model, and although much less likely, maybe our mathematical model is not applicable to this type of infinity, and new maths are needed.

 

[Kurious12]

On 1/23/2022 at 11:12 AM, Genady said:

Nothing slows down free fall. A matter falling into a black hole will change its shape, becoming "spaghettified." Anyway, it reaches singularity very fast. For example, in the supermassive black hole in the center of the Milky Way it will be a matter of seconds.

Some super massive blackholes can be the size of our entire solar system, so wouldn't matter have to travel faster than the speed of light to reach its center in just a matter of seconds?

[Genady]

2 minutes ago, Kurious12 said:

Some super massive blackholes can be the size of our entire solar system, so wouldn't matter have to travel faster than the speed of light to reach its center in just a matter of seconds?

Not in their proper time.

[Gian]

On 7/6/2021 at 12:01 PM, beecee said:

The singularity at the core of a BH is where our laws and GR break down, no question about that. But most physicists reject the singularity as defined by infinite spacetime curvature and density.

What we can reasonably expect is that which GR tells us...that is once the Schwarzchild radius is reach, further collapse is compulsory. Which means that most of the BH [ignoring in falling matter/energy] we can say is just critically curved spacetime, at least up to the quantum/Planck level where our singularity resides, and where our knowledge stops. Rejecting the singularity of infinite spacetime curvature and density, would mean a surface of sorts, in an unknown state, at or below that quantum/Planck level.

Thanks Mr Beece, that's interesting. I'll have to go and look up quantum/ planck theory, and also Planck volume. but well done for getting me motivated.

BTW I'm not naturally talented at maths, (highest; grade C at GCSE.) Do you think I'd need to be 1st class BA (hons.) material at mathematics to have a hope of being a professional astrophysicist working eg for nasa? 

 

Cheerz GIAN 🙂

 

Edited May 3, 2022 by Gian

[beecee]

6 minutes ago, Gian said:

Thanks Mr Beece, that's interesting. I'll have to go and look up quantum/ planck theory but well done for getting me motivated. Cheerz GIAN 🙂

No probs!

 

Cosmology/Astronomy as Carl Sagan said at the end of his "pale blue dot" narrative,   "astronomy is a humbling and character-building experience".

 

I would add awesome and mind-blowing to that description.

[Gian]

3 minutes ago, beecee said:

No probs!

 

Cosmology/Astronomy as Carl Sagan said at the end of his "pale blue dot" narrative,   "astronomy is a humbling and character-building experience".

 

I would add awesome and mind-blowing to that description.

 BTW I don't think Im naturally talented at maths, (highest; grade C at GCSE.) Do you think I'd need to be 1st class BA (hons.) material at mathematics to have a hope of being a professional astrophysicist working eg for nasa? 

Cheerz GIAN 🙂

 

[Genady]

16 minutes ago, Gian said:

 BTW I don't think Im naturally talented at maths, (highest; grade C at GCSE.) Do you think I'd need to be 1st class BA (hons.) material at mathematics to have a hope of being a professional astrophysicist working eg for nasa? 

Cheerz GIAN 🙂

 

Check e.g. here: What does an Astrophysicist Do and How to Become an Astrophysicist (yourfreecareertest.com)

"At a minimum, you would want to start off by attaining a bachelor’s degree in astronomy, physics, math, or electronics."

[Gian]

6 minutes ago, Genady said:

Check e.g. here: What does an Astrophysicist Do and How to Become an Astrophysicist (yourfreecareertest.com)

"At a minimum, you would want to start off by attaining a bachelor’s degree in astronomy, physics, math, or electronics."

Sounds terrifying lol 🥶🤪🥴 But thanks for the info and link 🙂GIAN

[beecee]

22 minutes ago, Gian said:

 BTW I don't think Im naturally talented at maths, (highest; grade C at GCSE.) Do you think I'd need to be 1st class BA (hons.) material at mathematics to have a hope of being a professional astrophysicist working eg for nasa? 

Cheerz GIAN 🙂

 

Listen matey, I'm only a poor old retired maintenance Fitter/Machinist/Welder, who has always had a great interest in cosmology and astronomy, but was having to much fun as a hairy arsed kid to do too  much about it.

If you want to gain knowledge in that arena, but havn't the qualifications, start by reading some reputable books....I started many years ago with Stephen Hawking's Brief History of Time....somewhat dated now though, but there are many others...The First Three Minutes by Stephen Weinburg...anything by Carl Sagan of course...Lawrence Krauss and Neil DeGrasse-Tyson are other notable authors of late.

[Gian]

1 minute ago, beecee said:

Listen matey, I'm only a poor old retired maintenance Fitter/Machinist/Welder, who has always had a great interest in cosmology and astronomy, but was having to much fun as a hairy arsed kid to do too  much about it.

If you want to gain knowledge in that arena, but havn't the qualifications, start by reading some reputable books....I started many years ago with Stephen Hawking's Brief History of Time....somewhat dated now though, but there are many others...The First Three Minutes by Stephen Weinburg...anything by Carl Sagan of course...Lawrence Krauss and Neil DeGrasse-Tyson are other notable authors of late.

There's absolutely nothing wrong with manual skills, it's what this country was built on including science. Ive done site labouring and you can't get bricklayers and plasterers. Alot of my schoolmates could sit in front of a screen pressing buttons all day, but were scared shitless of honest grime.

[Markus Hanke]

2 hours ago, Kurious12 said:

Some super massive blackholes can be the size of our entire solar system, so wouldn't matter have to travel faster than the speed of light to reach its center in just a matter of seconds?

The in-fall time is a function of the black hole’s mass, and if that is very large, then it takes a longer time to reach the singularity. For example, for a 15 billion solar mass supermassive Schwarzschild black hole, the proper in-fall time from horizon to singularity would be 71.2 hours, so nearly three days.

[Autistic girl]

A black hole is likely just a very dense spherical object, that has a gravitational field so strong that not even light can escape it. I do not think that the laws of physics inside it break.

[Gian]

1 hour ago, Autistic girl said:

A black hole is likely just a very dense spherical object, that has a gravitational field so strong that not even light can escape it. I do not think that the laws of physics inside it break.

Thanks. I don't really understand it all but I agree with you x

[Markus Hanke]

6 hours ago, Autistic girl said:

A black hole is likely just a very dense spherical object, that has a gravitational field so strong that not even light can escape it. I do not think that the laws of physics inside it break.

What force would counteract gravity in this case, in order to keep the object stable and stop it from collapsing?