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Offline SorryDnoodle

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Why are black holes special?
« on: 25/01/2016 03:45:34 »
I'm just a mere chemist at heart but I do find space-stuff very fascinating, and so far I have yet to find(understand) why black holes are so special, why can't they be simpler? In my mind they are just like a neutron star with a tad bit more mass making them 'suck' in light as well as matter.

How does an infinite density work? infinity doesn't sit well with me, it is a cop out for stuff we cannot explain, how could anything possibly have an infinite density without completely destroying the universe in the blink of an eye?

Any easy answers out there?


 

Offline alysdexia

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Re: Why are black holes special?
« Reply #1 on: 25/01/2016 07:10:58 »
Well look at Coulomb's law when you plug in r=0; you get infinite newtons and everything therefrom.

My explanations are at https://www.quora.com/Black-Holes/The-Year-2016-marks-100-years-of-black-hole-and-gravitational-singularity-formalism-How-do-I-engage-the-scientific-community-to-disprove-the-premise.  The Quora moderation made me overwrite the question in more polite terms.
 

Offline evan_au

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Re: Why are black holes special?
« Reply #2 on: 25/01/2016 10:13:02 »
Quote from: SorryDnoodle
infinity doesn't sit well with me
You are not the only one!

There are some cases where infinities can be managed, and still produce useful results - in mathematics see L'Hôpital's rule, and in quantum theory see  Renormalization.

In the case of stellar and galactic Black Holes, the mass is finite. And this finite mass creates an event horizon of finite volume, which produces a black hole of finite density. So, as far as we in the universe can see, a conventional black hole has a finite density; no infinities to explain away.

There is precious little that someone outside the black hole can learn about what is inside a black hole - and someone going into a black hole is not going to live long enough to see anything useful, either.

There are various potential ways around this particular potential infinity hidden behind an event horizon. In particular, Quantum Theory and Gravity do not yet have a consistent theory - the recent paper by Steven Hawking & others hints that string theory may be a better approach to the gravity of black holes than conventional quantum theory.
See: http://en.wikipedia.org/wiki/Gravitational_singularity

So now we just have to beware of a hypothetical construct called the "naked singularity"!
 

Offline alysdexia

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Re: Why are black holes special?
« Reply #3 on: 25/01/2016 11:33:45 »
Well sure, both superstrings and black holes don't exist, so of course they can explain each other.  It's like when creationists try to explain the Noaxian flood's firmament as a vapor canopy.
 

Offline puppypower

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Re: Why are black holes special?
« Reply #4 on: 25/01/2016 14:10:25 »
Here is a theory for blackholes that offers a unique spin. If the universe formed from the BB, where the entire mass/energy density of the universe begins as a singularity, could blackholes form directly from this high density of the primordial atom? The singularity already has black hole like parameters? This would make many black holes, especially the big ones, dense remnants, from the beginning of the universe.

There is an advantage to the black holes forming early. If we compare a BB singularity that expands and atomizes into sub particle matter and energy, to one where the primordial atom of the BB, quantum divides into two daughter black hole phenomena, the former defines much higher entropy, while the latter defines much lower entropy.

For entropy to increase, it need to absorb energy; heat. This means the former; the atomization scenario, will loose energy faster into its extreme entropy increase. It also means atomization needs much more energy, up front, to occur. The latter; quantum division, defines less entropy and therefore looses energy slower. It also means, it needs less energy, up front, to move the primordial atom to a first step.

The question becomes, is it easier to explain the extreme energy, up front, needed for the extreme entropy connected to the primordial atom's atomization into sub particles? Or is it easier to explain many orders of magnitude less energy, up front, needed for a quantum division. Less energy needs offers more options. Like in living cell cycles, separation into two daughter cells is energy friendly compared to atomizing the mother cell. A quantum division model for the BB, makes two daughter cell black hole caliber density singularities, separate, with both cells still at nearly primordial atom space-time contraction; minimal energy needs. I like this because we live in a quantum universe.

Say you compare two identical factories, side by side, where both make widgets and each makes one defective widget per hour. This is a measure of entropy.  If one factory was placed in a highly time contracted reference, and the other factory was in a highly time expended reference, the rates of entropy would appear different, if we compare these, side-by-side, from our earth reference.

The expansion of the universe, due to space-time expansion, increases the rate of entropy, based on any standard reference. This entropy driven increase, due to space-time expansion, will help drive quantum division, in an exponential way, until galaxy level quantum appears. The expansion of the universe, relative to the galaxies, implies a different phase change; mini-big-bangs from blackholes centers.

This quantum scenario does not require all the expansion energy up front, like the current model. If we assume dark energy is needed for the expansion, we need less dark energy at the beginning, with the dark energy source building up as a function of space-time expansion, providing energy for the entropy of further division.
« Last Edit: 25/01/2016 14:13:44 by puppypower »
 

Offline Space Flow

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Re: Why are black holes special?
« Reply #5 on: 25/01/2016 21:49:39 »
I'm just a mere chemist at heart but I do find space-stuff very fascinating, and so far I have yet to find(understand) why black holes are so special, why can't they be simpler? In my mind they are just like a neutron star with a tad bit more mass making them 'suck' in light as well as matter.
With you 100%.
An atomic element core or star exists until Electron degeneracy pressure is overcome by gravity, at which point electrons are forced to give up the space they maintain away from the nucleus.
We then collapse one order of structural complexity and go down to Neutrons.
A Neutron star of about 2.5 solar masses maintains a radius that is only just larger than that star's event horizon.
At the same time, a Neutron star is not made of fundamental particles. Neutrons represent a level of structural complexity of matter that is one level up from fundamental particles.
When Neutron degeneracy pressure is overcome, we don't end up with singularities, infinities, wormholes, other dimensions, or any of those imaginary wild ideas.
We end up with a ball of the very same fundamental particles that are the cause of the gravity in the first place.
The fundamental particles in perfect balance with the flow of spacetime that causes the effect of gravity, is the event horizon.
So you are absolutely right. There is a simpler answer.

More details here;
https://www.facebook.com/permalink.php?story_fbid=999378540105442&id=595088680534432
 

Offline SorryDnoodle

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Re: Why are black holes special?
« Reply #6 on: 26/01/2016 14:30:42 »
Thanks for all the answers, quite an interesting read even though it seems I have to wait for the proof, but very interesting none the less. Just hope someone figure's em out before i kick the bucket.
 

Offline Georgia

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Re: Why are black holes special?
« Reply #7 on: 26/01/2016 17:24:12 »
Hi SorryDnoodle,

We happen to have just made a podcast all about blackholes - it's on our front page now!

We discuss the basics of how they work and look at some more complicated ideas. Not the exact answers to your question but hopefully an interesting listen all the same!

 

Offline syhprum

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Re: Why are black holes special?
« Reply #8 on: 26/01/2016 20:59:19 »
I have often wondered why there is supposed to be something magical about black holes the density of the matter inside the event horizon does not need to be much greater than that of Neutrons that are composite particles i.e quarks .
why is it not possible that a further stage of compression can take place without the density becoming infinite
 

Offline SorryDnoodle

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Re: Why are black holes special?
« Reply #9 on: 26/01/2016 22:26:45 »
Hi SorryDnoodle,

We happen to have just made a podcast all about blackholes - it's on our front page now!

We discuss the basics of how they work and look at some more complicated ideas. Not the exact answers to your question but hopefully an interesting listen all the same!

Thanks! Never actually looked into your podcasts so this will be a good start i feel

 

Offline alysdexia

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Re: Why are black holes special?
« Reply #10 on: 30/01/2016 08:10:22 »
Hi SorryDnoodle,

We happen to have just made a podcast all about blackholes - it's on our front page now!

We discuss the basics of how they work and look at some more complicated ideas. Not the exact answers to your question but hopefully an interesting listen all the same!

Quote
Black holes are mysterious regions of space with sufficient gravity to bend the very fabric of space itself - called spacetime - in such a way that nothing, not even light, can escape. Anything unfortunate enough to come into contact with one will be annihilated, becoming part of the black hole itself.

You mean fictional religions of mathematics.  Black holes are a religion and nothing more.

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But how do these mysterious entities work and how did they form?

They don't work and they don't form.

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Matt - A black hole in it’s simplest possible terms is an object that is incredibly dense, and the speed that it takes to get away from an object is related to how dense it is.  The more dense it is, the faster you’ve got to go and there’s a point to which it so dense that not even light can get away from its surface.

Learn how to spell its.  This idiotic claim relies on Galilean, not Lorentzian, relativity.  It has already been disproven for feynmanium: https://en.wikipedia.org/wiki/Extended_periodic_table#End_of_the_periodic_table.

I hope Matt Middleton loses his job.

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Georgia - Like being the fastest thing in the universe.

The black hole is the fastest thing; the liht is the swiftest thing.

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Matt - Stars are in constant constant battle against themselves.  They’re producing lots of radiation; that radiation provides and outward push against the inward pull of gravity, and eventually stars sadly run out of fuel and then gravity’s going to win.

Sorry but this can't happen.

[badly-written non-new lave of the interview omitted]
 

Offline evan_au

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Re: Why are black holes special?
« Reply #11 on: 30/01/2016 11:22:20 »
Quote from: alysdexia
This idiotic claim ... has already been disproven for feynmanium: https://en.wikipedia.org/wiki/Extended_periodic_table#End_of_the_periodic_table.

I think that perhaps the tense is a little scrambled here.
This section in Wikipedia is talking about theoretical problems that might prevent elements beyond 137 (or 173) from being stable.

It was only at the end of 2015 that IUPAC formally recognized the fleeting existence of element 118.

So I am puzzled about why the hypothetical properties of element 137 (or 173), elements that have never been observed in the laboratory could already have proven something about black holes?

Black Holes don't rely on quantum theory or even general relativity. Even in Newton's classical physics, a sufficiently massive object would not allow light to escape.

Quote
Sorry but this can't happen.
Why can't stars be in a balance between gravitation, pressure and temperature?
And if stars run out of fusionable fuel, why won't the radius of the star shrink and the surface gravity increase?
 

Offline alysdexia

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Re: Why are black holes special?
« Reply #12 on: 30/01/2016 12:19:44 »
Quote from: alysdexia
This idiotic claim ... has already been disproven for feynmanium: https://en.wikipedia.org/wiki/Extended_periodic_table#End_of_the_periodic_table.

I think that perhaps the tense is a little scrambled here.
This section in Wikipedia is talking about theoretical problems that might prevent elements beyond 137 (or 173) from being stable.

It was only at the end of 2015 that IUPAC formally recognized the fleeting existence of element 118.

So I am puzzled about why the hypothetical properties of element 137 (or 173), elements that have never been observed in the laboratory could already have proven something about black holes?

A classic or semiclassic model like the Bohr model relies on escape velocity, or the virial theorem, thus for black holes this is equated to the light cone or Rindler horizon.

"Under this approximation, any element with an atomic number of greater than 137 would require 1s electrons to be traveling faster than c, the speed of light. Hence the non-relativistic Bohr model is clearly inaccurate when applied to such an element."

Quote
Black Holes don't rely on quantum theory or even general relativity. Even in Newton's classical physics, a sufficiently massive object would not allow light to escape.

Black holes rely on Galilean relativity (Newton-compliant) or general relativity (Einstein- and Rindler-compliant), not Lorentzian relativity.  The only effect that can override Lorentz corrections falls under Snell's law (thus the Chèrèncov effect) and that doesn't allow dark stars either, only a delay.

Quote
Quote
Sorry but this can't happen.
Why can't stars be in a balance between gravitation, pressure and temperature?
And if stars run out of fusionable fuel, why won't the radius of the star shrink and the surface gravity increase?

It shrinks until inertia catches up.  To shrink further requires input of pressure that gravity can't supply.
 

Offline MurBob

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Re: Why are black holes special?
« Reply #13 on: 31/01/2016 06:46:06 »
In my mind they are just like a neutron star with a tad bit more mass making them 'suck' in light as well as matter.

As I understand it, the path of a photon (Light) is not affected by mass or gravity.  Light travels in a straight line through space.

Mass bends space and curves it.  Because light travels in a straight line through space, the curved space makes the light look like its bending.  (IE: Gravitational lens).   

Light will curve around a neutron star because a neutron star's gravity is so extreme that it bends space.

The gravity of a black hole is so much more extreme that space-time is bent to a point where there's no exit for light.  Space kind of folds in on itself.
 

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Re: Why are black holes special?
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