Why a Black Hole like object can't collapse in a singularity ?

[czeslaw]

Why the Galaxy does not collapse into a central supermassive Black Hole ?
Everybady knows – because a kinetic energy of the galaxy is greater then gravitational energy.

Why a gasoeous nebula does not collapse into a Black Hole ?
Everybody knows its kinetic energy is greater then gravitational energy.
It may to collapse if it radiate out its kinetic energy and gasoeous nebulas do it and become a star.

When a star collapses into a neutron star ? When it radiate its kinetic energy and gravitational energy is greater then the energy of the EM field + remaining kinetic energy.

Sometimes a neutron star is more massive than 3 Suns and kinetic energy of the particles radiate out till ...
Till the object become Black Hole like object.

We know that Black Hole like object absorbs more energy than emits by definition.
That way it is a limit for this object and it can not violate. The particles inside this object can not lose their kinetic energy and they will move through the whole volume of the Black Hole like object for ever.

Do you know how to extract the kinetic energy from a such closed system ?
Help S. Hawking to get a Nobel prize.

[korjik]

uhhhh.... no
The galaxy dosent collapse due to angular momentum

the nebula dosent collapse due to angular momentum

the neutron star dosent collapse due to neutron degeneracy pressure

the black hole does collapse because the gravity exceeds neutron degeneracy pressure

for stellar mass black holes, the hawking radiation is miniscule. Trying to get energy from hawking radiation is kinda like trying to heat your home with rusting steel. technically, it is possible, but the quantity is so small it isnt really helpful.

As for how to extract KE, try a sail. the particles from the hawking radiation will bounce off and give you a net increase in energy.

[Astrowannabe]

What korjik said is correct.

I think where your confusion is coming from, czeslaw, is that you think a neutron star has to radiate out it's excess kinetic energy in order to collapse into a black hole. However, kinetic energy isn't what's keeping a neutron star up in the first place. A neutron star is no longer undergoing nuclear fusion, and so isn't producing any more of it's own internal energy. And while the heat generated from it's collapse is a lot, it's nowhere near enough energy to balance the inward pull of gravity. The only thing that is strong enough is the neutron degeneracy pressure, like korjik said. Once that is overcome the star simply collapses, without the star needing to radiate anything else.

Since the star doesn't need to radiate anything else to form a black hole, the fact that hawking radiation is so miniscule won't have an effect on it's collapse.

[czeslaw]

You are right if the neutron star has 3 to 7 solar masses. In this case a relative cold and nonrotating neutron star will demage its structure. It is a question.

What about a star with 7 and more solar masses ? When it become Black Hole like Object (just before the creation of the Event Horizon) all neutrons oscillate with a maximum velocity close to speed of light because they are accelerated by a strong gravitational field. This oscillation causes collisions with a relativistic velocity - it causes creation of the particles/antiparticles and annihilation. A gamma radiation can't go out because it is a Black Hole Like Object, There is a redshifted radio emision only and this object absorbs much more energy from an accretion disc and whole environment.

The neutrons are oscillating and can not stop because they even have more kinetic energy because more energy is absorbed than emitted.

The neutron oscillate and rotate like in gasoeous nebula. This cloud may collapse into a neutron star (there is enough mass) but it has to emit its kinetic energy. There is no other way. It is clear I think.

A big mass is not a sufficient cause.
The main cause is to stop oscillation and rotation - extract the kinetic energy.
If the kinetic energy is not extracted (emitted) like in BlackHole Like Object the collapse stops..
.

[korjik]

What you seem to be talking about is a type II supernova where the core winds up forming a black hole. In this case, most of the energy you are worring about is emitted as neutrinos as the core collapses past the electron degeneracy pressure max. The core itself will simply collapse straight to a singularity. the residual charge and angular momentum become properties of the black hole.

[czeslaw]

What you seem to be talking about is a type II supernova where the core winds up forming a black hole. In this case, most of the energy you are worring about is emitted as neutrinos as the core collapses past the electron degeneracy pressure max. The core itself will simply collapse straight to a singularity. the residual charge and angular momentum become properties of the black hole.

The neutrinos are emitted because the neutrons are created - it is very much energy. It is not all kinetic energy emitted. An ordinary neutron star oscillate and rotate, a greater becomes magnetars, pulsars...
The neutrons are not at rest.

A collapsing star with more than 7 solar masses has an average density like an ordinary neutron star or less. You may count it easy.
In a border condition just before the Event Horizon might be created every particle has an initial kinetic energy + potential energy. The potential energy is in this case almost E=pc - it may reach a relativistic velocity in the gravity well.
If you believe in energy conservation in a closed system -there is enough energy to pass the well of the Black Hole Like Object for all particles moving in this volume and they will move forever if the energy will not be extracted.

There is no Hawking Radiation at all. There is a radio emision only and we observe it from every Black Hole like Object. This objects are strong radio sources. Some radiation may be caused by particles falling down to the object but it is so strong that it is not explained yet.

[korjik]

The core of an exploding supernova is not like a normal neutron star, especially if it is collapsing into a black hole.

The bulk of the energy of the collapsing core is emmitted as neutrons, as the core passes the electron degeneracy pressure maximum. At this point in the collapse, the core has converted into a neutron star, but it is still collapsing. When the neutron degeneracy fails, and the core collapses into a black hole, most of the kinetic energy is straight towards the singularity. There will be some angular component to the KE, which seems to be where you have a problem, but any assymetry to the anglular momentum will quickly be radiated away via gravity waves. This should smooth out the surface of the newly formed black hole. Any particles inside the event horizon have to be in a decaying orbit, and will eventually be sucked into the singularity in the black hole. the energy loss mechanism for this is gravity waves.

While this is happening in the core of the star, the rest of the star is getting blown apart in a type II supernova.

[czeslaw]

If a theoretical Event Horizon has been created there may be everything.

The problem is how to create an Event Horizon. Before it is created the energy moves in every directions in the whole volume of the Black Hole Like Object , stay inside of it and drives (may be absobed) the particles. The energy causes oscillations.

You have to know that Black Hole Like Object is not a Black Hole with an Event Horizon. It is just a massive star with moving particles with a maximum kinetic energy in a closed system. This closed system is only one difference between collapsing Supernova and Black Hole Like Object.
Supernova collapses because it cools (neutrino emision, radiation) - it is not a closed system.
If the emision stops - collapse stops too. It is energy conservation. It stops before the Event Horizon would be created.

[RussT]

czeslaw, they really are 'The Real McCoy'!


http://www.newscientistspace.com/article/dn8025

Supermassive black hole
Measurements by the STIS instrument also allowed astronomers to determine the movement of the blue stars and therefore pinpoint the black hole's mass.

This proved conclusively that it really is a supermassive black hole, with a mass 140 million times that of our Sun - three times more massive than previous estimates.

Until these observations, it had been impossible to rule out some highly unlikely alternatives for the object in the centre of the galaxy - including an extremely dense star cluster, says team member John Kormendy at the University of Texas, US.

"Nailing the black hole in Andromeda" will be remembered as one of Hubble's most important findings, Kormendy says. "It makes us much more confident that the other central dark objects detected in galaxies are black holes too."

Also, remember I mentioned consistency between parts of theories. In grav's gravity thread, you have the whole universe 'inside' a Black Hole, but in this thread you are saying that event horizons don't exist and there is no 'inside' to a Black Hole.

[czeslaw]

There are Black Hole like object - massive and dark stars but they are not the classic BH with an Event Horizon.
How can you prove that they have an Event Horizon if it is impossible according to energy conservation law.
http://arxiv.org/PS_cache/astro-ph/pdf/0207/0207270.pdf no proof of Event Horizon existence.

[korjik]

If a theoretical Event Horizon has been created there may be everything.

The problem is how to create an Event Horizon. Before it is created the energy moves in every directions in the whole volume of the Black Hole Like Object , stay inside of it and drives (may be absobed) the particles. The energy causes oscillations.

You have to know that Black Hole Like Object is not a Black Hole with an Event Horizon. It is just a massive star with moving particles with a maximum kinetic energy in a closed system. This closed system is only one difference between collapsing Supernova and Black Hole Like Object.
Supernova collapses because it cools (neutrino emision, radiation) - it is not a closed system.
If the emision stops - collapse stops too. It is energy conservation. It stops before the Event Horizon would be created.

An event horizon isnt created. it isnt a surface like the surface of the earth, or even like the surface of the sun. An event horizon is where time dilation goes to infinity. It is merely a notional spot, normally in the shape of a surface. There is no creation involved.

the second part of this is that anything inside the event horizon must go into the singularity. No loss of energy is needed, because no energy is being lost. the equal energy orbital path just leads into the singularity. ALL the energy inside the event horizon, in any form, just becomes part if the mass of the black hole.

[czeslaw]

An event horizon isnt created. it isnt a surface like the surface of the earth, or even like the surface of the sun. An event horizon is where time dilation goes to infinity. It is merely a notional spot, normally in the shape of a surface. There is no creation involved.

the second part of this is that anything inside the event horizon must go into the singularity. No loss of energy is needed, because no energy is being lost. the equal energy orbital path just leads into the singularity. ALL the energy inside the event horizon, in any form, just becomes part if the mass of the black hole.

You are right about a clasic Black Hole. If the Mass/Radius = c^2/2G (a Schwarzschild Radius) the object is a clasic Black Hole with an Event Horizon.
I am interesting a moment before the star collapses and reaches this Schwarzschild Radius. Every particle is accelerated in the strong gravitational field to a relativistic velocity close to speed of light and at the Schwarzschild Radius it has reach a speed of light. All sychrotron radiation falls mostly into the heavy object and a redshifted radio emission goes away only. In classic Black Hole radio emision can't escape.

The most imprtant problem is that all particles move with a relativistic velocity and can't rest because they absorb more energy then emit. The collapse has to stop because the particles cant lose its kinetic energy and mass of the object is not under the Schwarzschild Radius.

It is like a boiled water. You can collect a water of a steam but you have to cool it. If you press the steam or gas the kinetic energy increases till the balance.
In Black Hole Like Object is a limited gravitational field causes a limited force F=GmM/r^2. it is not infinitely strong. The oscillations and rotations of the particles may create a balance before the Mass/Radius=c^2/2G.

[korjik]

The particles dont need to stop, they dont need to lose their energy to create a black hole.

This actually ties in with the incorrect analogy you have. If you collect steam, you can convert it back to water by compressing it. You will need alot of pressure, but it can be done.

In a collapsing star, the force on any particle is gravitational and pressure, not just gravitational. The whole point of the mass limit of a neutron star is that when you are above the limit, the collapse of the core does have enough energy to push a large portion of the core inside its Schwarzschild radius. The fact that the particles in the core that are now inside the schwarzchild radius still have KE isnt relevant. Once they are inside the radius, all pathlines head into the singularity. Inside the event horizion, you cannot orbit the singularity, you cannot oscillate around it, all you can do is fall into it. All that happens is the KE is part of the mass of the black hole

[czeslaw]

You write about a Clasic Black Hole, Korjik. Clasic Black Hole has Mass/Radius=c^2/2G and its mass is under an Event Horizon. In this case everything collapses into a singularity - it is a theory about it.

I write about a moment before the star reaches a Schwarzscild Radius and there is no theory how to cross an infinite time dilation, mass increase, length contraction. You may read arguments of Chapline and Laughlin - prophessional physicists (Nobel laureate).
http://www.newscientist.com/article.ns?id=mg18925423.600&feedId=online-news_rss20

I would like to prove that classic Black Hole does not exists because there is always kinetic energy more than gravitational potential energy.
Kinetic energy is 0,5 mv^2 and centrifugal force 0,5mv^2/r
Gravitational force is GmM/r^2 minus gravity of the outer mass.

We observe accretion disc around Black Hole like object and a matter falling down and jets from the Black Hole. The nature of the jets is not completely clear - you may read about it.
We observe binary stars and their collision - there are many unexplained questions.

A particle spiraling around a Black Hole reaches relativistic velocity close to speed of light. If all particles are moving with a relativistic velocity in a closed system before the star collapses under Event Horizon they will never create a Black Hole. They will exchange their kinetic energy like a nebula cloud.