Black Holes and suction of space

[KhashayarShatti]

From a scientific point of view, generally it is said that BH is defined as a source of suction of matter only. Is there the possibility that space may be sucked into BH in which case the suction of matter takes place similar to a vacuum cleaner? Perhaps it may not be similar to a kind of flow, but suction of space may become stabilized by the reaction of space creating a kind of space differential contour easing the fall of matter. As far as i can see artistic photos of BH swallowing stars, it makes me think of some scientific facts behind it!

[antoniseb]

From a scientific point of view, generally it is said that BH is defined as a source of suction of matter only. ...

Can you cite *any* source for this assertion? Several parts of this statement don't match with my understanding of how it works, but you and I might be having a terminology problem.

[KhashayarShatti]

Can you cite *any* source for this assertion? Several parts of this statement don't match with my understanding of how it works, but you and I might be having a terminology problem.

http://en.wikipedia.org/wiki/Black_hole
"Black holes of stellar mass are expected to form when very massive stars collapse at the end of their life cycle. After a black hole has formed it can continue to grow by absorbing mass from its surroundings. By absorbing other stars and merging with other black holes, supermassive black holes of millions of solar masses may form. There is general consensus that supermassive black holes exist in the centers of most galaxies."

[slang]

http://en.wikipedia.org/wiki/Black_hole
"Black holes of stellar mass are expected to form when very massive stars collapse at the end of their life cycle. After a black hole has formed it can continue to grow by absorbing mass from its surroundings. By absorbing other stars and merging with other black holes, supermassive black holes of millions of solar masses may form. There is general consensus that supermassive black holes exist in the centers of most galaxies."

Where is the word 'suction' in there? And a black hole will happily absorb a foton too, no mass there!

[Strange]

From a scientific point of view, generally it is said that BH is defined as a source of suction of matter only.

It is just gravity. Nothing special.

Is there the possibility that space may be sucked into BH in which case the suction of matter takes place similar to a vacuum cleaner?

Space isn't "stuff" that can be sucked into a black hole. Gravity can be described in terms of geometry: as the curvature of space time. This curvature changes the path of objects and causes the force of gravity. At the horizon of a black hole this curvature becomes so great that light cannot escape.

But there isn't any actual space-time "stuff" being curved; it is just a mathematical description.

[KhashayarShatti]

It is just gravity. Nothing special.



Space isn't "stuff" that can be sucked into a black hole. Gravity can be described in terms of geometry: as the curvature of space time. This curvature changes the path of objects and causes the force of gravity. At the horizon of a black hole this curvature becomes so great that light cannot escape.

But there isn't any actual space-time "stuff" being curved; it is just a mathematical description.

Bending of light also occurs when light enters different mediums the most famous one being when light enters water. A very clear bending occurs. This is in fact a proven scientific fact, but the validity of mathematical description of space may not be currently a proven scientific fact. So if space is not sensed as a medium of ingredients, there should be at least some proof of the wrong validity of refractive index of vacuum. I cannot find such a proof from scientific documents to convince myself though it may turn out to be wrong but scientifically this case should be rejected by a kind of proof.

[Strange]

Bending of light also occurs when light enters different mediums the most famous one being when light enters water. A very clear bending occurs.

I'm not sure how that is relevant...

This is in fact a proven scientific fact, but the validity of mathematical description of space may not be currently a proven scientific fact.

Well, apart from there is no such thing as a "proven scientific fact", the description of gravity as curvature of spacetime has been very thoroughly tested and is as close to "fact" as science every gets.

So if space is not sensed as a medium of ingredients, there should be at least some proof of the wrong validity of refractive index of vacuum.

The refractive index of vacuum is 1, by definition. But, again, I'm not sure how this is relevant.

I cannot find such a proof from scientific documents to convince myself though it may turn out to be wrong but scientifically this case should be rejected by a kind of proof.

I'm sorry. I don't understand that. I'm not even sure what you are looking for.

[KhashayarShatti]

......
I'm sorry. I don't understand that. I'm not even sure what you are looking for.

In gravitational lensing light is said to bend due to gravity, but generally it is not described by spectral components of light, only bending is generally cited. These two cases of bending of space-time and a medium with refractive index seem to be so similar that to prove one against the other seems to have been either neglected or impossible.
A light bow in the sky is a good proof of bending of light as it enters different gaseous medium of air.

[Swift]

In gravitational lensing light is said to bend due to gravity, but generally it is not described by spectral components of light, only bending is generally cited. These two cases of bending of space-time and a medium with refractive index seem to be so similar that to prove one against the other seems to have been either neglected or impossible.
A light bow in the sky is a good proof of bending of light as it enters different gaseous medium of air.

No, the bending of light by refraction and the bending of light by gravity (curvature of space-time) are completely different phenomena. And, as Strange said, the bending of light by the curvature of space-time has been experimentally shown multiple times.

[Strange]

In gravitational lensing light is said to bend due to gravity, but generally it is not described by spectral components of light, only bending is generally cited. These two cases of bending of space-time and a medium with refractive index seem to be so similar that to prove one against the other seems to have been either neglected or impossible.

Completely different. For example, the bending of light by changing refractive index causes "dispersion"; the amount of bending varies with wavelength. This is why we get a spectrum out of a prism. This is not the case for gravitational lensing.

[Cougar]

But there isn't any actual space-time "stuff" being curved; it is just a mathematical description.

Then how is frame-dragging explained? These "mathematical descriptions" describe what is observed.

[Strange]

Then how is frame-dragging explained? These "mathematical descriptions" describe what is observed.

They describe the (changing) geometry of space-time.

I don't think of space-time as a material substance though (despite the fact I have just had Einstein's "according to the general theory of relativity space is endowed with physical qualities; in this sense, therefore, there exists an ether" quote thrown at me in another forum).

[pogono]

Space isn't "stuff" that can be sucked into a black hole. Gravity can be described in terms of geometry: as the curvature of space time. This curvature changes the path of objects and causes the force of gravity. At the horizon of a black hole this curvature becomes so great that light cannot escape.

But there isn't any actual space-time "stuff" being curved; it is just a mathematical description.

I can not agree with this statement.
I would like to support "sucking space-time" as correct explanation.

In my article (please, notice, it is part of mainstream science, now) I prove, utilizing Rindler's transformation for spherically symmetric case, there is a way to consider curved space-time as locally accelerated photons!

I show, that by trying to accelerate photons we do not change its velocity, but instead, at the end of all calculations we obtain space-time curvature increase, while photons still move with constant speed of light!

It means, that we may try to reverse Einstein's reasoning as follows:

1. Gravity acts as attracting photons
2. Trying to accelerate photons we obtain space-time curvature increase
3. Space-time curvature change paths of material bodies

Therefore, it may be explained as space-time sucking situation.

[Ara Pacis]

I can not agree with this statement.
I would like to support "sucking space-time" as correct explanation.

In my article (please, notice, it is part of mainstream science, now) I prove, utilizing Rindler's transformation for spherically symmetric case, there is a way to consider curved space-time as locally accelerated photons!

I show, that by trying to accelerate photons we do not change its velocity, but instead, at the end of all calculations we obtain space-time curvature increase, while photons still move with constant speed of light!

It means, that we may try to reverse Einstein's reasoning as follows:

1. Gravity acts as attracting photons
2. Trying to accelerate photons we obtain space-time curvature increase
3. Space-time curvature change paths of material bodies

Therefore, it may be explained as space-time sucking situation.

I'm trying to visualize that. From what I surmise, you've just given us a good definition of suck, but by doing so, you've defined it such that the gas-pressure concept of suction should more appropriately be termed "blow". (cue Spaceballs reference) So, if I understand correctly, this would still argue against the OP.

[Strange]

It means, that we may try to reverse Einstein's reasoning as follows:

1. Gravity acts as attracting photons
2. Trying to accelerate photons we obtain space-time curvature increase
3. Space-time curvature change paths of material bodies

Therefore, it may be explained as space-time sucking situation.

You have just reversed the math and swapped cause and effect. Gravity works in the absence of photons so I don't see the point.

[KhashayarShatti]

You have just reversed the math and swapped cause and effect......

Generally , force doesn't seem to have an understandable microscopic meaning. If we think about it, energy in a peculiar way causes force, but sometimes perhaps it would be more understandable to say that acceleration appears first which gives the feeling of force. In this case we could say a*m =F rather than F=a*m.
When we pin point on the true nature of motion, it seems to me that when some sort of space-time change occurs, it produces acceleration which could be termed as force. As an example, when someone wants to start to walk, it is said that energy is used to create force, but when we deeply focus on how this force is generated, we realize that internally at microscopic scales some sort of change in space perhaps takes place which causes acceleration and accordingly a kind of motion by force. Sometimes we may have to swap cause and effect.
Another example: Electrostatic force and magnetic force, may have similar effects by causing a kind of change in space and hence, dx/dt and then d^2x/dt^2(Shaula thanks for your mentioning correct terminology). In this case all forces of nature may have similar definition and rising from change in space-time.

[cjameshuff]

Generally , force doesn't seem to have an understandable microscopic meaning.

What? It doesn't matter if you're looking at microscopic or macroscopic scales. Different forces may dominate, but the concept has the same meaning.

If we think about it, energy in a peculiar way causes force,

A misleading if not just wrong way to look at things. Energy is a conserved quantity with various relationships to force that depend on the system you are looking at.

but sometimes perhaps it would be more understandable to say that acceleration appears first which gives the feeling of force. In this case we could say a*m =F rather than F=a*m.

...those equations define a relationship between quantities. They don't imply any sort of sequential ordering or cause and effect relationship.

When we pin point on the true nature of motion, it seems to me that when some sort of space-time change occurs, it produces acceleration which could be termed as force. As an example, when someone wants to start to walk, it is said that energy is used to create force, but when we deeply focus on how this force is generated, we realize that internally at microscopic scales some sort of change in space perhaps takes place which causes acceleration and accordingly a kind of motion by force. Sometimes we may have to swap cause and effect.
Another example: Electrostatic force and magnetic force, may have similar effects by causing a kind of change in space and hence, dx/dt and then d^2x/dt^2(Shaula thanks for your mentioning correct terminology). In this case all forces of nature may have similar definition and rising from change in space-time.

What kind of "change in space-time"? How is this at all a useful way to look at things?

Your understanding of the fundamentals is incorrect, and your conclusions are variously either wrong or meaningless. I suggest learning more of basic physics before trying to redefine it.

[pzkpfw]

... (please, notice, it is part of mainstream science, now) ...

Please clarify that comment. e.g. Has your paper been "approved" by a recognised peer review committee? Has its content be "accepted" (as distinct from published)?

[pogono]

You have just reversed the math and swapped cause and effect. Gravity works in the absence of photons so I don't see the point.

Strange, please show me any place in space without photons ;-)
At least you find there micro-wave background.

Please clarify that comment. e.g. Has your paper been "approved" by a recognized peer review committee? Has its content be "accepted" (as distinct from published)?

pzkpfw, I do not want to hijack the thread talking about my paper, here.
I put below some short explanation. If you expected more, show me right place to do it.

1. My paper was reviewed by 2 professional reviewers and accepted by Editorial Office. It was regular peer-review process. Maybe JMP just use less censorious peers then other Journals.

2. Moreover, here, on BAUT, user Kuroneko already generalized my equations confirming its correctness (covariant and Tensor based). You may see there, exactly what I mention above - we may model curved space-time as locally accelerated photons. It is hard to argue with math!

3. Up to now, I got responses from at least 10 professional physicists from the world confirming my equations. If you wish I send you names and emails (I have to ask them, before). They were mostly shocked, but did not find any mistake in my reasoning. With 3 of them I prepare next publication in GR&G Journal. One of them is going to say few words about my approach at conference: Relativity and Gravitation 100 Years after Einstein in Prague.

I understand, that most of you have problem with my paper. It begun in ATM section and many of you was fighting against my idea. But, please notice two facts:
- present shape of my article is far from first shape of the paper presented in ATM.
- math says, that I have found a way to consider photon acceleration even if you judge it is ridiculous.

ETA:
For those, who do not want to follow Kuroneko reasoning, here are final Conclusions:

We've just seen that the following are all related:
gravitational acceleration ⇄ gravitational gamma or redshift ⇐ timelike Killing field, and similar but more complicated situation applies to stationary spacetime.
(...) we can do a backwards derivation of Schwarzschild spacetime using an additional free-falling velocity v_r = sqrt(r_s/r) (...)

Conclusion: The gravitational action of a static spacetime is equivalent to the action of a 3-dimensional spacelike manifold minimally coupled to a scalar field.

It means exactly, what I mention here.

[Ara Pacis]

Suction is caused by pressure. There is no pressure in space.

[trinitree88]

Suction is caused by pressure. There is no pressure in space.

Hmmmm, Ara.. there is a very, very slight radiation pressure due to the zeropoint radiation and the neutral current scattering by the neutrino sea in all of space.. pete

[Ara Pacis]

Hmmmm, Ara.. there is a very, very slight radiation pressure due to the zeropoint radiation and the neutral current scattering by the neutrino sea in all of space.. pete

Ah, true. I should have stated that I meant mechanical pressure as in a gas medium.

[chiragrav]

Who would need to stop thinking about this particular phenomenon of gravitational collapse!
Any body have any ideas/thoughts about Hawking Radiation>?

[Amber Robot]

Ah, true. I should have stated that I meant mechanical pressure as in a gas medium.

There's a lot of gas in space. So there's pressure there. Just not a lot compared to here on Earth.

[Ara Pacis]

There's a lot of gas in space. So there's pressure there. Just not a lot compared to here on Earth.

I'm not talking about space, I'm talking about vacuum.

[Ara Pacis]

Actually, gravity doesn't bend light. It bends space. Light is following a straight path through bent space and that makes it seem bent to us, but that's because we're in a different frame of reference. Refraction, on the other hand, occurs at density interfaces between different media and different frequencies are refracted at different angles.

Also, is it proper to say that vacuum is a medium or would it be better to say that vacuum is the absence of medium? I'm not sure.

[Shaula]

The red green and black components there are using different models. It says so in the key to the diagram, has nothing to do with colours of light.

[KhashayarShatti]

The red green and black components there are using different models. It says so in the key to the diagram, has nothing to do with colours of light.

Right. I didn't notice this"the black showing the situation when the Sun is not close to the star". So in fact the star is seen by the observer at many different positions which are shown by different colours. Now has it been experimentally observed that there is no dispersion of light in this situation where there is the combination of these lights from deflection and delay or is it a mathematical proof? You know that the gaseous state of matter around stars or galaxies does cause some dispersion which may make observation difficult to analyze the situation which only concerns the bending due to space-time.

[Ara Pacis]

Right. I didn't notice this"the black showing the situation when the Sun is not close to the star". So in fact the star is seen by the observer at many different positions which are shown by different colours. Now has it been experimentally observed that there is no dispersion of light in this situation where there is the combination of these lights from deflection and delay or is it a mathematical proof? You know that the gaseous state of matter around stars or galaxies does cause some dispersion which may make observation difficult to analyze the situation which only concerns the bending due to space-time.

It's not different positions shown by the colors, but different predictions based on two different mathematical models of the sun present, and one without the sun present for baseline comparison. Newtonian prediction does not, by observation, actually occur as light tends to more closely follow the Einsteinian prediction.

[KhashayarShatti]

Well. To focus on the main topic, whatever is shown, it is clear that the more the bending of space time , the more the effect of gravity. So in a physical sense gravity exists more closer to the surface of BH or a star.
In real sense there is the motion of matter being dragged into BH which is said to be due to bending of space time.It means that bending of space-time is the cause of motion which has a physical sense; it is acting as a force rising from a kind of energy to generate motion. In this case matter itself is not causing the actual motion, the space itself is causing this motion. My question is : could there be less space around BH(due to absorption of space by BH similar to absorption of matter by BH) causing straightening of space there and accelerating objects? Although it may be converging situation for matter, but it may be sensed as a situation that shows when there is less space, acceleration of matter may takes place. You see gravity causes acceleration in a converging situation and space expansion causes acceleration in a diverging situation and we know it as a scientific fact.
I'm not sure if i've been able to make it clear what i want to say. Sorry.
Let me puit it this way: Expansion of the universe and gravity have similar effect on the motion of matter, one being diverging the other being converging but both of them seem to rise from the same situation regarding the condition of space. I hope my bad description will not be regarded as ATM.