Black Hole: Infinite Density, Infinite Buoyancy?

In summary: According to the data in the chart, the slope of the curve crosses the y-intercept at a density of 1.6x10^21 kg/m^3.
  • #1
Ryan H
15
0
If a black hole has an infinite density, then one would think that anything would float inside of it. And since it's infinitely dense, the object(s) being pulled in would have an infinite buoyancy, causing it to be shot back out of the black hole at a seemingly infinite speed. So why don't these two forces cancle each other out?
 
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  • #2
quantum effects probably prevent a singularity from reaching zero/infinite parameters
 
  • #3
Ryan H said:
If a black hole has an infinite density, then one would think that anything would float inside of it. And since it's infinitely dense, the object(s) being pulled in would have an infinite buoyancy, causing it to be shot back out of the black hole at a seemingly infinite speed. So why don't these two forces cancle each other out?
Only the singularity at the center would have infinite density according to general relativity, inside the event horizon is empty space (and infalling matter) just like outside the event horizon.
 
  • #4
  • #5
There is no "inside" to a BH singularity (point).
 
  • #6
Orion1 said:

'non-rotating' Classical Universe-Schwarzschild Singularity Density solution for a one-dimesional 'point-like' object:
[tex]\boxed{\rho_u = \frac{M_u}{2} \sqrt{ \frac{c^3}{\hbar G}}}[/tex]

BH Singularity Density infinities do NOT exist.

Reference:
https://www.physicsforums.com/showpost.php?p=370142&postcount=24
Is this equation something you derived yourself based on your own ideas, or did you get it from a textbook or something written by a professional physicist? The derivation you gave on that thread seemed to involve both QM and GR...would you agree that according to classical GR alone, the singularity has infinite density?
 
  • #7
I would argue the Planck density is the limit in the physical universe.
 
  • #8
Planck Philosophy...

JesseM said:
Is this equation something you derived yourself based on your own ideas, or did you get it from a textbook or something written by a professional physicist?


[tex]\boxed{\rho_u = \frac{M_u}{2} \sqrt{ \frac{c^3}{\hbar G}}}[/tex]

The solution for this 'non-rotating' classical schwarzschild singularity density for a one dimensional 'point-like' object was derived by me based on research on these physical models.

Note that the Schwarzschild solution is only a solution for Schwarzschild BHs with zero angular momentum , this is a highly improbable state.

Neutron star spin increases with increased density, therefore an object generating in the core of a neutron star or supernova without spin is...impossible. Only BHs with angular momentum can exist in the Universe, a rotating Kerr BH.

JesseM said:
Would you agree that according to classical GR alone, the singularity has infinite density?

The Classical General Relativity model is based upon four total dimensional space-time [tex]n_t = 3 + 1 = 4[/tex] (3 space + 1 time). Solutions for models for that contain dimensions of less than four are not valid solutions in the Universe.

The classical solution stated for 1 dimension is actually 2 dimensions [tex]n_t = 1 + 1 = 2[/tex] (1 space + 1 time), because solutions with with a total dimensional range of less than 4 [tex]n_t < 4[/tex] cannot exist in the Universe, all solutions for total dimensional ranges between 0 and 3 are not real valid solutions because they cannot exist in a four total dimensional General Relativity Universe.

Classical General Relativity models based upon 0 to less than 2 total dimensions are typical of producing solutions with 'infinities', and is only a division by zero in an 'undefined' model.

This solution is based upon 2 dimensional space, the singularity described 'exists' in only 2 space dimensions (and 1 time) [tex]n_t = 2 + 1 = 2[/tex] (2 space + 1 time). [tex]n_t = n_s + n_t[/tex].

Classical Schwarzschild Singularity Dimension Number:
[tex]n_s = 2[/tex] - dimension #
[tex]dV_s = \pi r_p^2[/tex] - volume
[tex]L = 0[/tex] - angular momentum

Solution for 'non-rotating' Classical Schwarzschild Singularity Density for a two dimensional 'point-like' object: (flat disc)
[tex]\rho_s = \frac{dM_s}{dV_s} = \frac{dM_s}{\pi r_p^2} = \frac{M_u c^3}{\pi \hbar G}[/tex]

[tex]\boxed{\rho_u = \frac{M_u c^3}{\pi \hbar G}}[/tex]

[tex]
\begin{picture}(100,100)(0,0)
\put(0,0){\circle{3}}
\put(0,0){\line(1,0){100}}
\put(0,0){\line(0,1){100}}
\put(0,33){\circle{3}}
\put(34,55){\circle{3}}
\put(67,77){\textcolor{red}{\circle{3}}}
\put(67,77){\textcolor{blue}{\circle{6}}}
\put(100,100){\circle{3}}
\put(100,5){{n}}
\put(5,100){{ln p}}
\end{picture}
[/tex]

Chronos said:
I would argue the Planck density is the limit in the physical universe.
In a four dimensional space-time physical Universe, the average Planck density is a solution and a physical 'limit' in the Universe.

Based upon the current logarithmic slope in the chart, at what density value does the slope cross the y-intercept?

Reference:
https://www.physicsforums.com/showpost.php?p=370142&postcount=24
 
Last edited:

1. What is a black hole?

A black hole is a region in space where the gravitational pull is so strong that nothing, not even light, can escape from it. This is due to the immense amount of mass packed into a very small space, creating a gravitational force that is strong enough to trap everything within its event horizon.

2. How is infinite density possible in a black hole?

Infinite density is a theoretical concept that describes the amount of matter in a black hole being compressed into an infinitely small point. This is possible because, as an object gets closer to the center of the black hole, the gravitational force increases, causing it to shrink in size. As the object's size decreases, its density increases, eventually reaching infinite density at the singularity of the black hole.

3. What is infinite buoyancy and how does it relate to black holes?

Infinite buoyancy is another theoretical concept that describes the idea that objects within a black hole are not subject to the same laws of physics as objects outside of it. This is because the intense gravitational pull of a black hole warps space-time, causing objects to behave differently. As a result, objects within a black hole may appear to have infinite buoyancy, as they are not affected by the same forces that govern objects in our observable universe.

4. Can anything escape from a black hole?

Nothing can escape from a black hole once it has passed the event horizon, which is the point of no return. This includes light, as even photons (particles of light) are not fast enough to escape the intense gravitational pull of a black hole. However, there is still much we do not know about black holes, so it is possible that future research may reveal ways for objects to escape from them.

5. What is the significance of studying black holes?

Studying black holes can help us better understand the laws of physics and the universe as a whole. They also play a crucial role in the formation and evolution of galaxies. Additionally, studying black holes can provide insight into the nature of gravity and the potential for time travel. Furthermore, black holes are fascinating and mysterious objects that continue to captivate the curiosity and imagination of scientists and the general public alike.

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