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Black hole anatomy 
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#37
Mar512, 03:57 PM

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#38
Mar512, 04:20 PM

P: 1,261




#39
Mar712, 11:33 PM

P: 124

Why do black holes need to be so mysterious? Why cant they just be like every other mass. Just because g has an escape velocity faster than light who cares. Everything is still there we just can't see it. If we ever find a way to see black holes I would bet that the body of the black hole has an actual diameter and that its growing. 


#40
Mar712, 11:36 PM

P: 1,261

Consult the PF Forums rules on overly speculative posts. The burden is not on me to prove the established canon, nor to disprove your personal theory of the universe.



#41
Mar712, 11:50 PM

P: 6,863

The reason we know that protons are not point particles is that if you ram two protons together you get scattering angles that are consistent with substructure. If you ram quarks and electrons together, you get scattering that is consistent with point particles. Also thermodynamics and QM provide some limits on the types of viable preon models. http://en.wikipedia.org/wiki/Preon Essentially if quarks had substructure, the Heisenberg uncertainty principle would cause enough momentum uncertainty to be larger than the rest mass of the particle. There are also thermodynamic limits. If you have substructure you change the statistics of matter and so that changes its thermal properties. There are ways of getting around those limits, but right now the experimental data is consistent with nonsubstructure and there are some very strong limits as to what theories are consistent with observations. 


#42
Mar812, 12:30 AM

P: 6,863

This is a general argument that works with any set of particles. 


#43
Mar812, 12:31 AM

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#44
Mar812, 12:32 AM

P: 124




#45
Mar812, 12:35 AM

P: 6,863

The reason that solids are solids is because you've filled up all of the available energy states and to kick a particle into a higher energy state takes a lot of energy. If you create additional particles, then you increase the number of energy states, and things become softer. One way of thinking about this is imagine getting hit by a brick. And getting hit by a pile of sand. Because there are more ways that the sand can move, it's a lot softer, and this sort of thing happens at the subatomic level. 


#46
Mar812, 12:39 AM

P: 6,863




#47
Mar812, 12:50 AM

P: 6,863

Suppose you have an infinitely stiff stick. I push the stick on earth, then instantly the end of the stick on the moon moves. Uh. Oh. I just transmitted information faster than light, and that's a nono. So the speed of light puts limits on how stiff something is. So let's think of something else. I hit a table. The atoms in the table change directions and creates a force that pushes back. Now let's suppose I have something that is traveling near the speed of light. Since I can't push it past the speed of light, if I push on something that near the speed of light, it doesn't change speed very much. No matter how much energy I put into it, it won't go past the speed of light. This presents a problem. Suppose I have a table and the particles in it are vibrating at close to the speed of light. If I hit that table, the particles won't react, and so I won't get a force in the other direction. So if I hit a table with particles moving at close to the speed of light, then my hand will fall through the table, and since the particles don't react with each other, solid objects are impossible once you have particles that are moving at close to light speed. So the net result is that it doesn't matter what the table is made of. It doesn't matter how many particles there are. Once I crush the table enough so that the particles are moving near light speed, it will cease acting like a solid object. Having smaller particles makes the problem *worse* since it's easier to push a particle to light speed. This means that if Einstein is right, things will get crushed to nothing. Now this leads to some absurd situations, so we are pretty sure he is wrong. The trouble is that no one knows *how* he is wrong. 


#48
Mar812, 01:15 AM

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#49
Mar812, 01:16 AM

P: 124

Thanks 


#50
Mar812, 01:42 AM

P: 124

I know this is speculating (not overly I hope) but what if the speed of light was not the end all. What if that’s all the faster it could go because of some unknown resistance. It appears gravity out does the speed of light why not other things? 


#51
Mar812, 02:46 AM

Sci Advisor
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#52
Mar1012, 03:23 AM

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#53
Mar1012, 04:48 AM

Sci Advisor
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#54
Mar1012, 07:39 AM

P: 63

I tend to agree with Bill, the idea of a singularity just does not make sense. Why cannot a neutron star be massive enough or small enough to create a black hole. The smallest particle must be incompressible beyond some level of pressure.



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