Black hole vs. Black hole, who wins?

[PAllen]

ok; e=mc2...all energy has mass and all mass has energy. right? photons have energy..therefore must have mass. infinite energy vs. infinite mass...the particle achieved 99% of light speed when tried at accelerator..no more. so is a photon something akin to the higgs bosun? so very small that we can't measure it's mass or velocity? I'm just a curious guy and no phd to my name..hoping to get help in layman's understanding of this question. thanks to all.. terry

Many questions, none of them clear to me. One question is clearly for the Relativity forum. The FAQ's on the relativity forum touch on some of these issues, e.g the following:

https://www.physicsforums.com/showthread.php?t=511175

 

[PAllen]

tried your link...said corrupted??

Works for me. No idea what the issue is for you.

 

[Bernie G]

Yes, one might conclude many award winning "recognized authorities" in this field are talking & repeating mathematical baloney. I think the source you give doesn't describe the reasons for a singularity but presumes it. And if a singularity exists in a black hole their analysis of mergers seems valid. But if you have a science background, what is the gravitational energy of a singularity? Infinity? Greater than Mc^2?

Remember that gravitational energy is a required consequence of gravity varying as M/r^2.

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I'd like to discuss about how the maximum gravitational field in a relativistic star should occur at roughly half the radius (r/2), and is about double that at the surface, and is easily supported by pressure of (rho/3)c^2, but that discussion can wait a while as some people could need time to digest the above.

 

[PAllen]

Yes, one might conclude many award winning "recognized authorities" in this field are talking & repeating mathematical baloney. I think the source you give doesn't describe the reasons for a singularity but presumes it. And if a singularity exists in a black hole their analysis of mergers seems valid. But if you have a science background, what is the gravitational energy of a singularity? Infinity? Greater than Mc^2?

Remember that gravitational energy is a required consequence of gravity varying as M/r^2.

**********

I'd like to discuss about how the maximum gravitational field in a relativistic star should occur at roughly half the radius (r/2), and is about double that at the surface, and is easily supported by pressure of (rho/3)c^2, but that discussion can wait a while as some people could need time to digest the above.

I don't think anyone believes the actual singularity is real. I think a majority of experts think event horizons are real, and that these GR simulations are correct overall for external phenomena (GW emission, horizon merger), while not being correct for exactly what happens inside the horizon.

I am not aware of any treatment of BH merger based on a reputable alternative to GR. I have invited you to provide a reference to such in a peer reviewed journal.

If you post personal theories without such reference, you are in violation of PF rules.

 

[Bernie G]

"What goes on behind the event horizon is not knowable. "

Not so. But it takes the merger of two approximately equal size black holes to see what's inside. These mergers are rare and can only be realistically expected in merging galaxies. When 2 equal size black holes merge, gravity is nulled temporarily at the merger point, and if there's anything in the outer volume of the black holes it will eject. So you get to temporarily "see" what's inside. If "mainstream black hole science" concludes that the energy of a black hole is greater than Mc^2, than that science is wrong.

 

[Bernie G]

PAllen: Gravitational energy of (0.6GM^2)/R or (GM^2)/R can be found in numerous sources. You haven't answered a question a college freshman might be asked:

What is the gravitational energy of a singularity? Infinity? Greater than Mc^2?

 

[PAllen]

PAllen: Gravitational energy of (0.6GM^2)/R or (GM^2)/R can be found in numerous sources. You haven't answered a question a college freshman might be asked:

What is the gravitational energy of a singularity? Infinity? Greater than Mc^2?

These are classical formula, not valid at all in GR. The only allowed way to discuss alternatives to GR in these forums in "Beyond the standard model", and such discussion is limited to alternatives that have been published in peer reviewed journals (e.g. string theory, loop quantum gravity, causal dynamical triangulation, etc.).

 

[PAllen]

Remember that gravitational energy is a required consequence of gravity varying as M/r^2.

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M/r^2 is simply false in GR - it is Newtonian. It is also false in any hypothetical quantum gravity theory. So you want to disprove GR using a theory empirically disproven by GR.

 

[Bernie G]

Well said, although I don't think that's quite right. And there's no argument from me that event horizons are real. I have to go do animal rescue and then work, and will post a reply tonight.

 

[berkeman]

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