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rjbeery

Black holes and evaporation

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Posted (edited)
Quote

 

Yes but you can no longer track them past the EH...

Does the black region within the accretion disk not indicate no light signal at any spectrographic frequency ?

The image used more than visible light frequencies. A neutron star isn't a true blackbody while the event horizon is as close to perfect blackbody as you can get in nature. It's quite easy to tell the difference from a neutron star from a BH lol.

Are you intentionally trying to be obtuse ?

Edited by Mordred

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Posted (edited)
19 hours ago, rjbeery said:

Vaidya black holes do not allow the infinite observer to see the event horizon in finite time

So far as I know (without having been successful in completing the calculation myself, due to the presence of off-diagonal terms) they do. It is in Schwarzschild spacetime that coordinate time to the horizon diverges, but not in Vaidya spacetime. In either case, your argument was based on Schwarzschild spacetime, not Vaidya, so this isn't relevant to what you said. I'll see if I can get these maths worked out sometime.

19 hours ago, rjbeery said:

My objection to the original diagram used in the Hawking paper remains valid

More than one poster here has explained to you multiple times why it isn't.

19 hours ago, rjbeery said:

If I were going to criticize anything about this and related papers, it's the fact that they are using Hawking "back reaction"

Actually, I haven't got too much of an issue with that bit (though it is problematic too). What bothers me is that in my opinion they are not using the correct energy-momentum tensor, so that would be my main point of criticism.
Either way, there are certain differences between the KMY model and the traditional black hole which should be reflected in the gravitational wave signature of black hole mergers. At present we don't have enough data to support either one (afaik at least), but I am sure we will in the very near future. Let nature speak. Until then, there is little else to add to this thread. Personally I would be happy if it turns out that there are no horizons, because that places valuable constraints on possible models of quantum gravity (my main interest); but if that turns out to be so, then it won't be for the reasons you were trying to argue. And if they do exist, then that is fine with me too, as that in itself is also a valuable finding. As it stands though, the current consensus in the physics community is that horizons are part and parcel of black holes.

Edited by Markus Hanke

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15 hours ago, Mordred said:

The image used more than visible light frequencies. A neutron star isn't a true blackbody while the event horizon is as close to perfect blackbody as you can get in nature. It's quite easy to tell the difference from a neutron star from a BH lol.

Are you intentionally trying to be obtuse ?

You're presuming that either the object in that image is a stable neutron star or a fully-formed black hole. A "frozen star" would still asymptotically red-shift light, it's just that the traditionally predicted effects of an event horizon would exist at r=0.

3 hours ago, Markus Hanke said:

So far as I know (without having been successful in completing the calculation myself, due to the presence of off-diagonal terms) they do. It is in Schwarzschild spacetime that coordinate time to the horizon diverges, but not in Vaidya spacetime.

This is one of those times that my BS-meter is going off. If the static solution gives a full accountability of the future then introducing a change in M does not change that fact. If I may be blunt, I believe you're just presuming that the Vaidya solution says something which bolsters your argument. You've even hedged your bet by saying

Quote

In either case, your argument was based on Schwarzschild spacetime, not Vaidya, so this isn't relevant to what you said.

You've thrown out what I believe to be a false resolution to my objection, and then you say

Quote

Let nature speak. Until then, there is little else to add to this thread. 

This is intellectual insincerity. I raised an objection in the form of a logical contradiction in the OP. In an effort to respond to questions, I found three peer-reviewed papers which discuss my objection in detail (using the Schwarzschild metric), and agree with my objection. You throw out a comment about how the Vaidya solution resolves all problems, which you cannot prove but "may prove in the future", and until then we should just end the conversation.

Is making a concession really that difficult for you?

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On 7/8/2020 at 9:40 AM, rjbeery said:

My objection to the original diagram used in the Hawking paper remains valid,

!

Moderator Note

Ignoring the members who showed it's not is called soapboxing, and it's against the rules, and you've done it a number of times. And now you're starting to re-write history and insult the members who take the time to respond. You've had long enough to support your arguments, and frankly you've failed. You're obviously smart, but you aren't discussing science, you're just trying to make the above sentence seem true. No more preaching, and this thread is closed. Don't open any more threads on this topic, you've gone quite toxic about it.

 

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