Agreed, but I do find it humorous. I'm not here to convince anyone of anything; I use these posts as an opportunity to hone my explanations.
The black hole "frozen star" interpretation is the one that's right
- Thread starter Farsight
- Start date
Agreed: essentially, the event horizon blocks us from seeing the in falling observer cross the event horizon.
No, that's not what the theory predicts. Regardless what you think. Your biggest problem. You're just bullshiting while dodging what the theory predicts. This is what the theory predicts for remote observer and for the local observer. You could derive these formula from the theory if you knew how.
All those remote observers you mention in the other post.
dr/dt_bkkpr = (1-2M/r)(2M/r)^1/2 [at the event horizon dr/dt_bkkpr = 0]
Local observer
dr_shell/dt_shell = (2M/r)^1/2 [at the event horizon dr_shell/dt_shell = 1, c=1]
That's what the theory predicts for each set of coordinates. You want to argue that the 'real coordinates' are the remote bookkeeper coordinates. In the process you've shown you don't know what you're talking about. Pretty much it. For me it's pretty simple. You can't do any physics [or won't ?] yet you continue with the bullshit regardless how many folks point out it's bullshit. Mathematically you're a simpleton when you base reality on the unphysical consequences of a coordinate singularity.
RJ: I thought we'd already been through what you're saying here before:
No, because GR black holes can exist in an outside observer's causal present. This is different from the future death of our sun and the life of Napoleon which are, respectively, exclusively confined to our causal future and our causal past.
I've never seen you give a good explanation of why this discussion on defining "existence" should suddenly become a big deal for black holes or what difference you are expecting it to make.
I mean, suppose an astronomer looks into a telescope and sees something like this rapidly getting bigger in the sky. What kind of reaction are you expecting?
Astronomer: There's a black hole heading for us! It's going to swallow the Earth in less than an hour! According to GR I'm going to be spaghettified! I'm too young for that!
RJBeery: Actually, according to how I define "exist", the black hole you think you see approaching us doesn't "exist" "now".
Astronomer: Oh. I didn't think of it that way. That's okay then.
...?!
No, because GR black holes can exist in an outside observer's causal present. This is different from the future death of our sun and the life of Napoleon which are, respectively, exclusively confined to our causal future and our causal past.
I've never seen you give a good explanation of why this discussion on defining "existence" should suddenly become a big deal for black holes or what difference you are expecting it to make.
I mean, suppose an astronomer looks into a telescope and sees something like this rapidly getting bigger in the sky. What kind of reaction are you expecting?
Astronomer: There's a black hole heading for us! It's going to swallow the Earth in less than an hour! According to GR I'm going to be spaghettified! I'm too young for that!
RJBeery: Actually, according to how I define "exist", the black hole you think you see approaching us doesn't "exist" "now".
Astronomer: Oh. I didn't think of it that way. That's okay then.
...?!
That's because there are varying levels of understanding here. I would not give the same arguments to you. I don't even think you and I disagree on any objective points, just on their consequences or maybe even just their semantic interpretation.
What I find amusing is that nearly all our alternative hypothesis pushers, God Botherers, and Conspiracy claimers, are so easily offended with that often used cry of "ad-hominem abuse".
I've been accused of that in another thread, and yet no specific example of it in that thread, has been given, which I politely asked for. :shrug:
That and the demands by those opposing established science [in a couple of other threads] that scientific texts and quotes from the giants of the past, will not be considered. :shrug:
I mean all this type of anti establishment savagery by these people is really getting too funny for words!
Here's a great example of Farsight refusing to actually do scientific discussion, all the while lying about the relevant science.
It is not the case that, "He's at a place where light has stopped, his clock has stopped," that is clearly an artifact of the coordinates used. Every scientist working in GR today accepts this. Einstein accepted this. Farsight is presenting his own theory, a theory he has never tested because he refuses to work out any details.
If Farsight wants to do scientific discussion, all he has to do is show one physics application for his theory. But in over a decade he has avoided this. That is pathetic.
It basically is, but it really is a wrong semantic interpretation that you are applying: You define "now" and therefore "exist" for black holes in a way that you almost certainly don't apply to your everyday life. If you did, you'd be forced to claim anything you don't currently see doesn't exist, which is nonsensical. Night-time? Sun doesn't exist. Thunder and lightning? Two completely different and unrelated events that didn't get created at the same time. Mars probe? Crashed because you fired the retrorockets 15 minutes too late.
Just like these other events separated by space and/or time, you don't need to see the infaller cross the event horizon to conclude that he did or even calculate what time he did. The structure of space prevents you from seeing it, but you can conclude as surely as the sun didn't explode 7 minutes ago that he did indeed fall in.
Actually Einstein did not accept this. It was 1960-ish before there was even a general acceptance of event horizons.
wiki said:
This is not the same thing. The sun not exploding eventually appears in my past light cone. Any reasonable definition of "to exist now" should also allow us to conclude that it "existed in the past" (eventually). You cannot do that with an EH.
But it was accepted, and science/cosmology has advanced somewhat since then.
Einstein also did not accept QM, although he was one of the Instigators of its discovery.
Observational evidence in later years have shown BH's and EH's must exist, to explain those observations.
GR predicts EH's. It's overwhelming positive track record, leads most level headed cosmologists to accept that interpretation.
This is not strictly true. We have no observational evidence of BHs and EHs due to their very nature. Like I said before, the reason is subtle and it has to do with the lack of a rigorous definition of what it means "to exist". Although BHs and EHs are predicted by GR, GR does not provide a definition of existence. If you would like to take a stab at it I would be happy to discuss.
Care to explain the observations we do have that concludes BH's must exist, by other logical scientific means?
Your subtle reasoning about what exists and what does not exist, does not conform to accepted definitions of mainstream science.
You do not speak for mainstream science on the definition of existence because there isn't one; I'd still be happy to entertain any attempts though.
Yes there is, and you and Farsight have been informed and explained about this a few times.
What you see fit to interpret is not the logical mainstream interpretation.
Simple as that.
And please dont misinterpret what Hawking found nor ignore his tic humour.
Right: eventually -- but not now. So it doesn't "exist now". As you say, it can only be said to "exist now" after you've seen it exist in your present. But again, when you witness a distant event happen in your present, you surely don't have any confusion about why the clock you're reading on the distant event doesn't match your clock. You almost surely do not follow your own logic.
And evidently, since that's the only one of the examples you disagreed with, you must agree that my overall point is correct...
Regardless of if it is defined by scientists, it is still used by scientists so it is still correct to say that it is the mainstream view of the scientific community that black holes exist.
We do however have observational evidence that there's something very massive and very small and very dark in the centre of our galaxy. You could claim that this isn't actually a black hole, but you soon get into hair-splitting territory where we're arguing about the true nature of the thing people call a "black hole". But we all agree that light can't get out.
I think you should focus in on the point-singularity. That's something that only exists in the future. Which means it doesn't exist now. Which means it doesn't exist at all, and never ever will. Again see The Formation and Growth of Black Holes and note this:RJBeery said:
"According to the field interpretation, a clock runs increasingly slowly as it approaches the event horizon (due to the strength of the field), and the natural "limit" of this process is that the clock just asymptotically approaches "full stop" (i.e., running at a rate of zero) as it approaches the horizon. It continues to exist for the rest of time, but it's "frozen" due to the strength of the gravitational field. Within this conceptual framework there's nothing more to be said about the clock's existence. This leads to the "frozen star" conception of gravitational collapse".
That's what I'm saying. You might argue that the event horizon doesn't exist and the black hole doesn't exist, but like I said above, you soon get into hair-splitting territory. Now take a look at what comes next:
"In contrast, according to the geometric interpretation, all clocks run at the same rate, measuring out real distances along worldlines in spacetime. This leads us to think that, rather than slowing down as it approaches the event horizon, the clock is following a shorter and shorter path to the future. In fact, the path gets shorter at such a rate that it actually reaches (our) future infinity in finite proper time".
The clock reaches future in finite proper time? Whatever next?
"Now what? If we believe the clock is still running just like every other clock (and there's no local pathology of the spacetime) then it seems natural to extrapolate the clock's existence right past our future infinity and into another region of spacetime. Obviously this implies that the universe has a "transfinite topology", which some people find troubling, but there's nothing logically contradictory about it (assuming the notion of an infinite continuous universe is not itself logically contradictory)."
This is basically away with the fairies. The infalling clock has gone to the end of time, and then past it! Once you go past the event horizon and start talking about the point-singularity, you're into this never-never-land beyond the end of time. It's garbage, and yet it's mainstream. For the time being.
Now apply this logic to tomorrow mornings breakfast. Are you feasting or fasting?
That's a lie: we discussed this specifically and you are fully aware that regardless of your issues with the event horizon, the gravitational field is observable, now and in the past.