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Black Hole: Why do we believe that matter could be such dense?

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26 minutes ago, Q-reeus said:

It's typical of you to hunt for a contrary finding and just cut & paste it without acknowledging it represents conflicting opinions among assumed GR experts, or explaining your own pov and giving detailed reasoning why. So which of those two conflicting positions do you support, and why exactly? And btw, there is a link from my 2nd linked ref:

Not really, and the proof of the pudding is in any of my posts on this forum.

Quote

, that gives detailed calculations for (notionally)you, or Strange, to follow. Feel free to 'spot the fatal error'. And note I made it clear in earlier post this is all reasoned on the assumption GR is true hence EH's actually exist. I don't believe in either, but nevertheless expect a better, horizonless theory will share to some degree some of those general tendencies.

You made it clear? :rolleyes: You have attempted to make many things clear re GR and BH's and as I see it, failed. And of course what you believe is no more relevant then what some IDer believes, or any other alternative hypothetical speculator...take that with your false assumption about GR being "true" and many things are clear. A theory such as GR is our best estimation at any time, and in recent times, GR has confirmed many predictions and gained in certainty in what we do observe. That of course includes BH's and their existence.

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10 minutes ago, beecee said:

Not really, and the proof of the pudding is in any of my posts on this forum.

Why do you evade my clear and perfectly reasonable questions? That disjoint and vacuous line doesn't even attempt to address them. Similarly for what follows there.
The implication is obvious - you cannot provide straight and meaningful answers to my questions. Let's see how Strange fares.

10 minutes ago, beecee said:

You made it clear? :rolleyes: You have attempted to make many things clear re GR and BH's and as I see it, failed. And of course what you believe is no more relevant then what some IDer believes, or any other alternative hypothetical speculator...take that with your false assumption about GR being "true" and many things are clear. A theory such as GR is our best estimation at any time, and in recent times, GR has confirmed many predictions and gained in certainty in what we do observe. That of course includes BH's and their existence.

See above.

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Posted (edited)
1 hour ago, Q-reeus said:

Why do you evade my clear and perfectly reasonable questions? That disjoint and vacuous line doesn't even attempt to address them. Similarly for what follows there.
The implication is obvious - you cannot provide straight and meaningful answers to my questions. Let's see how Strange fares.

I'm interested in nothing more then what recent discoveries/experiments have achieved with relation to more certainty in GR and BH's. Both of which your reject and as such, irrelevant in mainstream science. I gave a link, which gives a reasonable answer, quite objectively, without malice or arrogance. I'm with that, OK? 

Quote

See above.

Again, You have attempted to make many things clear re GR and BH's and as I see it, failed. And of course what you believe is no more relevant then what some IDer believes, or any other alternative hypothetical speculator...take that with your false assumption about anyone taking GR as being "true" and many things are clear. A theory such as GR is our best estimation at any time, and in recent times, GR has confirmed many predictions and gained in certainty in what we do observe. That of course includes BH's and their existence.

again....https://jila.colorado.edu/~ajsh/bh/singularity.html

 

Redshift map

Redshift map of distant sky at 0.68 Schwarzschild radii.

This is a redshift map of the distant sky corresponding to the previous image. Red colours indicate regions of the sky where distant stars (like the blue, green, and yellow stars) would appear redshifted, their spectra shifted to longer wavelengths. Other colours, from orange to violet, indicate regions of the sky where distant stars would appear blueshifted.

The main effect is a strong blueshift of photons coming from ahead. This is a special relativistic beaming effect caused by our near light speed motion.

The blueshifted region also appears concentrated towards the horizon. This is caused by tidal effects from the gravity of the black hole. Just as the tide stretches you vertically, and squeezes you about your middle, so also photons from both above and below you get redshifted, while photons from the sides get blueshifted.

Blueshifted parts of the sky would appear brighter, redshifted parts dimmer.

 


Image distortion inside the black hole

Movie image at 0.35 Schwarzschild radii.

At 0.35 Schwarzschild radii. Compare this view to the unconventional view you would see if the Schwarzschild surface were attached to another Universe via a wormhole.

Images are being distorted by two effects: a tidal distortion from the gravity of the black hole, and a special relativistic beaming from our near light speed motion.

Just as the tidal distortion redshifts images from above and below, and blueshifts them about your middle, so also it tends to repel images from above and below, and concentrate them about your middle. At first, images appear distorted into a kidney shape. As the distortion grows, images become stretched and squashed into a doughnut shape about your waist.

Our near light speed motion concentrates our view ahead, by special relativistic beaming. Relative to observers freely falling radially from rest at infinity, our velocity increases towards the speed of light: the relativistic Lorentz gamma factor at radius rr is 1+2rs/r1+2rs/r.

 


The distortions grow

Movie image at 0.01 Schwarzschild radii.

At 0.01 Schwarzschild radii.

The tidal force continues to concentrate our view into a ‘horizon’ shape, while our near light speed motion further concentrates the view ahead.

The tidal force and our motion blueshifts photons from the outside world eventually to very high energies, which we would see as x and gamma rays.

<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Now my reasonable question. If you reject the reasoning and answer in my link, then please tell us why. And while you are at it, please try not to flavour your answers with your  "BELIEFS" concerning BH's and GR, which are entirely irrelevant in a mainstream physics discussion. More information re BH's is of course in the BH image thread.

 

Let's also clear up another apparent misconception you probably have. My take on this is from the view of someone who has already crossed the EH, viewing the outside universe. I believe that was Strange's view also, but he can speak for himself.

Edited by beecee

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1 hour ago, beecee said:

...Now my reasonable question. If you reject the reasoning and answer in my link, then please tell us why. And while you are at it, please try not to flavour your answers with your  "BELIEFS" concerning BH's and GR, which are entirely irrelevant in a mainstream physics discussion. More information re BH's is of course in the BH image thread.

 

Let's also clear up another apparent misconception you probably have. My take on this is from the view of someone who has already crossed the EH, viewing the outside universe. I believe that was Strange's view also, but he can speak for himself.

Recall that Strange made an unqualified "(the rest of the universe would look increasingly blue-shifted)", which is wrong. That's what I responded to. Sure within BH in-fall scenario an in-faller will encounter a mix of transverse and radial light ray components. The former becomes an increasingly minute contribution as in-fall proceeds to small r, since only the radial component of photon momenta get gravitationally boosted as in-fall proceeds.

Taking as a given the formal GR calcs of Hamilton are indeed valid, it's (sort of) obvious from his color coded movie that for the vast majority of in-fall, redshift entirely dominates.

And btw the reason all that is moot is that even assuming GR as Truth, contrary to many claims, it's no 'optical illusion' that the in-faller freezes at the EH - as seen from outside. The logical consequence of having coordinate c -> 0 at 'EH' is that from in-faller's 'stopped coordinate-time clock' pov the entire rest of universe is infinitely old at the moment he/she hits the 'EH'.
 

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Posted (edited)
1 hour ago, Q-reeus said:

Taking as a given the formal GR calcs of Hamilton are indeed valid, it's (sort of) obvious from his color coded movie that for the vast majority of in-fall, redshift entirely dominates.

And btw the reason all that is moot is that even assuming GR as Truth, contrary to many claims, it's no 'optical illusion' that the in-faller freezes at the EH - as seen from outside. The logical consequence of having coordinate c -> 0 at 'EH' is that from in-faller's 'stopped coordinate-time clock' pov the entire rest of universe is infinitely old at the moment he/she hits the 'EH'.
 

Quite admirable you take Professor Hamilton's calcs "as a given" particularly like the BH image as defined by GR, and the GW discoveries as also defined by the same GR and the fabricated templates which matched, his calcs also in agreement with GR.

GR remains the supreme supported mainstream theory of gravity. I am not interested in any other inferences or opinions, all of which appear "alternative" at best. and totally unevidenced at worst. 

Of course no one has ever suggested that anything is an optical illusion. All frames are as valid as each other, including the unlucky soul approaching the EH, and falling in. He does exactly that...fall in on a one way trip to oblivion.

 

Edited by beecee

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33 minutes ago, beecee said:

...Of course no one has ever suggested that anything is an optical illusion. All frames are as valid as each other, including the unlucky soul approaching the EH, and falling in. He does exactly that...fall in on a one way trip to oblivion.

 

Not so. See for instance the typical but not universal-within-GR-community claim of 'freezing at EH is just an optical illusion' made in article I first linked to here:
https://www1.phys.vt.edu/~jhs/faq/blackholes.html#q11
(last line, 2nd para under "Will an observer falling into a black hole be able to witness all future events in the universe outside the black hole?")
I made no mention of that bit back then as the key point was there dispelling the faulty position of some that only gravitational redshift inversely determined in-faller's view of outside universe.
That same 'optical illusion' claim is often trotted out by a number of GR buffs at e.g. PhysicsForums - and it's plain wrong.

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Posted (edited)
13 minutes ago, Q-reeus said:

Not so. See for instance the typical but not universal-within-GR-community claim of 'freezing at EH is just an optical illusion' made in article I first linked to here:
https://www1.phys.vt.edu/~jhs/faq/blackholes.html#q11
(last line, 2nd para under "Will an observer falling into a black hole be able to witness all future events in the universe outside the black hole?")
I made no mention of that bit back then as the key point was there dispelling the faulty position of some that only gravitational redshift inversely determined in-faller's view of outside universe.
That same 'optical illusion' claim is often trotted out by a number of GR buffs at e.g. PhysicsForums - and it's plain wrong.

 If all frames are as valid as each other, how can anyone of them be an illusion? Actually freezing at the EH could be construed as a poor choice of words. An observer from a distance, would simply see a body further and further redshifted along the spectrum, until beyond the ability of the telescope and simply fade from view. Perhaps that is what is meant.

 

Edited by beecee

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Posted (edited)
37 minutes ago, beecee said:

 If all frames are as valid as each other, how can anyone of them be an illusion? Actually freezing at the EH could be construed as a poor choice of words. An observer from a distance, would simply see a body further and further redshifted along the spectrum, until beyond the ability of the telescope and simply fade from view. Perhaps that is what is meant.

 

It's an easily established fact within GR that for a notionally inextensible string connecting two different radii both in a Schwarzschild metric exterior to any 'EH', there is an exact 1:1 correspondence in any measured radial displacement of the string, as determined at both radii. That is, there is no 'redshift' correction factor involved there.
And as mentioned in a previous post, coordinate clock-rate and radial length scale both -> 0 as r -> R_s (Schwarzschild radius). Combining above, it follows that radial motion, determined by a stationary external observer, of a string tied to an in-faller, goes to zero exactly as said in-faller hits R_s.
Which strangely ignored but easily determined thought experiment, gives the lie to the oft repeated 'optical illusion' claim. The in-faller 'really stops cold' at EH as directly measured by string motion at external observer. Caveat GR is correct.

Edited by Q-reeus

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23 minutes ago, Q-reeus said:

It's an easily established fact within GR that for a notionally inextensible string connecting two different radii both in a Schwarzschild metric exterior to any 'EH', there is an exact 1:1 correspondence in any measured radial displacement of the string, as determined at both radii. That is, there is no 'redshift' correction factor involved there.
And as mentioned in a previous post, coordinate clock-rate and radial length scale both -> 0 as r -> R_s (Schwarzschild radius). Combining above, it follows that radial motion, determined by a stationary external observer, of a string tied to an in-faller, goes to zero exactly as said in-faller hits R_s.
Which strangely ignored but easily determined thought experiment, gives the lie to the oft repeated 'optical illusion' claim. The in-faller 'really stops cold' at EH as directly measured by string motion at external observer. Caveat GR is correct.

I'll let others more qualified then I answer whatever claim you are making. Just a couple of corrections needed...There is no lie and such conspiracies concerning mainstream is without basis and that is shown every day, secondly, despite your continued excuse making re GR...No caveat is needed. It is correct as far as any scientific theory can be correct. I prefer, as I'm sure you remember, "near certain"

 

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9 minutes ago, beecee said:

I'll let others more qualified then I answer whatever claim you are making. Just a couple of corrections needed...There is no lie and such conspiracies concerning mainstream is without basis and that is shown every day, secondly, despite your continued excuse making re GR...No caveat is needed. It is correct as far as any scientific theory can be correct. I prefer, as I'm sure you remember, "near certain"

 

Those words are your own assertion/concoction and a term such as 'the lie' is contextually and/or rhetorically interpreted and need not at all imply deliberate deceit. Even less 'a conspiracy'. 'Optical illusion' is however a lie in in the sense of it's asserted factual basis being wrong. Since you cannot challenge that yourself, either wait for someone(s) else here who may think they can - or e.g. do what you customarily do and email say Hamilton on this - hoping of course for a 'fail' being handed out to me.

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Posted (edited)

Why don't you guys PM each other instead of posting your incessant arguing, it is boring.

Edited by Bufofrog

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7 minutes ago, Bufofrog said:

Why don't you guys PM each other instead of posting your incessant arguing, it is boring.

Are you a GR buff? If not, instead of boredom you should be able to learn something useful or at least be stimulated to check further, from my posts at least.

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16 minutes ago, Bufofrog said:

Why don't you guys PM each other instead of posting your incessant arguing, it is boring.

Get a room, as they say.

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1 minute ago, Q-reeus said:

Are you a GR buff? If not, instead of boredom you should be able to learn something useful or at least be stimulated to check further, from my posts at least.

I know this is not the only forum that you 2 go 'at it', and it just gets old really fast.  I do read your posts unless you 2 are arguing and then I ignore the whole page.

It certainly appears that you are not a fan of GR, in that you are looking for the next step in our understanding of gravity.   You also seem 'to this layman' to be quite knowledgeable.  So why don't you just ignore Beecee and make your points?  Just my humble opinion.

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9 minutes ago, Bufofrog said:

I know this is not the only forum that you 2 go 'at it', and it just gets old really fast.  I do read your posts unless you 2 are arguing and then I ignore the whole page.

It certainly appears that you are not a fan of GR, in that you are looking for the next step in our understanding of gravity.   You also seem 'to this layman' to be quite knowledgeable.  So why don't you just ignore Beecee and make your points?  Just my humble opinion.

I try, but there is a need at times to defend against mischaracterizations etc. that if left unanswered can be construed as de facto admission of wrong/error.
Still, the ongoing saga is probably riling others similarly so I will try and exercise more constraint as you have suggested. Cheers.

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5 hours ago, Bufofrog said:

Why don't you guys PM each other instead of posting your incessant arguing, it is boring.

 

5 hours ago, Strange said:

Get a room, as they say.

Other then getting a room, :P you blokes are correct. My argument is simply  as per the title of this thread, that GR and of course GR type BH's have over the last few years, gained much more certainty. If any anti GR/BH buff disagrees with that, perhaps they should take their arguments to speculations and put up a case there. I'm simply stating the mainstream position and showing the  attempts to discredit GR as stupidity and baseless conspiracy nonsense.

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8 hours ago, Q-reeus said:

Still, the ongoing saga is probably riling others similarly so I will try and exercise more constraint as you have suggested. 

!

Moderator Note

Saves us having to write new rules regarding ongoing feuds from other websites.

 

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57 minutes ago, Phi for All said:
!

Moderator Note

Saves us having to write new rules regarding ongoing feuds from other websites.

 

Too bad I never bothered to check out the political/ideological sections of this site before participating. I now have a good feel for what's really behind the unceasing negative reactions that are without rational, objective basis. And yes, I do understand that just saying that much will likely invite further hostile reactions!

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6 hours ago, beecee said:

 

Other then getting a room, :P you blokes are correct. My argument is simply  as per the title of this thread, that GR and of course GR type BH's have over the last few years, gained much more certainty. If any anti GR/BH buff disagrees with that, perhaps they should take their arguments to speculations and put up a case there. I'm simply stating the mainstream position and showing the  attempts to discredit GR as stupidity and baseless conspiracy nonsense.

But what will you do when it is finally usurped... "Would you like some salt with that hat, Sir?"  :P

 

11 hours ago, Q-reeus said:

I try, but there is a need at times to defend against mischaracterizations etc. that if left unanswered can be construed as de facto admission of wrong/error.
Still, the ongoing saga is probably riling others similarly so I will try and exercise more constraint as you have suggested. Cheers.

A silent response doesn''t mean you've lost the argument. It just means you've said your piece and there's nothing more to add. There's always a next time. Try it.

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31 minutes ago, StringJunky said:

But what will you do when it is finally usurped... "Would you like some salt with that hat, Sir?"  :P

When that time comes, if it comes, after all they have been at it for a while now [QGT] I'll take it with a smidgin of salt [careful about my salt intake, reason why I'm fit, taut, and tenacious] and pepper...:P Then rejoice again, at the inevitable progress of science! 

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26 minutes ago, beecee said:

When that time comes, if it comes, after all they have been at it for a while now [QGT] I'll take it with a smidgin of salt [careful about my salt intake, reason why I'm fit, taut, and tenacious] and pepper...:P Then rejoice again, at the inevitable progress of science! 

Absolutely.

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Posted (edited)
On 4/16/2019 at 9:18 AM, Q-reeus said:

[..] it's no 'optical illusion' that the in-faller freezes at the EH - as seen from outside. The logical consequence of having coordinate c -> 0 at 'EH' is that from in-faller's 'stopped coordinate-time clock' pov the entire rest of universe is infinitely old at the moment he/she hits the 'EH'.

Indeed. Although, I find "of having coordinate c -> 0 at 'EH" is that'" somewhat poorly phrased, I would say "of having c -> 0 at the 'EH' position" ; and it's a bit ambiguous that he referred to the pov of the outside observer, according to whom there would indeed be an "in-faller's 'stopped coordinate-time clock'" at that position.

Anyway, it makes much logical sense, even in relativity there can only be one single reality! He could be more polite though (not that he's the only one here...).

Note: yesterday Q-reuss mentioned this forum to me and just now I tried to search his contributions in other threads - but regretfully that became impossible! Apparently that is related to the fact that a few hours ago he was "permanently banned for spamming the forum with nonsense". :o

Well then, ... Good luck.

Edited by Tim88
mistake (kept visible) in view of reply

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17 minutes ago, Tim88 said:

Note: yesterday Q-reuss mentioned this forum to me and just now I tried to search his contributions in other threads - but regretfully that became impossible! Apparently that is related to the fact that a few hours ago he was "permanently banned for spamming the forum with nonsense". :o

Well then, ... Good luck.

Q-reeus

You need to use the correct username in your search, and as you’ve been a member for almost 3 years, you’ve known about this forum for a while

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Just now, swansont said:

Q-reeus

You need to use the correct username in your search, and as you’ve been a member for almost 3 years, you’ve known about this forum for a while

I meant that he reminded me of it. And oops you are right - thanks! OK that works :rolleyes:

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2 hours ago, Tim88 said:

Anyway, it makes much logical sense, even in relativity there can only be one single reality!

Happy to read that from someone like you.

On 4/16/2019 at 1:30 PM, Q-reeus said:

The in-faller 'really stops cold' at EH as directly measured by string motion at external observer. Caveat GR is correct.

If that is true, then for the external observer the BH is void, all its mass lies on its surface at the EH.

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