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Posted
1 hour ago, koti said:

My knowledge is limited but it would seem extremely exotic that matter which forms structures all over the universe like stars, planets, houses, animals would suddenly decide that its capable of squashing itself into a region so small its undefined, keep its mass and not rip the universe into oblivion. Not a very scientific statement, I know...but common.

That's exactly what I thought! Almost...

Posted
2 hours ago, koti said:

This video explains it pretty well:

 

The same bloke is narrating this video on this event.....

and this one on Kerr metric BH's 

One would need to go along way to hear anyone explain a subject matter, more clearly and succulently then this  this young fellow. 

Posted
12 minutes ago, Bill Angel said:

That black hole at the center of Messier 87 has a mass of 6.5 billion solar masses.

One wonders if any of those 6.5 billion suns had planets which supported intelligent life.

It would be a real bummer if the astronomers of an alien society had to inform their population that in the distant future their sun and the planet that this alien society occupys are going to be sucked into their galaxy's black hole and annihilated. 

Even if there was, we must assume they had seen it coming a long time, and that they were "technologically mature" enough to escape.

If not... bummer!

Posted (edited)

All the previous posts (which take as a given the correctness of GR or similar theories where horizons exist) speculating about 'the singularity', fail to note that in such classical theories 'the singularity' is from any exterior observer's perspective, an event that occurs in the infinite future! There is NO existing singularity.
Unless one wishes to take the hypothetical in-faller pov - where the exterior universe becomes infinitely old at the point of passing EH! Of course there now exists a menagerie of more exotic refinements/extensions/modifications. Where for instance the in-faller may be fried at a firewall horizon etc. and never makes it further in because there is no further in. Or other exotic possibilities like 'fireworks' 'bounces'. Take your pick.

For the enthusiast salivating that this EHT image of shadow of M87 central object has 'proven' BH's thus 'proven' GR - sorry, it has done no such thing. Any half-way viable gravity theory will predict a photon-sphere.
There is far more observational data needed and refining of that data before any kind of confident winnowing down of currently viable theories will be possible. Hype - nearly all of it pro GR, is rife. Settle down and prepare for a lengthy wait.

Edited by Q-reeus
correct typo 'in' to 'is'
Posted (edited)
1 hour ago, Q-reeus said:

All the previous posts (which take as a given the correctness of GR or similar theories where horizons exist) speculating about 'the singularity', fail to note that in such classical theories 'the singularity' is from any exterior observer's perspective, an event that occurs in the infinite future! There is NO existing singularity.
Unless one wishes to take the hypothetical in-faller pov - where the exterior universe becomes infinitely old at the point of passing EH! Of course there now exists a menagerie of more exotic refinements/extensions/modifications. Where for instance the in-faller may be fried at a firewall horizon etc. and never makes it further in because there is no further in. Or other exotic possibilities like 'fireworks' 'bounces'. Take your pick.

 Other then the singularity as defined by where our laws of physics and GR do not apply...that is the quantum/Planck level.

Quote

For the enthusiast salivating that this EHT image of shadow of M87 central object has 'proven' BH's thus 'proven' GR - sorry, it has done no such thing. Any half-way viable gravity theory will predict a photon-sphere.
There is far more observational data needed and refining of that data before any kind of confident winnowing down of currently viable theories will be possible. Hype - nearly all of it pro GR, is rife. Settle down and prepare for a lengthy wait.

Well actually nothing is proven in cosmology and physics theories, but they simply get more certain and viable over time as evidence mounts. And in this instant, ignoring all the so called  "salivating", certainly more evidence has just been verified, validating further, BH's and GR. But certainly, as I said previously, I'll wait for and research the thoughts on this evidence from the experts at the coal face.

I take it you are not going to join me in a beer to Albert?   :P

Edited by beecee
Posted
2 minutes ago, MaximT said:

57034699_2681918401901197_7759984032368033792_n.png.4dd6e3c6facfd56fe725db542fd821a4.png

Thanks for that Max...Great stuff!!!!

Scientists react to first image of a black hole

 

 

Posted
51 minutes ago, beecee said:

 Other then the singularity as defined by where our laws of physics and GR do not apply...that is the quantum/Planck level.

?????? A hypothesized spacetime quantization 'rescuing' classical GR from 'actual singularity' has NO bearing on that in either case such an 'extreme object' is, purely owing to existence of an EH, an event in the infinite future.

51 minutes ago, beecee said:

Well actually nothing is proven in cosmology and physics theories, but they simply get more certain and viable over time as evidence mounts. And in this instant, ignoring all the so called  "salivating", certainly more evidence has just been verified, validating further, BH's and GR. But certainly, as I said previously, I'll wait for and research the thoughts on this evidence from the experts at the coal face.

I take it you are not going to join me in a beer to Albert?   :P

Raise a Tooheys Blue to a blurry image exhibiting only the most basic features common to any generic metric theory of gravity? Umm...no. It is a fantastic technical achievement, so maybe that alone is a good enough excuse for you to keep swilling beer. But I shall reserve celebrations for the time - maybe not in our lifetime, when a final theory has been confirmed beyond any reasonable doubt. Via multiple observational methods. And GW 'astronomy' looks to be imo the best approach by far.

44 minutes ago, MaximT said:

57034699_2681918401901197_7759984032368033792_n.png.4dd6e3c6facfd56fe725db542fd821a4.png

'Single-handedly responsible'?! This is a sad example of what I meant earlier by hype being rife. The many able-bodied physicists and engineers working tirelessly on the huge collaboration that is EHT would be perfectly justified in feeling slighted indeed insulted by that absurd claim.

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

?????? A hypothesized spacetime quantization 'rescuing' classical GR from 'actual singularity' has NO bearing on that in either case such an 'extreme object' is, purely owing to existence of an EH, an event in the infinite future.

Umm, not sure what you are on about, but the quantum/Planck level exists, and we have no reason to not believe the same region does not exist at the core of a BH. Add that to the fact that GR says further collapse is compulsory once the EH/Schwarzchild radius is reached, and as we know, is useless at the quantum/Planck level, It's reasonable to assume [understanding the "hard to imagine" mathematical singularity  of infinite densities and curvature] that the mass should reside within that Planck region. But of course, actual observation of anything inside the EH is not on, and we just have the overwhelmingly tried and tested GR to rely on. 

Quote

Raise a Tooheys Blue to a blurry image exhibiting only the most basic features common to any generic metric theory of gravity? Umm...no. It is a fantastic technical achievement, so maybe that alone is a good enough excuse for you to keep swilling beer. But I shall reserve celebrations for the time - maybe not in our lifetime, when a final theory has been confirmed beyond any reasonable doubt. Via multiple observational methods. And GW 'astronomy' looks to be imo the best approach by far.

The fact remains, despite your unfounded  doubt that this further adds to the validation of GR and BH's in the opinion of most all astronomers/cosmologists so far, and adds even further to the validation that the 11 gravitational waves discoveries so far, gave to BH binary pairs  and as a consequence GR according to those at the coal face. GR, without doubt, has passed another crucial test.

And of course any final theory [if it is ever achieved] will in all likely hood encompass GR while extending the zones of applicability.

 

Oh, and its VB q-reeus, or Fosters possible. :P I would need to be desperate to drink Tooheys. :D

Edited by beecee
Posted

So we have an actual image of a BH, that aligns with everything GR was telling us, and adds to the certainty of GR and BH's. The more exciting aspect of this new methodology and the new science of gravitational wave detection, is that both the EHT and aLIGO, are just beginning. The GW detectors are about to start their third run, and the EHT will be focused on better resolutions, and the exploration of our very own SMBH at Sag-A.

Posted
2 hours ago, beecee said:

Umm, not sure what you are on about, but the quantum/Planck level exists, and we have no reason to not believe the same region does not exist at the core of a BH. Add that to the fact that GR says further collapse is compulsory once the EH/Schwarzchild radius is reached, and as we know, is useless at the quantum/Planck level, It's reasonable to assume [understanding the "hard to imagine" mathematical singularity  of infinite densities and curvature] that the mass should reside within that Planck region. But of course, actual observation of anything inside the EH is not on, and we just have the overwhelmingly tried and tested GR to rely on. 

That much in red is obvious, given the remainder of that passage completely misses the standard - yes standard - point I have repeatedly made about sungularities, or conjectured 'quantum/Planck level' singularity-like entities, lying in the infinite future in standard GR. They don't exist now - not from any external observers pov. Savvy?
One 'modifier' I failed to mention in an earlier post was 'Hawking radiation'. Another artifact of horizon existent theories of gravity, which if real logically disallows any singularity anyway. All such bizarre conundrums are absent from certain, inherently more self-consistent horizonless theories of gravity.

2 hours ago, beecee said:

Oh, and its VB q-reeus, or Fosters possible. :P I would need to be desperate to drink Tooheys. :D

So sorry. I had assumed given you are a resident of a Sydney NSW Australia suburb, you would be loyal to your locally brewed beer. My apologies!

1 hour ago, beecee said:

So we have an actual image of a BH, that aligns with everything GR was telling us, and adds to the certainty of GR and BH's. The more exciting aspect of this new methodology and the new science of gravitational wave detection, is that both the EHT and aLIGO, are just beginning. The GW detectors are about to start their third run, and the EHT will be focused on better resolutions, and the exploration of our very own SMBH at Sag-A.

That comment in red betrays your occasional, inconsistent claim to not be wedded to GR as THE classical-level theory of gravity.

My, someone here decided to 'red card' my earlier (annoyingly combined) post:

. Whoever you are, please have the courage and decency to step forward, here in this thread, and clearly explain your presumably rational and objective reason(s) for doing so!

Posted
2 hours ago, Q-reeus said:

'Single-handedly responsible'?! This is a sad example of what I meant earlier by hype being rife. The many able-bodied physicists and engineers working tirelessly on the huge collaboration that is EHT would be perfectly justified in feeling slighted indeed insulted by that absurd claim.

Ease up. It's a charming story and one that might encourage other youngsters to enter the field of science. And its a minor compensation for the Rosalind Franklins and Caroline Herschels of the world.

(For the record, since you asked, I didn't give you the downvote. I'm not competent to comment on the physics of postulated singularities and an ill judged opinion doesn't merit a downvote.)

Posted
12 minutes ago, Intrigued said:

Ease up. It's a charming story and one that might encourage other youngsters to enter the field of science. And its a minor compensation for the Rosalind Franklins and Caroline Herschels of the world.

Have no knowledge re "Rosalind Franklins and Caroline Herschels of the world.", but presumably that relates in some way to the 'feminist-empowerment/sexist-bias' angle being so aggressively pushed throughout not just academia but (Western)society in general. Whatever - it remains the case the absurd claim of 'single-handedly accomplishing' being attributed to ANY one individual re EHT preliminary results is unforgivable tripe. There is no valid excuse.
 

12 minutes ago, Intrigued said:

(For the record, since you asked, I didn't give you the downvote. I'm not competent to comment on the physics of postulated singularities and an ill judged opinion doesn't merit a downvote.)

Thanks for clarifying you are not the 'red carder'.

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

That much in red is obvious, given the remainder of that passage completely misses the standard - yes standard - point I have repeatedly made about sungularities, or conjectured 'quantum/Planck level' singularity-like entities, lying in the infinite future in standard GR. They don't exist now - not from any external observers pov. Savvy?
One 'modifier' I failed to mention in an earlier post was 'Hawking radiation'. Another artifact of horizon existent theories of gravity, which if real logically disallows any singularity anyway. All such bizarre conundrums are absent from certain, inherently more self-consistent horizonless theories of gravity.

My point re singularities defined where our laws break down stand, as opposed to your conjecture.

Quote

So sorry. I had assumed given you are a resident of a Sydney NSW Australia suburb, you would be loyal to your locally brewed beer. My apologies!

As per my science, I align with what is best evidenced at the time. 

Quote

That comment in red betrays your occasional, inconsistent claim to not be wedded to GR as THE classical-level theory of gravity.

I'm wedded to nothing despite your rhetoric. I align with what is supported by evidence as per the scientific method.  Having been labeled a GR fan boy, and science cheer leader in the past, I take both as great compliments, particularly when noting who is giving the compliment and what agenda is applicable.

Again as per common knowledge, BH's and GR as an extension, have had more certainty added, and been further validated as per the data available. This is the subject at hand, and just as certainly accepted by mainstream reputable scientists.

GR, without doubt, has passed another crucial test. 

 

Edited by beecee
Posted (edited)
19 minutes ago, beecee said:

...Again as per common knowledge, BH's and GR as an extension, have had more certainty added, and been further validated as per the data available. This is the subject at hand, and just as certainly accepted by mainstream reputable scientists.

There you go again - claiming certainty re validation of GR/BH's. Anyone with an ounce of caution would not use such commitment words. And btw the logical statement would have it

"GR, and BH's as an extension" and not the reverse as you incorrectly worded it.

Quote

GR, without doubt, has passed another crucial test. 

 

Not just GR but various other, rival theories, have also 'passed another crucial test'. Something tacitly denied by the hyped pro-GR rhetoric. I don't need resorting to bold text to emphasize that point.

Edited by Q-reeus
Posted
35 minutes ago, Q-reeus said:

Have no knowledge re "Rosalind Franklins and Caroline Herschels of the world.", but presumably that relates in some way to the 'feminist-empowerment/sexist-bias' angle being so aggressively pushed throughout not just academia but (Western)society in general.

If you had knowledge of the "Rosalind Franklins and Caroline Herschels" you would be far less likely to make such ill informed comments. I say that not as a barely concealed attack on your intellect, but as a hope that it might trigger you to take a closer look at the two examples I have given. If you are interested in science I hope you are also interested in the history of science. But this is already way off topic. Send me a pm if you wish to discuss further.

Posted
4 hours ago, MaximT said:

57034699_2681918401901197_7759984032368033792_n.png.4dd6e3c6facfd56fe725db542fd821a4.png

This Ladies & Gentlemen is what happens when you actually do something useful instead of running around demanding usage of pronouns. You go girl! 

Posted
Just now, Q-reeus said:

There you go again - claiming certainty re validation of GR/BH's. Anyone with an ounce of caution would not use such commitment words. And btw the logical statement would have it

You need to read again with more care and clarity. I said "have had more certainty added, and been further validated as per the data available". Off course I stand by those mainstream facts.

Quote

"GR, and BH's as an extension" and not the reverse as you incorrectly worded it

Whatever makes you happy. :P Both have had far more certainty added. 

Quote

Not just GR but various other, rival theories, have also 'passed another crucial test'. Something tacitly denied by the hyped pro-GR rhetoric. I don't need bold text to emphasize that point.

Your cynicism is noted, but this is the mainstream forum, and as such, GR is the incumbent theory that has had more certainty added, just as the 11 GW discoveries also added.

2 minutes ago, koti said:

This Ladies & Gentlemen is what happens when you actually do something useful instead of running around demanding usage of pronouns. You go girl! 

Totally agree. Shame some have taken it out of context.

Posted
4 minutes ago, Intrigued said:

If you had knowledge of the "Rosalind Franklins and Caroline Herschels" you would be far less likely to make such ill informed comments. I say that not as a barely concealed attack on your intellect, but as a hope that it might trigger you to take a closer look at the two examples I have given. If you are interested in science I hope you are also interested in the history of science. But this is already way off topic. Send me a pm if you wish to discuss further.

Indeed - with that in red agreed.

4 minutes ago, beecee said:

You need to read again with more care and clarity. I said "have had more certainty added, and been further validated as per the data available". Off course I stand by those mainstream facts.

Whatever makes you happy. :P Both have had far more certainty added. 

Your cynicism is noted, but this is the mainstream forum, and as such, GR is the incumbent theory that has had more certainty added, just as the 11 GW discoveries also added.

I tire of endless corrections. With you the cycle is endless. Time will eventually tell which theory is correct.

Posted
44 minutes ago, Q-reeus said:

Time will eventually tell which theory is correct.

Which theory are you refering to? 

Posted
8 minutes ago, koti said:

Which theory are you refering to? 

Whichever theory of gravity eventually proves true. Something bleeding obvious from preceding context I would have thought!

Evidently whoever red carded me earlier here is not up to justifying it - as i requested be done. The trouble with anonymity - too easy.

Posted
8 minutes ago, Q-reeus said:

Whichever theory of gravity eventually proves true. Something bleeding obvious from preceding context I would have thought!

What do you mean whichever theory of gravity proves true, what exactly is on the table for you? 

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

Indeed - with that in red agreed.

I tire of endless corrections. With you the cycle is endless. Time will eventually tell which theory is correct.

Your so called corrections are no more then opinions and/or pedant nonsense. So far GR has passed all tests thrown its way, and that has continued with GW's and now this EHT image. If and when any other model replaces GR, I'm, that will be a QGT which will probably encompass GR anyway.

36 minutes ago, Q-reeus said:

Evidently whoever red carded me earlier here is not up to justifying it - as i requested be done. The trouble with anonymity - too easy.

It is also off topic and against the rules to query rep points.

Here are reputable papers from the Astrophysical Journal

https://iopscience.iop.org/article/10.3847/2041-8213/ab0ec7/meta

https://iopscience.iop.org/article/10.3847/2041-8213/ab0c96/meta

https://iopscience.iop.org/article/10.3847/2041-8213/ab0c57/meta

https://iopscience.iop.org/article/10.3847/2041-8213/ab0e85/meta

https://iopscience.iop.org/article/10.3847/2041-8213/ab0f43/meta

https://iopscience.iop.org/article/10.3847/2041-8213/ab1141/meta

Edited by beecee
Posted (edited)
2 hours ago, koti said:

What do you mean whichever theory of gravity proves true, what exactly is on the table for you? 

I have elsewhere at SFN contributed to discussion of in particular Anatoly Svidzinsky's Vector Theory of Gravity:
https://www.scienceforums.net/topic/117068-vector-theory-of-gravity/?do=findComment&comment=1081799  and onwards there.
Making it clear I have no commitment to that theory, but noted it does tick a number of plus boxes GR cannot.
Self-consistency for any theory of gravity imo requires at least two characteristics absent in GR:
1: Exponential form for gravitational redshift for a spherically symmetric static central mass. Recently my thinking has shifted a little there, as per my comments here:
https://vixra.org/abs/1808.0642
At any rate, such exponential form, exact or as limiting case, forbids existence of EH's.
2: Intrinsic isotropy of exterior metric for a spherically symmetric static central mass (afaik my unique finding). Which again forbids existence of EH's.

To enlarge on above is getting way off topic. And not interested anytime soon starting or participating in a time-consuming thread going further there.

I had prepared a point-by-point rebuttal to a hostile posting by Strange, but now find it has been mysteriously vanished. So be it.

(Hope this and last post doesn't get to be merged, which annoyance has become my routine experience at SFN.)

Uh oh - it got merged. Sigh.

Edited by Q-reeus
Posted
7 minutes ago, Q-reeus said:

I have elsewhere at SFN contributed to discussion of in particular Anatoly Svidzinsky's Vector Theory of Gravity:
https://www.scienceforums.net/topic/117068-vector-theory-of-gravity/?do=findComment&comment=1081799    and onwards there.
Making it clear I have no commitment to that theory, but noted it does tick a number of plus boxes GR cannot.
Self-consistency for any theory of gravity imo requires at least two characteristics absent in GR:
1: Exponential form for gravitational redshift for a spherically symmetric static central mass. Recently my thinking has shifted a little there, as per my comments here:
https://vixra.org/abs/1808.0642
At any rate, such exponential form, exact or as limiting case, forbids existence of EH's.
2: Intrinsic isotropy of exterior metric for a spherically symmetric static central mass (afaik my unique finding). Which again forbids existence of EH's.

To enlarge on above is getting way off topic. And not interested anytime soon starting or participating in a time-consuming thread going further there.

Sounds like some exotic ( crackpot if you ask me) attempt at explaining the behaviour of gravity in the BH context, using physics nomenclature to fool people into believing its something worthwhile. Your vixra link is not opening which I would say is probably a good thing because its a crackpot site posing as legitimate science. 

So let me get this straight, are you saying that GR is wrong and you’re looking for alternatives?

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