Blackholes: Accretion Vs Expulsion

[warmingwarmingwarming]

Didnt know a naked singularity could exist.

https://www.sciencedaily.com/releases/2 ... 113758.htm

``Scientists have found new ways to detect a bare or naked singularity, the most extreme object in the universe. This finding has possible astrophysical implications.

When the fuel of a very massive star is spent, it collapses due to its own gravitational pull and eventually becomes a very small region of arbitrarily high matter density, that is a`Singularity', where the usual laws of physics may breakdown. If this singularity is hidden within an event horizon, which is an invisible closed surface from which nothing, not even light, can escape, then we call this object a black hole. In such a case, we cannot see the singularity and we do not need to bother about its effects. But what if the event horizon does not form? In fact, Einstein's theory of general relativity does predict such a possibility when massive stars collapse at the end of their life-cycles. In this case, we are left with the tantalizing option of observing a naked singularity.``

Naked Singularities could account for a lot of very strange behavior.

“If a naked singularity is found today, then no matter how hard we try, our current physics cannot predict the future behaviour of such objects,” Petters told New Scientist.

And if a singularity follows no rules, it could leak lawlessness into the universe, destroying any concept of cause and effect."

https://www.newscientist.com/article/dn ... ur-galaxy/

[warmingwarmingwarming]

An interesting read: "Off to Infinity in Finite Time."
Donald Saari and Zihong Xia.

http://www.ams.org/notices/199505/saari-2.pdf

[Chris Peterson]

I'm merely pointing out the consensus position... somewhat more significant that a simple majority.

Whether the Universe ultimately cools down or achieves an infinite energy density remains uncertain, as we still don't have a good understanding of dark energy. However, it doesn't matter for my purpose here, because in either case the Universe extends infinitely far into the future. The Big Rip does not produce an "end" to the Universe in a finite time.

Where do you reference that what you say is the consensus position?

You'll just have to take my word for it. That said, a little research would demonstrate the point. Almost all cosmologists accept that the rate of universal expansion is increasing, which leads to either the Big Rip or Heat Death.

The Big Rip, if it happens, produces an end to the universe, period, whether you call that a finite time or not, because matter is pulled apart to the utmost position where no matter is left to exists.

The Big Rip doesn't necessarily stop time; if not, then there is still no end of the Universe, merely a transition to an unvarying state. You don't need matter in order to have the Universe.

[warmingwarmingwarming]

]The Big Rip, if it happens, produces an end to the universe, period, whether you call that a finite time or not, because matter is pulled apart to the utmost position where no matter is left to exists.

The Big Rip doesn't necessarily stop time; if not, then there is still no end of the Universe, merely a transition to an unvarying state. You don't need matter in order to have the Universe.[/quote]

"Take my word for it." Famous last words.

The majority view of what I read is that we don't know what time is anyway.

Yes, with all matter destroyed, and with whatever remains, anything is possible .. even a new heaven and a new earth. (Oh of course, the heaven of the normal meaning for that word including stars, planets, galaxies .. not a purely theocratical heaven.

[Chris Peterson]

The majority view of what I read is that we don't know what time is anyway.

Perhaps you should broaden you reading.

[warmingwarmingwarming]

The majority view of what I read is that we don't know what time is anyway.

Perhaps you should broaden you reading.

Perhaps you should also. However .. that applies to each of us, especially from a scientific point of view. I do detect in your words a sense that you consider yourself a superior source of information, not to insult you, but just to tell you that your word means as much to me as mine to you, in general it will be only easily confirmed facts that will influence either of us, as our opinions are merely our own opinions, and I consider my sources of knowledge and my own peer group equal to yours. We are all 'weightless,' Chris, without gravity.

[Ann]

warmingwarmingwarming wrote:
Where do you reference that what you say is the consensus position?

Wikipedia is as good a source of the consensus position as anything, since Wikipedia is written and edited by a large number of users.

Wikipedia wrote:

There is a strong consensus among cosmologists that the universe is flat and will continue to expand forever.^[2][3]

The sources that Wikipedia links to are these:

Will the Universe expand forever?

What is the Ultimate Fate of the Universe?

Ann

[warmingwarmingwarming]

warmingwarmingwarming wrote:
Where do you reference that what you say is the consensus position?

Wikipedia is as good a source of the consensus position as anything, since Wikipedia is written and edited by a large number of users.

Wikipedia wrote:

There is a strong consensus among cosmologists that the universe is flat and will continue to expand forever.^[2][3]

The sources that Wikipedia links to are these:

Will the Universe expand forever?

What is the Ultimate Fate of the Universe?

Ann

Ann there is considerable garbage written in Wikipedia. I do use it often as a first quick reference, but go far beyond.

[warmingwarmingwarming]

warmingwarmingwarming wrote:
Where do you reference that what you say is the consensus position?

Wikipedia is as good a source of the consensus position as anything, since Wikipedia is written and edited by a large number of users.

Wikipedia wrote:

There is a strong consensus among cosmologists that the universe is flat and will continue to expand forever.^[2][3]

The sources that Wikipedia links to are these:

Will the Universe expand forever?

What is the Ultimate Fate of the Universe?

Ann

Will you find this in Wikipedia, Ann?

"Off to Infinity in Finite Time."
Donald Saari and Zihong Xia.

http://www.ams.org/notices/199505/saari-2.pdf

[Chris Peterson]

Ann there is considerable garbage written in Wikipedia. I do use it often as a first quick reference, but go far beyond.

For scientific information, Wikipedia ranks as high as the best encyclopedias in terms of quality and accuracy, and is much more current. It is one of the highest quality sources of information on scientific topics available. You can have a very high degree of confidence you are getting good information. The presence of "garbage" in scientific articles is virtually non-existent. Furthermore, scientific articles are almost always heavily referenced and footnoted, allowing you to move on to primary sources if you so desire.

[Chris Peterson]

I do detect in your words a sense that you consider yourself a superior source of information.

As a trained scientist actively working in astronomical fields, I am, in fact, an excellent and generally reliable source of information for many of the topics we discuss here. I make it a point to limit my technical input to areas where I have expertise or a fair degree of knowledge.

[warmingwarmingwarming]

I do detect in your words a sense that you consider yourself a superior source of information.

As a trained scientist actively working in astronomical fields, I am, in fact, an excellent and generally reliable source of information for many of the topics we discuss here. I make it a point to limit my technical input to areas where I have expertise or a fair degree of knowledge.

I have training also. Chris, please, your knowledge qualifies you in your own mind, and perhaps contributes to your standing with others, but I will not and cannot accept it as the final word or an authority on any subject. You may present your opinions here, as I do, but I repeat, please do not expect me to take your word as authority. However, if you provide urls to support your statements, your opinion may gain respect with me over time.

[warmingwarmingwarming]

Ann there is considerable garbage written in Wikipedia. I do use it often as a first quick reference, but go far beyond.

For scientific information, Wikipedia ranks as high as the best encyclopedias in terms of quality and accuracy, and is much more current. It is one of the highest quality sources of information on scientific topics available. You can have a very high degree of confidence you are getting good information. The presence of "garbage" in scientific articles is virtually non-existent. Furthermore, scientific articles are almost always heavily referenced and footnoted, allowing you to move on to primary sources if you so desire.

If so, you should be sourcing Wikipedia to credit your statements.

[warmingwarmingwarming]

I do detect in your words a sense that you consider yourself a superior source of information.

As a trained scientist actively working in astronomical fields, I am, in fact, an excellent and generally reliable source of information for many of the topics we discuss here. I make it a point to limit my technical input to areas where I have expertise or a fair degree of knowledge.

What is your opinion of this piece? Not found in Wikipedia.

"Off to Infinity in Finite Time."
Donald Saari and Zihong Xia.

http://www.ams.org/notices/199505/saari-2.pdf

[Chris Peterson]

What is your opinion of this piece? Not found in Wikipedia.

It isn't science. As far as the quality of the math, I have no opinion as I'm not interested in investing the effort to analyze it.

[Chris Peterson]

Ann there is considerable garbage written in Wikipedia. I do use it often as a first quick reference, but go far beyond.

For scientific information, Wikipedia ranks as high as the best encyclopedias in terms of quality and accuracy, and is much more current. It is one of the highest quality sources of information on scientific topics available. You can have a very high degree of confidence you are getting good information. The presence of "garbage" in scientific articles is virtually non-existent. Furthermore, scientific articles are almost always heavily referenced and footnoted, allowing you to move on to primary sources if you so desire.

If so, you should be sourcing Wikipedia to credit your statements.

This is not a forum that normally requires "credits". It's an educational forum, and references usually follow questions along the lines of "Where can I go to learn more about this?" Simple assertions regarding mainstream views are largely taken at face value.

[Chris Peterson]

I do detect in your words a sense that you consider yourself a superior source of information.

As a trained scientist actively working in astronomical fields, I am, in fact, an excellent and generally reliable source of information for many of the topics we discuss here. I make it a point to limit my technical input to areas where I have expertise or a fair degree of knowledge.

I have training also. Chris, please, your knowledge qualifies you in your own mind, and perhaps contributes to your standing with others, but I will not and cannot accept it as the final word or an authority on any subject.

I do not ask you to. If people ask questions that are within my areas of expertise, I'm happy to answer. If they don't want to accept those answers, that's their business.

[geckzilla]

I'm just not sure why people who get banned for breaking the rules and generally not liking the way things are around here have this burning desire to come back over and over again.

[Ann]

warmingwarmingwarming wrote:
Will you find this in Wikipedia, Ann?

"Off to Infinity in Finite Time."
Donald Saari and Zihong Xia.

http://www.ams.org/notices/199505/saari-2.pdf

Click to view full size image

Huey, Dewey, and Louie with The Junior Woodchucks’ Guidebook.
Source: Disney Comics.

Warming, when I was a kid, me and my brother used to read Donald Duck comics. (We read them in Swedish, of course, because back then neither of us knew any English.)

Anyway, I was always terrifically impressed that Donald's nephews owned a small book called The Junior Woodchucks’ Guidebook. This thin little volume, which fit perfectly in the pockets of the pants that the duckling boys weren't wearing, contained information about everything.

Wikipedia, unlike The Junior Woodchucks’ Guidebook, isn't a physical thing that you carry around in your pocket, not even the sort of encyclopedia which will fill a shelf and a half in your bookcase. Wikipedia exists in cyberspace, as it were, and can contain absolutely incredible amounts of information. Even so, I don't expect Wikipedia to be able to tell me everything, unlike The Junior Woodchucks’ Guidebook.

Frankly, Warming, I don't have the time, energy or inclination to be interested in everything, either. So, no, I don't know anything about what Donald Zaari and Zihong Xia have written. I guess they don't agree with the consensus opinion about the fate of the universe. Well, fine: there is no law that forces you to share the beliefs that most experts hold about their own field.

But there is also no law that forces whoever respects the consensus of the experts to read everything, or anything at all, that contradicts the consensus of the experts.

Life isn't long enough for us to read and carefully weigh everything that could have been found in the mythical Junior Woodchucks’ Guidebook.

Ann

[Chris Peterson]

Warming, when I was a kid, me and my brother used to read Donald Duck comics. (We read them in Swedish, of course, because back then neither of us knew any English.)

Funny. My first serious foreign language experience was with a bunch of Danish language versions of Tintin, Asterix, and Anders And (Donald Duck) books I got in Solvang, California, when I was around five or six years old. I remember carefully puzzling out the text with the help of the pictures. I dug them out some twenty years later when I had learned Danish, and found them fun reads.

[warmingwarmingwarming]

warmingwarmingwarming wrote:
Will you find this in Wikipedia, Ann?

"Off to Infinity in Finite Time."
Donald Saari and Zihong Xia.

http://www.ams.org/notices/199505/saari-2.pdf

Click to view full size image

Huey, Dewey, and Louie with The Junior Woodchucks’ Guidebook.
Source: Disney Comics.

Warming, when I was a kid, me and my brother used to read Donald Duck comics. (We read them in Swedish, of course, because back then neither of us knew any English.)

Anyway, I was always terrifically impressed that Donald's nephews owned a small book called The Junior Woodchucks’ Guidebook. This thin little volume, which fit perfectly in the pockets of the pants that the duckling boys weren't wearing, contained information about everything.

Wikipedia, unlike The Junior Woodchucks’ Guidebook, isn't a physical thing that you carry around in your pocket, not even the sort of encyclopedia which will fill a shelf and a half in your bookcase. Wikipedia exists in cyberspace, as it were, and can contain absolutely incredible amounts of information. Even so, I don't expect Wikipedia to be able to tell me everything, unlike The Junior Woodchucks’ Guidebook.

Frankly, Warming, I don't have the time, energy or inclination to be interested in everything, either. So, no, I don't know anything about what Donald Zaari and Zihong Xia have written. I guess they don't agree with the consensus opinion about the fate of the universe. Well, fine: there is no law that forces you to share the beliefs that most experts hold about their own field.

But there is also no law that forces whoever respects the consensus of the experts to read everything, or anything at all, that contradicts the consensus of the experts.

Life isn't long enough for us to read and carefully weigh everything that could have been found in the mythical Junior Woodchucks’ Guidebook.

Ann

Ann, 'Off to Infinity in Finite TIme' said nothing about the fate of the universe or about the value of consensus that I could fathom. Frankly, though, Donald Duck and the Junior Woodchuck's might be guides for some people, or even Zelda, http://www.ign.com/wikis/the-legend-of- ... _Labyrinth I prefer the great men of science including Newton, Eintein and those other types like Aristarchus of Samos, http://www.greeka.com/eastern_aegean/sa ... archus.htm. Sometimes it takes 2,000 years for a group of people to appreciate the genius among them, but hey, no one ever said we were intelligent as a race.

[warmingwarmingwarming]

Conclusion, black holes last forever, in all practical terms.

Nearly forever for observers on the outside.

But... those observers on the outside should also note that time nearly stops for objects falling into the event horizon.

So... do those observers who fall into the BH get to observe the black hole evaporate (as a blinding firewall)

Neufer .. the known laws of mathematics are said to break down in the Black Hole or even at the event horizon .. what do you think of the thought that material beyond those points may be transformed into a reverse state .. that matter could become anti-matter, and through a wormhole or other mechanism enter Voids as the anti-matter/anti-gravity 'material' causing the Voids expansions?

[Chris Peterson]

Conclusion, black holes last forever, in all practical terms.

Nearly forever for observers on the outside.

But... those observers on the outside should also note that time nearly stops for objects falling into the event horizon.

So... do those observers who fall into the BH get to observe the black hole evaporate (as a blinding firewall) :?:

Neufer .. the known laws of mathematics are said to break down in the Black Hole or even at the event horizon .. what do you think of the thought that material beyond those points may be transformed into a reverse state .. that matter could become anti-matter, and through a wormhole or other mechanism enter Voids as the anti-matter/anti-gravity 'material' causing the Voids expansions?

Art can answer your science question, but it isn't at all the case that any laws of mathematics break down inside black holes. Math works just fine. The problem comes in reconciling the math with physical reality. Our physical laws appear to break down when we have things like singularities (which math handles without difficulty).

[warmingwarmingwarming]

Nearly forever for observers on the outside.

But... those observers on the outside should also note that time nearly stops for objects falling into the event horizon.

So... do those observers who fall into the BH get to observe the black hole evaporate (as a blinding firewall)

Neufer .. the known laws of mathematics are said to break down in the Black Hole or even at the event horizon .. what do you think of the thought that material beyond those points may be transformed into a reverse state .. that matter could become anti-matter, and through a wormhole or other mechanism enter Voids as the anti-matter/anti-gravity 'material' causing the Voids expansions?

Art can answer your science question, but it isn't at all the case that any laws of mathematics break down inside black holes. Math works just fine. The problem comes in reconciling the math with physical reality. Our physical laws appear to break down when we have things like singularities (which math handles without difficulty).

Thanks Chris .. I examined your answer through google, and at this stage I have a picture of a 'breakdown' being all possible answers leading to infinity .. so yes, reconciling infinity to physical reality is quite a task. If you think you could add to that picture, clarify it, whatever, please feel free to do so.

[neufer]

Conclusion, black holes last forever, in all practical terms.

Nearly forever for observers on the outside.

But... those observers on the outside should also note that time nearly stops for objects falling into the event horizon.

So... do those observers who fall into the BH get to observe the black hole evaporate (as a blinding firewall)

Neufer .. the known laws of mathematics are said to break down in the Black Hole or even at the event horizon .. what do you think of the thought that material beyond those points may be transformed into a reverse state .. that matter could become anti-matter, and through a wormhole or other mechanism enter Voids as the anti-matter/anti-gravity 'material' causing the Voids expansions?

• 1) I don't understand your question.
  2) I can't even answer my own question.

Particle physics has been going in the direction of thinking of particles as (mem)branes free of singularities.

Perhaps, black holes should also be thought of as (2D event horizon) membranes free of singularities.