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Topic: Black hole in the laboratory?
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Tommy_Paine
rabble-rouser
Babbler # 214
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posted 18 March 2005 04:59 PM
I suspect that this is where half my socks have been going. And, Skdadl, maybe what you have worried about has already happened...... Late at night, when no one's watching, I have the very determined feeling that I was at one time a female that looks exactly like Mae West.
Maybe I was? Will be? Is that an alternate universe in your pocket, or are you just glad to see me?
From: The Alley, Behind Montgomery's Tavern | Registered: Apr 2001
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skdadl
rabble-rouser
Babbler # 478
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posted 18 March 2005 05:40 PM
Mike, I think you might enjoy -- well, let me rephrase that -- you might want? need? to read this review of two recent books about Doomsday from a recent edition of the NY Review of Books.I think that it is the Posner book that raises just the peril you warn us of here. Posner seems to take it seriously. Luckily, our reviewer, Clifford Geertz, who seems a lovely thinker and writer, does not seem to take Mr Posner all that seriously. (I believe that Mr Posner is a flaming neo-lib/con of the legalistic persuasion.)
From: gone | Registered: May 2001
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forum observer
rabble-rouser
Babbler # 7605
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posted 18 March 2005 05:41 PM
Space-tearing ConifoldsThere is lots of information on this subject throughtout thread supplied. Also reference to Steve Giddings and other issues in regards to blackholes. Just like Numb3rs show, there is going to be a show based on Blackholes as well. [ 18 March 2005: Message edited by: forum observer ]
From: It is appropriate that plectics refers to entanglement or the lack thereof, | Registered: Dec 2004
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Surferosad
rabble-rouser
Babbler # 4791
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posted 18 March 2005 06:01 PM
quote: Originally posted by nister: Is this the kind of thing they're doing at the new Sask. facility? [forget it's name]
Emphatic no. The Sask. facility is a synchroton: it accelerates electrons to produce intense x-rays. No need to slam electrons against a target to do this, since accelerating them is enough to produce x-rays. The x-rays are then used to investigate all kinds of things. I won't go into the details... It's called the Canadian Light Source by the way. http://www.lightsource.ca/ [ 18 March 2005: Message edited by: Surferosad ]
From: Montreal | Registered: Dec 2003
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Agent 204
rabble-rouser
Babbler # 4668
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posted 18 March 2005 06:07 PM
quote: Originally posted by skdadl:
I think that it is the Posner book that raises just the peril you warn us of here. Posner seems to take it seriously.Luckily, our reviewer, Clifford Geertz, who seems a lovely thinker and writer, does not seem to take Mr Posner all that seriously. (I believe that Mr Posner is a flaming neo-lib/con of the legalistic persuasion.)
Hmm. I looked at the review and it looks like Posner (who, incidentally, is a judge rather than a scientist by profession) is referring to the possibility of the formation of a stable "strangelet", creating a similar problem to the black hole problem. For what it's worth, physicists are less concerned: quote:
We discuss speculative disaster scenarios inspired by hypothetical new fundamental processes that might occur in high energy relativistic heavy ion collisions. We estimate the parameters relevant to black hole production; we find that they are absurdly small. We show that other accelerator and (especially) cosmic ray environments have already provided far more auspicious opportunities for transition to a new vacuum state, so that existing observations provide stringent bounds. We discuss in most detail the possibility of producing a dangerous strangelet. We argue that four separate requirements are necessary for this to occur: existence of large stable strangelets, metastability of intermediate size strangelets, negative charge for strangelets along the stability line, and production of intermediate size strangelets in the heavy ion environment. We discuss both theoretical and experimental reasons why each of these appears unlikely; in particular, we know of no plausible suggestion for why the third or especially the fourth might be true. Given minimal physical assumptions the continued existence of the Moon, in the form we know it, despite billions of years of cosmic ray exposure, provides powerful empirical evidence against the possibility of dangerous strangelet production.
What they're claiming is that if these effects could occur in the RHIC, they'd have occurred already from cosmic rays striking the Moon. The Moon is still there, ergo no problem. Of course, future particle accelerators, more powerful than the RHIC, might pose a problem... but they don't exist yet, and probably won't unless and until we're able to afford the energy to run them.
From: home of the Guess Who | Registered: Nov 2003
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maestro
rabble-rouser
Babbler # 7842
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posted 19 March 2005 07:01 PM
In one of Kurt Vonnegut's books he postulates the discovery of something called Ice-9.It has the property of making everything it touches freeze. Interesting book. Jeez, Skdadl - all that dizziness...you're not blonde, are you? oops, i never said that. icon
From: Vancouver | Registered: Jan 2005
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DrConway
rabble-rouser
Babbler # 490
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posted 19 March 2005 08:00 PM
Re: Black Hole Collapse RatesI don't have the math for it, but I do know that Stephen Hawking demonstrated that black holes leak energy ("Hawking radiation") and as a result, lose mass. The smaller the black hole, the faster it'll lose mass. Thus, "quantum black holes" would last for probably a microsecond or less and then go blip. I would not worry. The opportunity to gain mass and sustain a black hole only comes when the black hole is very large, which lengthens the inevitable leakage of Hawking radiation for some time, and allows the black hole to begin absorbing mass in its vicinity. There's a black hole, or several, at the center of our own galaxy, for example. This is shown by the spray of X-rays and radio waves that come off from the center, but even so they are no danger to us since we're just so far away.
From: You shall not side with the great against the powerless. | Registered: May 2001
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Surferosad
rabble-rouser
Babbler # 4791
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posted 24 March 2005 01:18 PM
Oh, and I read the following on Greene's book: "on October 15, 1991, the Fly's eye cosmic ray detector in the Utah desert, measured a particle streaking across the sky with energy equivalent to 30 billion proton masses. (..) about 100 milions times the size of the particle energies that will be produced by the large Hadron Colider." It's a mystery what produces these kinds of cosmic rays. The fact that we're bombarded by them, and that we're still around shows, I think, that we don't have much to worry about particle accelerator experiments. [ 25 March 2005: Message edited by: Surferosad ]
From: Montreal | Registered: Dec 2003
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DrConway
rabble-rouser
Babbler # 490
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posted 24 March 2005 06:24 PM
quote: Originally posted by Surferosad: Yes, I know. But according to Greene's "The Fabric of the Cosmos" book, string theorists argue that the weakness of gravity is due to "seepage" of gravity into other dimensions, roughly speaking. It's damn weird, but they argue that at very small distances, this effect is minimised, and gravity becomes stronger. As you can imagined, this is an effect that is pretty hard to measure... If you can get a hold of that book, read page 394 onwards, he explains it there.
Got the book, but managed to forget that part. I did remember the explanation for the weakness of gravity being due to leakage of its mediating particles (assuming we ever find a graviton), though, and rested on that for my explanation above.
From: You shall not side with the great against the powerless. | Registered: May 2001
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