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Strangelets at RHIC

Posted: 22.04.2008, 03:31
by yamo
How scared are you? How scared should i be(of greater import)? Goodby Earth. :(

Re: Strangelets at RHIC

Posted: 22.04.2008, 03:47
by selden
All of the particle reactions that might happen at any man-made particle accelerators have been going on in cosmic rays for billions of years. Please don't be taken in by the fear-mongers.

Re: Strangelets at RHIC

Posted: 22.04.2008, 04:11
by yamo
But this would occur here. Lots of cosmic phenomena i would not like to see on earth. i y2k scared.

Re: Strangelets at RHIC

Posted: 22.04.2008, 10:30
by selden
yamo,

Yup: it's much like y2k. A lot of fearmongering about nothing. Cosmic rays happen here. They are going through you all the time. A reasonable description is at http://en.wikipedia.org/wiki/Cosmic_ray

Re: Strangelets at RHIC

Posted: 22.04.2008, 14:42
by Hungry4info
Yamo, please, don't be consumed by the darkness of ignorance and irrational fear. The moon has been hit continuously by higher energy particles than the particle accelerator is producing. Furthermore, it's been exposed for billions of years. The moon is still there. Trust me, it is! Go out and see it (currently just past full, so you'll see it at night). I assure you, the particle accelerator will not destroy Earth. You've nothing to fear.

Please, rest easy. Nothing bad is going to happen. Just like Y2K.

Re: Strangelets at RHIC

Posted: 22.04.2008, 15:52
by yamo
http://chess.captain.at/strangelets-matter.html

This is the page that has me worried. Is this guy credible?

Re: Strangelets at RHIC

Posted: 22.04.2008, 16:01
by selden
While he seems to have had reasonable training in electrical engineering, he does not seem to have the necessary background in particle or theoretical physics.

Re: Strangelets at RHIC

Posted: 22.04.2008, 20:38
by t00fri
yamo wrote:http://chess.captain.at/strangelets-matter.html

This is the page that has me worried. Is this guy credible?

Come on...

Here is a concluding sentence of the respective review of Speculative "Disaster Scenarios" at RHIC by eminent theoretical physicists:
W. Busza, R. L. Jaffe, J. Sandweiss and F. Wilczek
Our conclusion is that the candidate mechanisms for catastrophe scenarios at RHIC are firmly excluded by existing empirical evidence, compelling theoretical arguments, or both. Accordingly, we see no reason to delay the commissioning of RHIC on their account.

The authors include people that I personally know very well since decades ( Bob Jaffe (MIT) as well as Frank Wilczek, who received the Nobel Prize for Quantum Chromodynamics (OCD) some years ago!

F.

Re: Strangelets at RHIC

Posted: 22.04.2008, 23:48
by yamo
well...einstein was just a patent clerk...can you say that the doomsday scenario he describes cannot happen? Are his refutations of the BNL Review flawed? In what way? have not even mentioned dropping the quantum foam into a lower energy state(thus destroying the universe)-'cause i understand that even less than i do strangelets...which i don't realy understand.

Re: Strangelets at RHIC

Posted: 23.04.2008, 00:36
by selden
Einstein was not "just a patent clerk". He had a degree in physics from ETH Zurich, and later a PhD in physics from the University of Zurich.

Neither Richard J. Wagner nor Walter L. Wagner (the person who keeps trying to bring suit) are credible.

Re: Strangelets at RHIC

Posted: 23.04.2008, 06:53
by t00fri
yamo wrote:well...einstein was just a patent clerk...

This must be a joke!
can you say that the doomsday scenario he describes cannot happen? Are his refutations of the BNL Review flawed? In what way? have not even mentioned dropping the quantum foam into a lower energy state(thus destroying the universe)-'cause i understand that even less than i do strangelets...which i don't realy understand.

I do understand strangelets ;-) and Nobel prize winner Frank Wilczek has been working on this sort of stuff for years as a leading world capacity!

F.

Re: Strangelets at RHIC

Posted: 23.04.2008, 13:18
by BobHegwood
This supposed threat must not be THAT much credible. If it were, you'd think that the author's web site would have been updated with more urgent information. Since the site was designed in 2002, and certainly doesn't appear to have been updated since then, I don't think I'd spend that much time worrying about it. Would you? Besides, what's the worst that could happen? The end of mankind? No big deal from where I'm sitting. :wink:

Re: Strangelets at RHIC

Posted: 24.04.2008, 12:48
by Nastytang
BobHegwood wrote:This supposed threat must not be THAT much credible. If it were, you'd think that the author's web site would have been updated with more urgent information. Since the site was designed in 2002, and certainly doesn't appear to have been updated since then, I don't think I'd spend that much time worrying about it. Would you? Besides, what's the worst that could happen? The end of mankind? No big deal from where I'm sitting. :wink:

Not so Bob

Copyright 2000-2002 by Richard J. Wagner, all rights reserved.
This page established March 8, 2000; last updated by Rick Wagner, March 21, 2007.:

But any ways that has been a little over a year now !!

Re: Strangelets at RHIC

Posted: 24.04.2008, 15:29
by BobHegwood
Nastytang wrote:Not so Bob

:D :lol: :wink:

Re: Strangelets at RHIC

Posted: 01.05.2008, 01:42
by Arenamontanus
I'm not losing any sleep over RHIC, but the critics have scored a few valid criticisms. Stationary beam targets like the moon produce rapidly moving remnants due to momentum conservation and anthropic selection effects bias our observations, making the cosmic ray argument much more complex than it looks. We have been having an interesting ongoing debate at our department blog about the whole issue (since we actually study end-of-the-world scenarios), with colleagues reaching quite different conclusions:
http://www.practicalethicsnews.com/prac ... -risk.html
http://www.practicalethicsnews.com/prac ... not-t.html
http://www.practicalethicsnews.com/prac ... ments.html

I'm working on a paper right now about why most defenders of accelerators have been mis-estimating the risks (for a subtle philosophical reason) and what to do about it. However, if the paper is accepted by the journal it will be published after the LHC is turned on. Even writing the critical paper is an act of faith in the safety of accelerators.

Re: Strangelets at RHIC

Posted: 01.05.2008, 03:26
by yamo
"However, if the paper is accepted by the journal it will be published after the LHC is turned on. Even writing the critical paper is an act of faith in the safety of accelerators."

Publish it here first. :idea:

Re: Strangelets at RHIC

Posted: 02.05.2008, 00:52
by Hungry4info
Forgive me for my limited knowledge on the subject, but isn't anthropic reasoning pretty much agreed upon to be rather... irrelevant?

Re: Strangelets at RHIC

Posted: 02.05.2008, 08:45
by eburacum45
Perhaps this is the Great Filter that Dr Bostrom talks about.
Every civilisation advances this far and disappears in a puff of smoke.

Re: Strangelets at RHIC

Posted: 02.05.2008, 13:32
by Arenamontanus
Nick Bostrom is actually my boss; we tend to talk great filter over dinner quite often. My take is that any future filter has to be something very hard to predict even knowing it is there, and it has to be large-scale: we could have had space colonies long before big accelerators, so at least some aliens ought to be able to survive physics risks - if there is a filter it has to be even more devious or wipe out entire solar systems extremely well.

Anthropic reasoning is tricky to use well. In the case of physics risks the argument runs like this: if cosmic rays had been really dangerous (planets and stars imploding left and right) most places would of course be or become uninhabitable. But a few planets would just be very, very lucky (it is a very, very big universe) and avoid getting imploded. Observers emerging on these worlds would be misled to think that there was no danger. Now, we do not observe planets imploding around us, so how do we tell whether we live in a safe universe or in a universe where we have been just lucky? The basic cosmic ray argument doesn't help because we will get a biased answer: if the moon had imploded, life on Earth would have been wiped out.

One way of finding out the risk is to look at the supernova rate, since it ought to be high in a risky universe and remote supernovas would not be biased (according to a nice paper by Dar looking at strangelets the rate appears rather low, fortunately). Another approach (used in a neat Nature paper my Nick and Max Tegmark) is to look at the age of the Earth and compare it to the time course of planet formation. Observers on lucky worlds in a risky universe tend to occur on young planets (because there will be few old planets) while observers in a safe universe should occur on average on average age planets. Earth appears to have formed close to the predicted median age of planet formation, so Nick and Max concluded that we have a very high probability of living in a safe universe. This gives a way of saving the cosmic ray argument, at the price of a much messier answer.

Re: Strangelets at RHIC

Posted: 03.05.2008, 10:47
by eburacum45
If there were a phenomenon which consistently removed advanced civilisations, such as a commonly repeated experiment in physics which all civilisations eventually attempt (unlikely in itself, I think), or perhaps a particularly unavoidable form of destructive warfare, then that phenomenon might be expected to be an energetic and observable event.

Given a hundred bilion or so galaxies in the observable universe, such eschatological events might be expected to be observed quite often in other galaxies, each one marking the end of a civilisation. Unless certain types of gamma-ray-bursters are associated with the termination of civilisations, I don't think these events have yet been observed.