Thursday, January 29, 2009
In case you missed it: micro black holes are news again
I've been slack lately and not following closely the arXiv papers on black holes at the LHC.
As those who read Instapundit would already have seen, there is a new paper by some credible European physicists (original is here) in which they re-visited the question of how long a micro black hole created at the LHC may last. The previous perceived wisdom was that it would be a tiny, tiny fraction of second before they disappeared into a spray of decay particles, which (presumably) the LHC could detect.
As I understand it, the new paper suggests that for a certain model, the decay rate may in fact be many seconds, even minutes; time enough for a micro black to shoot off through the earth. But they still think there is no likely risk of accretion starting and overwhelming the much-slower-that-previously-thought-possible decay rate.
As some are commenting (see the second link above), this still seems a pretty big revision of what was considered possible from the LHC, even if the authors are still arguing that there is no danger.
I note that the authors of the paper acknowledge discussions with physicists Giddings and Plaga, who themselves still (as far as I know) are stuck in disagreement as to whether Plaga's warning last year that a micro black hole could be an explosive danger was fundamentally flawed or not. At the very least, it indicates that other physicists consider that Plaga is not to be dismissed as a nutter.
Also on the topic of danger from the LHC, New Scientist has an article about a paper looking at (if I can paraphrase it correctly) how to judge the probabilities of something going wrong when you are not entirely sure of what may you might create in the first place. The general gist seems to be that it is potentially riskier than you think.
The guy who runs the Physics arXiv blog is probably really getting up the nose of CERN now, as the effect of both of these recent papers is to make him start worrying about safety issues. Fox News's version of the story probably annoys them even more.
As those who read Instapundit would already have seen, there is a new paper by some credible European physicists (original is here) in which they re-visited the question of how long a micro black hole created at the LHC may last. The previous perceived wisdom was that it would be a tiny, tiny fraction of second before they disappeared into a spray of decay particles, which (presumably) the LHC could detect.
As I understand it, the new paper suggests that for a certain model, the decay rate may in fact be many seconds, even minutes; time enough for a micro black to shoot off through the earth. But they still think there is no likely risk of accretion starting and overwhelming the much-slower-that-previously-thought-possible decay rate.
As some are commenting (see the second link above), this still seems a pretty big revision of what was considered possible from the LHC, even if the authors are still arguing that there is no danger.
I note that the authors of the paper acknowledge discussions with physicists Giddings and Plaga, who themselves still (as far as I know) are stuck in disagreement as to whether Plaga's warning last year that a micro black hole could be an explosive danger was fundamentally flawed or not. At the very least, it indicates that other physicists consider that Plaga is not to be dismissed as a nutter.
Also on the topic of danger from the LHC, New Scientist has an article about a paper looking at (if I can paraphrase it correctly) how to judge the probabilities of something going wrong when you are not entirely sure of what may you might create in the first place. The general gist seems to be that it is potentially riskier than you think.
The guy who runs the Physics arXiv blog is probably really getting up the nose of CERN now, as the effect of both of these recent papers is to make him start worrying about safety issues. Fox News's version of the story probably annoys them even more.
Wednesday, January 28, 2009
"Chris, want to know who I just spoke to?"
Obama and Rudd discuss financial crisis - Yahoo!7 News
So, Obama finally got around to ringing our PM. I like to imagine Kevin doing a little dance in his office in celebration and relief. Then a phone call to Chris Mitchell to tell him all about it.
So, Obama finally got around to ringing our PM. I like to imagine Kevin doing a little dance in his office in celebration and relief. Then a phone call to Chris Mitchell to tell him all about it.
The trouble in Egypt
Gaza crisis threatens outlook for Mubarak - International Herald Tribune
Egyptians and Arab countries complained that Mubarak kept the official border crossing between Egypt and Gaza closed before and during much of the war. The most populous Arab country - and the first to sign a peace treaty with Israel, in 1979 - Egypt has been subject to scorn in Yemen and Lebanon, where mobs have marched on its embassies in the past few weeks. It has also been the target of criticism from the tiny Gulf oil state of Qatar, as well as Syria and Iran. All support Hamas.Surely this issue with the Egyptian control of the border is not an insurmountable problem.
At the same time, Israel complained that the Egyptian police turned a blind eye to arms smuggled though hundreds of tunnels beneath the Gaza border.
This is modern art (Part 1)
Kulik confounds critics with multisensory Monteverdi in Paris | guardian.co.uk
This is a somewhat amusing report on a very avant garde reworking of classical concert material in Paris:
This is a somewhat amusing report on a very avant garde reworking of classical concert material in Paris:
Behold, the classical concert is reborn! Its saviour? A man whose career high until now has been crawling naked on all fours barking like a dog. The Russian artist Oleg Kulik is notorious for biting critics when his canine alter ego occasionally breaks the leash in galleries — now he has taken a nip at the heels of an artform that has been getting a bit doddery on its feet....As for that dog act of Kulik, it sounds like he, um, role plays it to the extreme:
The resulting two-and-a-half hour "trip" – think William Blake meets Jean-Michel Jarre, crossed with Peter Greenaway's Prospero's Books – is either a flabbergasting reworking of one of the most sublime works in the classical repertoire, or what the dependably crusty French daily Le Figaro today called an "indigestible visual minestrone".
The critic accused Kulik of doing to Monteverdi what French police suspected the artist did to a dog in some of his "man-dog, couple of the future" photographs recently seized from a Paris art fair.Ugh.
Synergy
Last night I read this story:
Then this morning I learn that:Seven diners fell ill, one critically, after eating "fugu" globefish at a restaurant whose owner was unlicensed to safely prepare the notorious winter delicacy, police said Tuesday.
The seven consumed sashimi and fish testes at Kibun-ya restaurant in Tsuruoka, Yamagata Prefecture, at around 6:30 p.m. Monday and one of them, identified as Asakichi Sato, 68, fell ill on the spot and was taken to a hospital, where he was listed in critical condition, the police said.
Taiwan has a smorgasboard of theme diners, including one modeled after a hospital ward, one that holds puppet shows and two that seat customers on toilet bowls.Am I the only person in the world to see the potential for a fugu restaurant done up as a hospital ward? (Or cut out the middle man: just locate it in a real ward.)
Tuesday, January 27, 2009
Moral panic delayed
The Myth of Rampant Teenage Promiscuity - NYTimes.com
The general gist of the article is that the number of teenagers having sex in American (including oral sex) is not as high as some recent reports have indicated. In fact, some participation rates have dropped over the last 20 years or so. For example:
The general gist of the article is that the number of teenagers having sex in American (including oral sex) is not as high as some recent reports have indicated. In fact, some participation rates have dropped over the last 20 years or so. For example:
A 2002 report from the Department of Health and Human Services found that 30 percent of 15- to 17-year-old girls had experienced sex, down from 38 percent in 1995. During the same period, the percentage of sexually experienced boys in that age group dropped to 31 percent from 43 percent.This part of the report seemed particularly surprising:
The reality is that the rate of teenage childbearing has fallen steeply since the late 1950s. The declines aren’t explained by the increasing availability of abortions: teenage abortion rates have also dropped.Damn. I hate it if a perfectly good moral panic is shown to be illusory.
The ever helpful drug
BBC NEWS - Aspirin 'could cut liver damage'
Yet another way in which aspirin may prove to have unexpected benefits:
Here's a surprising figure from the report:
Have I mentioned here before that a nurse told me years ago that suicide by paracetamol overdose could be one of the most tragic ways to die, as the person (if not treated quickly enough) could wake up feeling relatively OK, realise what they have done and regret it, but may have irretrievably damaged their liver anyway. What may have been a "plea for help" type suicide attempt may therefore turn into the real thing, and the help they are offered won't make any difference. It's an awful scenario.
(Geoff can correct me if this is medically wrong.)
Yet another way in which aspirin may prove to have unexpected benefits:
A dose of aspirin may be able to prevent liver damage caused by paracetamol or heavy drinking, suggest researchers.It only has been shown in mice so far, but still it sounds hopeful.
Here's a surprising figure from the report:
Rates of liver cirrhosis have risen in the UK in recent years as people drink more alcohol, and paracetamol overdose, both deliberate and accidental, accounts for well over 100 deaths per year.That's more than I would have expected.
Have I mentioned here before that a nurse told me years ago that suicide by paracetamol overdose could be one of the most tragic ways to die, as the person (if not treated quickly enough) could wake up feeling relatively OK, realise what they have done and regret it, but may have irretrievably damaged their liver anyway. What may have been a "plea for help" type suicide attempt may therefore turn into the real thing, and the help they are offered won't make any difference. It's an awful scenario.
(Geoff can correct me if this is medically wrong.)
He's a poet, but didn't know it
Praise song for the first day for the school year (Brisbane version)
Hooray, hooray, is the cry of a million parents, as we catch the joy in each other’s eyes.
The noise all about us at home for the last six weeks is finished, and a tidied house again may stay that way for more than one hour.
No more cinema queues to be endured for the latest movie about dogs.
No more cartoons every morning.
No more outings just to find time in airconditioning.
Say it plain: we love you kids, but jeez it’s good to get you out of the house again.
Learn well, and don’t expect us to do your homework for you. (Tell the teacher that too.)
Praise the day, that domestic peace rules again for 8 hours a day.
Hooray, hooray, is the cry of a million parents, as we catch the joy in each other’s eyes.
The noise all about us at home for the last six weeks is finished, and a tidied house again may stay that way for more than one hour.
No more cinema queues to be endured for the latest movie about dogs.
No more cartoons every morning.
No more outings just to find time in airconditioning.
Say it plain: we love you kids, but jeez it’s good to get you out of the house again.
Learn well, and don’t expect us to do your homework for you. (Tell the teacher that too.)
Praise the day, that domestic peace rules again for 8 hours a day.
Monday, January 26, 2009
Nudge nudge, wink wink...
Grand Arabian nights Geert Jan van Gelder TLS
This is a long review on a new translation of 1,001 [Arabian] Nights, which I found of limited interest. However, being kind, I will extract for you the best bit:
This is a long review on a new translation of 1,001 [Arabian] Nights, which I found of limited interest. However, being kind, I will extract for you the best bit:
Some readers will be delighted to learn some naughty Arabic, but surely English has a profusion of equally vulgar words for the sexual organs. It should be stressed, however, that obscenities, Arabic equivalents of English four-letter words, are few and far between in the original, where sexual intercourse is often simply expressed as “lying with” or more elaborately by means of metaphors martial (“storming the fortress”) or religious (“circumambulating the Kaaba”, “putting the imam into the prayer niche”), with the mildly shocking profanity that was common in pre-modern Arabic.
Naked science revisited
Do Naked Singularities Break the Rules of Physics?: Scientific American
Interesting article here arguing that a growing body of physicists are now not so sure that black holes always have an event horizon hiding their core from view. Some may be genuine naked singularities, the exact behaviour of which remains very unclear.
In September 2007, I mentioned a paper on arXiv which said that the Large Hadron Collider may also produce tiny naked singularities. Although the author was not worried that they would be dangerous, the issue of how a stationary one on the earth could behave has not, as far as I know, ever been addressed in the LHC safety reviews. (The general argument that cosmic ray collisions of higher energies have been safe for the earth is the only argument I suppose you could use, given the lack of knowledge about their behaviour. It's not a bad argument, except that the issue of whether there is a difference between moving and stationary ones would have to be addressed, as it was for micro black holes.)
Call me overly cautious if you want, but I am not entirely comfortable with the idea of a European lab possibly creating something the behaviour of which can only be guessed.
Interesting article here arguing that a growing body of physicists are now not so sure that black holes always have an event horizon hiding their core from view. Some may be genuine naked singularities, the exact behaviour of which remains very unclear.
In September 2007, I mentioned a paper on arXiv which said that the Large Hadron Collider may also produce tiny naked singularities. Although the author was not worried that they would be dangerous, the issue of how a stationary one on the earth could behave has not, as far as I know, ever been addressed in the LHC safety reviews. (The general argument that cosmic ray collisions of higher energies have been safe for the earth is the only argument I suppose you could use, given the lack of knowledge about their behaviour. It's not a bad argument, except that the issue of whether there is a difference between moving and stationary ones would have to be addressed, as it was for micro black holes.)
Call me overly cautious if you want, but I am not entirely comfortable with the idea of a European lab possibly creating something the behaviour of which can only be guessed.
Bad ocean forecast of the week
Dramatic expansion of dead zones in the oceans
From the above report at PhysOrg:
Go to the links for more details. Not exactly encouraging, as it shows what is potentially at stake if the warming skeptics are wrong. (And it is an additional risk to that of ocean acidification, which of itself is a major concern for future ocean health.)
From the above report at PhysOrg:
A team of Danish researchers have now shown that unchecked global warming would lead to a dramatic expansion of low-oxygen areas zones in the global ocean by a factor of 10 or more.The New Scientist version of the story adds this detail:
Under the worst-case scenario, average ocean oxygen levels will fall by up to 40%, and there will be a 20-fold expansion in the area of "dead zones", like those already discovered in the eastern Pacific and northern Indian Ocean, where there is too little oxygen for fish to survive. Even in the mid-range scenario, dead zones would expand by a factor of 3 or 4. Cold, deep waters will also be affected if warming stifles the currents that deliver oxygen to greater depths.
Shaffer's projections suggest that the oxygen content in surface layers will dip to its lowest levels during the 22nd century, and in deep water a thousand years later. Recovery to pre-industrial levels will be very slow: "Even after 100,000 years, oxygen levels will only have recovered by around 90%," he says.
Go to the links for more details. Not exactly encouraging, as it shows what is potentially at stake if the warming skeptics are wrong. (And it is an additional risk to that of ocean acidification, which of itself is a major concern for future ocean health.)
The problems on Broadway
BBC NEWS | Mary Poppins - a tale for our times
The article is all about the current woes of Broadway. Strangely, though, it doesn't mention the lack of likeable or memorable musicals written in the last 30 odd years.
The article is all about the current woes of Broadway. Strangely, though, it doesn't mention the lack of likeable or memorable musicals written in the last 30 odd years.
Remarkable
How low can you go? : Nature News
This is pretty mind boggling, even if it is of no practical application (yet!):
This is pretty mind boggling, even if it is of no practical application (yet!):
The ones and zeroes that propel the digital world — the fording of electrons across a transistor, or hard drives reliant on electrons' intrinsic spin — are getting packed into smaller and smaller spaces. The limit was thought to be set: no more than one bit of information could be encoded on an atom or electron.
But now, researchers at Stanford University in Palo Alto, California, have used another feature of the electron — its tendency to bounce probabilistically between different quantum states — to create holograms that pack information into subatomic spaces. By encoding information into the electron's quantum shape, or wave function, the researchers were able to create a holographic drawing that contained 35 bits per electron.
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