In today's Herald: why the Mersey Hospital is like a puppy. The analogy is surprisingly exact.
Style warning: The last sentence of this otherwise fine article is an appalling pun.
Tuesday, 9 October 2007
Friday, 5 October 2007
Tangled up in (quantum) blue
An object goes "bang" in the middle of a room and two pieces go flying off, one to the left and one to the right. Each one follows the laws of physics just by itself, and is influenced only by things that touch it (and gravity etc.[1]). To know what the left piece will do, you needn't bother about the right piece in any special way: no more than you'd bother about the influence of your shoes, the ceiling, or the planet Jupiter.
Sorry: not true, so far as we understand.
If you believe quantum mechanics, those two pieces are in a certain sense still a single object ... even if the two pieces are on opposite sides of the room, or in separate towns many kilometres apart. It's called entanglement, a.k.a. "spooky action at a distance", a.k.a. "weird quantum s***".
I mention this because our paper on quantum entanglement at the Belle experiment has been published in Physical Review Letters.[2] The theory does just fine at predicting our data --- that's not unexpected, since it's done just fine on all the data it's been confronted with. The real interest in this kind of measurement is to see if one can go beyond testing quantum predictions, and test entanglement itself: to show that entanglement is just-a-fact-about-how-the-world-is-put-together which we'll always be stuck with, even if we eventually improve on quantum mechanics in some way.[3]
The gold standard for proving entanglement is a theorem by the late John Bell (no relation): our experiment couldn't meet this standard, even if our equipment were perfect (for rather technical reasons). What we can do is put other specific models --- other ways of explaining the data that don't involve entanglement --- to the test. The ones we have been able to try, fail; quantum mechanics succeeds. So entanglement wins this round, yet again, but some alternatives still live to fight another day ...
Here ends the lesson. It's not usually my aim to post such pedagogical material on this site, but there is no end to the flaky silliness on these topics doing the rounds in popular culture, so I feel some kind of duty to fly the flag when I've been a part of the work. What the bleep do we know? Um, well, quite a bit actually.
Sorry: not true, so far as we understand.
If you believe quantum mechanics, those two pieces are in a certain sense still a single object ... even if the two pieces are on opposite sides of the room, or in separate towns many kilometres apart. It's called entanglement, a.k.a. "spooky action at a distance", a.k.a. "weird quantum s***".
I mention this because our paper on quantum entanglement at the Belle experiment has been published in Physical Review Letters.[2] The theory does just fine at predicting our data --- that's not unexpected, since it's done just fine on all the data it's been confronted with. The real interest in this kind of measurement is to see if one can go beyond testing quantum predictions, and test entanglement itself: to show that entanglement is just-a-fact-about-how-the-world-is-put-together which we'll always be stuck with, even if we eventually improve on quantum mechanics in some way.[3]
The gold standard for proving entanglement is a theorem by the late John Bell (no relation): our experiment couldn't meet this standard, even if our equipment were perfect (for rather technical reasons). What we can do is put other specific models --- other ways of explaining the data that don't involve entanglement --- to the test. The ones we have been able to try, fail; quantum mechanics succeeds. So entanglement wins this round, yet again, but some alternatives still live to fight another day ...
Here ends the lesson. It's not usually my aim to post such pedagogical material on this site, but there is no end to the flaky silliness on these topics doing the rounds in popular culture, so I feel some kind of duty to fly the flag when I've been a part of the work. What the bleep do we know? Um, well, quite a bit actually.
[1]Gravitational and electromagnetic forces act "at a distance" but their influence is not instantaneous: it's bound by the speed of light. For everyday purposes that's so fast that the influence might as well be instantaneous, but a lot hangs on the distinction. You can think of it this way: it's the gravitational and electromagnetic fields right where you are ("touching" you) that affect you, and they take time to catch up on what's going on elsewhere, the same as you do. These forces are still local in this sense.
The "spooky" part about quantum entanglement is that the connection between the parts of an entangled system works without any regard to distance whatsoever --- with no speed limit --- yet it turns out that you still can't use the thing to send a signal faster than the speed of light. Put like that, it seems somewhat contrived, and this is one of the things behind the intuition that it's our assumption of separability that's the problem, not the assumption of locality: it's not that relativity doesn't describe spacetime, it's that things really can't be divided up into "parts" the way we tend to think they can.
[2] It's also publicly available on the arXiv preprint server as quant-ph/0702267.
[3] Like many people (physicists included) I have my doubts about quantum mechanics: I suspect that there's something more going on. However, I also suspect that the "something more" will still leave us stuck with entanglement: that the weirdness is real.
Thursday, 4 October 2007
Fifty years ago today ...
... Sputnik went "beep, beep, beep", and the world changed.
It's Space Week from 4-10 October in celebration; there is probably a series of events on near you.
Normally, I only post on the planetary programme, but of course Sputnik was the public beginning of human effort in space, so it's only right to join in the party.
Happy birthday ...
UPDATE: There is an article in The Australian today on a push to establish an Australian space programme.
It's Space Week from 4-10 October in celebration; there is probably a series of events on near you.
Normally, I only post on the planetary programme, but of course Sputnik was the public beginning of human effort in space, so it's only right to join in the party.
Happy birthday ...
UPDATE: There is an article in The Australian today on a push to establish an Australian space programme.
Wednesday, 3 October 2007
Rate Your Students
Featured a few months back by Blogger: Rate Your Students. Its motto: Email us your pain.
I would not want to spend all my days reading American professors venting about their students --- I would not want to spend all my days reading any blog, or anything on the Web for that matter --- but this thing is worth a look. And I guess the www.ratemyprofessors.com site needed some kind of counterweight.
Today's RYS post: A New Correspondent Shares Some of the Normal Disgust Concerning Her "Special," Most Favoritest Student.
I would not want to spend all my days reading American professors venting about their students --- I would not want to spend all my days reading any blog, or anything on the Web for that matter --- but this thing is worth a look. And I guess the www.ratemyprofessors.com site needed some kind of counterweight.
Today's RYS post: A New Correspondent Shares Some of the Normal Disgust Concerning Her "Special," Most Favoritest Student.
Saturday, 29 September 2007
Australian Research Fellowship
On Wednesday the Australian Research Council announced the "outcomes" for the 2008 round of Discovery Project applications.
I've received an Australian Research Fellowship for the next five years, and some additional funding: not as much as I asked for, but hey. I'll still be based at the University of Sydney, but with a proper job --- who knows, maybe even a proper office --- and will once again be doing work at CERN, the Jerusalem of particle physics. [Sigh.] I have been away for too long.
Some colleagues from Melbourne were also successful in this round: Prof. Geoff Taylor (overboss of particle physics in Australia) has received a Professorial Fellowship, freeing him from other duties over the next five years, as ATLAS starts taking data; and A/Prof. Martin Sevior and Dr Glenn Moloney received a grant to use the (computing) Grid to support particle physics work. Congratulations, guys.
Oh, and an old schoolfriend who is working on the theory of freedom of expression, in the law faculty at U.Melbourne, also received a grant. The DP process funds all sorts of things, medical research excepted ...
I've received an Australian Research Fellowship for the next five years, and some additional funding: not as much as I asked for, but hey. I'll still be based at the University of Sydney, but with a proper job --- who knows, maybe even a proper office --- and will once again be doing work at CERN, the Jerusalem of particle physics. [Sigh.] I have been away for too long.
Some colleagues from Melbourne were also successful in this round: Prof. Geoff Taylor (overboss of particle physics in Australia) has received a Professorial Fellowship, freeing him from other duties over the next five years, as ATLAS starts taking data; and A/Prof. Martin Sevior and Dr Glenn Moloney received a grant to use the (computing) Grid to support particle physics work. Congratulations, guys.
Oh, and an old schoolfriend who is working on the theory of freedom of expression, in the law faculty at U.Melbourne, also received a grant. The DP process funds all sorts of things, medical research excepted ...
Thursday, 27 September 2007
Wednesday, 19 September 2007
The New York Times is free again
Editorial and other opinion columns at the New York Times, and the archive, are once again free online.
I've been a subscriber since this content went secured --- because the NYT is that good --- but on everyone else's behalf at least, I'm glad that it's back out in the open. Do I prefer that people's blogs link to some other unverifiable ranting guy, or to articles in a disciplined and relatively independent paper? Hmm, lets see, difficult choice ... not sure what I think about that ...
I've been a subscriber since this content went secured --- because the NYT is that good --- but on everyone else's behalf at least, I'm glad that it's back out in the open. Do I prefer that people's blogs link to some other unverifiable ranting guy, or to articles in a disciplined and relatively independent paper? Hmm, lets see, difficult choice ... not sure what I think about that ...
Sunday, 16 September 2007
Playing with loaded dice
Consider the contrast between the following news items:
In the New York Times: There is a gene called BRCA1; a woman with a defective copy of this gene has a 60 to 90 percent chance of developing breast cancer in her lifetime, and about 50 percent of getting ovarian cancer (cf. 2 percent for other women). It's possible to test for this gene. One woman discussed in the article, a 33-year-old who tested postive --- some of whose relatives came down with cancer in their thirties --- has just had a double mastectomy as a preventative measure. She is going to have her ovaries removed when she gets to forty.
All over The Sunday Telegraph (and the evening news): "The Royal Australian Navy is paying for women sailors to have breast enlargements for purely cosmetic reasons, at a cost to taxpayers of $10,000 an operation." The women in question were officers, not enlisted, a point not unnoticed in the online comments. There is something of an irony here: on the Navy's current PR vehicle, the fictitious patrol boat HMAS Hammersley, two out of the three officers are women, remarkably good-looking, and unlikely to win a breast-size contest any time soon. The least the Senior Service could do, it seems to me, is to get its story straight in this important matter.
"Are you happy to pay for this surgery with your taxes? Vote in our home page poll", the Telegraph howls. I would suggest as an alternative that $10,000 per episode of Sea Patrol be removed from the budget for fancy helicopter shots, and spent on a decent script doctor. Because at present, this show is making Patrol Boat look better every day.
Back to the New York Times article (which is extensive and very good, by the way): the story does at least have a hero. Cancer girl, while considering her eventual choice of mastectomies followed by reconstructive surgery, consults her boyfriend:
Good on you, mate.
In the New York Times: There is a gene called BRCA1; a woman with a defective copy of this gene has a 60 to 90 percent chance of developing breast cancer in her lifetime, and about 50 percent of getting ovarian cancer (cf. 2 percent for other women). It's possible to test for this gene. One woman discussed in the article, a 33-year-old who tested postive --- some of whose relatives came down with cancer in their thirties --- has just had a double mastectomy as a preventative measure. She is going to have her ovaries removed when she gets to forty.
All over The Sunday Telegraph (and the evening news): "The Royal Australian Navy is paying for women sailors to have breast enlargements for purely cosmetic reasons, at a cost to taxpayers of $10,000 an operation." The women in question were officers, not enlisted, a point not unnoticed in the online comments. There is something of an irony here: on the Navy's current PR vehicle, the fictitious patrol boat HMAS Hammersley, two out of the three officers are women, remarkably good-looking, and unlikely to win a breast-size contest any time soon. The least the Senior Service could do, it seems to me, is to get its story straight in this important matter.
"Are you happy to pay for this surgery with your taxes? Vote in our home page poll", the Telegraph howls. I would suggest as an alternative that $10,000 per episode of Sea Patrol be removed from the budget for fancy helicopter shots, and spent on a decent script doctor. Because at present, this show is making Patrol Boat look better every day.
Back to the New York Times article (which is extensive and very good, by the way): the story does at least have a hero. Cancer girl, while considering her eventual choice of mastectomies followed by reconstructive surgery, consults her boyfriend:
“Does the thought of plastic surgery bother you?” she asked.
A moment passed.
“It would if I thought the person I was with was doing it because they didn’t like the way they looked,” he said. “But that isn’t this situation.”
Good on you, mate.
Saturday, 15 September 2007
Do the math, as they say
Polygamous sects have been in the news recently, with a New York Times article on the vile practice of driving teenage boys out of isolated communities into a wider world they are not equipped to handle, and separating them from their families. Such sects are said to be into control, and so an uneasy relationship with teenage boys is no great surprise; and of course it serves the older men's interest in a more sinister way. Unless men are being lost to war or accident (or expulsion), a community in which all men are expected to take several wives cannot be sustained ... but then, so much the worse for community commitment to such rules. Can't maintain your way of life? Surely the answer is just "Well, that is too bad!"
(Viewers of Big Love will recall that Bill Henrikson was run out of the Juniper Creek compound as a teenager, as a threat to its leader in several senses.)
Meanwhile mainstream Mormons and other folk are in some places learning to co-exist with polygamous sect-members via the classic means of cooperation, and respect for virtuous individuals. In certain senses one cannot argue with this, and nor should one want to. But it provides an interesting test-case for prevailing ideas on tolerance:
Polygamists (and especially their children) should not be subject to relentless taunts, quasi-legal harrassment, or irrelevant discrimination. Amen. Individuals should be treated on their merits, and ideally one should "take them as you find them" in social settings. Sure. Allowance for their customs should be made in forming moral assessments. Well of course, although this is not the same as bracketing polygamy as an issue, or approving of it: as discussed in an earlier post on Bill and Barb's "affair", it's difficult to express a coherent opinion on certain individual actions (I was against the affair) without taking a position on the lifestyle as a whole (I think Bill taking second and third wives was wrong, and the fact that his domestic commitments now prevent him from devoting himself to his first and "true" wife, even despite his feelings, is part of what made it wrong in the first place).
But it is somehow illegitimate to express moral disapproval or criticism of this lifestyle choice, provided it stays within norms of informed consent (and so on)? Um, no. Acceptance of such customs should be taught, for the sake of integration/respect/choice/whatever? Nope, doesn't follow. And so on ...
"Gay marriage" always seems to float around the back of these discussions, and to some extent discussion of polygamy can serve as a proxy for discussion of homosexual partnerships. To me, this last approach seems unhelpful: each case should be treated on its merits. Polygamy is useful to the discussion precisely because it is different, and thus throws our concepts and rhetoric into relief. For example, what does one make of "rights" in this case? What about arguments on "orientation" and "choice"?
(Viewers of Big Love will recall that Bill Henrikson was run out of the Juniper Creek compound as a teenager, as a threat to its leader in several senses.)
Meanwhile mainstream Mormons and other folk are in some places learning to co-exist with polygamous sect-members via the classic means of cooperation, and respect for virtuous individuals. In certain senses one cannot argue with this, and nor should one want to. But it provides an interesting test-case for prevailing ideas on tolerance:
Polygamists (and especially their children) should not be subject to relentless taunts, quasi-legal harrassment, or irrelevant discrimination. Amen. Individuals should be treated on their merits, and ideally one should "take them as you find them" in social settings. Sure. Allowance for their customs should be made in forming moral assessments. Well of course, although this is not the same as bracketing polygamy as an issue, or approving of it: as discussed in an earlier post on Bill and Barb's "affair", it's difficult to express a coherent opinion on certain individual actions (I was against the affair) without taking a position on the lifestyle as a whole (I think Bill taking second and third wives was wrong, and the fact that his domestic commitments now prevent him from devoting himself to his first and "true" wife, even despite his feelings, is part of what made it wrong in the first place).
But it is somehow illegitimate to express moral disapproval or criticism of this lifestyle choice, provided it stays within norms of informed consent (and so on)? Um, no. Acceptance of such customs should be taught, for the sake of integration/respect/choice/whatever? Nope, doesn't follow. And so on ...
"Gay marriage" always seems to float around the back of these discussions, and to some extent discussion of polygamy can serve as a proxy for discussion of homosexual partnerships. To me, this last approach seems unhelpful: each case should be treated on its merits. Polygamy is useful to the discussion precisely because it is different, and thus throws our concepts and rhetoric into relief. For example, what does one make of "rights" in this case? What about arguments on "orientation" and "choice"?
Friday, 14 September 2007
Midgley on rights and social ethics
Here is my current author-crush, the moral philosopher Mary Midgley, writing in 1989, near the end of her book Wisdom, information, and wonder: What is knowledge for? (which I've recently been re-reading):
The trouble wrought by mere disputatiousness is one of her themes in this book (and indeed throughout her writings), and is a standing challenge to all of us with strong opinions: one must ask, does a boofhead cease to be a boofhead, simply because he/she is an intellectual, or --- even worse --- an activist?
For instance, questions such as euthanasia and abortion are often made unmanageable by being treated in arbitrary isolation, as if they were the only moral issues in sight. They cannot be effectively thought about apart from wider issues. To name just one, they lead us into questions about the emphasis on brute, unreasoning competition that arises from arguing always in terms of absolute, competing `rights', rights which are not brought into intelligible relations within any wider system. They also bring in question the general unrealistic attitude to the inevitability of death which has long prevailed in our society ... But, besides this lack of a proper background, much-litigated questions like these are bedevilled by the disputants' refusal to admit that they are dealing with a genuine conflict, a real choice of evils. Out of the welter of previous argumentation, argumentative people have constantly picked in advance some set of concepts which favours their own attitude, and refused to extend it so as to make recognition of opposing arguments possible ...
The trouble wrought by mere disputatiousness is one of her themes in this book (and indeed throughout her writings), and is a standing challenge to all of us with strong opinions: one must ask, does a boofhead cease to be a boofhead, simply because he/she is an intellectual, or --- even worse --- an activist?
Dawn and the darkness
Dawn is being prepared for launch, after an earlier postponement due to a kind of traffic jam at Cape Canaveral. Good luck for the now-or-never launch window that's about to open ...(I have posted previously on the Dawn mission and its delay.)
Meanwhile, in orbit of Saturn, Cassini has recently had a bad cosmic ray day, just after a close flyby of the moon Iapetus. It seems to have recovered now, and there's been no loss of data. The manoeuvre was set up using an earlier pass by Saturn's two largest moons, Titan and Rhea, shown here with the sun behind them. (The difference in appearance, due to Titan's atmosphere, is striking.)
Image Credit: NASA/JPL/Space Science Institute. More information on this image can be found here.
Sunday, 9 September 2007
Brave, or foolish?
Manohla Dargis of the New York Times has written an article on Jodie Foster and her new film, "The Brave One", which is both sensible and interesting. That's not especially easy.
I don't know about anyone else, but I'm looking forward to this film with some trepidation. Ms Foster's best roles recently have been smaller ones, where semi-villainy (The Dangerous Lives of Altar Boys), French (A Very Long Engagement), or if you can believe it Spike Lee (Inside Man) have given her the freedom to interpret a character, rather than perform: in each of those films her work was fresh, even witty, words one doesn't readily associate with her. Yet this new film could not be more central to her oeuvre: a strong woman, made a victim, and then turned Travis Bickle. Yes, I know. It could be a triumph or a fiasco, or just about anything in between.
It's directed by Neil Jordan --- a choice Ms Foster apparently had a hand in --- and that would seem like a good sign. One can only hope, because at the top of her form, and in the right company ...
... I might as well give up on the "Ms Foster" routine right here: it's no secret that I'm a Jodie tragic. At the top of her form, and in the right company, Alicia Christian Foster is one of the greatest actors alive and utterly fascinating. As for this film: fingers crossed.
I don't know about anyone else, but I'm looking forward to this film with some trepidation. Ms Foster's best roles recently have been smaller ones, where semi-villainy (The Dangerous Lives of Altar Boys), French (A Very Long Engagement), or if you can believe it Spike Lee (Inside Man) have given her the freedom to interpret a character, rather than perform: in each of those films her work was fresh, even witty, words one doesn't readily associate with her. Yet this new film could not be more central to her oeuvre: a strong woman, made a victim, and then turned Travis Bickle. Yes, I know. It could be a triumph or a fiasco, or just about anything in between.
It's directed by Neil Jordan --- a choice Ms Foster apparently had a hand in --- and that would seem like a good sign. One can only hope, because at the top of her form, and in the right company ...
... I might as well give up on the "Ms Foster" routine right here: it's no secret that I'm a Jodie tragic. At the top of her form, and in the right company, Alicia Christian Foster is one of the greatest actors alive and utterly fascinating. As for this film: fingers crossed.
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