illuminating science

Well, in the end I said pretty much all I wanted to say on auctions and Ebay. The whole reason I first posted about Ebay was because of an item I was bidding on, and some interesting bidding psychology. It retails for $80 here, but goes for just $10 (!) on Ebay - or, at least, that’s the starting price, and it goes up from there. I saw that a few of them had gone for between $20-30, so I ended up bidding $31.73 as my top bid - after all, that’s still half price. I missed out on two of them due to snipers (people who put in bids at the very last second, giving you no chance to respond) - very frustrating! Of course, logic dictates that if I put in my maximum bid, then I can’t be disappointed if I miss out. But on the other hand, for just a dollar more, I could have the item - and what’s a dollar, compared to 30?

In the end, I put in a bid for $37.73 (again, note the psychology of my maximum bid!) and was beaten again - only to have the highest bidder pull out, and for them to offer me the item for $37.73. I ummed and ahhed, and eventually decided to take it - after all, I had been prepared to pay that before, and since all the others had gone for at least $30, it wasn’t a bad deal.

Now that I’ve bought it, of course, suddenly demand has died off - they’re going for $10!!! $10 - can you believe it?! Overpaid by $30…GAH! There’s probably a business opportunity here… Anyway, if I’d followed my normal practice of studying the market very thoroughly first, instead of jumping in, I would have gotten a much better deal - but I was worried that this guy would only have a few of them to sell at that price. Instead, he seems to be churning them out at 2 a day - don’t know how he makes any money!

But it made me wonder - how can both the auctioneer and the bidder ensure that they get good prices for their items? A little bit of digging came up with the Vickrey auction. Everyone makes secret, sealed bids - then the winning bidder pays the amount bid by the second highest bidder! (The second highest bidder neither pays nor receives anything - they simply set the selling point.) It’s actually quite easy to prove that the optimal strategy in this auction is to bid what you think the item is worth - any more, and you pay too much, any less and you don’t gain anything but might miss the item. Neat, hey? Now, think about whether the auction would work if you didn’t have silent bids, and ran it like a normal auction (going once, going twice…) except with the winner paying the second highest bid. Could you beat the system?

There’s an interesting article on Gene Expression about co-operation in evolution. The basic idea is that many groups of animals (or whatever) show cooperation, working together for the good of the group but not necessarily the individual. What’s strange is that it should be possible for an individual renegade to not cooperate and take advantage of everyone else’s generosity. Although they come out ahead, if everyone were to cheat, then the group as a whole would lose out. So how do you make this this sort of thing stable?

The post explains one possible explanation for it, and summarises a recent paper which suggests how this kind of situation could evolve. It’s quite interesting!

I’ve been doing a little bit of Ebay shopping recently, and have come across some interesting scenarios that got me wondering about the game theory of auctions. Game theory is just what it sounds like - how should you play a game in order to maximise your winnings (or, at least, get the best outcome?) This can be the usual games like poker, naughts and crosses or chess, but it can also be things like deciding how much to sell your new toy for, whether to invest in a certain business, or whether to bother recycling your garbage.

The first interesting auction I found was a guy selling a
$500 gift certificate (actually 10 x $50 certificates, depsite the picture) for Myers, a large department store in Australia. The bidding started at $400, and is now at $416 - only 3 bids so far, but still 10 hours to go, and previous sale of the same thing went for $465! Is it worth bidding on? Clearly, any bid less than $500 is a profitable one provided there’s something you want from Myers. This isn’t quite so clear cut - Myers is quite an upmarket store, and generally is more expensive than other shops, so $500 in Myers might not go as far as $500 in Target, say. And $500 cash in hand is always better than gift certificates that you can only use in a certain store. But there are some things than you can only get in Myers (e.g., some clothes) and some things which are no more expensive than anywhere else (e.g., kitchenware, some appliances). And with no expiry date, and in $50 units, I’m sure you could use them, or even give them as gifts, etc. So probably any bid less than $500 is a good bid. I probably won’t, because I don’t really have $500 I want to tie up right now, but it will be interesting to see where it gets to!

But what is the seller getting out of this? If he actually paid for the vouchers, he’s making a loss. The only reasonable idea I can come up with is that this is a Myers scam to get people to shop there. They’re having a store-wide 25% of sale at the moment, so %10 off Ebay vouchers, with a guaranteed $500 in Myers has to be a profitable venture. And, of course, a limited Ebay release is probably the only way they can do it without people refusing to spend anything except with 10%-off gift certificates! And yet, that means they’re only reaching a pretty limited audience (e.g., 1 a fortnight) - does the resulting advertising contribute enough?

After thining about this, a little Googling turned up an interesting, if somewhat unrelated, mathematical game - the dollar auction. In this game, sometimes run (with hilarious results at business seminars, potential buyers are asked to bid on a $1 bill. They’re allowed to bid any amount, and there’s no reserve (minimum price). There’s only one slight twist: the highest bidder pays her bid and gets the $1 bill, but the second-highest bidder must also pay their bid, but gets nothing in return. So what happens? Well, the first person bids “one cent!” and everyone laughs - what a good deal. Then someone bids “2 cents!” - a natural step, since they still make a good profit. Other people may continue the bidding - after all, just like the Myers vouchers, anything less than $1 is a good deal. For the auctioneer, once bidding gets to about 51 cents, they’re making a profit - they earn 51c from the highest bidder, and (say) 50c from the next, and they’re ahead.

Finally, someone bids 99 cents - and they probably look pretty smug, since no-one is going to bid more than that for a $1 bill. Except, the next highest bidder is caught - they stand to lose 98 cents, as they must still pay their bid. And so, to cut their losses, they bid $1 for a $1 bill. But now the other guy is set to lose 99c! And so, the unthinkable happens - they bid $1.o1, more than the prize is worth! In fact, the entire auction is now unstable - both bidders keep increasing their prices, throwing good money after bad, neither willing to admit defeat. The more proud your bidders, the better the auction goes! Finally, someone decides enough is enough and cuts their losses, and the winner accepts their $1 note, handing over as much as $3 or $4 in its place.

What’s really interesting is that this kind of game might model certain business practices. If you’re competing with another business, then coming second might actually lose you money, and perhaps you’d be willing to accept a loss and come first, to prevent the larger loss associated with coming second. If both businesses are playing this game, then perhaps things escalate! It’s also interesting to note that the auctioneer really wants people to keep bidding - it’s in their interest to stroke the egos of the bidders and encourage them to try and recover their losses. I guess any auction is like that, but here emotions are probably running higher!

Okay, I’m going to take a break for now - I’ll post about my experiences with snipers tomorrow!

It’s funny isn’t it, how quickly we become accustomed to things? A few years ago, discovering an extrasolar planet (i.e., a planet orbitting around a star that wasn’t our sun) was pretty incredible - and yet now, with dozens already discovered, it’s nothing to write home about. However, there’s always something new on the horizon. So far, all the planets that have been discovered have been big planets - a thousand times the size of Earth, objects, a bit like Jupiter, that aren’t quite suns but are pretty close. This is because they’re the only ones big enough to see, or to have a significant gravitional effect that we can detect. And while these are interesting, they couldn’t support life (as we know it, anyway) - they’re gas giants, with no solid surfaces!

So, how could we detect Earth sized planets, ones like ours? Well, one technique is to look for gravitational lensing effects (specifically microlensing), where the planet’s gravity literally bends the path of the light around it in a way that we can detect. And the planet recently discovered (in part by an Australian team!) was found using this technique. Again, it’s a big planet, but it means that this gravitational lensing technique is a realistic possibiliity.

I thought this article was quite amusing, as an Aussie anyway. It’s about red-back spiders being found in the U.A.E. (United Arab Emirates, a country of eastern Arabia). It goes on to describe how red-backs are more dangerous than poisonous snakes, and that a bite to a child less than six is certainly deadly. Apparently, the sightings are leading to bit of a panick!

In contrast however, Aussies have red-backs pretty much everywhere, and we pretty much take it in our stride. They used to be under the stairs at primary school, and various of my brave (read, stupid) classmates would venture under to crush the invaders (poor little guys!). And while I really don’t like them (scary!), they’re actually not very agressive nor particularly dangerous. Apparently, only one person has died from a red-back bite since 1956 when an antivenom was developed, and most Aussies aren’t really “afraid” of red-backs - they’re just a part of life. That said, the news report says that no anti-vaccine is available in Dubai hospitals, which is a serious concern - without it, the bites may well be more deadly.

It’s just interesting that so many foreigners consider Australia to be infested by deadly and dangerous creatures who are all out to get us. And it’s only when I talk to them that I realise they’re right - you can’t go swimming in the north in summer because of the box jelly fish, you have to be careful cleaning under the stairs, and if the snakes don’t get you when bushwalking, the leaches will! And yet, it’s just part of the beautiful Australian lifestyle!

Apparently, parents who are in stereotypically “masculine” professions such as physics, accounting or engineering are more likely to have a baby boy than those in nursing or other more “feminine” jobs.

This is interesting enough that I went back to the original article [ I doubt that link will work in general. The reference is: Kanazawa and Vandermassan, Journal of Theoretical Biology, 233(4) pp589-599 (2005)] They were exploring a proposed explanation for autism - that there exists “the “male brain,” which is particularly designed for “systemizing,” and the “female brain,” which is especially suited for “empathizing.” The systemizing brain, as you’d expect, is all to do with understanding the underlying laws of a system, whether that’s mathematics or how to play darts. The empathizing brain, again as you’d expect, is all about understanding emotions and responding appropriately to emotional triggers, understanding what people are thinking. The theory seems to be that men typcially have systemizing brains (”Type S”), while women have empathizing (”Type E”), which gave them specific evolutionary advantages (hunting/tools/etc and making friends within new groups respectively). Basically, it’s just putting the (perhaps justified) stereotypes on a more physiological footing, I think. It’s suggested then that autism may result when someone has an excessively male-type brain, and so excel at certain tasks, but may not have “normal” social skills. This explains many, but not all, of the clinical signs of autism.

Anyway, the upshot of this is that the researchers wanted to look at the correlation between professions (which should in turn correlate, even if weakly, with brain type, particularly, they claim, in the U.S. where people are reasonably free to choose the job best suited to them) and the sex of the children in order to investigate the heriditary connection. They found that parents in engineering, science and mathematics are more likely to have sons, while therapists, school teachers and nurses are more likely to have daughters. The odss seem about 130 boys to 100 girls for male professions, and visa versa for the females. Furthermore, having more sons results in having fewer daughters, with all other variables controlled for, and visa versa. So that really seems to suggest that if you’ve had one son, your chances are actually higher of having more, and the Malcom in the Middle family of four boys perhaps isn’t as unlikely as it seems! They suggest that as males typically have systemizer brains, they’ll tend to have male children, and similarly for females - so as a couple, they battle it out for brain type dominance! Two mathematicians are more likely to give birth to a boy, while two nurses are more likely to have a girl. A physicist with a therapist, or two more “average” professions will have a 50/50 chance, as you’d typically expect.

They’re very cautious about interpreting the cause of their results, and what conclusions could be drawn. One suggestion is that the level of hormones (e.g., tetosterone) in both parents plays a role in determining the sex of the baby. I don’t really understand this myself - I’m not sure if they’ve established a link between hormones and “brain type”. But there really does seem to be something there - their results are quite convincing, at least to a non-specialist like myself.

Of course, the media has promptly taken things one step further and suggested that “Couples desperate to produce a son could boost their chances if one or both of them switches to a “masculine” profession such as engineering or accountancy”. Perhaps this is true - but that might be reading more into the report than is good for it.

On Thursday, Brisbane had a fantastic storm - complete with wind, rain, lightning, thunder and hail! Of course, “great” is a relative term - I didn’t get hurt or have any of my property damaged, whereas many cars/houses probably suffered - so my apologies to them! I, however, was in a bus along one of the main roads, and had a wonderful view of the hail bucketing down outside and making a glorious sound on the roof. I’ve always been a big fan of storms - I used to sit out on my balcony when I was a kid, and measure time between the thunder and the lightning to see how far away the hits were. (Light (from the lightning) reaches you almost (or near enough) instantaneously, while the resulting thunder can only travel at the speed of sound, about 330 metres per second. Therefore, measuring the time between seeing the lightning and hearing the thunder can tell you how far away the lightning is - every 3 second interval corresponds to one kilometre, or about 5 seconds to the mile.) And hail, well what can I say. I used to dash outside and try and grab the ice to look at it, cut it open and try and see the concentric rings that form when hailstones make multiple trips through the clouds and build up more layers. (Unfortunately, this only happens with the larger stones (>1 inch, say) and so isn’t that common. The ones last week didn’t have rings!)

Just to give you an idea of how cool the storm was, I took a movie of it while I was on the bus - here’s an edited clip. The white stuff on the road is note snow - it’s actually hail! Pretty amazing, hey? Remarkably (at least to me) the hail survived for a full 24 hours - when I got home, there was a pile of hail outside my door, and it was still there the next morning and evening, though was gone by Saturday. Near the Uni, hail was banked up on the side of the road so that it really did look like snow…at least one person made snowmen! (Hailmen?) I don’t really understand how it’s able to last so long - I guess that ice is a pretty poor conductor of heat, and so even in the sunshine and on the ground it didn’t melt. The days have been cold, but nowhere like sub-zero…interesting!

Anyway, I’ve should get back to my PhD - no Star Wars this week, so there’s nothing for me to be distracted by!

So I just wanted to post some quick thoughts about Revenge of the Sith, and some of the questions it answered and raised. Sure, it’s not physics, but what better way to spend your day than analysing the mysterious of the Universe, even someone else’s?! Read on if you’ve seen the movie - spoilers follow!
(more…)

Well, the midnight screening went off without a hitch! We arrived around 8pm or so, and I have to confess that I was in a Jedi outfit, which my partner made me for my birthday. I had also constructed a lightsabre (you’d be amazed at what you can find at your local hardware store!) which, while not being able to glow, was pretty darn cool Quite a few characters were dressed up, though not as many as last year - there were surprisingly few character battles, although two Jedi/Sith battled it out complete with force pushes.

As for the movie - what can I say. I won’t give any spoilers here (I might raise some questions in a later post though! Yeah, so I’m a little geeky), but this is definitely the highlight of the trio, and a strong contender with the original trilogy to boot. While the first quarter or so was a little slow, it picked up pace and by the end was rollicking along, and despite being about 2am, I was absolutely gripped.

Anakin was wonderful, and I thought he played the tormented soul beautifully - his slow fall to the dark side was delighttful to watch (I’ve always had a soft spot for the villains). And Palpatine was absolutely superb - there was a surprising amount of insight into his character and his history - he stole the show, as far as I’m concerned. The interaction between these two characters was definitely the highlight of the movie for me, and I think George Lucas did a brilliant job of tying everything together and creating a memorable Star Wars story.

And, of course, no Star Wars movie would be complete without lightsabers, and this was no exception. Being their last chance to show off their stuff, the choreographers spared no effort (or expense) in creating simply superb fight sequences that really showed off their skills. Anakin’s final battle was absolutely brilliant - like the first Matrix (and unlike its sequels) the emotion and the story was worked into the battle, so that every blow really counted, and we really saw what true Jedi (or Sith!) can do with the force. And Anakin’s final transformation was very cool too

Of course, this movie was far darker than any of the others in the series so far - it has an M (voluntary 15+) rating here in Australia. Anakin’s final transformation, the destruction of the Jedi, and many other scenes really added a realism to the story that was perhaps a little lackin the in first two movies (though I liked them as well) and it really enhanced this movie. You really felt for the characters. And let me tell you, if I didn’t know how 4,5 &6 go, I’d be quite depressed right now.

So, overall opinion is that it was a tops movie - everything came together: story, acting, special effects, battles…just brilliant. I can only advise you to go and see it for yourself. Even if you’re not a Star Wars fan, I think it will be a most enjoyable experience!

There are a few inconveniences associated with living in Australia - we can’t buy anything but books and CDs from Amazon, and even then the postage is ridiculous, we’re a long way from both America and Europe which is a bummer for travellers or for swing dancers who really want to attend some cool workshops. But all of these are outweighed on those rare occasions when movies are released, worldwide, at a definite local date and time.

Yes, I’m talking about Star Wars Episode III: Revenge of the Sith. It opens on Thursday the 19th of May (which is tomorrow here in Oz!) and I’m going to the midnight screening, at 12:01am Thursday morning! It’s a little bit of a tradition around the physics department here - in the past, we rock up at 7pm so that we’re about 20th or 30th in line (I have no idea what time the true diehards get there…) then make trips to the supermarket and food court downstairs from the cinema for our food supplies. I think tonight, though, we’ll be arriving a bit later as everyone has other commitments on. The queue grows rather rapidly over the intervening time, but hopefully we’ll still get okay seats.

It should be great fun indeed - and I’ll let everyone know my opinions tomorrow!

Last Friday, I went to a fascinating talk by Justin Marshall, an professor here at UQ. I’ll give his abstract, then briefly discuss what he talked about:

My principle aim and that of the team I work with is to understand how other animals perceive their environment. As arrogant humans we tend to assume we are the pinnacle of evolution, however, certainly in sensory terms this is far from true. By taking an approach to sensory systems which is based around ecology and includes physiology, anatomy, behaviour, neural integration and machine vision, we hope to decode signals and their intension in the animal kingdom. As part of the desire to look at the world
through the eyes of crustaceans, fish, and even birds, I spend much of my time looking at the colours of The Great Barrier Reef and other underwater environments (see National Geographic May 2005). This led to the discovery of a prawn with a visual system almost identical to push-broom cameras and we are now part way through a project known as “Prawns in Space”, an effort to help re-design man-made imaging systems using biological systems.

As you can probably guess, he was a very entertaining speaker. The main focus of his talk was about vision, and the role of colour in various environments, particularly the Great Barrier Reef. He had some brilliant pictures of the different camouflage techniques used by fish, from simply blending in to using stripes to disrupt their lines. (He had an amazing picture where he Photoshopped stripy fish onto a picture of coral (since they wouldn’t all co-operate together) - I didn’t notice two of them until he actually pointed them out - and they were so obvious!) It was also interesting that even though some fish appeared really visible to us, we see differently to fish, so to other sea creatures they probably just blend right into the water.

But the most interesting topic for me was the Stomatopod, or mantis shrimp, which is a cute little guy that lives in the shallows of tropical and sub-tropical waters. Although they max out at about 25cm long, these stomatopods have “raptorial appendages” that are capable of delivering a strike equivalent to a 22 calibre bullet! A 9-10cm guy can smash an aquarium (glass) tank if he wants to, or cut straight to the bone of your finger… Apparently, it’s the second fastest action in the animal kingdom (I’m not sure what the first is - any ideas?) and might make a cool first year physics problem (5kg of force in 3ms - calculate the impulse, and perhaps compare the resulting pressure to the breaking stress of skin…)

But their super powers doesn’t stop there. They have the most sophisticated visual system in the world - they have 16 different receptors in their eye, capable of detecting 12 different colours, compared to human’s 3 (red, green, blue). They can see in the UV (4 colours) and they can detect the polarisation of light! (We can’t see this property directly - but Polaroid sunglasses can easily show that it’s there. Just rotate the glasses (or your head) while looking at the ocean, say.) From the talk, I don’t think anyone really knows why it’s necessary, but it might be to do with very sensitive communication methods that involve colour.

So why don’t we get this fancy vision setup? Well, partly it’s overkill - three colour sensors give fine colour vision. Even just six apparently does all you could ever want. But there’s also another question - if you look at what colours of light our sensors absorb (on this picture, or this one) you see that we detect blue, green and red light as expected, but the red and green sensors overlap big time, pretty much on the yellow part of the spectrum. Surely it would make more sense to put the green sensor in the middle?

Apparenty, it all comes down to bananas! Since we evolved from primates, we needed to be very good at seeing fruit, leaves and berries. What colours are these? Red, green and yellow! It would be a big advantage for us to be able to tell exactly when fruit (say, a banana) is ripe, so being able to detect shades of yellow well is an evolutionary advantage - and lo and behold, the eyes have it! (There’s a joke there, in case you missed it…)

So this is just a smattering summary - if you ever get a chance to hear Justin Marshall talk, definitely take advantage of it - he’s on my top speakers list for certain!

Interesting article from Wired about researchers who have been able to heal rats with crushed spinal cords. The research sparked controversy when it was first announced a while ago because it treated the rats with humanembryonic stem cells, which come from embryos (that are destroyed in the process) and are opposed by some groups of people. These cells have the power to become any other type of cell in the human body, and when injected into the rats they found their way to where they were needed most - the spinal cord. In rats with recent injuries (7 days) the rats were able to walk and use their tails again. This was pretty impressive proof of the power of embryonic stem cells. Unfortunately, it turns out that older injuries (10 months) can’t be healed in the same way, perhaps due to scar tissue.

Best of all, they’re considering human trials as early as next year, 2006! I’m always feel that when someone develops a technology or treatment such as this that is something that “might” become useful 10-15 years from now. It’s always hard to believe that it might become a practical reality only a few years from now. Very exciting! Of course, as pointed out above, it seems that this treatment would only work if applied very shortly after the injury, which would help long-term sufferers. But none-the-less, this is pretty amazing.

So, if you’re recovered from your maths humour, here’s proof that chemists also have a little of the absurd in them - intentionally or otherwise!

From Bristol in the UK comes Molecules with Silly or Unusual Names, which lists real molecules with hard to believe names - Bastardine, Moronic acid, Vomicine, Erotic acid and, my favourite, Crapinon are just a few!

I’m sure there’s an opportunity for students of chemistry to practise these on your lecturer or teacher. “Sir, I spilt some Uranate on the desk…” or “Have you finally run out of Crapinon?” The possibilities are endless…

After a tip off by Andrew White (a rather entertaining physicist at UQ in his own right) comes this fantastic group: Klein Four. They’re a bunch of (apparently!) mathematicians and musicians, and they’ve put together some pretty amazing stuff.

Pretty high on the list is their original song Finite simple group (of order two), a mathematicians love song. What I find most amazing is that they’ve managed to work so much maths terminology in to the lyrics, but still make it sound like a genuine love song! And perhaps even more amazing is that simply by the way they phrase their words I would believe they’re mathematicians even if they didn’t say a word of actual maths - they just talk like mathematicians! (And, to a lesser extent, physicsists ;)) (Incidentally, I wrote a vaguely related piece a few years ago - an advertisement for a new service: Numeric Dating.)

They also do a brilliant rendition of The Twelve Days of Christmas in true mathematician style, and their bottle blowing ensemble is something to behold.

All I can really say is that these guys are just amazing, and I wish there was a group like this at my Uni! Of course, if you’re a non-mathematician then you might not be able to appreciate all of their jokes (actually, I only recognise some of the words - I don’t know what they really mean! But I know they’re being clever, so that’s good enough for me…). So, Klein Four - my hat’s off to you.

Wired news is running an article which suggests that life on Mars, long a favourite topic of science fiction writers, might now be “more a likelihood than merely a possibility.”

While it’s quite thrilling to think that life on other planets, even just within our solar system, might really be a possilibity, I can’t help but think that the article presents an overly optimistic viewpoint. Do most astrobiologists (basically scientists who study life on other planets) believe it? There seems to be quite a few tantalising hints, but nothing conclusive, or even firm.

Of course, I’d love there to be life on Mars - even if it’s just some sort of bacteria (almost certainly) it’s still expected provide a wealth of information about how life started on Earth, and perhaps about how likely it is to form elsewhere in the Universe. With more missions planned, hopefully it won’t be too long before we have an answer…

I’m sure everyone’s played this game - you and your partner count “one, two, three!” and then make your hands into different shapes (”throwing” a shape) - scissors beats paper, paper beats rock but rock beats scissors. (Feel free to make up your own arguments for why this is the case…) Basically, if there were no psychology involved, the game is completely random - each throw has an even chance of winning, drawing or losing. But we like to think that we can predict what our opponent is going to do next (”Yeah, he’s a rock kind of guy.” or “She’s thrown 18 papers in a row…she’s totally going to do scissors this time!”) and that’s where the fun comes in. I know that one of my buddies and I in high school maths could draw 10-15 throws in a row - we just knew how each other’s brains worked!

While for most of us this is just a fun way to pass the time, or to gamble for that last slice of pizza, it can be more serious. There is an international RPS club, which hold regular tournaments (and yes, I really think they’re for real). These guys have published a strategy guide which sounds quite entertaining! Various strategy guides can also be found on the internet.

But for some people, this game could cost you a twenty million dollar deal. Art gallery giants Christie’s and Sotheby’s battled it out in a single round of RSP (written on paper) to dcecide who got to sell the art collection of Tashi Hashiyama, who couldn’t decide between the two galleries. What I love best is that they seemed to have taken it really seriously! Said Christie’s executive:

“In Japan it is not uncommon that a decision will be made where this game will be played.

“When [Mr Hashiyama] mentioned this, we were not surprised. We’ve heard this before and we took it very seriously and we started researching.”

Representatives of each firm wrote their choice on a piece of paper instead of playing in the traditional fashion with hands.

Mr Maclean said Christie’s decided to play the eventual winner - ’scissors’ - after doing some research.

“A lady in Japan did her own research and she independently came with the idea that scissors should be the way we should go,” he said.

“I spoke to my own children and they also felt that that was the way - so between us we decided to go with scissors.”

On the other hand, Sotheby’s response was a blunt, “I don’t discuss our negotiations or relationships with clients”. After all, they wouldn’t want to give away their losing strategy, would they?

I thought this report was really interesting. Apparently, for reasons still not understood, acupuncture really does help reduce migraines - but so does a needling technique that resembles acupuncture, but isn’t.

The idea behind acupuncture is that needles are inserted into the skin at certain points around the body which in some way reduces pain or cures other symptoms. In particular, it is supposed to reduce the frequency of migraine headaches.

In this study, three groups were used - one was a control group who received no treatment (they were told they were on the waiting list), one group received real acupuncture, and the other received a “made-up” needle treatment. In this fake version of acupuncture, the needles weren’t inserted as deeply into the skin, and weren’t placed at the regular acupuncture points.

Amazingly, both needle groups reported a 50 per cent reduction in headaches, compared to only 15 per cent for the control group. This has got to be statistically significant!

One explanation is the placebo effect - that when people think they’re receiving a great treatment, their body responds appropriately. According to the chief author of the study, Kalus Linde, “There is, for example, evidence that expectancy modulates pain perception and many patients in Germany have a very positive attitude toward acupuncture.” I think it would be interesting to repeat the study somewhere where acupuncture wasn’t believed to be an effective treatment (or perhaps simply by a group of people who didn’t believe in acupuncture).

Another option is that needling the skin in any form somehow affects pain receptors (or something called “pain memory”) which might reduce the headaches. Or perhaps it’s a combination of both physiological and psychological factors.

Regardless of the answer, it’s a very interesting study - if it’s psychological, it’s fascinating (I love the placebo effect!). If it’s physiological, then perhaps that’s even better, because we can produce effective treatments once we understand how it works! (The disadvantage of the placebo effect is that once you know about it, and know it’s being used on you, it stops working! I’m reminded of the joke where the doctor asks the woman if she’s got private health insurance, and when she says no, he tells the nurse to fetch the placebo instead…)