Tuesday, 30 January 2007

The Etymology of Spectrometry

It's life or death. You're looking down at a mess of wires connected in varying combinations to a sturdy looking array of explosives. A red LED clock ticks the seconds down. 10, 9... In your hands is a pair of wire cutters. The radio stutters to life, "Cut the blue wire!" your temperamental commander shouts. You remember your dead partner and realise that after the events of the last two days, death would be a welcome change. You reach out and cut the wire. The universe skips a heartbeat before the clock flickers and dies. You saved the city, Seargeant, or should I say Captain. Unless you happen to be Welsh, that is.
In Welsh, as in a number of other languages, the word for blue encompasses green. Does this mean that, because they lack a mental label, they are unable to distinguish between the two colours? Colours are just words which have been invented to describe different sections of the visible electromagnetic spectrum from short-wavelength violet light to long wavelength red light. In this article from the Economist, two viewpoints among psychologists are identified. One states that human brains are hardwired to recognise and separate the 6 basic colours you might find in a cheap children's painting set. The other states that the spectrum is arbitrarily chopped up into segments based on social and linguistic factors. As always with these kinds of nature-nurture debates the answer probably lies somewhere in the middle; my personal bias tends towards the latter. Another recurring feature of these kinds of debates is that anyone can weigh in and sound like an expert, which makes it something ideal to save up for your next dinner party or night at home alone with your thoughts and a bottle of red. Or is that yellow?

Monday, 29 January 2007

The problem with parasites

There are many things that you don't want to get in your brain: annoying pop songs, advertising jingles, unfortunate images. All of these pale in comparison to a hydatid cyst. The cyst is a larval stage of a tapeworm called Echinococcus granulosus, which is a parasite found in canines. These organisms are present in the feces of infected dogs, and are transferred, thankfully rarely, to humans through ingestion. It is therefore more common in countries where dogs are used to herd livestock. Once the cyst is inside the gut it can sometimes break into the bloodstream. From there the most common route is directly to the liver. A person can survive with several small hydatid cysts in their liver and suffer no ill effects. Sometimes, however, the cysts can wend its merry way to other parts of the body including the brain, where it can grow to the size of a golf ball.
By now you probably have a picture in your mind of what this cyst might look like. You're probably wrong. Happily though, I have found a video of a hydatid cyst being removed successfully from some poor guy's brain. It is not for the faint hearted, but it is morbidly fascinating.

Saturday, 27 January 2007

The Causality of Obesity

The worldwide shortage of pirates is causing global temperatures to rise! As pirate numbers have decreased since the halcyon, pirate friendly days of the 18th and 19th centuries global temperatures have risen, damaging ecosystems, causing sea-levels to rise and even threatening coastal cities with utter annihilation. Surely a bit of good-natured piracy is preferable? It certainly worked for Johnny Depp.
There are, as Benjamin Disraeli said, three types of lies: Lies, damn lies, and statistics. Just because there is a correlation between decreased swashbuckling and increased temperatures, does that mean that there is a causal relationship? It seems pretty clear that there is not. The same logic, however, is used often in the popular media and even in serious scientific publications. Recently, in articles about obesity, "scientific articles" have been cited as stating that urban sprawl causes obesity. Look!, they say, there are fat people living in the suburbs, so the suburbs must cause people to be fat. It's a tempting jump to make. People in the suburbs do spend more time in their cars, and they do tend to walk less. But does living in the suburbs make people fat? Probably not, or at the very least there is not enough evidence to prove it. Several studies, in fact, have come to the conclusion that low-density areas merely attract inactive people who are prone to obesity.
It is extremely tempting to make statements which are based on a correlation and phrase them in such a way as to imply a causal relationship. It makes for interesting reading and adds a veneer of respectability, but science it is not. It pays to use a skeptical eye when reading the news, just remember the pirates.

Wednesday, 24 January 2007


Yesterday I alluded to the existence of giant sloths: king-size, extinct cousins of the modern South American mammal. Some species reached lengths of up to 6m, and when standing on their hind legs they would have been twice as tall as an African bull elephant, and of similar bulk (around 5 tonnes). It has even been speculated that they would have driven sabre tooth tigers from their kills using their foot-long claws as daggers. This is particularly unslothful behaviour.
Their modern descendants, however, fully deserve their name. Sloths move so slowly that algae flourishes in their fur, giving them a sort of shimmering, one-with-the -forest look. Recently, after 3 years of attempting, unsuccessfully, to coerce a sloth to climb up and down a pole as part of an experiment in animal movement, German scientists gave up and banished the individual to a local zoo. "(He) obviously wanted nothing to do with furthering science," a university spokesman lamented.

Tuesday, 23 January 2007

Biplanes of the primordial treetops

When I was younger I had a book about dinosaurs and other related ancient fauna. In this book was a picture of a huge dragonfly flying off with a dead mouse clutched limply in its jaws. I thought this was the best thing ever. I've always thought that the huge versions of modern day animals (giant sloth-bears, giant bear-bears, sabre-tooth tigers etc.) were more interesting than dinosaurs for which I had, and still have, no possible models for comparison. The strange thing is that I've never in my adult life been able to find that picture, so I'm beginning to wonder if I didn't just make it all up. Wouldn't that be great though? A giant dragonfly eating a mouse.
That rambling story brings me to the main point of this post. In 2003 Chinese scientists announced the discovery of a winged dinosaur in the same family as Archaeopteryx, the oldest known bird. This dinosaur, microraptor gui, has two sets of wings, one on its forelimbs and one on it's hind limbs. It was supposed that it would glide from tree to tree, with the wings held out like a giant dragonfly, as the feathers on the hind limbs would hinder its progress on the ground. Recent research using computer simulations of the biomechanics involved, however, suggests that the wings would have been held one on top of the other like some kind of fantastic, ancient, biological biplane, approximately 125 million years before the Wright brothers were even thought of. Now if it only ate mice, I'd be really interested.

Monday, 22 January 2007

Why can we ask who we are?

The source of our concept of self, the seat of the soul if you're that way inclined, is one of the great mysteries. What is it about humanity which allows us to feel that we are conscious, to have a sense of ourselves? In 2000 Edge.org posted an essay by V S Ramachandran entitled "Mirror Neurons and imitation learning as the driving force behind the "Great Leap Forward."" He was referring to the great leap that humankind has made, far outstripping the rate of progress of any other observed species. The essay was about the so-called "mirror neurons." In experiments on apes, it was found that specific groups of neurons fired whenever the apes performed voluntary tasks such as button pushing or reaching out for food. This is not particularly interesting in and of itself; the interesting part is that a small subset of these neurons fired when the apes merely watched other apes performing the task. Ramuchandran speculated that the presence of these mirror neurons in humans permitted us to learn by imitation, sparking the great leap which allowed the sharing of knowledge about how to replicate useful events which would otherwise have occurred only once.
Now, nearly 7 years later Ramuchandran has extended the theory in the new issue of Edge. He speculates that it is these very neurons that allow us self awareness by allowing us to imagine ourselves performing an action as if we were someone else. That is a gross oversimplification, so if you have any interest at all I would suggest that you read the full text of his surprisingly concise essay.

Sunday, 21 January 2007

Battle of the sexes

It's tough being a guy in a Darwinian world. Sure, you can sit back and let the female bear many of the costs of childbearing: producing costly eggs filled with precious nutrients, or even carrying them to term within their own bodies. Sure, there's that, but males face a wholly different challenge: how can they know if the hatched babies they're helping to care for are their own?
Cuckoldry is rife in the animal kingdom (and not just in the animal kingdom); is there any better strategy for gene propagation at minimal cost than letting some other poor schmuck look after your kids while you swan off to mate with other females? It is predicted by theory, then, that males would have developed strategies to counter this and, indeed, many of these have come to light. For instance, the first thing a male lion will do on taking over a new pride is to kill off all the cubs, as it is really not in his best interest to raise somebody else's genetic progeny, or to allow his new harem to do so at the expense of raising infants with his own genes. It has even been speculated that we look like our parents so our fathers can be sure of their, um, involvement. A recent study, however, has documented behaviour which really takes the cake: A species of fish in Indonesia is actually more likely to cannibalise children, which are at least in theory his own, if he is unsure of his claim. The likelihood of this happening is, predictably, predicted by the number of males present at spawning.
Nature is nothing if not unrelentingly, horrifyingly efficient.

Saturday, 20 January 2007

What has natural selection ever done for us?

Pictured left is the goddess Parvati, consort of Lord Shiva. In the Hindi pantheon she represents feminine attributes desirable by Hindi tradition. She is depicted in art as buxom, wide of hip, narrow of waist and bounteous of bosom. She's a porn starlet for the 12th century. In a 2003 lecture Vilayanur S. Ramachandran, the director of the Centre for Brain and Cognition at the University of California at San Diego, suggests that this form was found by amplifying the differences between male and female to create a kind of uber-femme, a body fit for a goddess. Everything down to the posture is throwing femininity in the viewer's face. When westerners arrived in India they saw the images in a different light. Seen through the lens of a lifetime's exposure to classical and renaissance art, the image looks unrealistic and cartoonish; it was declared primitive and unworthy of consideration. In this case, cultural conditioning had overcome the natural reaction that viewing this almost scientifically derived expression of ultimate womanhood would be expected to have caused.
As an analogue, when a woman is caught by surprise in a state of undress in the US, she covers her breasts and genitals with such unthinking rapidity that it could be taken to be a universal human trait. In Arab countries, however, the natural reaction would be to cover her face, and in Samoa the startled woman would rush to cover her navel. In every case culture is the dominant force in the nature of the reaction.
What biological natural selection has done for us is well documented by now; in the light of the frenetic speed of cultural evolution, maybe the real question is: What has it done for us recently?

Friday, 19 January 2007

5 minutes to midnight

"In these dangerous times, scientists have a responsibility to speak truth to power especially if it might provoke actions to reduce threats from the preventable technological dangers currently facing humanity. To do anything else would be negligent." Lawrence M. Krauss

The Bulletin of Atomic Scientists (BAS) has since 1947 been keeping a countdown to doomsday, when civilization will be decimated by some disaster, whether it be nuclear war or climate change. The hands were moved two days ago for only the 17th time since it's inception. The reasons cited for this update, which moves the clock 2 minutes from 7 minutes to 5 minutes to midnight, include the lack of adequate security on existing weapons-grade nuclear material, the proliferation of combat ready missiles worldwide including those recently acquired by countries such as N. Korea and Pakistan, and, finally, the growing climate crisis.
This is not exactly a feel-good magazine.
With so many nuclear weapons and so many itchy fingers controlling them, it's not hard to conceive of a situation where climate change becomes directly responsible for a nuclear "exchange"; as crops start to fail and people start to starve, it will be almost irresistible for affected nations to look towards the countries who have been fuelling this crisis for reparations or, worse, for vengeance.
Things aren't all bad; the clock moved back in 1991, and it could happen again.
As Steven Hawkings says in the article: "As citizens of the world, we have a duty to alert the public to the unnecessary risks that we live with every day, and to the perils we foresee if governments and societies do not take action now to render nuclear weapons obsolete and to prevent further climate change." Let's hope it's taken seriously.

Thursday, 18 January 2007

Journey to the Pole Of Inaccessibility

The Guardian has an article about a jaunt to the "Pole of Inaccessibility" being mounted by a British and Canadian team of 4. This pole is defined as the point furthest from the coasts of the continent, which is quite distinct from the geographic or magnetic poles (More about poles). When they get there, they expect to find a hut, built by a previous Russian expedition, replete with a bust of Lenin on the roof. This is only the first of the interesting points; it transpires that for "general kiting incompetence and muppetry"- kites being the de rigeur power option for the Antarctic professional on the go- team members are given the "Ovary Award". It's still a man's world out on the new frontier, apparently.
As well as raising money for charity, the team also has a serious scientific mission: counting penguin colonies. Apparently somehow counting penguin colonies will somehow help decide if there's enough food in the Antarctic to transplant a few polar bears (whose northern habitat is rapidly shrinking). Presumably the idea that we're supposed to get is that if there's enough fish for penguins, there's enough for polar bears. However, polar bears can charge on land at 25mph, while any nature documentary I've seen has penguins waddling along at a comically slow, grandma-like pace. Makes you wonder if fish-sharing is exactly what the scientific community has in mind.

Wednesday, 17 January 2007

Last chance to see

In 1990 Douglas Adams wrote "Last Chance to See", a book about animals veering perilously close to extinction. Since then the news about these species hasn't been good, as the blog "Another Chance to See" documents.
However, it's not all bad new in the bringing threatened species back from the brink community. The Zoological Society of London has recently launched a new campaign in a blitz of publicity, The EDGE Top 100. EDGE stands for Evolutionarily Distinct, Globally Endangered, and the top 100 lists some of the world's most endangered and charismatic mammals. Included are the Amazonian Manatee (pictured), and at least two mole species which keep a "pantry" of earthworms by biting off their heads to prevent them from escaping. That fact alone is worth a visit, but even better is the fact that you can donate to save these living repositories of biodiversity. So head over there, be informed and be generous, it might be your last chance.

Tuesday, 16 January 2007

What do we have to smile about?

Bad news sells papers. People like to hear about misfortune; it either gives them something to moan about or provides them with a little schadenfreude-inspired lift. Not here, though. Not today, anyway.
No, today we are celebrating the triumph of reason, the vanquishing of ignorance, and edge.org, the world's greatest website, which not entirely coincidentally has a feature in which top scientists and thinkers of all stripes list their top reasons for optimism.
Every year Edge asks a question. In the past these have included: "What's your dangerous idea?" and "What do you believe is true even though you cannot prove it?". This year's question is "What are you optimistic about?" The answers range from predictable (arch atheists Dawkins and Dennett predict the passing of religion's relevance) to the snarky (Karl Sabbagh's "The optimism of scientists") to the brilliant (all of it, really).
It's nice to see science being portrayed as a harbinger of optimism rather than as either the bearer of bad news or the dark force handing god a kicking. I'll return to science as a social phenomenon in a future post, but in the meantime please head over to Edge and enjoy some well written and deeply considered reasons to be cheerful.

Monday, 15 January 2007

Drink yourself thin, the Scienceology way

I think that the Enviga post was maybe a bit negative for the inaugural post on this blog. I'm therefore going to make it up to everyone by showing how you can make your very own "Negative calorie" drink at home. For free! Don't say I never do anything for you.
1) Fill up a 1L bottle with water. Ordinary tap water will do unless you live in the sort of places I like to go on holiday. Use your judgement.
2) Put bottle in fridge until it's nice and cold.
3) Drink.

Hey presto, your very own negative calorie drink. The energy used by your body to heat the icy water up to body temperature is greater than then energy you receive by ingesting it (0 calories, if any one's counting). It's even possible to work out exactly how many calories you burn using this method:
The specific heat capacity of water is 4.2 Joules/g/degree centigrade. This means that it takes 4.2 Joules of energy to heat 1g of water by 1 degree centigrade. As we have 1000g of water, it takes 4200J per degree centigrade to heat it. The temperature difference between you and your fridge is about 35 degrees, so in bringing this water up to body temperature uses 4200 x 35 = 147000J, which is about 35 calories.
So, you can spend $5 on Enviga to possibly lose 120 calories or you can drink cold water for free and definitely lose 35. You can all thank me later.

Sunday, 14 January 2007

Enviga - Coca Cola to save the world's asses?

What a brilliant idea: A drink that increases your metabolism while clocking in at a svelte 5 calories per can providing a "Negative calorie" effect. At last, sitting around on your ass while drinking carbonated beverages can now actually reduce the size of that very ass! Well sadly, not quite.
A quick survey of the Enviga website reveals a number of things:

1) The Enviga website is so flash that something has to be up.
2) EGCG is the active ingredient in this drink, and is an antioxidant found naturally in green tea.
3) Enviga contains more EGCG than any other premixed beverage (Which presumably means that it contains less than regular green tea).
4) Of the 5 studies cited in its "Science Section", two show no effect on metabolism following the consumption of EGCG and the only study which shows results like the ones reported on the front page of the website is both unpublished and conducted by Nestle scientists. Nestle is, entirely unsurprisingly, Coca-Cola's partner in this venture.
5) In order to achieve the advertised effect, one must consume 3 cans of Eviga per day at a cost of around $1600 per year. Actually, that isn't mentioned, but I just worked it out and I hate to waste effort.

Things are starting to look less promising for the "lose weight while merely watching people exercise on TV" idea. In fact the claims made by Coca-Cola are considered to be so flagrantly overblown by the Centre for Science in the Public Interest that it has issued the makers with a warning that it will sue if the claims are not discontinued.
In the meantime, people looking to lose a little weight would probably be better advised to head down to the local supermarket and buy some green teabags. Or, better yet, I'm sure that $1600 would some way towards a membership at the local gym.