Yesterday was square root day, and we imagine that most of you celebrated it in the customary fashion by eating square vegetables. It was square root day because the date was 03/03/09 and 3 times 3 is 9. The last square root day was on the 2nd of February 2004, and the next one will be on the 4th of April 2016, so they're relatively rare occurrences. Far more common are Plus's own
invention, addition days. The coming Friday is one of them, because the date will be 06/03/09 and 6+3=9. Of course there could also be subtraction days, or maybe exponential days. In fact, with a bit of numerical skill, you can probably turn every day into a maths holiday.
A far more serious affair is World Maths Day, which is in fact today. It's celebrated on the first Wednesday in March and involves student and student groups from around the world competing to solve 182,445,169 mental arithmetic challenges in 48 hours. The winners receive medals and certificates, but of course it's the glory of winning that counts,
and last year this was bestowed on teams from Malaysia and the UK, as well as individual students from Australia and the UK. It's too late to register for this year's event, but why not start practicing for next year?
We may be in a recession, but according to Gordon Brown, that's all the more reason to invest in science and maths education. In a speech in Oxford today, Brown pledged to increase the number of students taking maths A level from the current 56,000 to 86,000 in 2014, and to make sure that 90% of state schools teach physics, chemistry and biology as separate subjects, also by 2014. The measures
are meant to help ensure Britain's future competitiveness, and ease its over-dependence on financial services, which have got us into this mess in the first place. Some of the losers of the recession, those who have lost their jobs but have maths, science and IT degrees, are to be encouraged and supported to take up teaching, to tackle the lack of specialist teachers in these subjects. Brown also
pledged to encourage a positive public debate about science in order to improve the public's understanding of its role in society.
It's not often that maths makes it into the mainstream media, and when it does, it's usually a very specific bit of maths — a statistical result or a certain application — that's being examined. An article published yesterday on the Guardian website makes a nice exception. It explores
how maths underlies almost every aspect of modern life, from traffic lights to iTunes. Thank you, Guardian!
You can find out more about some of the topics mentioned in the article on Plus:
Geneticists are usually concerned with picking apart the individual genes that make up a genome, but now two biochemical engineers from the University of Wisconsin Madison have decided to re-assemble all the pieces and give them a good shake. They found that it's not just the genes themselves, but also the way in which they are organised within the genome, that determine the characteristics of
This type of permutation is exactly what keeps us "interesting" despite greater evidence of mechanistic implementation and structure in biology. Even given the fact that "not all permutations are equally likely" the variation in time and space and the Hilbert spaces of DNA, neural nets and life threads are still enormously re-combinatorial.
Sometimes a boring story can become a lot more interesting if you do some skilled number juggling. This is what seems to have happened in an article in The Daily Telegraph, which claims that 90% of us carry a gene which increases the risk of high
blood pressure by 18%. And high blood pressure is of course linked to dreaded killers like stroke and heart disease.
In his Understanding Uncertainty blog David Spiegelhalter traces the story back to a paper in Nature Genetics. The authors of the paper investigate three gene variants that can occur in the human genome. Two of them are rare, only about 10% of the population
carry them, while the third is present in 90% of the population. The authors show that the gene variants are associated to proteins called natriuretic peptides, which are linked to blood pressure (this is the main point of the paper, since such a genetic connection had never before been found). The two rarer gene variants, according to the paper, reduce the risk of high blood pressure by
15%. The phrase "18% increased risk of high blood pressure" appears nowhere in the paper. Rather it's the result of some creative accounting on the part of someone operating in the media chain which links the actual paper to the final article in The Daily Telegraph. Here's how it's done:
Say that the risk of high blood pressure for someone carrying the more common gene variant is x. Now the 15% decrease associated to the two less common variants takes this down to 0.85x. To get back to x, we need to add 0.15x, and this is exactly 17.647% of 0.85x — hence the claim of an 18% increase in risk.
The calculation is undoubtedly correct, but it puts a spin on the story. Rather than taking the common case as a base line and talking about the risk reduction associated to the less common cases, it does things the other way around. This is in stark contrast to the paper's authors own turn of phrase, which links the rarer variants to risk reduction, but says that the common variant "was not
significantly associated with either systolic or diastolic blood pressure." It's a bit like noting that some people live to 110 and then complaining that most of us die prematurely. "This is a masterful piece of re-framing of the evidence," says Spiegelhalter on his blog. "Not exactly wrong, but definitely changing the story. Just like a
change from 98% to 96% in a survival rate seems a lot more innocuous than a doubling of the mortality rate from 2% to 4%."
How many arms does a spiral galaxy have? Can you spot a galaxy with a "peanut" bulge? Or how about a galactic merger? You — yes, you — can answer these and other strange questions, along with other ordinary web users who, by working together, have proven to be just as good at galaxy-spotting as professional astronomers.