On Tuesday I went to one of the general evening physics run by the local group of the Institute of Physics, mainly Paul Stevenson and others on the committee. Future talks here. It was on climate change and the figure that really stood out for me in the talk is above. It is taken from the newly released physical science bit of the 5th report of the IPCC (Intergovernmental Panel on Climate Change). Basically it shows the temperature averaged over the whole of the Earth and over a decade of time, as a function of time. I.e., the average temperature in the 1980s, in the 1990s, etc. The y-axis is in ºC and is I think the difference in temperature in a decade relative to the average temperature between 1961 and 1990.
Correlation does not imply causation is a useful statement for a scientist to bear in mind. It is also good to remember it whenever a politician is claiming some statistic says their policy is a success, they are almost always using correlation to imply they their policy has caused the effect. The best way to see that correlation does not necessarily mean there is cause and effect, is to look at some examples of where two variables are correlated, i.e., where on a plot is one variable is changed so does the other, but where it would be very surprising if one causes the other. There are many examples of this, this paper goes for showing that as the USA imported more lemons from Mexico, fatalities on US highways dropped. Lemons are fine things, a slice of lemon is excellent in a G&T, but the only way they save lives if you have very bad scurvy.
Semester 2 starts on Monday, so I’m revising my lecture notes for my course on partial differential equations. This includes what is called the principle of superposition, which underlies what we know as the interference of waves. This picture (from a user called Spiralz on Wikimedia) shows interference off beautifully. Perhaps this is clearest on the left at about the same height as the ducklings, where the waves set up by the rear duckling intefers with that of its mother to produce a cross-hatched appearance on the water surface due to the addition (superposition) of the two waves going in different directions at that point. Beautiful physics, cute ducklings, what’s not to like.
Probably not, I wouldn’t. But neither of us are the brilliant but eccentric mathematician Grigori Perelman. On Friday I took our seminar speaker to lunch and we chatted about different perspectives on science and maths. The speaker is a mathematician at New York University (NYU), and briefly overlapped with Perelman when Perelman was at the Courant Institute at NYU. Perelman proved the Poincaré conjecture, a very important problem in maths. So important that it is one of the 7 Millenium Prize Problems, each of which has a $1 million prize. Incidentally, 5 of these are still unclaimed if you fancy a challenge.
Most of the science I do is pure research, research that does not make money. But last week my colleague at Surrey, Joe Keddie, and I went to the kick off meeting of a consortium called Barrier-Plus. It is an EU funded consortium of a bunch of SMEs (Small and Medium Enterprises), the Universities of Lyon and Surrey, and the Paint Research Association. Basically it is funded by EU (taxpayers’) money to fund research mostly by Lyon and us to address research problems the SMEs can’t solve themselves. It’ll run for 3 years, and Joe and I are currently hiring two postdocs (i.e., scientists trained to PhD level) to do the work at Surrey (applications still open of you’re interested …). The kick-off meeting was at the Paint Research Association in Hampton Court, west London.
As I guess many of you (but perhaps not my colleague Paul Stevenson) know, this is a quote from the movie The Princess Bride. For those of you who have sadly missed out on this excellent movie, our hero, Wesley, is chasing one of the bad guys, Vizzini. Vizzini thinks he’s a genius but sadly he isn’t and Wesley keeps thwarting Vizzini’s attempts to throw him off his trail. This irritates Vizzini who keeps exclaiming ‘inconceivable’ when I guess he means ‘impossible’. Finally, one of the guys with Vizzini snaps and says the line above.
The two sexes must be equal. This is true in us, the cells in both men and women need the same amounts of the essential proteins that run these cells. It is also true in all other animals. These proteins are made from the genes on our chromosomes and this is called gene expression. For example muscle cells are the same in men and in women – in both their job is to exert forces – and so in both there will be an optimum amount of a protein that needs to be made from a gene.