Chance & Necessity

Working out which one goes on top

ed-2011-008262_0006 We all know that oil and water do not mix. But they are not alone, oil, water and mercury also don’t mix, and so water, oil and mercury form three separate liquids, one on top of the other. And if you are really determined you can find not three but six different liquids, none of which mix with any of the others. This is what Ecklemann and Luning did*, to produce the test-tube shown to the lefy, containing six layers, each of a different liquid.

The top layer is a type of oil (petroleum ether), the next is alcohol’s slightly smaller cousin, methanol. Below those are a silicone oil, and then water (with potassium carbonate added so it won’t mix with methanol). Finally, at the bottom is a fluorinated molecule, and then mercury. The mercury is obvious as it is the only metal, the water, methanol and oil are dyed blue, yellow and red, respectively, so we can tell them apart.

Stuck in wet cement

I spent part of this week at the kick-off meeting for an EU-funded PhD training network: Engineered Calcium-Silicate-Hydrates for Applications (ERICA for short). The network is run from Surrey and I was invited along to give a talk, and to help out. These calcium-silicate-hydrates are better known as cement. Cement is, very roughly speaking, a type of artificial stone in the sense that when poured it crystallises to form a semi-crystalline solid. The world’s most widely used construction material, concrete, is basically cement plus gravel filler. Concrete is not the most glamorous, but it is strong and above all it is cheap, less than £100 for a ton.

A trip to Bordeaux to learn about very tiny plumbing

I would to start this post by acknowledging how impressed I am with the style of the French guy who strode confidently onto Friday’s flight from Bordeaux to London wearing a large string of cloves of garlic draped around his neck. Some people just have natural style. As someone who does not, I am a bit envious. My PhD student and I were in Bordeaux as part of an EU research network (called RAMP) on crystallising proteins. There is a research lab in the suburbs of Bordeaux that is world leading at what is called microfluidics — essentially plumbing but instead of pipes centimetres across that move litres, microfluidics has pipes that are less than 1 millimetre wide and move as little as billionth of a litre, a nanolitre. The channels above in the microfluidic device shown above are only 0.15 mm wide.

Brine pockets on the march

Over the last six months I have been thinking a lot about the movement of small solid particles in liquids, but a couple of weeks ago I came across examples, that were new to me, of the reverse. The motion of liquid droplets or gas bubbles in solids. I think they are fascinating. One example of liquid droplets moving inside a solid, are pockets of brine (i.e., salty water) moving inside ice.

The life of an academic involves a certain amount of travel, in my case to Manchester in January. This as glamorous as it sounds, the drizzle has been unrelenting. Although on the bright side I was able to finish my talk for tomorrow in the Lass o Gowrie, which I can recommend; friendly barstaff, and the Citrus IPA was good. Tomorrow, I am going to give a talk about growing crystals, in particular growing crystals of a small molecule called glycine. We* studied the glycine molecule because when crystallised from water, it forms not one but two types of crystals.

How lucky are you feeling?

cumul_rich I am rewriting a computational modelling project on modelling the stock market, so I am doing a bit of background reading. Fortune’s Formula by William Poundstone is a good general-interest description of some work from the 1950s onwards, on developing models for both the stockmarket, and gambling in casinos. In terms of mathematical modelling, gambling (aka investing) in the stock market, and gambling in casinos are almost the same — the aim is the same in both: maximise the money acquired while minimise the risk.

Redistribution in UK universities, from wealthy overseas parents to the British taxpayer and to charities

Universities that do research as well as teach, like Surrey, are funded from many different sources, and their finances are complex. But roughly two-thirds of the money the Department has to pay my salary comes from student fees and government funding for teaching, leaving one-third of my salary to be paid for from research income. The distribution of my time between teaching and research is maybe half-and-half*. Teaching is subsidising research, in the sense that student fees are paying my salary for some time when I am doing research.

Gambling with £9,000

p_rich Teaching for semester one has just ended. Almost all the undergraduates have left, and so campus is quiet in the run up to Christmas. But although the pressure is off (thankfully!), there are still things to do. In particular, I want to improve semester-two’s computational project on modeling the stock market. The current version is very popular with the students, but many of them slightly run out of steam when they do it, so I think there is room to improve it. The plot above shows some results for some calculations I am doing to scope out a new project.

My most cited paper of the last two years is wrong

Academics are assessed in a number of ways, and one proposal that keeps coming up to assess us is via citations. The idea being is that if nobody cites your work (i.e. refers to your paper in their paper) you must be doing boring work, but if your paper is being cited by many others then it is clearly popular so must be good. And almost whenever someone suggests this, it is pointed out that papers that are obviously wrong can be highly cited, particularly if they are published in a prestigious journal. This is a fair point. For example Wolfe-Simon et al.‘s Science paper of 2011 has been cited over 400 times, and is clearly wrong, as a number of the citing articles state.

Picking a language

One of the thorniest questions in the teaching of physics at degree level, is which computer language to teach. There is no consensus on this, and I am not sure that there will every be. Getting everyone to agree on the best computer language to teach at first year would be harder than getting everyone to agree on a favourite ice-cream flavour. However hard you tried there would always be one person holding out for pistachio.