The graph above shows the numbers of earthquakes in the US state of Oklahoma, for each year from 1978 to 2016 (2016 data is only up September). The number is for earthquakes with magnitude greater than 3.0. There is a striking increase from 2008, when there were 2 earthquakes, to 2015, when there 890.
Yesterday Sir Fraser Stoddart won a one third share of the 2016 Chemistry Nobel Prize, for developing molecular machines, i.e., molecules that act like machines in the sense that they can move, exert forces etc. Stoddart was an academic in the Department of Chemistry at the University of Sheffield, when I started as an undergraduate. He never taught me as I didn’t take his course, but he did teach friends of mine. They were not impressed by the future Nobel Laureate. Continue reading
Above are crystals in a cave in the Mexican state of Chihuahua. They are huge, note that the person in the picture shows the scale. The crystals are up to 10 m long, have masses of tens of tons, and are made of gypsum, a form of calcium sulphate. It is estimated that they took hundreds of thousands of years to grow. So around about the time our ancestors were wandering around Africa, a tiny nucleus formed, and started to grow. Hundreds of thousands of years later, we have these enormous crystals.
Seeing is believing, so it is good to see evolution in action. The above movie shows a huge petri dish with bacteria starting at both edges where there is no antibiotic. The dish has a gradient of increasing concentration of this antibiotic towards the centre of the plate. Initially they can’t grow in the regions where the antibiotic concentration is high. But they evolve resistance and just march up the gradient of the antibiotic. This takes about two weeks. Impressive.
I was on the Physics stand for Saturday’s university open day for prospective students and their parents. I got a lot of questions from prospective students who were still deciding whether to do a maths degree, a physics degree, or maths & physics. They were doing maths and physics A levels, but unless they go for a maths & physics joint honours, they will have choose one or the other at university.
I am reading, and enjoying, Weapons of Math Destruction by Cathy O’Neil. It is on the problems created for society by the use of algorithms and data. Data analysis is key to science and engineering, and so lies behind new medicines, faster computers etc, but like most powerful tools it is not guaranteed to always lead to good. It can create problems or make existing problems worse if used incompetently and/or in a way that benefits a few while hurting many.
A basic question we can ask about any crystal is: How big is it? Many properties depend on size, so this is often a key question. Often it is not as easy to answer as you might hope. Take a look at the crystalline nanocrystal above. Its total size is about 59,000 atoms, or about 40 atoms across. But it is actually made up of two crystalline domains. To see this, look at the rows of yellow and orange coloured atoms, in most of the particle they are roughly vertical, but at the top right they are tilted a bit below the horizontal. So this is two crystals not one.
The molecules in a crystal are in a regular arrangement, in which ideally they are all in identical positions, like soldiers in a perfectly ordered parade. And crystals have many useful properties, they are the best conductors of electricity. But crystals are rarely perfect, and these imperfect crystals may have higher resistance to electricity.
I am currently pondering this question. UK Universities are assessed by the UK government in many ways. One of which is via the “impact” of our research, defined as being “An effect on, change or benefit to the economy, society, culture, public policy or services, health, the environment or quality of life, beyond academia.”. At the University of Manchester, Andre Geim and Constantin Novosolev won the 2010 Nobel Prize in Physics, for their pioneering research on graphene – a hi-tech material made of incredibly thin chicken-wire-like arrangements of carbon atoms.
I have just come across a striking but slightly scary paper. The paper looked at errors in scientific papers reporting on the use of stem cells to treat heart problems. Our heart is a muscular pump, and its muscle tissue has very little regenerative capacity*, so a heart attack can damage it permanently. The idea here is that by transplanting stem cells into a damaged heart, the stem cells can partially regenerate damaged muscle tissue, and so reverse damage due to the heart attack. The repair can be measured by what is called the ejection fraction (EF), which measures basically the fraction of the blood inside a heart chamber that is pumped out in one heart beat.