Friday, 18 December 2009

Dark Matter - Detected?

Stealing a march on the LHC, it seems that groups looking for Dark Matter in a low-background experiment in a copper mine in the States may be about to announce the detection of dark matter. I noticed the story a day too late to put it in my particle physics course...

Monday, 14 December 2009

Interesting days ahead

It can't have escaped many people's attention that there is a serious worldwide financial crisis going on.  There have been innumerable reports in the news about forthcoming cuts, even before the recent pre-budget report.

It would be nice to try to place the financial responsibility of recovering from the crisis on the banking sector, which was largely responsible for the problems, but the time for that is long past.  They have been bailed out and the City shown up as not the contributor to tax revenue it has liked to claim but a drain of historic proportions.   This leaves the rest of the economy to figure out how to keep going.  Whole countries are at peril of defaulting; Iceland a few months ago, and Greece in the news today.

Now it's the task of the rest of the UK economy to recover from the debts we've incurred.  Science funding will take its part alongside everything else, as it must.  I'm a nuclear physicist (hence the purpose of this blog) and nuclear physics will no-doubt be part of the cuts, of course.  There is a fear in the nuclear physics community that (university) nuclear physics may be cut from the budget outright.  A recent story in the Guardian quoting my colleague Jim Al-Khalili highlights some of the issues.  You might well expect me, as a nuclear physicist, to say that funding in academic nuclear physics should be increased, rather than cut, because my job depends on it.  In truth, my job doesn't - at least I hope the University of Surrey would give me support and a little time to make headway into other research areas - or if not, the skills that working in nuclear physics have given me would make me pretty employable.  But the UK funding of Nuclear Physics is embarrassingly small by the standards of competitor countries, yet it was just judged in an independent review as high quality despite at a scale below OECD norms. It really is at such a low level that to cut it a bit is to essentially get rid of it.  It may be that we can do without it, despite having plans to increase nuclear power to counter global warming.  We can always buy the expertise in from elsewhere if we think that's right for the UK, but I can't really believe that cutting science that we'll then have to buy from outside can be cost-effective.  I rather fear we'll find out pretty soon.

Expect announcements in the next few days.

Tuesday, 17 November 2009


On Friday I went to a school in Slough to give my nuclear physics talk entitled "Field guide to the isotopes" which consists of a whistlestop tour of different isotopes, their uses and their significance in the realm of nuclear physics, in society, in medicine, in geology, in biology and ... just about every branch of science.

I used to worry about going into schools to talk, since I figured I'd be no good at dealing with naughty students (despite working at a University). I've long realised that it's not that hard - at least not as a guest speaker, so I wasn't too worried, and indeed it turned out fine. In fact, I found, as I always do, that the pupils were interested, they paid attention, and asked lots of interesting questions. One of these was related to a picture of the JET fusion reactor in Oxfordshire which showed it both in action (with a hot plasma of hydrogen isotopes) and out of action (to see the apparatus without all that hot plasma). One of the students asked, "how did they take the picture when it was switched on?" and I had to admit that I didn't really know. It's a good question: The temperature inside the reactor when it is on is exceedingly high and would destroy a camera. The answer I gave (with a caveat that it might be wrong) was that the plasma is contained in a magnetic field, which keeps it away from the walls, and a camera could be attached near the wall and away from the plasma. It's probably the right answer, but I don't know (if anyone does, please comment!). But that's one of the nice things about giving these talks - I get a combination of questions that make me think and comments that inform me of things I didn't know.

One of the best comments I have got when giving the talk was about the medical imaging technique which is these days known as MRI ("Magnetic Resonance Imaging") and used to be known as NMR ("Nuclear Magnetic Resonance"). I ask, as I usually do, if anyone in the audience knows the difference. Usually noone answers, and I explain that there is no difference, except that the word "nuclear" was removed to avoid worrying people that there was something nuclear about the technique. One time that I gave the talk, and told this story, someone came up to me at the end and said that actually the reason that they changed the name was because "NMR" sounds too much like "enema" and that people would get confused about what they were going in to hospital for. I told this story on Friday, and I thought that I got some glowering looks from the teachers. Oh well. It's a good story. I don't know if it's true though.

P.S. I'm glad that when this post is mirrored on facebook that people comment. I'd rather, though, that you'd do it on the original blog post so that everyone can see the comments and comment on the comments whether they are looking on facebook or not. Thanks!

Tuesday, 3 November 2009

Science and Politics

So: the Home Secretary dismissed a scientific advisor for being a scientist and complaining that the Government deliberately ignored the advice of his panel. There's been a huge amount of rather interesting commentary about the link between science and government during the fall-out of the sacking of Prof David Nutt (which has the glorious Twitter hashtag of #NuttSack). It sort of surprises me and sort of doesn't that one arm of the people who run the country (the government) think that basing decisions on scientific evidence is a bad thing to do, and that another (the Daily Mail and its constituency) rants that it would be hell on earth to be governed by those that weigh up the balance of evidence and come to conclusions based on that evidence.

It's a real shame - and part and parcel of the two cultures that are as alive today as they were 50 years ago. It's a bit tiresome when the presenters of the Today program fail to challenge scientists like they do politicians because they don't have the ability or confidence to do so. It's a little annoying when Jeremy Paxman is impressed and surprised when contestants in University Challenge answer a basic science question but is scathing when a poor guess is made to a question in the arts. It's really annoying, though, when things that really matter - things like government policy - deliberately ignore the evidence.

Still, in other news, universities aren't going to be "ivory towers" anymore, with the intellectual and research freedom that goes with it. Instead they must concentrate on being drivers of the economy and respond to social need (which they already do alongside the "ivory tower" aspect). Research grants will be rated according to their financial payoff (as if it could be measured), not the science. Soon Universities can be a fully paid-up part of the service economy too, and we will no longer have to worry about troublesome disinterested scientists and their crazy evidence-based reasoning.

Thursday, 22 October 2009

Sharing your bed with radiation

So, last night I gave my "Field Guide to the Isotopes" talk at my home institution, the University of Surrey. It went, I think, pretty well, though the turn-out was on the low side for our evening lectures programme. I guess people must have been paying attention, as there were a few very pertinent questions along the way, and some interesting comments and questions at the end.

One of the comments was about the isotope potassium-40 (K-40). Potassium is an alkali metal, element number 19, which sits under sodium in the periodic table. It sits there because it has chemical properties similar to sodium, so it readily forms salts which are vital in the human body for the proper functioning of cells.

So, potassium is element number 19, which means that every nucleus of potassium has 19 protons in it but there are a few naturally-occurring isotopes which differ in the number of neutrons they have. The most common is K-39, next is K-41. They are both stable, but about 0.01% of potassium atoms has a K-40 nucleus at its centre. K-40 is radioactive (it will decay either to argon-40 or calcium-40), with a half life of around 1 billion years. Now, the earth is not so very much older than this (at around 4 billion years) so there is still some remaining K-40 that was created some time before 4 billion years ago to be found on the earth. Unlike the other main long-lived naturally-occurring radioactive isotopes (of Uranium and Thorium), Potassium is actually a biologically useful element, and so we all have some small amount of radioactive K-40 in us.

I expressed this in the talk by saying (and I don't take credit for it - it's been pointed out before) that if you sleep with someone else, you are getting an increased dose of radiation from their body by doing so - and vice versa. A questioner at the end was quite worried. Fortunately, humans have been sleeping with other humans for a long long time, and the doses are clearly not high enough to cause any trouble.

Still, all other things being equal, single people have a lower radiation dose!

Sunday, 18 October 2009

First Post!

Hello and welcome to my new blog about nuclear physics; Blog of the Isotopes. I've been occasionally writing a personal blog for many years, and often going off and talking about nuclear physics as part of my job as an academic nuclear physicist, also for many years, so it seemed like it was about time to join those two things up. So here we are: the blog of the isotopes - all about nuclear physics. The blog's name comes from the fact that nuclei - the tiny clusters made of protons and neutrons at the centre of each atom - come in different isotopes, just meaning a unique combination of a number of protons and neutrons in the same way that each chemical element differs from the others by having a different number of electrons in an atom.

Of course, it might be that blogs are on their way out and that I should be tweeting about nuclear physics instead, but maybe that will come too :-)

Anyway - a little about me: I work at the University of Surrey, which has the largest nuclear physics group in a UK university#. I call myself a nuclear structure theorist, which means that I do calculations of the structural properties of nuclei (things like their size, shape, mass, and the ways in which they can vibrate) using our knowledge about the nuclear force - then I see how well these ideas about the nuclear force really agree with what my experimental colleagues observe and refine my theories based on that. No doubt I will be talking about this in future blog posts.

I plan to keep an eye out for topical nuclear physics news stories and talk about them from the point of view of a nuclear physics researcher, and also to share some of my interests in the wider field of nuclear physics beyond what I do research into... but I don't want to do it all in this first entry; so let me just justify the fact that I have chosen to start today by saying that I will be giving a public lecture at the University of Surrey this Wednesday (21st October) in Lecture Theatre M at 7pm on nuclear physics. The title of the talk is "Field Guide to the Isotopes," and it will be a little tour of some of the exciting things that nuclei are used for elsewhere in science and society from understanding climate change and other geological processes to medical diagnosis and treatment, to determining the ways that astronomical processes take place. If you wish to come, please just turn up in time for a 7pm start. Details are at or leave a comment here.

more soon!

# probably - it's slightly hard to count