Condensed concepts

Sometimes I bemoan the decline of scholarship in science, and in academia more broadly. About six years ago I posted about Ph.D's without scholarship , which generated a lot of comments. This decline is reflected in a range of phenomena: hype, making hiring and promotion decisions based on metrics rather than actual scientific achievements, people writing more papers than they read, "review" articles merely listing references rather than providing critical analysis,... But, this is all negative, it is what scholarship is not, ... what does real scholarship look like? I think classic books give a feel for what scholarship is all about. For example, Eisenberg and Kauzmann on Water, Ashcroft and Mermin, Hewson's Kondo Problem, Coulson's Valence, and Mott's monographs. Consider the Oxford Classic Texts in the Physical Sciences . Similarly, I am challenged by some of the monographs that some  humanities colleagues produce. (For example, Stephen Gaukroger &#

Liquid 3He is amazing stuff. Below temperatures of a few hundred milliKelvin it forms a model (and the original inspiration for) Landau Fermi liquid. Furthermore, below about 1 mK it forms two different superfluid states, involving Cooper pairs in a spin triplet state. This is the model case for unconventional superconductivity. Liquid 3He is actually of great practical use since it the crucial ingredient of dilution refrigerations that allow cooling from a few Kelvin to temperatures as low milliKelvin. But where do labs get 3He from? Well, it is a very useful by-product of nuclear weapons production. Currently, the scientific community (which consumes only about 1% of the supply) is experience supply problems and dramatic price increases (a 15-fold increase between 2004 and 2010). Why is this happening? Thankfully, we are cutting back on nuclear weapons production! One practical way to solve this problem is to develop alternative materials for ultra-low temperature refrigerat

A wonderful thing about the web is that now there is so much material online. A pioneer in putting all their seminars and colloquia online is the KITP at Santa Barbara . I know some people who regularly watch seminars (both old and recent). Others do not know it exist. This is a particularly valuable resource for students and those of us in distant countries. I have to confess that until yesterday I have never actually watched a talk; just occasionally skimmed some slides. Generally I find I don't have the patience to watch talks online. I just seem to prefer to look at papers. However, yesterday I was forced to do this because at the weekly UQ condensed matter theory group meeting we watched a nice talk by Antoine Georges on Hund's metals.  Although, I have read and blogged about some of the relevant papers, I really found it helpful seeing what was highlighted and going through the material at a "slow pace". Hopefully, I will do this more often. What do you thi

Administrators and senior management seem to love coming up with new policies and procedures for everything. These are designed to make things "better". However, a colleague recently emphasised to me that each one of these initiatives should be subject to a cost-benefit analysis . This is a point I have also heard made by my UQ law colleague, James Allen, author of a provocative essay about Australian universities. Consider the follow examples: * requiring grant applications to provide more information (whether reports on previous grants, details about university policies, longer project descriptions, relevance to society, ....) * more details in course profiles * larger committees to ensure more input, consultation, representation of diversity, accountability, and expertise * procedures and policies to increase transparency and accountability * broadening eligibility criteria so more people can apply for a particular grant or fellowship program. Every one

A few years ago I decided I wanted to include brief biographies of relevant great scientists in my undergraduate lectures. I posted (5 years ago!) about how I started with Landau  but I lost momentum. This year I have put more effort into it. I just taught my second year undergraduate thermo class about Gibbs free energy and so I profiled Gibbs. In solid state physics I have profiled Drude, Sommerfeld, von Laue, and Bloch. I have found this quite enjoyable for myself and hopefully for the students. I have learnt quite a bit, just by reading the relevant Wikipedia pages. It also introduces students to the human dimension of science. For example, Drude died by suicide and so it is a good opportunity to flag mental health issues. Sommerfeld was a mentor of many great scientists. von Laue actively opposed the Deutsche Physik of the Nazis. Bloch was the first Director General of CERN. Has anyone else experience at doing similar things? Any suggestions?

Producing a thesis (Ph.D, Masters, or undergraduate honours) is a monumental task that can create significant stress. Here I am just going to focus on the mechanics of producing the final document, not the greater challenge of producing the intellectual content. In most cases there is a deadline, whether imposed by the program, funding running out, or (hopefully) a fixed date to start a job. For many students there is a big rush at the end featuring very long hours, missing "life", neglecting family and sometimes health, exhaustion, anxiety, ... These problems are compounded if one starts "writing" and producing the thesis document at the very end, with the final deadline looming. Furthermore, this can be much slower and more frustrating if you have to do some of the mechanics (e.g. ordering and numbering references) by hand or at least learn to use software to do it automatically. Compared to 30 years ago, the mechanics is now so much easier because of software

This week in my Solid State Physics class I taught covered weak periodic potentials (including higher Brilloiun zones and Fermi surface reconstruction) and the tight binding model. I closely follow chapters 9 and 10 in Aschroft and Mermin, which was published in 1975. This topic is somewhat iconic in that it features on the front and back cover of the book. I think for the first time I understood the higher Brilloiun zones (rather than being overwhelmed by the geometrical complexity) and how this leads to the complex hole Fermi surfaces for metals of valence 2, 3, and 4. The key to visualising this better is just to do the problem in two dimensions first. This got me wondering: why do we teach this stuff to students? First, there is the intellectual beauty of the subject: how simple analytical and geometrical models can capture the complex band structures and Fermi surfaces of elemental metals. However, today almost no one cares about elemental metals, or at least does r

I recently read a couple of review articles about topics I am trying to learn about. What was really striking was how much the authors cited their own work. Indeed, in one review the majority of references were those of the author! Sometimes it is very appropriate that authors cite their own work.  This previous work is relevant and the current work builds on the foundations of earlier work by the author. Sometimes it gives necessary background and more detail for understanding the current work. However, there are bad reasons for authors to cite themselves. 1. It is a cynical exercise in boosting their own citation metrics. 2. They actually don't care what others are doing. 3. They don't want to acknowledge other work which contradicts or criticises their own, or at least presents an alternative picture of the problem. Most people are concerned about 1, and this is certainly a legitimate concern, particularly as metric madness increases. My focus is more on 3. When

It is good to encourage students to be reflective in a concrete way about how they are going in a course. It is even better if the teacher knows what they are thinking. I recently stumbled across the following idea. Include the following questions on a homework problem set. (a) What is the most interesting thing that you have learnt in the course so far?  (b) What is the concept that you understand the least?  (c) What specific action are you going to take to address (b)?  (d) List some of the skills required in this course. Which one do you think that you most need to improve? How might you do that? I recently did this for my undergraduate solid state physics course. I found the answers to (a) interesting. Sometimes the things that we think are interesting or boring are not necessarily the same as students. Many of my students said they really liked learning about crystal structures. (c) is good because it makes the student actually reflect on what they

Chemical Reviews just published an article Nuclear Quantum Effects in Water and Aqueous Systems: Experiment, Theory, and Current Challenges  Michele Ceriotti, Wei Fang, Peter G. Kusalik, Ross H. McKenzie, Angelos Michaelides, Miguel A. Morales, and Thomas E. Markland (Trivia: 4 out of 7 authors have a surname beginning with M!) One of the unifying themes in the review is that of competing quantum effects, illustrated above. This article is a direct outcome of the NORDITA program, "Water - the most anomalous liquid" that I attended about 18 months ago. Other reviews from the program will appear together in a special issue of the journal. I must confess I was skeptical that we were going to be able to pull off these reviews, written by large teams of busy and opinionated individuals. For ours, we are greatly in debt to Tom Markland for his perseverance and leadership. We welcome any comments about the contents of the review.

As one moves around the periodic table the extent of delocalisation of valence electrons varies significantly and in a systematic way, particularly in transition metals and rare earths. This leads to a subtle competition between metallic and magnetic behaviour and is nicely codified in a reorganised periodic table presented by Smith and Kmetko  in 1983. The version below is presented by Piers Coleman in his long-awaited textbook Introduction to Many-Body Physics . The bottom part illustrates how as one moves from 3d to 5f to 4f the electrons become more localised due to the tail of the atomic wave function becoming smaller. As the principle quantum number (n=3,4,5) increases the electrons become more delocalised to the larger number of nodes in the radial wave function. Materials near the localisation-delocalisation boundary are both the most interesting and the most challenging to describe theoretically. Note that plutonium is at the boundary , which is arguably why it has s

Some witty colleagues might say it is because I am not doing anything worth scooping! Some scientists live in a constant fear of being scooped, i.e. not being the first to publish their latest research result. This can lead to people being very secretive about what they are working on and/or being in an incredible rush to publish . Some groups even require members to sign confidentiality agreements about talking to outsiders. I always find it strange and disappointing when I ask someone what they are working on and then at some point they say, "I can't say anymore because I don't want to be scooped." In most cases this strikes me as both egotistical and unrealistic. Most of what we are working on is not so important that others are going to drop everything they are currently doing, steal our idea, work out all the details, and rush to publish... Sorry to disillusion you. I often write on this blog about things I am currently working on, long before I have a p

Each week I read The Economist . Many of their articles feature graphs of social or economic data. To me some of them are just random noise. But others are quite dramatic or insightful. Previously, I posted a famous one about smoking. Below I show two graphs that I thought were quite useful about universities. This is from an article Brains without borders This is from an article about how university students often unfairly evaluate their lecturers.