Condensed concepts

According to Wikipedia, " A perverse incentive is an incentive that has an unintended and undesirable result which is contrary to the interests of the incentive makers. Perverse incentives are a type of negative unintended consequence ." There is an excellent (but depressing) article Academic Research in the 21st Century: Maintaining Scientific Integrity in a Climate of Perverse Incentives and Hypercompetition Edwards Marc A. and Roy Siddhartha I learnt of the article via a blog post summarising it, Every attempt to manage academia makes it worse. Incidentally, Edwards is a water quality expert who was influential in exposing the Flint Water crisis. The article is particularly helpful because it cites a lot of literature concerning the problems. It contains the following provocative table.  I also like the emphasis on ethical behaviour and altruism. It is easy to feel helpless. However, the least action you can take is to stop looking at metrics when reviewing

To the uninitiated (and particularly physicists) computational quantum chemistry can just seem to be a bewildering zoo of multiple letter acronyms (CCSD(T), MP4, aug-CC-pVZ, ...). However, the basic ingredients and key assumptions can be simply explained. First, one makes the Born-Oppenheimer approximation, i.e. one assumes that the positions of the N_n nuclei in a particular molecule are a classical variable [R is a 3N_n dimensional vector] and the electrons are quantum. One wants to find the eigenenergy of the N electrons. The corresponding Hamiltonian and Schrodinger equation is The electronic energy eigenvalues E_n(R) define the potential energy surfaces associated with the ground and excited states. From the ground state surface one can understand most of chemistry! (e.g., molecular geometries, reaction mechanisms, transition states, heats of reaction, activation energies, ....) As Laughlin and Pines say, the equation above is the Theory of Everything! The problem is

I am spending more time with undergraduates lately: helping in a lab (scary!), lecturing, marking assignments, supervising small research projects, ... One issue keeps coming up: physical units! Many of the students struggle with this. Some even think it is not important! This matters in a wide range of activities. Giving a meaningful answer for a measurement or calculation. This includes canceling out units. Using dimensional analysis to find possible errors in a calculation or formula. Writing equations in dimensionless form to simplify calculations, whether analytical or computational. Making order of magnitude estimates of physical effects. Any others you can think of? Any thoughts on how we can do better at training students to master this basic but important skill?

What are the big questions that people are (or should be) wrestling within universities? What are the grand intellectual challenges, particularly those that interact with society? Here are a few. A common feature of those I have chosen is that they involve emergence: complex systems consisting of many interacting components produce new entities and there are multiple scales (whether length, time, energy, the number of entities) involved. Economics How does one go from microeconomics to macroeconomics? What is the interaction between individual agents and the surrounding economic order? A recent series of papers(see here and references therein) have looked at how the concept of emergence played a role in the thinking of Friedrich Hayek . Biology How does one go from genotype to phenotype? How do the i nteractions between many proteins produce a biochemical process in a cell? The figure above shows a protein interaction network and taken from this review. Sociology Ho

My post, "Do we need more journals?" generated a lot of comments, showing that the associated issues are something people have strong opinions about. I think it important to consider some distinct questions that the community needs to debate. What research fields, topics, and projects should we work on? When is a specific research result worth communicating to the relevant research community? Who should be co-authors of that communication? What is the best method of communicating that result to the community? How should the "performance" and "potential" of individuals, departments, and institutions be evaluated? A major problem for science is that over the past two decades the dominant answer to the last question (metrics such as Journal "Impact" Factors and citations) is determining the answer to the other questions . This issue has been nicely discussed by Carl Caves. The tail is wagging the dog. People flock to "hot&quo

At UQ there is a great  student physics club, PAIN . Their weekly meeting is called the "error bar." This friday they are having a session on the history of physics and asked faculty if any would talk " about interesting stories or anecdotes about people,  discoveries , and ideas  relating to physics." I thought for a while and decided on John Bardeen . There is a lot I find interesting. He is the only person to receive two Nobel Prizes in Physics. Arguably, the discovery associated with both prizes (transistor, BCS theory) are of greater significance than the average Nobel. The difficult relationship with Shockley , who in some sense became the founder of Silicon Valley. Here are my slides. In preparing the talk I read the interesting articles in the April 1992 issue of Physics Today   that  was completely dedicated to Bardeen. In his article David Pines, says [Bardeen's] approach to scientific problems went something like this:   Focus fir

The past two decades have seen impressive advances in Angle-Resolved PhotoEmission Spectroscopy (ARPES). This technique has played a particularly important role in elucidating the properties of the cuprates and topological insulators. ARPES allows measurement of the one-electron spectral function, A(k,E) something that can be calculated from quantum many-body theory. Recent advances have included the development of laser-based ARPES, which makes synchrotron time unnecessary. A recent PRL shows the quality of data that can be achieved. Orbital-Dependent Band Narrowing Revealed in an Extremely Correlated Hund’s Metal Emerging on the Topmost Layer of Sr2RuO4  Takeshi Kondo, M. Ochi, M. Nakayama, H. Taniguchi, S. Akebi, K. Kuroda, M. Arita, S. Sakai, H. Namatame, M. Taniguchi, Y. Maeno, R. Arita, and S. Shin The figure below shows a colour density plot of the intensity [related to A(k,E)] along a particular direction in the Brillouin zone.  The energy resolution is of the order of m

Should you ban cell phones in class? I found this video quite insightful. It reminded me of the gulf between me and some students. It confirmed my policy of not allowing texting in class. Partly this is to force students to be more engaged. But it is also to make students think about whether they really need to be "connected" all the time? What is your policy of phones in class? I think that the characterisation of "millennials" may be a bit harsh and too one dimensional. Although I did encounter some of the underlying attitudes in a problematic class a few years ago. Then reading a Time magazine cover article was helpful. I also think that this is not a good characterisation of many of the students that make it as far as an advanced undergraduate or Ph.D programs. By then many of the narcissistic and entitled have self selected out. It is just too much hard work.

NO! Nature Publishing Group continues to spawn "Baby Natures" like crazy. I was disappointed to see that Physical Review is launching a new journal Physical Review Materials. They claim it is to better serve the materials community. I found this strange. What is wrong with Physical Review B? It does a great job. Surely, the real reason is APS wants to compete with Nature Materials [a front for mediocrity and hype] which has a big Journal Impact Factor (JIF). On the other hand, if the new journal could put Nature Materials out of business I would be very happy. At least the journal would be run and controlled by real scientists and not-for-profit. So I just want to rant two points I have made before. First, the JIF is essentially meaningless, particularly when it comes to evaluating the quality of individual papers. Even if one believes citations are some sort of useful measure of impact, one should look at the distribution, not just the mean . Below the distribution

For me, global economic inequality is a huge issue. A  helpful short video describes the problem. Recently, there has been a surge of interest among development policy analysts about how complexity theory may be relevant in poverty alleviation programs. On an Oxfam blog there is a helpful review of three books on complexity theory and development. I recently read some of one of these books, Aid on the Edge of Chaos: Rethinking International Cooperation in a Complex World , by Ben Ramalingham. Here is some of the publisher blurb. Ben Ramalingam shows that the linear, mechanistic models and assumptions on which foreign aid is built would be more at home in early twentieth century factory floors than in the dynamic, complex world we face today. All around us, we can see the costs and limitations of dealing with economies and societies as if they are analogous to machines. The reality is that such social systems have far more in common with ecosystems: they are complex, dynamic, di

The past few decades has seen impressive achievements in molecular biophysics that are based on two techniques that are now common place. Using X-ray crystallography to determine the detailed atomic structure of proteins. Classical molecular dynamics simulations. However, there is a fact that is not as widely known and acknowledged as it should be. These two complementary techniques have an unhealthy symbiotic relationship. Protein crystal structures are often "refined" using molecular dynamics simulations. The "force fields" used in the simulations are often parametrised using known crystal structures! There are at least two problems with this. 1. Because the methods are not independent of one another one cannot claim that a because in a particular case they give the same result that one has achieved something, particularly "confirmation" of the validity of a result. 2. Classical force fields are classical and do not necessarily give a goo

A common quote about history is that "History is written by the victors". The over-simplified point is that sometimes the losers of a war are obliterated (or at least lose power) and so don't have the opportunity to tell their side of the story. In contrast, the victors want to propagate a one-sided story about their heroic win over their immoral adversaries. The origin of this quote is debatable but there is certainly a nice article where George Orwell discusses  the problem in the context of World War II. What does this have to do with teaching science? The problem is that textbooks present nice clean discussions of successful theories and models that rarely engage with the complex and tortuous path that was taken to get to the final version. If the goal is "efficient" learning and minimisation of confusion this is appropriate. However, we should ask whether this is the best way for students to actually learn how to DO and understand science. I have bee