Condensed concepts

I am a vocal critic of the use of metrics to evaluate individuals, single scientific papers, journals, sub-fields, institutions, .... However, my problem is really one of abuse. I don't think metrics are totally meaningless or useless. Rather, it is the mindless use of metrics, with a disregard for their limitations, that is a problem. This post is not about metrics, jobs, and funding. I have probably already written too many posts on that. Rather, I want to give two examples where I have found some multi-dimensional metrics helpful, when considering issues relating to public policy and development, particularly in the Majority World. The case is that of the HDI ( Human Development Index ). Prior to its introduction people tended to use GDP (Gross Domestic Product) as a measure of how a country was performing and where it ranked in the world. In contrast, the HDI is a composite metric, factoring in income per capita, life expectancy, and education. The map below gives a sense

I am working with a graduate student beginning research and she has asked this important question. I don't think there is a simple universal answer. Background material includes review articles of a field, details of an experimental technique or computer code, details of derivations, seminal articles on the topic, .... At the UQ condensed matter theory group meeting, we had a brief discussion about the question. Answers from students, both beginning and advanced, were helpful. It also underscored how important the question is because students really do struggle with this issue. One shared how he developed some mental health problems because at the beginning of his Ph.D. he was too obsessive about understanding all the details. The question and discussion underscored to me how we need to have more discussions of this nature. Beginning research is a difficult transition for most graduate students. When they were undergraduates they often could understand all the details and wor

On Friday there was a nice UQ Maths and Physics Colloquium, Beyond the Gaussian Universality Class , given by Ivan Corwin , The talk was a very nice example of synergy between fundamental physics and maths research. There are interesting connections with simple one-dimensional models for surface growth, the Kardan-Parisi-Zhang equation , the KPZ universality class, traffic models, random matrix theory, directed polymers in random media, .... Much of the content of Corwin's talk is in a helpful article , from 2016 in the American Mathematical Society Notices. Although this field is motivated by very concrete physical problems, actually doing experiments to test the theory is difficult. One of the few examples is in a  paper , by Takeuchi and Sano, who studied ``topological-defect turbulence in the electroconvection of nematic liquid crystals.'' A good summary of the field from the physics side is A KPZ Cocktail-Shaken, not Stirred... Toasting 30 Years of Kinetic

In the next month, I have been asked to give a talk and to write an article about universities in two different forums. What are universities for? How do they promote human flourishing? Before I get too carried away I thought I would float a few ideas/claims/hypotheses that will be central to my argument that there needs to be a greater debate about fundamental issues and about the history of universities. Some of the claims are interconnected. In future posts, I may expand on some of these claims. Universities are currently having a crisis of identity, mission, and purpose. This crisis arises because there is a multitude of competing and conflicting visions from a range of "stakeholders". This crisis and the degree of conflict is far greater and deeper than those faced by other institutions : government, schools, hospitals, business, charities, ... Over time universities have been one of the most successful human institutions for promoting human flourishing (br

There is a nice paper Bad metallic transport in a cold atom Fermi-Hubbard system  Peter T. Brown, Debayan Mitra, Elmer Guardado-Sanchez, Reza Nourafkan, Alexis Reymbaut, Simon Bergeron, A.-M. S. Tremblay, Jure Kokalj, David A. Huse, Peter Schaus, and Waseem S. Bakr The paper represents a significant experimental advance in using ultracold atoms to investigate questions directly relevant to strongly correlated electron systems. In this case, the system Hamiltonian can be tuned to be a Hubbard model on a square lattice, such that the model parameters, U and t, and the doping, n are known. One limitation is that current experiments can only be performed down to the lowest temperature of T/t =0.3. [For comparison, for cuprates this is of the order of 1000 K!]. Using imaging techniques the authors are able to directly extract the density (charge) diffusion constant D and the density susceptibility, chi, shown below. The experimental data are red dots. The blue curve is the result of c