Condensed concepts

I am often on the lookout for interesting molecules and solids which involve short hydrogen bonds, particularly biomolecules where this bond may play a key role in functionality . Such bonds are of interest from a physics point of view because then the quantum motion of the proton matters. Consequently, the following paper (published in October 2016) caught my attention. Proton Probability Distribution in the O···H···O Low-Barrier Hydrogen Bond: A Combined Solid-State NMR and Quantum Chemical Computational Study of Dibenzoylmethane and Curcumin Xianqi Kong, Andreas Brinkmann Victor Terskikh, Roderick E. Wasylishen, Guy M. Bernard∥, Zhuang Duan∥, Qichao Wu∥, and Gang Wu The authors state their motivation. Curcumin was selected in our study, in part because it is being touted as a wonder drug and is of intense interest to the pharmaceutical and medical community.31−33 This sounds quite exciting. Could low barrier hydrogen bonds be important in curing cancer? Curcumin is a maj

Steve Blundell has written a very nice article Emergence, causation and storytelling: condensed matter physics and the limitations of the human mind The article is lucid, creative, and stimulating. He explores some issues that are of particular interest to philosophers such as the differences between "weak" and "strong" emergence, which are sometimes called "epistemological" and "ontological" emergence, respectively. Part of his argument is based on the fact that human minds are finite and constrained by the physical world and that "information is physical". Unlike the philosophers, he argues that emergence always has both an ontological and an epistemological character. To illustrate his arguments Steve uses several beautiful examples. Storytelling. "To work, stories have to be succinct, told well, have a point and express some truth." This is to accommodate the physical limitations of the human mind. Number the

A central concept of quantum-many body theory is that of coherent quasi-particles. Their key property is a well-defined relationship between energy and momentum (dispersion relation). Prior to the rise of ARPES (Angle-Resolved Photo-Emission Spectroscopy) over the past three decades, the existence of electronic quasi-particles was only inferred indirectly. A very nice paper just appeared which shows a new way of measuring quasi-particle excitations in a strongly correlated electron system. Furthermore, the experimental results are compared quantitatively to state-of-the-art theory, showing several subtle many-body effects. Coherent band excitations in CePd3: A comparison of neutron scattering and ab initio theory  Eugene A. Goremychkin, Hyowon Park, Raymond Osborn, Stephan Rosenkranz, John-Paul Castellan, Victor R. Fanelli, Andrew D. Christianson, Matthew B. Stone, Eric D. Bauer, Kenneth J. McClellan, Darrin D. Byler, Jon M. Lawrence The mixed valence compound studied is of pa

The Chronicle of Higher Education has an excellent (but depressing) article, Higher Education is Drowning in BS , by Christian Smith. In both scope and eloquence, this article goes far beyond my post, The rise of BS in science and academia . Furthermore, as a sociologist, Smith argues that one of the challenges, is to the think about the problem in collective ( dare I say emergent! ) terms, rather than just individualistic terms. Essential to realize in all of this is that most of the BS is produced not by pernicious individuals, but instead by complex dysfunctions in institutional systems. It is easy to be a really good academic or administrator and still actively contribute to the BS. So we need to think not individualistically, but systemically, about culture, institutions, and political economies. Pointing fingers at individual schools and people is not helpful here. Sociological analysis of systems and their consequences is. Smith also spells out the broader moral and polit

The problem of the irreproducibility of many results in psychology and medical research is getting a lot of attention. There is even an Wikipedia page about the Replication Crisis.  In the USA the National Academies have just  launched a study of the problem. This naturally raises the question about how big is the problem is in physics and chemistry? One survey showed that many chemists and physicists could not reproduce results of others.  My anecdotal experience, is that for both experiments and computer simulations, there is a serious problem. Colleagues will often tell me privately they cannot reproduce the published results of others. Furthermore, this particularly seems to be a problem for "high impact" results, published in luxury journals. A concrete example is the case of USO's [Unidentified Superconducting Objects] . Here is just one specific case. A recent paper looks at the problem for the case of a basic measurement in a very popular class of material