This past term I taught my “Biophysics for non-science majors” course, actually called “The Physics of Life,” for the first time since 2018, and, more notably, for the first time since writing my pop-science book, So Simple a Beginning: How Four Physical Principles Shape Our Living World (blog post; Amazon) — published in 2022 (and now out in paperback!). The course and the book aren’t directly related, but teaching early versions of the course, and writing things for it, put me on the path towards the book. Now, appropriately, I used the book for the course, though it’s not written as a text ..read more

Usually when I write about biophysics, it’s with the uplifting message that understanding physics helps us make sense of biology, bringing varied phenomena together under umbrellas of general principles. This is true, and there are countless examples. Brownian motion explains the meandering of neurotransmitters and the patterning of embryonic body segments. Electrical interactions influence the packaging of DNA and the expansion of mucus. The list is long. Now, however, I’ll write a dismal post. Our microbial systems journal club at the University of Oregon includes a wonderful collection of ..read more

Several times so far I’ve taught a graduate course on biophysics. Last term I taught it again, but with a twist: it was a combined graduate and undergraduate course. There were two motivations for this. First, biophysics is unfamiliar enough to physics graduate students that upper-division undergraduates aren’t at any significant disadvantage. In fact, I’ve had a few undergraduates take the graduate course in the past, successfully. Second, the undergrad/graduate combination can boost enrollment numbers enough to offer the course every year, which is otherwise a bit of a struggle. We’re a med ..read more

Here’s this year’s recap of notable books I read, featuring Russians new and old, Scythians (all old), and criminals of various sorts. (Previous years: 2022, 2021, …, 2015.) 1965 vs. 2023 I wrote a few months ago about my excursion into 1965, reading seven books published in that year. I won’t revisit any of these here except to note again that Claude Brown’s memoir of growing up in Harlem in the mid-twentieth century, Manchild in the Promised Land, and John Fowles’ novel, The Magus, were phenomenal. How does 1965 compare to the present? This year I read four books published in 2023 — for me ..read more

Each of us has a genome of about 3 billion DNA nucleotides — a sequence of 3 billion As, Cs, Gs, and Ts. Knowing what this sequence is, whether our own sequence or that of a bacterium, a barley plant, a baboon, or anything else, tells us about the repertoire of tools its genome encodes, which can reveal such characteristics as susceptibility to disease or evolutionary relatedness. In 1982, we had read the 48,000 nucleotide genome of a virus. The first human genome sequence was essentially complete in 2001, after about a decade of work. How much did it cost? I asked students (graduate and unde ..read more

Perhaps when blowing your nose, or the nose of a sick child, you’ve wondered where all this stuff comes from. How can one nose make so much mucus? The answer involves electrical forces and the physical character of mucus. Mucus, the gooey liquid secreted by your nose as well as by the linings of other body parts, is made of polymers — long, string-like molecules. The polymer molecules are negatively charged; imagine lots of speckles each with one electron’s worth of negative charge along each string: For every negative charge, there’s a positive charge somewhere, an ion floating around in th ..read more

Viruses encode their genomes in RNA or DNA, which they pack into a tiny space. For example, Varicella zoster, the virus that causes chickenpox and shingles, stuffs a double-stranded DNA molecule about 40,000 nm in length into a shell about 200 nm in diameter. This is even more impressive than it may seem because DNA and RNA are rather stiff molecules, and so resist being bent, and are highly charged, and so repel themselves strongly if confined. As a result of the viral packaging, the genomic contents are highly pressurized. We might suspect that, like a champagne bottle with the cork lopped ..read more

There’s a lot of advice out there for prospective applicants for academic faculty positions [1], so you don’t really need mine. However, some advice is outdated and some is incomplete, so I thought it would be worthwhile to add a small bit of information based on experiences from my department’s search last year (Physics, University of Oregon, U.S.A.). There are details regarding how applicants are evaluated that are not widely known, even by existing faculty, involving for example Zoom interviews and DEI statements; perhaps cataloging this will be of use to people on the U.S. STEM academic j ..read more

Last Spring, I taught the second term of University of Oregon’s statistical mechanics / thermodynamics for physics majors course (syllabus). I might at some point describe how the course went and what lessons might be drawn, beyond the key lesson that statistical mechanics is a wonderful subject. For now, something far less substantial: I often play music before the start of classes I teach, usually something instrumental. For this course, however, I thought I’d play songs that have some (perhaps tenuous) connection to the subject of statistical mechanics and thermodynamics. It was a lot of f ..read more

What makes one microscope better than another? A few weeks ago I co-ran a week-long Physics and Human Physiology day camp for high school students, part of the University of Oregon’s “SAIL” program that especially targets low-income students. I’ve written about SAIL before (2019, 2017, 2014) — this was our 14th Physics + Human Physiology camp, and the 16th time I’ve run a SAIL camp of any sort! I bent my policy of “if it ain’t broke don’t fix it” and designed two new activities, running them along with a piece on surface tension that I’ve done many times. The new activities involved microscop ..read more