We’ve all seen ants carrying seeds, crumbs, other insects — things whose mass is a good fraction of their own. Most of us couldn’t lift things that are so heavy relative to ourselves, and so ants and many other tiny creatures have reputations for being strong. Is this justified? Answering this question brings up the … Continue reading Are Ants Really So Strong? — What is biophysics? #5
I wrote this essay for the Princeton University Press “Ideas” site as a stand-alone piece connected to my new pop-science biophysics book. It appeared yesterday, and I’m posting it here as well (with permission). DNA is stuff: physical, tangible, material. We all know this; we can even picture in our minds its famous double helical … Continue reading The Physicality of Life
The fourth in a series of biophysical questions (one, two, three). If you put your hand on your chest you’ll probably realize that your heart is a bit left-of-center. Or perhaps not: about one in 10,000 people have their heart on the right. No one’s heart lies exactly on the body’s midline, nor does anyone’s … Continue reading Why is your heart on your left side? (Or is it?) — What is biophysics? #4
The third in a series of biophysical questions (one, two). Finding food is an essential activity for any organism. We and many other animals interpret sights, sounds, and smells to make decisions about where to go or what to do to get things to eat. But what about a bacterium, a single-celled organism just a … Continue reading Can a brainless bacterium navigate? (What is biophysics? #3)
This past term (Fall 2021) I taught a course on image analysis. It was a new course — not just new for me but completely new, though it grew out of an informal image analysis class I’ve taught “off the books” before and have posted about. The class went well, though I severely underestimated how … Continue reading Image Analysis: Reflections on a New Course
Once again, my favorites of the books I read during the past year, plus some that weren’t favorites but worth noting nonetheless. (Previous posts: 2020, 2019, 2018, 2017, 2016, and 2015.) The Covid-19 pandemic continues, though halfway through 2021 we were at least allowed to browse the public library in person again, which the kids … Continue reading The Year in Books, 2021
The second in a series of biophysical questions. Proteins are molecules. As is the case for every molecule, the constituent atoms and inter-atomic bonds determine the overall shape. In general, a small or stiff molecule has a well-defined form. In contrast, long, chain-like molecules as found in plastics or the gel-formers of the last post … Continue reading What’s the shape of a protein? (What is biophysics? #2)
An introduction to the series: It’s easy to write that biophysics is the intersection of biology and physics, but this is a minimal and cryptic description. We could elaborate, and describe biophysics as the study of how living things use physical forces to shape themselves, how we can harness physical processes for technological ends, and … Continue reading How can you push DNA through Jello? (What is biophysics? #1)
A terrible question to ask in science is unfortunately quite common: Does something affect something else? It seems innocuous enough — after all, one might want to know whether exposure to sunlight affects one’s risk of skin cancer, or whether the location of the moons of Jupiter affects the stock market. The answer, however, is … Continue reading Pushed around by stars
Our microbial ecology journal club, in addition to being fun and educational, is a limitless source of data presentation examples both wonderful and terrible. Here’s a recent example that drives me up the wall. It’s from a study [1] on correlations between pre-term births and various chemicals that may or may not be associated with … Continue reading When Should You Make a Plot of p-values? Never.
The Eighteenth Elephant 