Ph.D. McGill University, 2015
My research is at the interface of biological physics and soft condensed matter. I am interested in using tools provided from biology to answer questions about the physics of soft materials. In the past I have investigated how DNA partitions itself into small spaces and how knots in DNA molecules move and untie. Moving forward, I will be investigating the physics of non-covalent chemical bonds using "DNA chainmail" and exploring non-equilibrium thermodynamics and fluid mechanics using protein gels.
Paper discussion: Solar system expansion and strong equivalence principle as seen by the NASA MESSENGER mission. Antonio Genova, Erwan Mazarico, Sander Goossens, Frank G. Lemoine, Gregory A. Neumann, David E. Smith & Maria T. Zuber. Nature Communications volume 9, Article number: 289. Students of physics learn some interesting facts about the sun, spread over different lessons and…
Macromolecules A joint computational-experimental paper that I worked on was just published in MacroLetters, a journal that covers all topics relating to macromolecules (polymers and the like). In it, we looked at simulations of knotted polymer chains being stretched by an external flow field and studied how the knot affected the response of the polymer…
A new paper from a collaboration of Canadian physicists has demonstrated how simply twirling a wire through a solution of DNA molecules can align the molecules around the wire, similar to the way that twirling a fork can align noodles around it. The paper was published in Physical Review X (PRX), an open-access journal that…
This article won’t contain much about physics that typical readers of this site don’t already know. However, deconstructing improper physics in literature and film can be a good exercise for physics teachers to share with their students. I’ll focus on one story, in particular, Edmond Hamilton’s The Second Satellite. Just for a bit of context, I’ll…
In this Insight, I’m going to talk about two of the first science experiments in recorded history. One was allegedly performed by the Prophet Elijah in Israel in the 800s BC [1], and the other by the Pharaoh Psammetichus in Egypt in the 600s BC [2]. In each case, we only have one primary source…
Introduction My main research focuses on using DNA molecules to study polymer physics. Theoretical polymer physics is based on the thermodynamic behavior of microscopic chains, but experiments examining single-chain behavior weren’t possible until improvements in fluorescence microscopy in the 1990s allowed us to visualize the dynamics of DNA molecules in real time. DNA makes a…
I recently wrote a post on my blog about a fairly esoteric idea regarding sound propagating through light. This inspired me to write an article about the more down-to-earth interactions between light and sound. Light is a transverse electromagnetic wave and sound is a longitudinal density wave through a medium, and it’s generally taught that they…
In the early 20th century, an eccentric businessman named Roger Babson declared gravity to be mankind’s greatest threat. He devoted part of his fortune to defeating it, creating the Gravity Research Foundation which sponsors a yearly essay contest focused on the understanding of gravity. This contest has been won by the likes of Stephen Hawking…
Practical applications of fundamental theoretical physics Less often, people ask about potential applications of anti-matter. Both of those questions can be answered with a common medical diagnostic technology, Positron Emission Tomography, or PET. Positrons were first theorized by Paul Dirac in 1928 when he realized that his equation describing the electron admitted solutions for particles with…
Many are familiar with the “fundamental forces” of nature: gravity, electromagnetism, and the strong and weak nuclear forces. Three of these tend to bind things together in stable ways: as orbits, as atoms, or as nucleons. Once these systems are stable, there are still “residual” effects that the objects can have on one another through…
Earth’s gravitational field at the surface is approximately 9.8 Newtons/kilogram or 9.8 meters/second/second. But how does that change due to its shape, rotation, composition, and various locations along its surface and interior? This article will answer those questions. Latitude dependence due to Earth’s shape and rotation One can simply calculate the centripetal acceleration at Earth’s…
Introduction In this article, I will discuss some experiments in the 19th and early 20th centuries that looked at how the velocity of a light source affects the speed of the light emitted from it. In particular, the Fizeau water experiment, the de Sitter double star experiment, and the Michelson-Morley experiment, which is the most…
I was perusing the Nature Nanotechnology website today when I came across an interesting article by Funke and Dietz, called “Placing molecules with Bohr radius resolution using DNA origami.” The authors created a hinge out of DNA which they selectively open or close by varying the length of one of the DNA molecules, which allows…
This post is about some simulations I did of self-avoiding random walks. These are what they sound like with each step, the position of the walk moves randomly, with the constraint that it can’t visit the same spot more than once. These are mathematically somewhat interesting and crop up in a few areas of physics;…
In this article, I will discuss how these images of atoms are made, what exactly we are looking at, and what it means to see an atom. Over the decades there have been many attempts, claims, and misconceptions surrounding what atoms look like and how we can photograph them. Let’s set that all straight below!…
In a recent paper published in Physical Review Letters (PRL), one of the top physics journals, Jérôme Duplat and Emmanuel Villermaux developed a method to generate centimeter-sized vacuum bubbles in water with miniature laser-driven explosions and observed the flash of light produced as the bubble collapsed, a not-fully-understood phenomenon known as sonoluminescence. They measured the temperature…
The Planck length is an extremely small distance constructed from physical constants. Many misconceptions generally overstate its physical significance, stating that it’s the inherent pixel size of the universe. The Planck length does have physical significance, and I’ll discuss what it is and what it isn’t. What is the Planck Length? Planck units are defined…
Introduction In a recent American Journal of Physics issue, I read an interesting paper by Nicole Meyer-Vernet and Jean-Pierre Rospars examining the top speeds of organisms of varying sizes, from bacteria to blue whales. They found that the time it takes for an animal to move its body length is almost independent of mass, across…