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. Key Points Students of physics learn about the sun‘s gravitational influence, which causes planets to…
Polymer Key Points The published paper studied how knots in polymers respond to an external flow field and how the knot affects the response of the polymer Experiments and simulations of knotted polymer chains being stretched by an extensional flow field The coil–stretch transition occurs when the flow is weak enough for the molecule to…
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. Second Satellite Key Points The article focuses…
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…
Polymer Key Points DNA is a good model system for polymer physics as it is small enough to observe single–molecule dynamics and large enough to be thermodynamically driven When DNA is coiled in the cell nucleus, it has no direct correlation between spatial position and genetic position When stretched out in a nanochannel, there is…
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…
PET Key Points Paul Dirac first theorized positrons in 1928 and they were observed four years later by Carl Anderson. Positron Emission Tomography (PET) was developed in the 1950s–1980s as a medical diagnostic technology. PET works by administering a radioactive isotope, Fluorine–18, to the patient and detecting the positron emission and the subsequent gamma photons….
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. Earth’s Gravity Key Points Earth’s gravitational field at the surface is approximately 9.8 Newtons/kilogram. The deviation in…
Speed of Light Key Points Early experiments attempted to measure the speed of light, including Galileo‘s lantern experiment, Ole Rømer‘s eclipse experiment, and James Bradley‘s stellar aberration experiment. Hippolyte Fizeau was the first to accurately measure the speed of light with his cogwheel and water experiments. The Fizeau water experiment showed that light velocity is…
DNA Hinge Key Points Funke and Dietz created a DNA hinge which is adjustable by varying the length of one of the DNA molecules, allowing positioning of molecules attached to the hinge by as little as 0.04 nanometers. DNA origami was one of the first successful methods of “bottom–up” nanotechnology, allowing structures such as cubes,…
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!…
Key Points Jérôme Duplat and Emmanuel Villermaux published a paper in Physical Review Letters (PRL) to generate centimeter–sized vacuum bubbles in water with miniature laser–driven explosions Observed the flash of light produced as the bubble collapsed, a phenomenon known as sonoluminescence Measured the temperature inside the bubble to be upwards of 20,000 Kelvin Bubbles generated by…
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. Key Points The Planck length is a distance constructed…
Key Points Scaling arguments are powerful tools in physics between vague descriptive arguments and rigorous formulae. Examples of scaling arguments include the Square–Cube Law and Terminal Velocity. A paper by Nicole Meyer–Vernet and Jean–Pierre Rospars examines the top speeds of organisms of varying sizes from bacteria to blue whales. The paper finds that the time…