Entries by Alex Klotz

History’s First Science Experiments

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], the other by the Pharaoh Psammetichus in Egypt in the 600s BC [2]. In each case, we only have one primary source from […]

I recently defended my PhD in physics, studying confined polymer physics by squishing DNA into tubes. I have also worked on other topics, including the physics of bubbles and falling through the Earth.

Polymer Physics and Genetic Sequencing

Introduction My main research focuses on using DNA molecules to study polymer physics. Theoretical polymer physics is based on the thermodynamic behaviour of microscopic chains, but experiments examining single chain behaviour wasn’t possible until improvements in fluorescence microscopy in the 1990s allowed us to visualize the dynamics of DNA molecule in real time. DNA makes […]

I recently defended my PhD in physics, studying confined polymer physics by squishing DNA into tubes. I have also worked on other topics, including the physics of bubbles and falling through the Earth.

The Interaction of Sound and Light

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 […]

I recently defended my PhD in physics, studying confined polymer physics by squishing DNA into tubes. I have also worked on other topics, including the physics of bubbles and falling through the Earth.

Roger Babson’s Anti-Gravity Contest

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 […]

I recently defended my PhD in physics, studying confined polymer physics by squishing DNA into tubes. I have also worked on other topics, including the physics of bubbles and falling through the Earth.

The Basics of Positron Emission Tomography (PET)

People often ask about the 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 […]

I recently defended my PhD in physics, studying confined polymer physics by squishing DNA into tubes. I have also worked on other topics, including the physics of bubbles and falling through the Earth.

Secondary Forces Explored

Many are familiar with the “fundamental forces” of nature: gravity, electromagnetism, and the strong and weak nuclear forces. Three of these have a tendancy 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 […]

I recently defended my PhD in physics, studying confined polymer physics by squishing DNA into tubes. I have also worked on other topics, including the physics of bubbles and falling through the Earth.

All about Earth’s Gravity

Earth’s gravitational field at the surface is approximately 9.8 Newtons/kilogram, or equivalently, 9.8 meters/second/second. But how does that change due to its shape, rotation, and composition and various locations along its surface and within its interior? This article will answer those questions. Latitude dependence due to Earth’s shape and rotation One can simply calculate the […]

I recently defended my PhD in physics, studying confined polymer physics by squishing DNA into tubes. I have also worked on other topics, including the physics of bubbles and falling through the Earth.

The Speed of Light and Galilean Relativity

Introduction In this article I will discuss some experiments in the 19th and early 20th centuries that looked 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 well […]

I recently defended my PhD in physics, studying confined polymer physics by squishing DNA into tubes. I have also worked on other topics, including the physics of bubbles and falling through the Earth.

Atomic Positioning with DNA Hinges

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 […]

I recently defended my PhD in physics, studying confined polymer physics by squishing DNA into tubes. I have also worked on other topics, including the physics of bubbles and falling through the Earth.

Fun with Self-Avoiding Walks

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; […]

I recently defended my PhD in physics, studying confined polymer physics by squishing DNA into tubes. I have also worked on other topics, including the physics of bubbles and falling through the Earth.

Can We See an Atom?

If you look on the internet for pictures of atoms, you will see images like this: Or like this: Or like this: In this article I will discuss how these images are made, what exactly we are looking at, and what it really means to see an atom. See with your eyes. The answer to […]

I recently defended my PhD in physics, studying confined polymer physics by squishing DNA into tubes. I have also worked on other topics, including the physics of bubbles and falling through the Earth.

Explosion-Generated Collapsing Vacuum Bubbles Reach 20,000 Kelvin

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 inside the […]

I recently defended my PhD in physics, studying confined polymer physics by squishing DNA into tubes. I have also worked on other topics, including the physics of bubbles and falling through the Earth.

A Hand-Wavy Discussion of the Planck Length

The Planck length is an extremely small distance constructed from physical constants. There are a lot of misconceptions that generally overstate its physical significance, for example, stating that it’s the inherent pixel size of the universe. The Planck length does have physical significance, and I’ll talk about what it is, and what it isn’t. What […]

I recently defended my PhD in physics, studying confined polymer physics by squishing DNA into tubes. I have also worked on other topics, including the physics of bubbles and falling through the Earth.

Scaling Laws and the Speed of Animals

In a recent issue of the American Journal of Physics, I read an interesting paper by Nicole Meyer-Vernet and Jean-Pierre Rospars examining the top speeds of organisms of varying sizes, from bacteria up to blue whales. They found that the time it takes for an animal to move its own body length is almost independent of […]

I recently defended my PhD in physics, studying confined polymer physics by squishing DNA into tubes. I have also worked on other topics, including the physics of bubbles and falling through the Earth.