Physics in a nutshell

Electromagnetism is the training ground for modern physics, both in its historical development and in classrooms today. It is the simplest of the four forces, compared to the nuclear weak force, nuclear strong force and gravitation, but it gives rise to intricately rich patterns. All of the complex phenomena of everyday life, except for gravity and radioactivity, are due to the workings of electromagnetism. It makes chemical bonds, forming the basis of life, gives structure to solid and liquid matter,…

At the subatomic level, forces appear because one matter particle emits a force particle. When you throw a heavy sack off a boat, the boat recoils. Similarly, when one particle emits another one, the original particle recoils (moves). This is fundamentally how forces work at the subatomic level. Image courtesy of Dan Claes Read the complete column on subatomic forces. Particle physicists explore the subatomic realm, which consists of quarks, leptons and the four forces that govern them. These forces…

At the subatomic level, forces appear because one matter particle emits a force particle. When you throw a heavy sack off a boat, the boat recoils. Similarly, when one particle emits another one, the original particle recoils (moves). This is fundamentally how forces work at the subatomic level. Image courtesy of Dan Claes Particle physicists explore the subatomic realm, which consists of quarks, leptons and the four forces that govern them. These forces are the strong nuclear force, the electromagnetic…

A beam of particles is like a shower of arrows— the probability of any one hitting the target depends on their cross-sectional area and the space between them. Sometimes, everyday words are co-opted by scientists and used as technical terms. One of these is the word “berry.” Talking to a botanist friend of mine, I learned that tomatoes are berries, but strawberries are not—the scientific meaning of a berry has more to do with the reproductive structures of the plant…

If you magnify an extended particle, it will look bigger. A point-like particle will not change in size, but the more closely you look at it, the stronger the field surrounding it becomes. The field of particle physics is full of what can be confusing dichotomies: fermion vs. boson, hadron vs. lepton, paper vs. plastic (okay, not that last one). You can add yet another to the list: extended particles vs. point-like particles. The quarks, leptons and bosons of the…

Quantum foam

The foam on a head of root beer is a complicated environment, with bubbles appearing and disappearing in a dizzying display of change. Empty space experiences similar activity, with subatomic particles winking in and out of existence. These ephemeral subatomic particles are real and have a measurable impact on our universe. Modern physics deals with some ridiculously non-intuitive stuff. Objects act as though they gain mass the faster they move. An electron can’t decide if it’s a particle, a wave…

In some Civil War battles, the shooting was dense enough and prolonged enough for bullets to collide. The atoms of the metal bullets redistributed themselves as a liquid, much like the quarks and gluons of heavy ion collisions. Image source: brotherswar.com In most particle physics experiments, physicists attempt to concentrate as much energy as possible into a point of space. This allows the formation of new, exotic particles like Higgs bosons that reveal the basic workings of the universe. Other…

GUTs and TOEs

GUTs and TOEs may sound like funny looking body parts, but for scientists, they are acronyms for Grand Unified Theories and Theories of Everything. These theories aspire to unify all of physics into a single idea. Let’s talk about GUTs. No, I’m not talking about that extra weight you put on when you visited your mom over the holidays. I’m talking about nothing less than the ultimate goal of all Fermilab physicists. I’m talking about a Grand Unified Theory. There…

If we represent electron neutrinos (νe), muon neutrinos (νμ), and tau neutrinos (ντ) by pure red, pure green and pure blue, respectively, the three neutrino mass states (ν1, ν2 and ν3) would be fuchsia, lime and periwinkle, a mixture of the primary colors. Quantum mechanics is an everyday fact of life for particle physicists. Most particles are short-lived and decay before they can be directly observed, and the weirdest quantum shenanigans are perpetrated by systems that can’t be observed. Neutrinos…

Hadron? Baryon? Meson? What’s what? Who’s who? And why do physicists insist on tacking the suffix “on” onto the name of just about every particle they encounter? Unlike the NFL, it is common in high-school football that a team’s jerseys won’t have the players’ names emblazoned on the back. That can make watching a game very confusing for the casual spectator. While the experts know who is who without thinking, the casual spectator can easily lose track of which player…