## How Big Data Carried Graph Theory Into New Dimensions

Graph theory isn’t enough. The mathematical language for talking about connections, which usually depends on networks—vertices (dots) and edges (lines connecting them)—has been an invaluable way to model real-world phenomena since at least the 18th century. But a few decades ago, the emergence of giant data sets forced researchers to expand their toolboxes and, at […]

## How to Ace Physics Class (Even if You Don’t Ace Physics)

Let me give a real-world example. Once my class was working on the momentum principle, which gives a relationship between the net force on an object and that object’s change in momentum. (Momentum is the product of mass and velocity.) It’s a super useful principle and used in a lot of different ways. A student […]

## Animals Can Count. How Far Does Their Number Sense Go?

One explanation for the same neural framework evolving in such different brains is simply that it’s an efficient solution to a common computational problem. “It’s actually exciting, because it suggests that it’s just the best way,” Avarguès-Weber said. Maybe there are physical or other internal constraints on how the brain can process zero and other […]

## The Physics of Johnny Knoxville, Human Cannonball

The important thing is that this is the equation of a parabola. Looking back at the vertical position data from the video, it at least seems fairly parabolic. Even better, the coefficient in front of the t2 term should be the acceleration divided by two. Using the parabolic fit, this gives a vertical acceleration of […]

## Gymnasts Make the Wolf Turn Look Easy. Physics Shows It’s Not

Yes, this is just an image—but it’s really balanced. If you run the code, you can see that it is indeed stationary and doesn’t tip over. It seems pretty clear that it should work—I mean, we humans do this all the time in order to stay upright. Spinning About an Axis of Rotation If the […]

## A Failed Star Called ‘The Accident’ Puzzles Astronomers

Dan Caselden was up late on November 3, 2018, playing the video game Counter-Strike, when he made astronomy history. Every time he died, he would jump on his laptop to check in on an automated search he was running of NASA space telescope images. Suddenly, in the early hours of the morning, something bizarre popped […]

## How Did People Find the Fundamental Charge With Drops of Oil?

Right now, you can probably just ask your smartphone to tell you the charge of a single electron—the fundamental unit of charge. (It has a magnitude of 1.6 x 10–19 coulombs, the common unit for electric charge.) But in 1909, things weren’t so simple. Back then, physicists Robert Millikan and Harvey Fletcher figured it out […]

## Why Even the Fastest Human Can’t Outrun Your House Cat

This weekend, the fastest sprinters on the planet came together at the Tokyo Olympics to compete for the gold in the 100-meter dash. Lamont Marcell Jacobs crossed the finish line in 9.80 seconds to bring Italy its first gold in the event. In the women’s race, Jamaica won the gold, silver, and bronze—a clean sweep […]

## Fractons, the Weirdest Matter, Could Yield Quantum Clues

Your desk is made up of individual, distinct atoms, but from far away its surface appears smooth. This simple idea is at the core of all our models of the physical world. We can describe what’s happening overall without getting bogged down in the complicated interactions between every atom and electron. So when a new […]

## The Incredible Physics of Simone Biles’ Yurchenko Double Pike

Gymnastics is an extremely difficult sport, and not just extreme for Olympic athletes like five-time (so far) medalist Simone Biles. The physics is also quite challenging. Let’s consider something seemingly simple, like a flip. There will be some version of a flip in all four of the women’s gymnastics events: floor, bars, vault, and beam. […]

## What Causes Gamma-Ray Bursts? Their ‘Afterglows’ Hold Clues

In July 1967, at the height of the Cold War, American satellites that had been launched to look for Soviet nuclear weapons tests found something wholly unexpected. The Vela 3 and 4 satellites observed brief flashes of high-energy photons, or gamma rays, that appeared to be coming from space. Later, in a 1973 paper that […]

## How to Prepare for the Robot Apocalypse (If You’re a Robot)

Since we know the height is 128 stories, and one story in a typical building equals 3.3 meters, then I can find the number of hex pods that will stack up in the inverted V. But that leaves a question: How many layers of hex pods would you need for all 1.14 billion pods? OK, […]

## Mathematicians Prove Symmetry of Phase Transitions

The presence of conformal invariance has a direct physical meaning: It indicates that the global behavior of the system won’t change even if you tweak the microscopic details of the substance. It also hints at a certain mathematical elegance that sets in, for a brief interlude, just as the entire system is breaking its overarching […]

## Mathematicians Prove a 2D Version of Quantum Gravity Works

It’s an elegant idea that yields concrete answers only for select quantum fields. No known mathematical procedure can meaningfully average an infinite number of objects covering an infinite expanse of space in general. The path integral is more of a physics philosophy than an exact mathematical recipe. Mathematicians question its very existence as a valid […]

Blackstreet’s “No Diggity” kicks off the virtual mixer as people excitedly connect in the Zoom chat. “Love the vibe right now,” says Brionna Davis-Reyes in appreciation of both the DJ and the sign language interpreter, who is also doubling as a background dancer. Davis-Reyes introduces herself as a Yale neuroscientist studying addiction and impulsivity. She’s […]

## How Underground Fiber Optics Spy on Humans Moving Above

When last spring’s lockdown quieted the Penn State campus and surrounding town of State College, a jury-rigged instrument was “listening.” A team of researchers from the university had tapped into an underground telecom fiber optic cable, which runs two and half miles across campus, and turned it into a kind of scientific surveillance device. By […]

## How to Break Into the Hex From ‘WandaVision’—With Physics!

I’m a huge fan of both science and the Marvel Cinematic Universe, so it’s awesome when these two collide. That’s exactly what happened in Episode 5 of WandaVision. Here is my super basic introduction to WandaVision for those of you that haven’t seen it. Wanda is a superhero with magical powers that allow her to […]

## Ranked Choice Voting Reveals the Weird Math of Elections

On the first day of class, Daniel Ullman—a mathematician at George Washington University—has his students run an exercise. Ullman presents a hypothetical three-way election, with candidates designated as A, B, and C vying for the win. Then he gives his students 99 voter profiles. This one prefers A over B and B over C. The […]

## No, Covid-19 Vaccines Won’t Make You Magnetic. Here’s Why

So, how do you make it happen? Simple: You use another magnet. Putting a strong magnet near those unaligned domains will force them to line up. It’s actually possible to find rocks in the ground that are both ferromagnetic and have their domains aligned. We call these lodestones. They may have been magnetized by the […]

## The Mystery at the Heart of Physics—That Only Math Can Solve

“It’s totally boring, because you’ve described a lonely field with nothing to interact with, so it’s a bit of an academic exercise,” said Rejzner. But you can make it more interesting. Physicists dial up the interactions, trying to maintain mathematical control of the picture as they make the interactions stronger. This approach is called perturbative […]