Category: quantum mechanics

If there’s one law of physics that seems easy to grasp, it’s the second law of thermodynamics: Heat flows spontaneously from hotter bodies to colder ones. But now, gently and almost casually, Alexssandre de Oliveira Jr. has just shown me I didn’t truly understand it at all. Take this hot cup of coffee and this… Continue reading A Thermometer for Measuring Quantumness

There’s a simple story of the greenhouse effect: A blanket of carbon dioxide envelops the planet, letting sunlight in but trapping its heat. As a result, Earth warms. But how does this actually work? Carbon dioxide amounts to only a tiny smattering of gas molecules — 0.042%, or roughly 420 parts per million — in… Continue reading The Quantum Mechanics of Greenhouse Gases

As we listen to a piece of music, our ears perform a calculation. The high-pitched flutter of the flute, the middle tones of the violin, and the low hum of the double bass fill the air with pressure waves of many different frequencies. When the combined sound wave descends through the ear canal and into… Continue reading What Is the Fourier Transform?

In 2012, physicists showed that this paradox is tightly linked to the nature of the event horizon. They’d known since the 1970s that black holes emit radiation, and that this radiation probably somehow carries the scrambled information about the stuff that fell into the hole. Now they imagined what would happen if an astronaut who… Continue reading Astrophysicists Find No ‘Hair’ on Black Holes

Beneath the richness of our world lies a pristine simplicity. Everything is made of a set of just 17 fundamental particles, and those particles, though they may differ by mass or charge, come in just two basic types. Each is either a “boson” or a “fermion.” The physicist Paul Dirac coined both terms in a… Continue reading Matter vs. Force: Why There Are Exactly Two Types of Particles

The French scholar Pierre-Simon Laplace crisply articulated his expectation that the universe was fully knowable in 1814, asserting that a sufficiently clever “demon” could predict the entire future given a complete knowledge of the present. His thought experiment marked the height of optimism about what physicists might forecast. Since then, reality has repeatedly humbled their… Continue reading ‘Next-Level’ Chaos Traces the True Limit of Predictability

At the beginning of time and the center of every black hole lies a point of infinite density called a singularity. To explore these enigmas, we take what we know about space, time, gravity and quantum mechanics and apply it to a place where all of those things simply break down. There is, perhaps, nothing… Continue reading New Maps of the Bizarre, Chaotic Space-Time Inside Black Holes

As memes go, it wasn’t particularly viral. But for a couple of hours on the morning of November 6, the term “darkest timeline” trended in Google searches, and several physicists posted musings on social media about whether we were actually in it. All the probabilities expressed in opinion polls and prediction markets had collapsed into… Continue reading Do We Really Live in the Darkest Timeline?

It’s not easy to study quantum systems — collections of particles that follow the counterintuitive rules of quantum mechanics. Heisenberg’s uncertainty principle, a cornerstone of quantum theory, says it’s impossible to simultaneously measure a particle’s exact position and its speed — pretty important information for understanding what’s going on. In order to study, say, a… Continue reading ‘Quantum Memory’ Proves Exponentially Powerful