Physics – Quanta Magazine

Seventy years ago, the physicists Clyde Cowan and Frederick Reines took a custom-built 10-ton detector, surrounded it with thick lead walls and wet sandbags, and placed it near a powerful nuclear reactor at the Savannah River Plant in South Carolina. They called the experiment “Project Poltergeist,” designed as it was to catch a ghost. More than a quarter of a century before…...

For those who see the world as a dark place, the universe seems to offer little solace. According to current estimates, approximately 70% of the stuff that makes up the cosmos consists of dark energy, an unknown force that pushes space to expand. And another 25% consists of dark matter, a mysterious material that holds galaxies together. But semantically speaking, dark energy...

Every time I write about particle physics, I encounter a moment of uncertainty about a quantity that, at first glance, ought to be clear. How many kinds of elementary particles should I say there are? In experiments at the Large Hadron Collider, physicists smash together beams of protons, breaking them up into all possible elementary bits and pieces. Meanwhile, they have an i...

At this moment, a spacecraft is headed from Earth to Europa, an ice-veiled moon of Jupiter thought to contain an ocean similar in some ways to one of our own. NASA engraved a metal plate affixed to the spacecraft with a poem, commissioned from Ada Limón during her time as poet laureate of the United States. It reads, in part: And it is not darkness that unites us, not the col...

In 1973, John Archibald Wheeler described the relationship between space and matter in two sentences: “Space acts on matter, telling it how to move. In turn, matter reacts back on space, telling it how to curve.” Wheeler’s words serve as a pithy encapsulation of general relativity, Albert Einstein’s theory of gravity. Wheeler’s sentences also lay out a challenge that theorist...