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,
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
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
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
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
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
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
“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.