Tag: Quantum Stuff

Conserved physical quantities should not vary, or appear to do so, based on how we choose to label things. That was the situation that Chen, Wang, Wang, and Yau hoped to rectify. Starting with their 2015 definition of quasilocal angular momentum, they computed the angular momentum contained within a region of finite radius. Then they… Continue reading Mass and Angular Momentum, Left Ambiguous by Einstein, Get Defined

In November 2020, the GOP tweeted a C-SPAN clip of Trump campaign lawyer Sidney Powell saying, “President Trump won by a landslide. We are going to prove it.” It was retweeted over 22,000 times and still hasn’t been deleted. Powell’s claim, of course, was not true. Biden officially won the election. Currently the Select Committee… Continue reading Don’t Give Up on Facts

How can anyone speak with certainty about infinity? What can we really know about the mysterious prime numbers without knowing all of them? Just as scientists need data to assess their hypotheses, mathematicians need evidence to prove or disprove conjectures. But what counts as evidence in the intangible realm of number theory? In this episode,… Continue reading How Do Mathematicians Know Their Proofs Are Correct?

In 1850, Thomas Penyngton Kirkman, a mathematician when he wasn’t fulfilling his main responsibility as a vicar in the Church of England, described his “schoolgirl problem”: “Fifteen young ladies in a school walk out three abreast for seven days in succession: it is required to arrange them daily, so that no two shall walk twice… Continue reading Hypergraphs Reveal Solution to 50-Year-Old Problem

President Biden used his first State of the Union address to reset his administration after a year of inflation and crises at home and abroad that has left him with nearly record-low approval ratings. But Biden did little to restart his stalled climate agenda. He spoke only briefly about climate change—talking about it roughly as… Continue reading What Biden Said—and Didn’t Say—on Climate during the State of the Union

Explore A gulp of air, a kick of flippers, and the elephant seal dives. Sunlight slants through the Southern Ocean’s melting roof of sea-ice, its solid dome shattered by the arrival of Antarctic summer. The seal—Mirounga, we’ll call her—descends many times each day to snatch fish and squid in her toothy jaws; she spends 90… Continue reading What Oceanographers Can Learn From Their Animal Colleagues

Inside, the office is spare, pragmatic: just a computer, printer, chalkboard, papers and books, with few personal effects. The place where the magic happens seems not so much a physical location in space-time as a higher-dimensional world of abstractions in Viazovska’s mind. Across the small table in her office, the world’s preeminent sphere-packing number theorist… Continue reading Ukrainian Mathematician Maryna Viazovska Wins Fields Medal

One question for Lee McIntyre, research fellow at the Center for Philosophy and History of Science at Boston University. McIntyre is the author of The Scientific Attitude: Defending Science from Denial, Fraud, and Pseudoscience, and How to Talk to a Science Denier. How do we get people who believe in pseudoscience to trust science? We… Continue reading How Do We Get People Who Believe in Pseudoscience to Trust Science?

Ever since it was approved in 2000 as an abortion pill, mifepristone has been regulated as if it were a dangerous substance. The U.S. Food and Drug Administration required doctors to be specially certified to prescribe it. Patients had to sign an agreement confirming that they had been counseled on its risks. Most onerously, the… Continue reading Abortion Pills Are Very Safe and Effective, yet Government Rules Still Hinder Access