Seiberg and his colleagues imagined the one-dimensional string as being surrounded by a surface, a two-dimensional plane, so that it looked like a line drawn on a sheet of paper. Instead of measuring charge along the string, they described a method for measuring the total charge across the surface surrounding the string. “The really new… Continue reading A New Kind of Symmetry Shakes Up Physics
Tag: Quantum Stuff
How Can Some Infinities Be Bigger Than Others?
The idea of infinity is probably about as old as numbers themselves, going back to whenever people first realized that they could keep counting forever. But even though we have a sign for infinity and can refer to the concept in casual conversation, infinity remains profoundly mysterious, even to mathematicians. In this episode, Steven Strogatz… Continue reading How Can Some Infinities Be Bigger Than Others?
Proteins Never Seen in Nature Are Designed Using AI to Address Biomedical and Industrial Problems Unsolved by Evolution
Machine learning (ML) and other AI- based computational tools have proven their prowess at predicting real-world protein structures. AlphaFold 2, an algorithm developed by scientists at DeepMind that can confidently predict protein structure purely on the basis of an amino acid sequence, has become almost a household name since its launch in July 2021. Today,… Continue reading Proteins Never Seen in Nature Are Designed Using AI to Address Biomedical and Industrial Problems Unsolved by Evolution
How Magnetic Fields Control Galactic Growth
The Milky Way’s rotating disk of gas and dust gives rise to graceful spiral arms, which make up the galaxy’s most active star formation sites. Now researchers using an airplane-borne telescope high in Earth’s atmosphere have found a mechanism for how magnetic fields shape star birth in the dense filaments, or “bones,” that wind their… Continue reading How Magnetic Fields Control Galactic Growth
Why the Brain’s Connections to the Body Are Crisscrossed
Dazzling intricacies of brain structure are revealed every day, but one of the most obvious aspects of brain wiring eludes neuroscientists. The nervous system is cross-wired, so that the left side of the brain controls the right half of the body and vice versa. Every doctor relies upon this fact in performing neurological exams, but… Continue reading Why the Brain’s Connections to the Body Are Crisscrossed
How Physicists Cracked a Black Hole Paradox
A few years ago a team of chemists unboiled an egg. Boiling causes protein molecules in the egg to twist around one another, and a centrifuge can disentangle them to restore the original. The technique is of dubious utility in a kitchen, but it neatly demonstrates the reversibility of physics. Anything in the physical world… Continue reading How Physicists Cracked a Black Hole Paradox
Greatest Migration on Earth Happens under Darkness Every Day
Every evening around the world trillions of zooplankton, many smaller than a grain of rice, hover hundreds of feet below the surface of the sea, waiting for their signal. Scientists long considered these tiny animals to be drifters, passive specks suspended in the ocean, moved by the whims of tides and currents. And yet, just… Continue reading Greatest Migration on Earth Happens under Darkness Every Day
The Number 15 Describes the Secret Limit of an Infinite Grid
For a first-year grad student who’d roped a big-time professor into working on his pet problem, it was an unsettling discovery. “I was horrified. I had basically been working for several months on a problem without realizing this, and even worse, I had made Marijn waste his time on it!” Subercaseaux wrote in a blog… Continue reading The Number 15 Describes the Secret Limit of an Infinite Grid
Even Machine Brains Need Sleep
We all might wish for minds as retentive as a hard drive. Memory file created. Saved. Ready for access at any time. But don’t yet go wishing for the memory performance of AI. Artificial neural networks are prone to a troublesome glitch known, evocatively, as catastrophic forgetting. These seemingly tireless networks can keep learning tasks… Continue reading Even Machine Brains Need Sleep
Tiny Jets on the Sun Power the Colossal Solar Wind
Torrents of charged particles continuously lift off the sun’s atmosphere and radiate outward at millions of kilometers per hour, yielding a solar wind so immense that its limit defines the outer edge of our solar system. Despite the vast reach of this wind, its formation has long been a puzzle. Now a new analysis argues… Continue reading Tiny Jets on the Sun Power the Colossal Solar Wind