Quanta Magazine

When I was first learning to write, my letters and words ran from right to left, reversed as if in a mirror. Being left-handed, I was imitating the hand strokes of my right-handed teachers instead of reversing their strokes to replicate the letters. I gradually got the hang of writing in the correct direction, but it still feels natural for me to mirror-write. I have a mirror-written childhood diary. Leonardo da Vinci, another lefty, did that too. Being left-handed is mostly no big deal.

Thamires Lima, a research professor in chemical engineering at Drexel University, studies the properties of thick, viscous liquids — think honey or molasses, though in a lab you’re more likely to find polypropylene or crude oil. Using a method called extensional rheology, Lima stretches liquids between metal plates to find the force that makes them flow.

Does intelligent life exist elsewhere in the universe? The question has captivated us for centuries, but despite decades of searching it remains frustratingly unanswered. Every so often a curious signal appears — fossilized structures in a meteorite, say, or an unusual gas in an exoplanet’s atmosphere — and for a moment it seems possible that we are not alone before the excitement gives way to a more mundane explanation.

In 1993, a team led by the planetary scientist Carl Sagan tentatively concluded that there is life on Earth. Not much of a deduction, you might think — except that the researchers confined their evidence to observations made by the Galileo spacecraft, which had flown past our planet three years earlier on a looping journey to Jupiter. So great is the transformative power of life that its presence can be detected just from the light and radio waves our planet emits or reflects into space.

Ada Zejun Shen/Quanta Magazine Introduction More than 30 years ago, researchers discovered that hypothetical computers based on the laws of quantum physics would be able to rapidly solve difficult math problems. Ever since then, they’ve sought to pinpoint cases where quantum computers are more powerful than their ordinary “classical” cousins.

Kristina Armitage/Quanta Magazine Introduction When Charlotte Mason ponders cosmic mysteries, she likes to doodle. “I am quite a visual person,” she said. “I usually draw a lot of pictures trying to understand what’s going on.” Mason, an astrophysicist at the Cosmic Dawn Center in Copenhagen, has lately been filling pages with sketches of “little red dots,” perplexing objects discovered by the hundreds in images from the James Webb Space Telescope (JWST).

For the very first time, biologists packed nonliving components into a cell-like membrane, piece by piece, and witnessed the bag of molecules start to behave like life. The lab-made synthetic cell grew, replicated its DNA, and divided, demonstrating the basic functions of a cell cycle. It’s “an impressive step,” said Jack Szostak, who studies the origins of life at the University of Chicago and was not involved in the research.

As the mitotic spindle tightens to separate chromosomes during cell division, it produces and absorbs forces. Ada Zejun Shen/Quanta Magazine Introduction The cells of animals, plants, and fungi start their lives by being torn apart. Cells are born by division, and just before a parent cell becomes two daughters, it doubles its nuclear DNA and carefully condenses it into X-shaped chromosomes.

In 1947, Paul Erdős, the itinerant Hungarian mathematician, introduced what would become one of math’s most powerful tools. He wanted to prove that a certain kind of object existed — in this case, a network made of interconnected nodes. But strangely, his proof didn’t specify how to build it. Instead, he showed that if you consider all networks and select one at random, the chances that you’ll find a network with the property you want is greater than zero.

Chanelle Nibbelink for Quanta Magazine Introduction What links certain mathematical models of traffic flow, shallow-water waves, and quantum particle scattering? The surprising answer lies in a corner of the algebraic combinatorics world that goes by the name of positive Grassmannian. In simple terms, the positive Grassmannian is a shape that classifies other shapes.