By Exploring Virtual Worlds, AI Learns in New Ways

In 2009, a computer scientist then at Princeton University named Fei-Fei Li invented a data set that would change the history of artificial intelligence. Known as ImageNet, the data set included millions of labeled images that could train sophisticated machine-learning models to recognize something in a picture. The machines surpassed human recognition...

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Mathematical Connect-the-Dots Reveals How Structure Emerges

Imagine 100 dots scattered in front of you. In a haphazard variation on connect-the-dots, start drawing lines between the points. How many lines can you draw without producing a triangle? A square? An 11-pointed star? These types of problems have a long history in mathematics. In a paper posted on April 26, Oliver Janzer and Benny Sudakov of the Swiss...

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The Spooky Quantum Phenomenon You’ve Never Heard Of

Perhaps the most famously weird feature of quantum mechanics is nonlocality: Measure one particle in an entangled pair whose partner is miles away, and the measurement seems to rip through the intervening space to instantaneously affect its partner. This “spooky action at a distance” (as Albert Einstein called it) has been the main focus of tests of...

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An Immunologist Fights Covid with Tweets and a Nasal Spray

In the United States and some other countries, the Covid-19 pandemic has entered a paradoxical stage in which the coronavirus has evolved into a highly contagious variant and sent cases soaring, but the public’s attitude has evolved toward indifference, deflating precautionary measures. Immunologists like Akiko Iwasaki of the Yale School of Medicine,...

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Surfaces So Different Even a Fourth Dimension Can’t Make Them the Same

In geometry and the closely related field of topology, adding a spatial dimension can often have wondrous effects: Previously distinct objects become indistinguishable. But a new proof finds there are some objects whose differences are so stark, they can’t be effaced with a little more space. The work, posted at the end of May, solves a question posed...

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What Is Life?

Scientists don’t really agree on a definition for life. We may recognize life instinctively most of the time, but any time we try to nail it down with set criteria, some stubborn counterexample spoils the effort. Still, can we really search for life on other worlds, or understand the earliest stages of life on this planet, if we don’t know what to look...

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Wheel Made of ‘Odd Matter’ Spontaneously Rolls Uphill

In a physics lab in Amsterdam, there’s a wheel that can spontaneously roll uphill by wiggling. This “odd wheel” looks simple: just six small motors linked together by plastic arms and rubber bands to form a ring about 6 inches in diameter. When the motors are powered on, it starts writhing, executing complicated squashing and stretching motions and...

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The Brain Has a ‘Low-Power Mode’ That Blunts Our Senses

When our phones and computers run out of power, their glowing screens go dark and they die a sort of digital death. But switch them to low-power mode to conserve energy, and they cut expendable operations to keep basic processes humming along until their batteries can be recharged. Our energy-intensive brain needs to keep its lights on too. Brain cells...

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The Computer Scientist Who Parlays Failures Into Breakthroughs

Nestled among the impressive domes and spires of Yale University is the simple office of Daniel Spielman. His shelves are lined with tall black notebooks, containing decades of handwritten notes, and against a wall sits a large, comfortable couch that looks particularly well used. “I’m sort of built for sitting still and thinking,” he admitted. What...

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Astronomers Reimagine the Making of the Planets

Start at the center, with the sun. Our middle-aged star may be more placid than most, but it is otherwise unremarkable. Its planets, however, are another story. First, Mercury: More charred innards than fully fledged planet, it probably lost its outer layers in a traumatic collision long ago. Next come Venus and Earth, twins in some respects, though...

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