Can You Use an Infrared Camera to Detect a Fever?

It turns out that the highest-intensity wavelength produced—the peak in the curve above—depends on the temperature of the object. As it gets hotter, the wavelength of peak emission decreases—it moves to the left, back towards the visible spectrum. So for something at room temperature (like 300 Kelvin), this peak wavelength is about 9.7 μm (micrometers). […]

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Death Cuts the Degree of Separation Between You and Covid-19

One of the first things they teach wannabe epidemiologists is the shape of the exponential growth curve—how epidemics spread slowly at first, and then take off like a rocketship as the numbers of infected people double, double, and double. But unless you’re actually fighting an outbreak, or are in one, that can all feel academic. […]

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After 50 Years of Effort, Researchers Made Silicon Emit Light

Within the wafer, the silicon atoms are arranged as a cubic crystal lattice that allows electrons to move within the lattice under certain voltage conditions. But it doesn’t allow similar movement for photons, and that’s why light can’t move through silicon easily. Physicists have hypothesized that changing the shape of the silicon lattice so that […]

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Why Do Matter Particles Come in Threes?

The universe has cooked up all sorts of bizarre and beautiful forms of matter, from blazing stars to purring cats, out of just three basic ingredients. Electrons and two types of quarks, dubbed “up” and “down,” mix in various ways to produce every atom in existence. Original story reprinted with permission from Quanta Magazine, an […]

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Where Did Plants Come From? This Ancient Algae Offers Clues

Andrew Knoll, a professor of natural history at Harvard University, expressed similar reservations. “It is quite possible that the fossils reflect an extinct, early branching group,” he said in an email. “Various forms of multicellularity have evolved repeatedly within the greens, so such an interpretation isn’t a stretch.” The evolutionary innovations seen in Tang’s fossil […]

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How to See the World’s Reflection From a Bag of Chips

However, some experts caution that future versions of the technology are ripe for abuse. For example, it could enable stalkers or child abusers, says ethicist Jacob Metcalf of Data & Society, a nonprofit research center that focuses on the social implications of emerging technologies. A stalker could download images off of Instagram without the creators’ […]

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Physicists Chip Away at a Mystery: Why Does Glass Exist?

If ultra-stable glass’s exceptionally low heat capacity really does come from having fewer two-level systems, then ideal glass naturally corresponds to the state with no two-level systems at all. “It’s just perfectly, somehow, positioned where all the atoms are disordered—it doesn’t have a crystal structure—but there’s nothing moving at all,” said David Reichman, a theorist […]

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Two Physicists Bet Over a Quantum Computing Moon Shot

In February, two physicists made a bet on Twitter. Jonathan Dowling, a professor at Louisiana State University, and John Preskill of Caltech wagered a pizza and a beer over whether 10 years from now, someone will have finally invented a machine of longtime physics fantasy: the so-called topological quantum computer. Preskill bet yes; Dowling bet […]

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A Computer Science Proof Holds Answers for Math and Physics

After Turing, computer scientists began to classify other problems by their difficulty. Harder problems require more computational resources to solve — more running time, more memory. This is the study of computational complexity. Ultimately, every problem presents two big questions: “How hard is it to solve?” and “How hard is it to verify that an […]

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Science Has a New Way to Gauge the Universe’s Expansion Rate

The catch is that directly measuring the Hubble constant is very tricky. To do so, astronomers like Riess and Freedman must first find and calibrate “standard candles”: astronomical objects that have a well-known distance and intrinsic brightness. With these values in hand, they can infer the distances to standard candles that are fainter and farther […]

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Katherine Johnson’s Math Will Steer NASA Back to the Moon

Katherine Johnson blazed trails, not just as a black female mathematician during the Cold War, but by mapping literal paths through outer space. Her math continues to carve out new paths for spacecraft navigating our solar system, as NASA engineers use evolved versions of her equations that will execute missions to the moon and beyond. […]

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