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chelsea wald

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    How to Be Lucky

    It pays to imagine your life is on a winning streak.

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    The Surprising Importance of Stratospheric Life

    The science of bacteria in the atmosphere is getting its moment in the sun.

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    Is Facebook Luring You Into Being Depressed?

    Social media encourages us to follow those we envy.

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    Why Red Means Red in Almost Every Language

    The confounding consistency of color categories.

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    Why Your Brain Hates Slowpokes

    The high speed of society has jammed your internal clock.

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    When Does a Consciousness Test Not Test for Consciousness?

    A pigeon looks at its reflection in the mirror. It sees a blue dot on the reflection’s breast. It reaches down and pecks at the dot on its own breast. This is the classic behavior required for passing the “mirror test,” an influential experiment used to test for self-awareness in animals. Chimpanzees became the first […]

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    Our Cities Could Get a Whole Lot Smarter

    Pieces of SolaRoad, concrete blocks topped with solar cells, were recently installed in a bike path in Holland.SolaRoad Remember having to stay at home and wait for phone calls? (If you’re below a certain age, you can consult old movies, books, or TV shows—or just trust me on this.) It wasn’t so long ago that […]

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    5 Things That Sound, Move, or Smell Like a Nuclear Explosion

    The Licorne (“Unicorn”) thermonuclear test; Fangataufa, French Polynesia; 1970CTBTO After most of the world’s nations signed the Comprehensive Nuclear-Test-Ban Treaty, in 1996,  they set up a new commission to watch out for clandestine explosions. Since then the commission (CTBTO) has wired the world with hundreds of seismometers, infrasound detectors, radionuclide sniffers, and underwater microphones. The […]

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    What Do Animals See in a Mirror?

    A controversial test for self-awareness is dividing the animal kingdom.

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    Austria’s Ahead-of-Its-Time Institute That Was Lost to Nazis

    In 1911, Popular Science Monthly published an enthusiastic description of a young, private experimental-biology institute in Vienna, lauding its “remarkable scientific productivity resulting from only eight years of research.” The author, zoologist Charles Lincoln Edwards, attributed the success of the Biologische Versuchsanstalt (Insitute of Experimental Biology) to its many advanced experimental devices. The institute, popularly known […]