• The FDA Asks Companies to Stop Selling Ranitidine

    With its promise of taming the ravages of stomach acid, ranitidine—best known under the brand name Zantac—was counted among the agents of pharmaceutical salvation, the enduring and reliable drugs that treat intractable diseases and make daily life more tolerable. In 1987, Zantac became the most-prescribed drug in the world.

    But last week ranitidine was essentially erased from the US market. The US Food and Drug Administration asked manufacturers to withdraw ranitidine products, both in prescription and over-the-counter forms, because of an “impurity” in the pharmaceutical compound. Over time or in the presence of heat, ranitidine can form unacceptable levels of a probable carcinogen known as N-nitrosodimethylamine, or NDMA, the agency determined.

    “We didn’t observe unacceptable levels of NDMA in many of the samples that we tested. However, since we don’t know how or for how long the product might have been stored, we decided that it should not be

  • The US Hitches Its Final Ride to Space From Russia—for Now

    On Thursday, a Soyuz rocket carrying three astronauts to the International Space Station is scheduled to depart from the Baikonur Cosmodrome in the Kazakhstan desert. The coronavirus pandemic means there won’t be the usual crowds of wellwishers lining the streets to see the astronauts on their way, but the flight is a historic one. It marks the end of NASA’s dependence on Russian rockets for human spaceflight and the return of crewed launches to the United States. But NASA says American astronauts may still end up hitching rides to space in a Soyuz capsule in the future.

    Ever since NASA called it quits on its space shuttle program in 2011, the Russian spaceport has been the only facility operating crewed flights outside of China. But that’s about to change. SpaceX is preparing for its first crewed NASA mission to the space station, which could launch from Florida by the

  • Why Does Covid-19 Make Some People So Sick? Ask Their DNA

    SARS-CoV-2, the pandemic coronavirus that surfaced for the first time in China last year, is an equal opportunity invader. If you’re a human, it wants in. Regardless of age, race, or sex, the virus appears to infect people at the same rate. Which makes sense, given that it’s a totally new pathogen against which approximately zero humans have preexisting immunity.

    But the disease it causes, Covid-19, is more mercurial in its manifestations. Only some infected people ever get sick. Those who do experience a wide range of symptoms. Some get fever and a cough. For others it’s stomach cramps and diarrhea. Some lose their appetite. Some lose their sense of smell. Some can wait it out at home with a steady diet of fluids and The Great British Baking Show. Others drown in a sea of breathing tubes futilely forcing air into their flooded lungs. Old people,

  • The Deliciously Surprising Science of Taste

    It’s one of the world’s most famous maps, along with that of the New York City subway system and the one for the Game of Thrones world: the map of your tongue. You probably saw it in high school, and learned that your loquacious mouth muscle is neatly divided into sections responsible for tasting sweet, sour, salty, and bitter.

    You learned very wrong.

    The myth of the taste map goes back to the early 1900s and a German scientist named David Hänig, whose experiments found that the tongue is particularly sensitive to tastes along the edges, and not so much at the center. Which is true—modern science backs that up. “But this has been converted down the years into a more extreme version of the taste map that says sweet is at the front of the tongue, bitter is at the back, and salty and sour at the sides,”

  • 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 editorially independent publication of the Simons Foundation whose mission is to enhance public understanding of science by covering research develop­ments and trends in mathe­matics and the physical and life sciences.

    But puzzlingly, this family of matter particles—the up quark, down quark, and electron—is not the only one. Physicists have discovered that they make up the first of three successive “generations” of particles, each heavier than the last. The second- and third-generation particles transform into their lighter counterparts too quickly to form exotic cats, but they otherwise behave identically. It’s as if the laws of

  • Space Photos of the Week: Awesome Planets and Ancient Gods

    In 1781, astronomer William Herschel discovered a new planet. He wanted to name it Georgian Sidus (George’s Star) after King George III, but all of the other planets in the solar system were named after Roman gods. Fellow astronomer Johanne Bode suggested the name Uranus (a Greek god) would be a better fit, though it took another 50 years for the name to catch on.

    Almost every major planet in the solar system is named after a Roman god or goddess. Some of the planets are named because of their behavior: Mercury, for example, is named after the messenger of the gods because it appears to move through the sky so quickly. (It does so because it orbits so close to the sun.) And behemoth Jupiter is named after the king of the gods. While the planets are named after Roman deities in the Western world, they have different names