Feature

  1. Chemistry

    Where the Gems Are

    By using a novel tool to figure out an emerald’s oxygen-isotope ratio, gemologists can now determine which mine the precious stone came from and, possibly, gain insights into the formation and history of these coveted gems.

    By Corinna Wu
  2. Health & Medicine

    Is Snoring a DiZZZease?

    Snoring may trigger high blood pressure, which can lead to heart disease or stroke.

    By Damaris Christensen
  3. Animals

    Pregnant—and Still Macho

    Some of the basic theories of sexual behavior and sexual selection are getting attention thanks to a burst of new studies in the topsy-turvy social world of the seahorse, where the males get pregnant.

    By Susan Milius

  4. Save Our Sounds

    Some 14 libraries around the world have built up substantial collections of natural sounds, from bird songs to fish hums.