Feature

  1. Health & Medicine

    Immunity’s Eyes

    Proteins called toll-like receptors allow human immune cells to detect microbes.

    By John Travis
  2. Math

    Pi à la Mode

    A potential link between two disparate mathematical fields—number theory and chaotic dynamics—could lead to a proof that every digit of pi occurs with the same frequency.

    By Ivars Peterson
  3. Tech

    The Seeing Tongue

    Blind people can now use their tongues to see, albeit crudely, thanks to prototype technology that involves licking arrays of electrodes attached to video cameras.

    By Peter Weiss
  4. Chemistry

    Chemistry of Colors and Curls

    Chemists are using new technology and experiments to discover how hair becomes damaged and how to protect it.