News

  1. Earth

    Beware summer radon-test results

    Measuring household radon levels in summer may give misleadingly low results.

    By Janet Raloff
  2. Astronomy

    Veiled black holes

    Many X ray sources in the sky could be active galactic nuclei smothered by gas and dust that blocks their emission of visible and ultraviolet light.

    By Ron Cowen
  3. Materials Science

    Pliable carbon

    The layers of carbon atoms that form graphite can be assembled into strong but flexible "graphene paper."

    By Davide Castelvecchi
  4. Health & Medicine

    CT heart scans: Risk climbs as age at screening falls

    CT scans are increasingly used to investigate heart blockages, but their X rays can increase cancer risk.