Contents

23 December 2016
Vol 354, Issue 6319

    About The Cover

    Cover image expansion

    COVER Star trails arc above a 4-kilometer-long arm of the Laser Interferometer Gravitational-Wave Observatory (LIGO) detector in Hanford, Washington (for more on the photograph, see http://scim.ag/2gGRzG7). Early this year, LIGO scientists announced that their two detectors—the second is in Livingston, Louisiana—had recorded a minuscule quiver in spacetime, generated by black holes colliding in the distant universe. The feat, Science's 2016 Breakthrough of the Year, confirmed a century-old prediction by Albert Einstein and opened a new window on the universe. See page 1516.
    Photo: © Rich Frishman