Uncategorized

  1. Astronomy

    Gravity’s lens: Finding a sextet of images

    Astronomers have for the first time found a gravitational lens in which the image of a distant galaxy has been split into six distinct images.

    By Ron Cowen
  2. Astronomy

    Gravity’s lens: Finding a dim cluster

    Relying solely on a gravitational mirage rather than visible images, astronomers have discovered a previously unknown cluster of galaxies and measured its distance from Earth.

    By Ron Cowen
  3. Earth

    Dust, the Thermostat

    Analyses suggest that dust has profound, complex, and far-reaching effects on the planet's climate.

    By Sid Perkins

  4. Issues of Medical Research

    Should researchers be allowed to tinker with our genetic codes, or create copies of human beings? Could we somehow be harming future generations by aiding sick people today? Public Agenda Online offers a nonpartisan guide to these and other policy issues related to medical research.