Uncategorized

  1. Earth

    Traces of lead cause outsize harm

    Minute amounts of lead in blood are worse for children than had been realized.

    By Ben Harder
  2. Math

    Recycling Topology

    It’s hard to miss the triangle of three bent arrows that signifies recycling. It appears in newspapers and magazines and on bottles, envelopes, cardboard cartons, and other containers. The recycling symbol. Alternative (incorrect?) rendering of the recycling symbol. Cliff Long made a Möbius band the basis of his wood carving “Bug on a Band.” Photo […]

    By Ivars Peterson
  3. Paleontology

    Ancestors Go South

    A group of new and previously excavated fossils in South Africa represents 4-million-year-old members of the human evolutionary family, according to an analysis of the sediment that covered the finds.