Uncategorized

  1. Math

    SET Math

    The card game known as SET® is deceptively simple. Its object is to identify, as quickly as possible, a grouping (SET) of three cards, selected from 12 cards laid out face up on a table. A SET deck has 81 (34) cards. Each card displays a design with four attributes: shape, number, shading, and color. […]

    By Ivars Peterson

  2. The Naked Truth? Lice hint at a recent origin of clothing

    A study of genetic differences among human lice hints at the origin of clothing.

    By John Travis
  3. Earth

    Clearing the Air: Ozone-killing bromine is on the decline

    Chemical analyses of Earth's lower atmosphere show that the overall concentration of bromine, a component of some potent ozone-destroying chemicals, has dropped by 5 percent since peaking in 1998.