Uncategorized

  1. Math

    Plato’s Molecule

    In his dialogue Timaeus, the Greek philosopher Plato (427–347 B.C.) carefully laid out his reasoning for ascribing certain geometric shapes to the minuscule particles that constituted the four elements of matter. In his view, these elements–fire, air, water, and earth–were all aggregates of tiny solids, each one having the shape of one of the regular […]

    By Ivars Peterson
  2. Math

    Plato’s Molecule

    In his dialogue Timaeus, the Greek philosopher Plato (427–347 B.C.) carefully laid out his reasoning for ascribing certain geometric shapes to the minuscule particles that constituted the four elements of matter. In his view, these elements–fire, air, water, and earth–were all aggregates of tiny solids, each one having the shape of one of the regular […]

    By Ivars Peterson
  3. Tech

    Refueling Rockets

    Hybrid-rocket fuels—part solid, part liquid—have been around for a half-century, and they may just now be taking off.