Column

  1. Math

    Knotted Strings and Inca Accounts

    Researchers are starting to untangle mysterious Inca messages encoded in knotted strings.

    By Ivars Peterson
  2. Math

    Strange Orbits

    Orbiting bodies can follow weird trajectories, from figure-eight loops to complex, interlocked paths.

    By Ivars Peterson
  3. Math

    Playing with Ruth-Aaron Pairs

    Home-run records lead to intriguing prime-number patterns.

    By Ivars Peterson
  4. Math

    Ticket to Cooperstown

    Is it getting easier to get into baseball's Hall of Fame?

    By Ivars Peterson
  5. Math

    Paper Bags and Tricky Folds

    Folding a grocery bag flat takes a special kind of effort.

    By Ivars Peterson
  6. Math

    Closing the Gap on Twin Primes

    A long-sought proof that there are infinitely many pairs of primes that differ by only 2 may not be far away.