Rip Currents

  • Powerful
  • Dangerous
  • Pulls swimmers away from shore
  • Affects thousands of people every year
 ripcurrent

    Sensors

  • Have the ability to measure chemical or physical qualities.
  • Discovered in late 1800's
  • Infrared sensors since the late 1940's
  • Today, sensors used in a wide variety of devices
 sensor

    GPS

  • First GPS was the North Star!
  • Originally used by government.
  • Now available to anyone with a receiver.
 bigdipper