1785: Jean-Charles-Athanase Peltier, discoverer of the effect whereby current passing through a junction of dissimilar metals produces heat or cold depending on polarity, was born. 1857: German physicist Heinrich (Rudolf) Hertz, who was the first to broadcast and receive radio waves, was born. 1876: Johns Hopkins University opened for business in Baltimore, MD 1900: Paul Kollsman, inventor of the first accurate barometric altimeter, was born. 1974: Barbara Allen Rainey became the first female aviator in the U.S. Navy. 1994: The Justice Department charged 31-year CIA veteran Aldrich Ames and his wife, Rosario, with selling national security secrets to the Soviet Union (Ames was later sentenced to life in prison; his wife received a 5-year term).