1822: Rudolf Clausius, who developed the 2nd law of thermodynamics, was born. 1893: The first U.S. commemorative postage stamps were issued. 1920: Prolific science fact and fiction writer Isaac Asimov was born. 1921: The first broadcast of religious services aired on KDKA in Pittsburgh. 1941: American physicist Donald Keck, inventor of the first practical optical fiber communications cable (fused silica), was born. 1959: The first spacecraft to orbit the Sun, Mechta (Luna 1), was launched by the USSR. 1968: Dr. Christiaan Barnard performed the first successful (563 days of survival) heart transplant. 1974: The Emergency Highway Energy Conservation Act limited highway speeds to 55 mph due to Arab Oil Embargo. 1975: The "U.S. Patent Office" was renamed "U.S. Patent and Trademark Office."