Johann Karl Friedrich Zöllner

"Johann Karl Friedrich Zöllner (8 November 1834, Berlin – 25 April 1882, Leipzig) was a German astrophysicist who studied optical illusions. He was also an early psychical investigator."

https://en.m.wikipedia.org/wiki/Johann_Karl_Friedrich_Z%C3%B6llner

April 5

Booker T. Washington born (1856); Actress Bette Davis born (1908); Actor Gregory Peck born (1916); Former Secretary of State Colin Powell born (1937); Kareem Abdul-Jabbar surpasses Wilt Chamberlain as all-time leading scorer in the NBA at the time (1984); Kurt Cobain dies (1994).

April 6

The first modern Olympics begin in Athens, Greece (1896); US declares war on Germany in WWI (1917); First Tony Awards ceremony held in New York City (1947); Italian Renaissance painter Raphael born (1483); Actor Paul Rudd born (1969); Science fiction writer Isaac Asimov dies (1992)

April 4

Ninth US President William Henry Harrison dies of pneumonia, shortest presidency ever at just 31 days (1841); American poet and activist Maya Angelou born (1928); NATO is created (1949); Martin Luther King Jr. is assassinated (1968).

April 3

American politician Boss Tweed born (1823); Actress Doris Day born (1922); Eddie Murphy born (1961); First mobile phone call is made (1973); Apple releases the first iPad (2010).

April 2

Ludwig van Beethoven premieres his First Symphony (1800); Danish author Hans Christian Andersen born (1805); Samuel Morse, inventor of Morse code, dies (1872); Singer Marvin Gaye born (1939); Pope John Paul II dies (2005).

April 1

Actress Debbie Reynolds born (1932); Apple Computer founded by Steve Jobs and Steve Wozniak ... and don't forget Ronald Wayne (1976); Iran officially becomes an Islamic republic after the Shah is overthrown (1979); Singer Marvin Gaye shot and killed by his father (1984).