1969 – The first permanent ARPANET link is established between UCLA and SRI.

1959 – American disc jockey Alan Freed, who had popularized the term "rock and roll" and music of that style, is fired from WABC radio over allegations he had participated in the payola scandal.

1905 – Albert Einstein's paper that leads to the mass–energy equivalence formula, E = mc², is published in the journal Annalen der Physik.

1877 – Thomas Edison announces his invention of the phonograph, a machine that can record and play sound.

1676 – The Danish astronomer Ole Rømer presents the first quantitative measurements of the speed of light.

1985 – Microsoft Windows 1.0, the first graphical personal computer operating environment developed by Microsoft, is released.

1945 – Nuremberg trials: Trials against 24 Nazi war criminals start at the Palace of Justice at Nuremberg.

1820 – An 80-ton sperm whale attacks and sinks the Essex (a whaling ship from Nantucket, Massachusetts) 3,200 kilometres (2,000 mi) from the western coast of South America. (Herman Melville's 1851 novel Moby-Dick was in part inspired by this incident.)

1805 – Beethoven's only opera, Fidelio, premieres in Vienna.

1985 – The first comic of Calvin and Hobbes is published in ten newspapers.

1928 – Release of the animated short Steamboat Willie, the first fully synchronized sound cartoon.

2019 – The first known case of COVID-19 is traced to a 55-year-old man who had visited a market in Wuhan, Hubei Province, China.

1939 – Nine Czech students are executed as a response to anti-Nazi demonstrations prompted by the death of Jan Opletal. All Czech universities are shut down and more than 1,200 students sent to concentration camps. Since this event, International Students' Day is celebrated in many countries, especially in the Czech Republic.

1869 – In Egypt, the Suez Canal, linking the Mediterranean Sea with the Red Sea, is inaugurated.

1800 – The United States Congress holds its first session in Washington, D.C.

1974 – The Arecibo message is broadcast from Puerto Rico.

1938 – LSD is first synthesized by Albert Hofmann from ergotamine at the Sandoz Laboratories in Basel.

1914 – The Federal Reserve Bank of the United States officially opens.

2022 – The world population reached eight billion.

1971 – Intel releases the world's first commercial single-chip microprocessor, the 4004.