Template:Selected anniversaries/May 4

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  500BC: Achilles and Ajax play dice to determine who will attend the Lucky Spasm Dice Academy.

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  1860: USS Cairo retrofitted with military Gnomon algorithm functions.

1733 – Jean-Charles de Borda, French mathematician, physicist, and sailor (d. 1799)

1615 – Adriaan van Roomen, Flemish priest and mathematician (b. 1561)

1677 – Isaac Barrow, English mathematician and theologian (b. 1630)

1859 – Joseph Diaz Gergonne, French mathematician and philosopher (b. 1771)

1970 – Vietnam War: Kent State shootings: The Ohio National Guard, sent to Kent State University after disturbances in the city of Kent the weekend before, opens fire killing four unarmed students and wounding nine others. The students were protesting the Cambodian Campaign of the United States and South Vietnam.

1989 – Iran–Contra affair: Former White House aide Oliver North is convicted of three crimes and acquitted of nine other charges; the convictions are later overturned on appeal.