In 1853, Gregorio Ricci-Curbastro, an Italian mathematician, was born.
He was instrumental in the development of absolute differential calculus, formerly called the Ricci calculus, but now known as tensor analysis.
Learn more at http://www.gap-system.org/~history/Biographies/Ricci-Curbastro.html
In 2001, William Hewlett died at age 87.
William Hewlett and David Packard founded Hewlett-Packard. The company’s first product was an audio oscillator invented by William Hewlett named the HP model 200A.
In Walter Isaacson’s book, Steve Jobs, William Hewlett is credited with giving 12-year-old Steve Jobs parts to build a frequency counter. We all know what happened after that.
Learn more at http://inventors.about.com/od/hstartinventors/a/William_Hewlett.htm
