Today in History – February 1, 1972 – First scientific hand-held calculator, the HP-35, introduced for $395. I was an undergraduate in engineering when the HP-35 was released. I couldn’t afford to buy one and stuck with my slide rule. But the next year, I gave in and bought the next model, the HP-45 and [...]

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Today in History – January 31, 1958 – Explorer 1 became the United States of America’s first satellite to orbit the Earth after it was launched on January 31, 1958. After the Soviet Union’s successful launch of Sputnik I on October 4, 1957, the United States of America embarked upon a program to launch it [...]

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Today in History – January 26, 1697-  Isaac Newton solves Bernoulli’s brachistochrone problem, inventing the “calculus of variations”. The story goes that Jean Bernoulli gave Isaac Newton a challenge solve the following problem in six months: We are given two fixed points in a vertical plane. A particle starts from rest at one of the [...]

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Today in History – January 17, 1871 - U.S. patent issued for an “endless wire rope way” cable car (No.110,971). The inventor of the cable car was Andrew S. Hallidie (center image above) and contracted by the Clay Street Hill Railroad Company in San Francisco. Hallidie’s system used a continuous looped wire rope that was placed [...]

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Today in History – January 14, 2005 – Huygens Probe Lands on Titan. After spending seven years in space, the Huygens probe separated from the main Cassini spacecraft on December 24, 2004, and spent the next three weeks traveling to the moon Titan. After beginning its descent, it transmitted scientific data for nearly five hours [...]

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