Tech History Today – Feb. 23

In 1893 – Germany's Imperial Patent Office granted Rudolph Diesel Patent No. 67207 for "a new efficient thermal engine". We just call it, the Diesel engine.

In 1927 – President Calvin Coolidge signed Public Law no. 632 establishing the Federal Radio Commission which was later replaced by the Federal Communications Commission.

In 1927 – German physicist Werner Heisenberg wrote a letter to Wolfgang Pauli, describing the uncertainty principle for the first time. He submitted a paper on the principle for publication the following March.