In 1806 – Englishman Ralph Wedgwood received the first patent on carbon paper, which led to the initials cc to indicate a carbon copy which led to the email option to “cc” somebody.
In 1954 – IBM sounded the death knell of vacuum tubes, building the first calculating machine to use solid-state transistors. It was an experimental version of the IBM 604 Electronic Calculating Punch, that was desktop-sized and slow just like it’s vacuum-tube powered brother, but it used 5% of the power!
In 1959 – The Soviet Space Probe Luna 3 took the first photographs of the dark side of the moon. You’re welcome Pink Floyd.