Video encyclopedia

Flashback calendar

Sony introduces the Betamax videocassette recorder in Japan

Betamax is an analog-recording and cassette format of magnetic tape for video developed by Sony. It was released in Japan, having lost the videotape format war to VHS, Betamax is obsolete. The production of Betamax recorders ceased in 2002 and cassettes ceased in 2016.

Around the globe under the water

American submarine USS Triton surfaced off the coast of Rehoboth Beach, Delaware, after a submerged circumnavigation of the Earth. The voyage, codenamed Operation Sandblast, was part of her shakedown cruise. Triton's navigational track followed that of the first circumnavigation of the world, led by Ferdinand Magellan.

Valence theory

English chemist Edward Frankland published his theory of chemical valence. It states atoms come together to make chemical compounds in regular ratios. This was – according to Frankland – caused by combining power of each element. Later August Kekulé proposed fixed valences for many elements, such as 4 for carbon.

Anniversaries of the (in)famous