John Carlos Baez on Nostr: The period from 1920 to 1940 was just as explosive in fundamental physics. In 1922, ...

The period from 1920 to 1940 was just as explosive in fundamental physics.

In 1922, Friedmann used Einstein's theory of gravity to predict that the universe is expanding: galaxies are moving away from each other. In just 4 years this was confirmed by Hubble!

Einstein's predicted particles of light were found in 1923 and eventually called 'photons'.

But the biggest revolution occurred around 1925, when Schrödinger, Heisenberg, Born, Jordan, Dirac and others discovered that most of the universe was governed by linear algebra. This new way of understanding physics is called 'quantum mechanics'. One of its first big successes was computing the spectrum of light emitted by hydrogen, but thousands more came soon.

Then in orange we see a bunch of shocking experimental discoveries that eventually fit into the Standard Model... and one in red that we *still* don't understand!

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