Einstein died in 1955. Redshift observations started in 1912 but weren’t clear on what was happening or why, Friedmann etc al’s calculations in 1922 probably raised the question in a serious context, and Hubble’s law was published in 1929. He knew about it, probably at least from the early '20s.
whotookkarl@lemmy.dbzer0.com 3 days ago
Einstein died in 1955. Redshift observations started in 1912 but weren’t clear on what was happening or why, Friedmann etc al’s calculations in 1922 probably raised the question in a serious context, and Hubble’s law was published in 1929. He knew about it, probably at least from the early '20s.
wikipedia.org/wiki/Hubble's_law