"New" 1931 Einstein mss: one math boo-boo away from expanding universe?

Here’s an article on an obscure Einstein manuscript recently re-discovered. It makes it sound like Einstein made his decisions pretty damn quick, which I can’t believe, or that’s one mean mother of an equation (or two) upon which A Lot rested.

That’s a question I quickly had, but of course am interested in Einstein’s approach to the subject in general. I know there’s an active bunch of friendly physicists aboard. Or abroad. Or about. :: neat how each word is acceptable… ::

One can get such a model out of general relativity, and it used to be a somewhat popular model. Checking Wikipedia, though, it looks like it was first proposed in the 1920s, so Einstein probably didn’t have anything new in 1931.

So what was he on about, as the Brits say?

Here’s a link to the full paper.

Some key quotes.

Einstein would’ve been well aware of expanding cosmology when he wrote that. The equations he wrote are based on the Friedman equations describing an expanding Universe from 1922.

It’s difficult to know without context, but he probably wrote an equation for the dynamics of the Universe which achieved the steady state he was looking for, but quickly saw that it violated general relativity and moved on. In some ways not that interesting.