Einstein on the edge of a wedge in De Sitter space-time

In July, Vol. 8 of The Collected Papers of Albert Einstein, covering correspondence from 1914 to 1918, will hit the bookstores. Among many other things, this volume will bring together for the first time all correspondence related to the famous debate between Einstein and the Leyden astronomer Willem de Sitter over whether or not general relativity does away with the notion of absolute space.

Much of the debate revolves around De Sitter's vacuum solution of the field equations with cosmological term which Einstein proposed in early 1917. Examining this solution, Einstein and De Sitter had to confront the question whether singularities encountered in various coordinate representations of the solution are intrinsic or just artifacts of the coordinates. This issue was settled only with the help of the mathematicians Hermann Weyl and Felix Klein, who joined the discussion over the De Sitter solution in 1918. This whole episode not only sheds light on Einstein's thinking about general relativity in the years immediately following his formulation of the theory, it also makes for an amusing comedy of errors.