Einstein's Chalkboard

Einstein wrote equations and numerical estimates concerning the expanding universe during an Oxford lecture in 1931. The calculations relate to contemporary cosmological models rather than his original 1905 work on special relativity.

Oxford physicist E. J. Bowen reportedly arranged for the board to be saved after Einstein's lecture. Its survival turned an ordinary teaching surface into a physical record of cosmology during a period of rapid scientific change.

It is held in Oxford by the History of Science Museum, formerly called the Museum of the History of Science. The museum occupies the historic Old Ashmolean building on Broad Street.

The figures on the board have prompted discussion because one displayed estimate does not straightforwardly match the written formula. Historians therefore treat it as a snapshot of a live lecture, not as a polished scientific paper.