**Einstein's Zurich Notebook**The Zurich notebook, held by the Albert Einstein Archives at the Hebrew University of Jerusalem, represents an almost complete testimony of Einstein's thinking in an intermediate phase of the emergence of General Relativity, beginning in mid-1912 and ending in early 1913.

In the center of his thinking as it is documented by the notebook was the problem of combining the available physical knowledge on gravitation with a generalization of the mathematical formalism of Minkowski's four-dimensional spacetime, with the aim to create a relativistic theory of gravitation which makes sense from a physical point of view and which corresponds, at the same time, to a consistent mathematical framework.

The principal challenge which Einstein faced consisted in constructing a field equation which, on the one hand, satisfies the requirements resulting from his ambitious program of formulating a theory of gravitation generalizing the principle of relativity, and which, on the other hand, can be reduced by an appropriate specialization to the familiar Newtonian law of gravitation. The history of Einstein's search for such an equation can, on the background of the Zurich notebook, essentially be written as that of a mutual adaptation between mathematical formalism and physical meaning.

This notebook, handwritten by Einstein and found after his death, has been put online for anyone to read.

Give it a try here:

http://alberteinstein.info/vufind1/Digital/EAR000034421#page/1/mode/2up #einstein #physics #zurichnotebook