100 years ago Albert Einstein submitted a paper to the Royal Prussian Academy of the Natural Sciences which contained what we today call the Einstein field equations: the new law of gravity that superseded Isaac Newton’s inverse square law of gravity. On the same day, 25 November 1915, that Einstein submitted said paper, his preceeding paper on Mercury's perihelion was published. Here, Einstein correctly calculated an anomoly in Mercury's motion that had remained an unsolved puzzle in the context of the Newtonian theory of gravity. The paper had been submitted only a week earlier in turn, but it did not yet contain the final gravitational field equations that would become the core of the general theory of relativity.
Ten days prior to his submission of the final field equations, Einstein wrote to David Hilbert that he was suffering from exhaustion and abdominal pains. His intense work on general relativity and poor nutrition caused by the ongoing war had clearly taken their toll on Einstein's health. Still, when Einstein submitted the field equations on 25 November 1915, he was aware that he had reached his goal: the discovery of a law of gravity more accurate than Newton's, consistent with the results of special relativity, and indeed a generalisation of the latter theory. From the very beginning of searching for this new law of gravity, Einstein took the lesson from special relativity that mass and energy are equivalent as one of his starting points; or rather the idea that both mass and energy have to produce gravitational fields. The main question was what the resulting gravitational fields would be represented by, what the "left-hand side" of the Einstein field equations would be, given that their "right-hand side" was mass-energy. [Read more] 11-25-15
Einstein became an overnight celebrity in November 1919 upon the sensational press coverage of the confirmation of his general theory of relativity, following the astronomical observations of a solar eclipse. The popular dissemination of his theories, his desire to forge closer ties with members of the international scientific community, political unrest in Germany, his involvement in the Zionist movement, and his curiosity to explore distant lands all led Einstein to undertake a number of overseas tours. Prior to his meteoric rise to fame, he had only visited a few countries within Europe, most notably the Netherlands and France. However, during the 1920s and the early 1930s, he embarked on a series of ocean voyages – to the USA, the Far East, Palestine, Spain, South America, and the USA again. Travelling within Europe he often wrote postcards and occasional letters to his wife and stepdaughters, detailing his experiences. Sea travel afforded Einstein the leisure to note down impressions of his trips, the interesting individuals he encountered, and the events he attended in meticulously kept travel diaries. These notebooks are among the most fascinating and revealing documents we have penned by Einstein. In spite of his hectic schedules during his tours of these countries, he always found time to record his experiences. As the diaries were intended to eventually be read by his relatives back in Berlin, one can view them as long letters directed homewards.
In the following months we plan to post a series of short pieces on Einstein’s travel diaries and the observations he made during his international trips. The first post in this series presents Einstein’s journey to the Far East, Palestine, and Spain in late 1922 and early 1923. It was prepared as an exhibit for the Google Cultural Institute; find it here. 10-27-15
One might think that if there is any scientist whose work has been thoroughly researched and studied, whose every manuscript and letter has been scrutinized by scholars and other scientists, it would be Albert Einstein. He created the idea of the light quantum, the special and general theories of relativity, wrote the decisive paper establishing the existence of atoms, suggested the first model of the universe as a whole, introduced the principles that gave rise to lasers, and many more things. He also invented a design for a new kind of refrigerator, a gyrocompass, and worked on designs for a tape recorder and a camera that would self-adjust to light intensity. He was instrumental in bringing German science back into the fold of international cooperation after the First World War, and in creating the Hebrew University in Jerusalem. He became a major figurehead of the international pacifist movement in the interwar period and the disarmament movement in the postwar period. He exchanged letters with all the great physicists of his time over decades, with senior political leaders, writers, musicians, and artists.
Of whom, if not of Einstein, would we expect that every piece of paper he had ever set his pen to had been studied with great care already?
And yet, it has not happened so far. Einstein’s literary estate, his published and unpublished manuscripts, his letters and notebooks, contain tens of thousands of pages, mostly handwritten. Much of it has likely not been read by anybody, let alone been researched thoroughly, and followed through line by line. [Read More]. 09-21-15
The History Channel's documentary about Einstein has been reposted on YouTube. Take a look:
The Digital Einstein Papers continues to captivate attention; here is a recent interview about the project with the Einstein Papers Project's Ze'ev Rosenkranz on Arise America.