At the beginning of the 20th century science was progressing quickly and the inner workings of the atom were just beginning to be discovered. In 1900, Max Planck proposed the quantum theory, the idea that all energy moves in discrete amounts called quanta. In 1905, Albert Einstein published his theory of special relativity, which would be instrumental in the progression of physics and the understanding of the universe. Around 1927, Niels Bohr and Werner Heisenberg, collaborating with many other physicists, developed the Copenhagen interpretation of quantum theory, determining the probabilities of the movement of particles. These breakthroughs provided the model for the structure and workings of the atom and drove the revolution that would sweep up Nathan Rosen.
Work with Einstein
In 1932 with a ScD degree from MIT, he went to do research at Princeton University. In 1934 he became Albert Einstein's assistant at The Institute for Advanced Study in Princeton, New Jersey and continued in that position until 1936. In July 1935 Einstein and Rosen published an article developing a concept of folded space time in parallel layers connected by a bridge, using only General Relativity and Maxwell Equation. Earlier while working with Einstein, Rosen had pointed out the peculiarities of Einstein's studies involving entangled wave functions, and, in coordination with Boris Podolsky, a paper was drafted and published in May 1935 helping to develop a theoretical basis for the July 1935 publication. The May 1935 paper, entitled "Can quantum-mechanical description of physical reality be considered complete?" labeled these effects the Einstein-Podolsky-Rosen paradox or EPR paradox. Einstein helped Rosen to continue his career in physics with a letter to Molotov in The Soviet Union resulting in a temporary position during which in 1947 Einstein And Rosen published an article "On Gravitational Waves" in which they further developed the concept of folded space time caused by rotating cylinders. In 1952 Rosen became a professor at Technion in Haifa, Israel and remained in Haifa doing research until his death in 1995. After leaving Princeton, Rosen continued to publish on relativity with "General Relativity and Flat Space" in 1940 and "Energy and momentum of cylindrical gravitational waves" in 1958, further developing folded space time. Einstein-Rosen Bridges are purely theoretical. It was shown in a 1962 paper by theoretical physicists John A. Wheeler and Robert W. Fuller that these types of wormholes are unstable. Other researchers worked on the concept of wormholes and "Robert Hjellming in 1971 presented a model in which a black hole would draw matter in while being connected to a white hole in a distant location, which expels this same matter." "In a 1988 paper, physicists Kip Thorne and Mike Morris proposed that such a wormhole could be made stable by containing some form of negative matter or energy." This later work is not attributable to Rosen. Between 1940 and 1989 Rosen published a series of articles on his versions of bimetric gravity, an attempt to improve on General Relativity by removing singularities and replacing pseudo-tensors with tensors to eliminate nonlocality. The effort eventually failed in 1992 with conflicting pulsar data.
Rosen made a number of contributions to modern physics. One of the most lasting discoveries Rosen brought to physics was his formulation of the structure of the hydrogen molecule, a molecule where none of the electrons have a definite quantum number, but the pair of electrons has a pure state. Rosen used what he called "entangled" wave functions to represent the molecule's structure. He also developed a theoretical analysis of the neutron as combination of proton and electron in an article in Physical Review 1931.
