Unified field theory classical field theory and, two years later, that of Theodor Kaluza, who extended General Relativity to five dimensions. Continuing in this latter direction, Oscar Klein proposed in 1926 that the fourth spatial dimension be curled up into a small, unobserved circle. In Kaluza–Klein theory, the gravitational curvature of the extra spatial direction behaves as an additional force similar to electromagnetism. These and other models of electromagnetism and gravity were pursued by Albert Einstein in his attempts at a classical unified field theory. By 1930 Einstein had already considered the Einstein–Maxwell–Dirac System [Dongen]. This system is (heuristically) the super-classical [Varadarajan] limit
Unified Patents Unified Patents Unified Patents is a member-based organization whose goal is reducing the number of non-practicing entity (NPE) assertions in specific technology areas. Instances of NPE patent litigation have grown recently: NPEs (commonly referred to as patent trolls) accounted for the majority of patent infringement litigation in the U.S. in 2012, compared to less than a quarter in 2007. This is because NPEs can achieve a quick return on investment since most companies settle rather than fight, even if they believe the assertion to be invalid. Unified permits small and large companies alike to become members. Smaller members act as