Classical unified field theories to isospin rather than electromagnetism; this is related to a discrete (or ""internal"") symmetry known to Einstein as "displacement field duality". Einstein became increasingly isolated in his research on a generalized theory of gravitation, and most physicists consider his attempts ultimately unsuccessful. In particular, his pursuit of a unification of the fundamental forces ignored developments in quantum physics (and vice versa), most notably the discovery of the strong nuclear force and weak nuclear force. Inspired by Einstein's approach to a unified field theory and Eddington's idea of the affine connection as the sole basis for differential geometric structure for space-time,
Unified primary Unified primary A unified primary is a proposed electoral system system for narrowing the field of candidates for a single-winner general election, similar to a nonpartisan blanket primary, but using approval voting for the first round. In the US, most primary elections are party-specific: voters select a political party, either as part of the voter registration process or at the ballot box, and may vote only for candidates sharing that same party affiliation. These primary systems use plurality voting, where each voter may express a preference for one candidate per office. The candidate in each party receiving the most votes