relativity

Who needs quantum gravity?

Who needs quantum gravity?

By Sandipan Sengupta, Dept of Physics, IIT Kharagpur Nature is made up of elementary particles, the interactions among them being manifested as forces of various kinds. A modern language to describe these phenomena is provided by quantum field theory, which is based on a set of relativistic fields. Within this framework, particles typically emerge as excitations over a (quantum) ground state, and macroscopic forces arise due to the exchange of particles. For instance, for the all so well-known case of the electromagnetic force, the associated particle is the photon, whose exchange between a source and a sink leads to their…
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