Content deleted Content added
→Feynman's later years: fix subchapter |
Crosbiesmith (talk | contribs) m →The Caltech years: disambig 'parton' |
||
Line 60:
Feynman diagrams are now fundamental for [[string theory]] and [[M-theory]], and have even been extended topologically. Feynman's mental picture for these diagrams started with the ''hard sphere'' approximation, and the interactions could be thought of as ''collisions'' at first. It was not until decades later that physicists thought of analyzing the nodes of the Feynman diagrams more closely. The ''world-lines'' of the diagrams have become ''tubes'' to better model the more complicated objects such as ''strings'' and ''M-branes''.
From his diagrams of a small number of particles interacting in [[spacetime]], Feynman could then [[model (abstract)|model]] ''all of physics''{{ref|FeyFP}} in terms of those particles' [[spin]]s and the range of coupling of the [[fundamental force]]s. The [[quark]] model, however, was a rival to Feynman's [[Parton (particle physics)|parton]] formulation. Feynman did not dispute the quark model; for example, when the 5th quark was discovered, Feynman immediately pointed out to his students that the discovery implied the existence of a 6th quark, which was duly discovered in the decade after his death.
After the success of quantum electrodynamics, Feynman turned to quantum gravity. By analogy with the photon, which has spin 1, he investigated the consequences of a free massless spin 2 field, and was able to derive the [[Einstein field equation]] of general relativity, but little more{{ref|FeyLG}}. Unfortunately, at this time he became exhausted by working on multiple major projects at the same time, including his ''Lectures in Physics''.
| |||