Bootstrap model: Difference between revisions

Revision as of 10:23, 5 September 2007

Revision as of 10:26, 5 September 2007

Line 1:

In [[physics]], the term '''bootstrap model''' is used for the class of theories that assume that very general [[consistency]] criteria are sufficient to determine the whole theory completely.

In the 1960s and '70s, an ever-growing list of [[strong interaction|strongly interacting]] particles — [[meson|mesons]] and [[baryon|baryons]] — caused some physicists to question the distinction between [[composite particle|composite]] and [[elementary particle|elementary particles]]. In particular, [[Geoffrey Chew]] and others advocated "nuclear democracy", which foreswore the idea that some particles were more elementary than others. Instead, they sought to derive as much information as possible about the strong interaction from plausible assumptions about the [[S-matrix]], which describes what happens when particles of any sort collide. It is so difficult to find formulas for a nontrivial S-matrix obeying these assumptions that some believed there might be a unique solution. This led to a bootstrap program often associated with the phrase "the analytic S-matrix".

In particular, [[Geoffrey Chew]] advocated "nuclear democracy", which foreswore the idea that some particles were made of other more elementary ones. Instead, he pursued an approach which sought to derive as much information as possible about the strong interaction from simple assumptions about the [[S-matrix]], which describes what happens when particles of any sort collide. It is so difficult to find formulas for a nontrivial S-matrix obeying these assumptions that some believed there might be a unique solution. This led to a bootstrap program often associated with the phrase "the analytic S-matrix". Later this appproach to the strong interaction fell out of favor with the success of [[quantum chromodynamics]]. According to this theory, mesons and baryons are made of elementary particles called [[quarks]] and [[gluons]].

This bootstrap program had limited success, and it fell out of favor with the rise of [[quantum chromodynamics]]. It is now believed that mesons and baryons are made of elementary particles called [[quarks]] and [[gluons]].

These are a number of other more successful examples of using general principles to derive specific theories of physics, starting from [[Einstein]]'s 1905 paper on [[special relativity]]. The form of [[general relativity]] is almost entirely specified from general principles including the [[principal of equivalence]]. There has also been partial sucess in deriving [[Quantum mechanics|quantum theory]] from axioms of [[quantum logic]].