Changes

'''String theory''', (or super-string theory when coupled with [[Supersymmetry]]), is a class of models in [[theoretical physics]] which replace zero-dimensional points (particles) in four-dimensional spacetime with one-dimensional strings in an eleven-dimensional spacetime as the fundamental building block of the universe.  The elusive goal is to develop a set of equations that unify all known natural forces (gravitational, electromagnetic, weak, and strong), according to some preconceived philosophical beliefs about how they ought to be unified.  Leading proponents of string theory have been Edward Witten of the [[Institute for Advanced Study]] and [[Brian Greene]], the renowned author of ''The Elegant Universe''. String theory has never successfully been used to generate a model of the universe resembling our own, with previously observed particles and forces in place.

'''String theory''', (or super-string theory when coupled with [[Supersymmetry]]), is a class of models in [[theoretical physics]] which replace zero-dimensional points (particles) in four-dimensional spacetime with one-dimensional strings in an eleven-dimensional spacetime as the fundamental building block of the universe.  The elusive goal is to develop a set of equations that unify all known natural forces (gravitational, electromagnetic, weak, and strong), according to some preconceived philosophical beliefs about how they ought to be unified.  Leading proponents of string theory have been [[Institute for Advanced Study]]'s Edward Witten, who was a history major in college, and [[Brian Greene]], the author of book for popular consumption called ''The Elegant Universe''. String theory has never successfully been used to generate a model of the universe resembling our own, with previously observed particles and forces in place.

Some physicists argue that string theory (and its alter ego M-theory) is currently the most viable candidate for a unified theory of physics which describes all forces of nature, encompassing the physics of gravity as well as quantum field theory. Major research centers include, for example, MIT, with five faculty members and numerous postdocs and graduate students working in this area.<ref> see [http://ctp.lns.mit.edu/research-strings.html MIT Center for Theoretical Physics]</ref> At present, however, the potential status of string theory as a genuine "theory of everything" remains uncertain.

Some physicists argue that string theory (and its alter ego M-theory) is currently the most viable candidate for a unified theory of physics which describes all forces of nature, encompassing the physics of gravity as well as quantum field theory. Major research centers include, for example, MIT, with five faculty members and numerous postdocs and graduate students working in this area.<ref> see [http://ctp.lns.mit.edu/research-strings.html MIT Center for Theoretical Physics]</ref> At present, however, the potential status of string theory as a genuine "theory of everything" remains uncertain.

Princeton University researchers have found new mathematical evidence that some aspects of string theory may be related to a well-respected body of physics called "gauge theory," which has been demonstrated to underlie the interactions among quarks and gluons, the vanishingly small objects that combine to form protons, neutrons and other, more exotic subatomic particles. The discovery, say the physicists, could open up a host of uses for string theory in attacking practical physics problems.<ref>See [http://www.princeton.edu/main/news/archive/S17/80/32S21/index.xml?section=newsreleases "Princeton physicists connect string theory with established physics," May 1, 2007] </ref>

Princeton University researchers made a mathematical claim that some aspects of string theory may be related to a well-respected body of physics called "gauge theory," which has been demonstrated to underlie the interactions among quarks and gluons, the vanishingly small objects that combine to form protons, neutrons and other, more exotic subatomic particles. The discovery, say the physicists, could open up a host of uses for string theory in attacking practical physics problems.<ref>See [http://www.princeton.edu/main/news/archive/S17/80/32S21/index.xml?section=newsreleases "Princeton physicists connect string theory with established physics," May 1, 2007] </ref>

==History==

==History==

String theory originated in 1970 when particle theorists realized that the theories developed in 1968 to describe the particle spectrum also describe the quantum mechanics of oscillating strings. Supersymmetry was introduced in 1971. The watershed year was 1984, when string theory became accepted by the mainstream physics community as an actual candidate theory that could unite quantum mechanics, particle physics, and gravity. Around 2000, many physics conceded that string theory was a failure, and that it had no hope of realizing any of its goals.

String theory originated in 1970 when particle theorists realized that the theories developed in 1968 to describe the particle spectrum also describe the quantum mechanics of oscillating strings. Supersymmetry was introduced in 1971.  

 

Many physicists have long been critical of string theory, with some portraying it "as anything from a mathematically obtuse minefield to a quasi-religion that has precious little to do with science."<ref>http://www.newscientist.com/article/mg20227101.300-what-string-theory-is-really-good-for.html?full=true</ref>  By 2000, many physicists conceded that string theory was a failure, and that it had no hope of realizing any of its goals.

==Falsifiability==

==Falsifiability==