M-theory is not complete, butand the mathematics of the approach hasare beennot exploredyet inwell great detailunderstood. However,M-theory sois fara notheory of quantum gravity; and as all others it as not gained experimental evidence forthat M-theorywould confirm its existsvalidity.<ref name=atlantic/> Some physicists are skeptical that this approach will lead to a physical theory describing our world, due to its lack of predictive power.<ref name="Smolin_Response">[[Lee Smolin]], April 2007:[https://web.archive.org/web/20130621085800/http://www.kitp.ucsb.edu/joep/links/on-some-criticisms-of-string-theory/lee-smolins-response Response to review of ''The Trouble with Physics''] by [[Joe Polchinski]].</ref>
Nevertheless, some physicists are drawn to M-theory because of its degree of uniqueness and rich set of mathematical properties, triggering the hope that it may describe our world in a single framework.
