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This article is an accessible, non-technical introduction to the subject. For the main encyclopedia article, see M-theory[->0].
String theory|
[->1][->2]|
Superstring theory[->3]|
Theory[hide] · String theory[->4] Superstring theory Bosonic string theory M-theory (simplified) Type I string Type II string F-theory Heterotic string String field theory|
Concepts[show] · [->5]|
Related topics[show] · [->6]|
Scientists[show] · [->7]|
GlossaryHYPERLINK \l ""[show][->8] · [->9]|
· v[->10] t e|
In non-technical terms, M-theory[->11] presents an idea about the basic substance of the universe[->12].
Contents[hide] · 1 Background 2 Status 3 See also 4 References 5 Books 6 External links|
[edit] Background
In the early years of the 20th century, the atom[->13] – long believed to be the smallest building-block of matter[->14] – was proven to consist of even smaller components called protons[->15], neutrons[->16] and electrons[->17], which are known as subatomic particles[->18]. Beginning in the 1960s, other subatomic particles were discovered. In the 1970s, it was discovered that protons and neutrons (and other hadrons[->19]) are themselves made up of smaller particles called quarks[->20]. Quantum theory[->21] is the set of rules that describes the interactions of these particles.
In the 1980s, a new mathematical model of theoretical physics[->22] called string theory[->23] emerged. It showed how all the particles, and all of the forms of energy in the universe, could be constructed by hypothetical one-dimensional "strings", infinitesimal building-blocks that have only the dimension of length, but not height nor width. Further, string theory suggested that the universe is made up of multiple dimensions[->24]. Height, width, and length constitute three-dimensional space, and time gives a total of four observable dimensions; however, string theories initially supported