How many dimensions does M-theory propose?

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What is string theory? — string theory Brian Greene explains the basic idea of string theory in under three minutes.

M-theory proposes a total of 11 dimensions.1

While earlier versions of string theory required six extra spatial dimensions—resulting in a 10-dimensional framework—research in the mid-1990s revealed that the theory actually incorporates seven extra spatial dimensions. By unifying previously distinct versions of string theory, M-theory establishes an 11-dimensional framework that provides a more comprehensive, albeit still theoretical, approach to understanding the fundamental particles and forces of nature.231