In the book the Grand Design by Stephen Hawking, he wrote about the M-theory, and how in that theory it has 11 dimensions. I do not quite get that, so can someone explain it to me a little bit. I understand four dimension is where space and time combine together, and there is no movement in four dimensional space because an event over time is represented by a line. I get that, but I do not quite understand how 11 dimension works, so I would really appreciate if anyone could help me understand this concept.

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    $\begingroup$ Related: physics.stackexchange.com/q/10527/2451 and links therein. $\endgroup$ – Qmechanic Jul 14 '16 at 22:18
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    $\begingroup$ That's really a rather broad question, and perhaps impossible to answer in a way that is both understandable to you and correct. A useful answer would involve first explaining the ten dimensions of superstring theories and then explaining why an eleven-dimensional theory called M-theory is believed to exist that "connects" there, which really amounts to a textbook. For a general discussion of extra dimensions, see here, for a specific discussions of 10d in string theory, see here $\endgroup$ – ACuriousMind Jul 14 '16 at 22:21
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    $\begingroup$ At the smallest scales, instead of being able to move forward/back along three orthogonal axes (and forward through time), you are able to move forward/backward along ten orthogonal axes (and forward through time). Easy peasy! $\endgroup$ – user12029 Jul 14 '16 at 22:22
  • $\begingroup$ Read the link Qmechanic has listed above, and Google a free e-book , using the keywords String Theory For Dummies Pdf. The book is very good, it tells you why some people like string theory and what it's drawbacks are. $\endgroup$ – user108787 Jul 14 '16 at 22:24