#### PhanthomJay

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*numerical*significance of the 11 dimensions in this Universe? I'm not talking about the mathematical solution, but rather, what are the properties of the Universe that limit this number to 11? Or is it as significant or insignificant as the properties of the Universe that limits lightspeed or the dimensionless constants to certain numbers? Could other Universes have more, or less, dimensions? Or even an infinite number? I don't see why there should be a finite limit.

And as I recall, String theory used to say 10 dimensions, or perhaps 21 dimensions; apparently, the math worked out for both numbers. What happened to the 21?