Does String Theory tell us the size of Extra Dimensions.

[hankaaron]

Does the math in string theory tell us anything about the size of any of the extra dimensions?

 

[Naty1]

no so much.

for one thing there are many models with varying 'extra dimensions'...sometimes
Calabi-Yau [which I think are small, 'compactified'] and other times branes [bigger] and sometimes a mix...Then there is an ADD model with large extra dimensions.

Some discussion on extra dimensions here:

http://en.wikipedia.org/wiki/String_theory#Extra_dimensionsedit: a discussion with some background...no precise answer...here:

https://www.physicsforums.com/showthread.php?t=421326

This discussion brings out some of the complexities in addressing your question

 

[mitchell porter]

To a first approximation, string theory in its current form tells us nothing. Instead, you tell it what you want.