The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos

by Brian Greene

One of the most beautiful features of string theory (and the facet that most impressed me when I learned the subject) is that particle properties are determined by the size and shape of the extra dimensions. Because strings are so tiny, they don’t just vibrate within the three big dimensions of common experience; they also vibrate into the tiny, curled-up dimensions. And much as air streams flowing through a wind instrument have vibrational patterns dictated by the instrument’s geometrical form, the strings in string theory have vibrational patterns dictated by the geometrical form of the curled-up dimensions. Recalling that string vibrational patterns determine particle properties such as mass and electrical charge, we see that these properties are determined by the geometry of the extra dimensions.

Does this reduce the degrees of freedom vs specifying particle properties of quantum field theory? Sounds like yes. But just shifting the input parameters back one layer itself doesn’t improve the elegance of the model.

And so, when it comes to explaining the properties of the fundamental particles, string theory has yet to realize its promise. In this regard, it so far offers no improvement over quantum field theory.13

Heh, ok, thought he was building toward the opposite conclusion.