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Notes and Reflections on Books and Media

by Hannah Leitheiser

universe according to superstring theory

the elegant universe: superstrings, hidden dimensions, and the quest for the ultimate theory

brian greene




so, the universe according to superstring theory:

in the beginning there was a 10 or 11 dimension calabi–yau manifold filled with strings (and higher dimensional p-branes in m theory). it was small relative to the plank length, which is the length at which length becomes a thing. it was nice and symmetric.

then expansion started. once three-spacial dimensions started to expand, it became harder for the others, so they remained small. a variety of particles started to 'precipitate' out with cooling. the holes in the calabi-yau manifold determined the various properties of the fundamental particles (some of which carry force). dot dot dot: today.

the problems in superstring theory are that it's hard to distinguish between many possible calabi-yau manifolds -- they can't be explicitly described. perhaps many are effectively the same (they call this duality), perhaps not. the math is hard all around. some versions make accurate postdictions (account for science already known) but to make predictions they generally must describe a particle accelerators could measure. most newly described particles would take universe size accelerators to see, which i suppose is another way of saying, you'd probably need another big bang. obviously not going to happen in the lab.