String theory, which was first proposed in the 1970s, suggests that the universe is not composed of particles as we think of them, but of very small loops of string that vibrate at certain frequencies. As Brian Greene, a string theory physicist, says in his book The Elegant Universe, the universe consists of “loops of strings and oscillating globules, uniting all of creation into vibrational patterns that are meticulously executed in a universe with numerous hidden dimensions capable of undergoing extreme contortions in which their spatial fabric tears apart and then repairs itself” (386). The frequency at which the strings vibrate determines what the string is; that is, electrons vibrate one way, photons another. These strings are so small that we currently cannot see them, being only 10–33centimeters long also called the Planck length. String theory postulates that the Planck length is as small as things get in this physical universe. String theory does not attempt to describe what might exist below the Planck length.
Our study of string theory has not yet revealed how it explains non-locality(i.e., simultaneous communication between separated particles that seems to exceed the speed of light) as proven in Bell’s theorem, nor does it directly address the hierarchy of levels proposed by Bohm. This may be because string theory is silent on these points, or because we have not studied string theory long and hard enough. However, our initial impression of string theory is that it does not conflict with either non-locality or Bohm’s hierarchy of levels since both of the latter are postulated to occur outside of space-time, or below the Planck length. String theory may one day address these deeper levels, as Brian Greene tells us on page 387 of The Elegant Universe: “We have seen glimpses of a strange new domain of the universe lurking beneath the Planck length, possibly one in which there is no notion of time or space. At the opposite extreme, we have also seen that our universe may merely be one of the innumerable frothing bubbles on the surface of a vast and turbulent cosmic ocean called the multiverse. These ideas are at the current edge of speculation, but they may presage the next leap in our understanding of the universe.”