Interpretations of Quantum Mechanics
And Superstring Theories
"After the Rain - How the West Lost the East"
Click Here for Information about "Malignant Self Love - Narcissism Revisited" !
Time Asymmetry Re-Visited (Abstract Only)
Anthropic Agents and the Increase of Entropy (Abstract Only)
The Science of Superstitions
The Decoherence of Measurement
The Quantum of Continuity
F. The Micro and the Macro
Strings have two types of energy states, depending on the shape of space time. If curled (cylindrical) space-time is "fat" (let's say, the whole universe) there will be closely spaced energy states, which correspond to the number of waves (vibrations) of the string and its length, and widely spaced energy states, which correspond to the number of loops a string makes around curled (cylindrical) space-time (winding modes). If the curled (cylindrical) space time is "thin" (let's say a molecule), a mirror picture emerges. Obviously, in both cases - "fat" space-time and "thin" space-time - the same vibrations and winding states are observed. In other words, the microcosm yields the same physics as the macrocosm.
G. Black Holes
String theory, which is supposed to incorporate quantum gravity, should offer insights regarding black holes. String theories make use of the General Relativity Theory (GRT) formalism and add to it specific matter fields. Thus, many classical black hole solutions satisfy string equations of motion. In an effort to preserve some supersymmetry, superstring theory has devised its own black hole solutions (with D-branes, or "black branes", as the description of certain supersymmetric black holes). A match was even found between types of supersymmetric black holes and supergravity including greybody factors (frequency dependent corrections). String theorists have derived most of Hawking's (and Bekenstein's) work regarding the entropy of black holes from string theories.
This led to novel ways of thinking about strings. What if "open" strings were really closed ones with one part "hidden" behind a black brane? What if intersecting black branes wrapped around seven curled dimensions gave rise to black holes? The vanishing masses of black branes delineate a cosmological evolutionary tree - from a universe with one topology to another, with another topology. Our world may be the "default" universe on the path of least resistance and minimum energy from one universe to another.
H. From Supergravity to Membranes - A Recap
The particles with half integer spins predicted by supersymmetry are nowhere to be found. Either supersymmetry is a wrong idea or the particles are too heavy (or too something) to be detected by us with our current equipment. The latter (particles too heavy) is possible only if supersymmetry has broken down (which is almost the same as saying that it is wrong). Had it existed, it would probably have encompassed gravity (as does the General Theory of Relativity) in the form of "supergravity". The non-supersymmetric equivalent of supergravity can be gravity as we know it. In terms of particles, supersymmetry in an 11-dimensional universe talks about a supersymmetric gravitino and a spin 2 graviton.
Supersymmetric supergravity was supplanted by 10-dimensional
superstring theory because it could not account for handedness in nature
(i.e., the preference of left or right in spin direction and in other physical
phenomena) and for many quantum effects. From there it was a short - and
inevitable - way to membrane theories. Branes with "p" dimensions moved
in worldvolumes with p+1 dimensions and wrapped around curled dimensions
to produce strings. Strings are, therefore, the equivalents of branes.
To be more precise, strongly interacting (10-dimensional) strings are the
dual equivalent of weakly interacting five-branes (solitons) (Duff, Scientific
American, February 1998). Later, a duality between solitonic and fundamental
strings in 6 dimensions (the other 4 curled and the five-brane wrapped
around them) was established and then dualities between strings from the
5 string theories. Duff's "duality of dualities" states that the T-duality
of a solitonic string is the S-duality of the fundamental string and vice
versa. In other words, what appears as the charge of one object can also
be construed as the inversion of the length of another (and, hence, the
size of the dimension). All these insights - pulled together by Witten
- led to M Theory in 11 dimensions. Later on, matrix theories replaced
traditional coordinates in space time with non-commutable matrices. In
other words, in an effort to rigorously define M Theory (that is, merge
quantum physics with gravity), space time itself has been "sacrificed"
or "quantum theorized".
to Part VI --->
<--- Go Back to Part IV