QUESTION FIVE
5. How does superstring (or super membrane) theory reconcile Einstein's general theory of relativity with quantum mechanics? More precisely, how does superstring theory reduce the four forces of the universe (name them) into one super force?
early theories that tried to combine the four forces of the universe --- electromagnetic force, gravitational force, strong force, and weak force --- called the "supergravity theories," have failed because they result in infinity. the introduction of the concept of supersymmetry, which claims that each particle has a so-called "superpartner" whose spin is 1/2 greater or smaller than the particle itself, allows these supergravity theories to continues to exist, but not for long. supersymmetry cancels the "biggest infinities" (hawking 52) in supergravity theories, but no one knows whether the leftover quantities will be infinite or not. this uncertainty causes scientists to abandon the supergravity theories because theories that result in infinities are considered to be "fatally flawed" (hawking 52) and introduce the idea of string theory.
superstring theory is a theory that starts out by assuming that every particle in this universe is made out of tiny vibrating strings of energy, with different vibration modes on the string correspond to different particles. these strings that the string theory predicts to exist, are "one-dimensional extended objects," (hawking 52) which only have length dimension. if vibrations of the string correspond particles (namely bosons and fermions) and the strings have grassman dimensions, then as hawking claims it: "positive and negative ground state energy will cancel so exactly that there will be no infinities even of the smaller sort." (hawking 52) when one combines electromagnetic force with the strong and weak force, one still gets a consistent, finite answer from the theory, but when one takes gravity into play, one starts getting infinities. these infinities are the biggest obstacle to physicists who are trying to formulate ONE theory that explains everything in this universe, namely the TOE (theory of everything). string theory, however, manages to eliminate these infinities without much hassle like the old supergravity theories, thus making string theory the strongest candidate for TOE.
early theories that tried to combine the four forces of the universe --- electromagnetic force, gravitational force, strong force, and weak force --- called the "supergravity theories," have failed because they result in infinity. the introduction of the concept of supersymmetry, which claims that each particle has a so-called "superpartner" whose spin is 1/2 greater or smaller than the particle itself, allows these supergravity theories to continues to exist, but not for long. supersymmetry cancels the "biggest infinities" (hawking 52) in supergravity theories, but no one knows whether the leftover quantities will be infinite or not. this uncertainty causes scientists to abandon the supergravity theories because theories that result in infinities are considered to be "fatally flawed" (hawking 52) and introduce the idea of string theory.
superstring theory is a theory that starts out by assuming that every particle in this universe is made out of tiny vibrating strings of energy, with different vibration modes on the string correspond to different particles. these strings that the string theory predicts to exist, are "one-dimensional extended objects," (hawking 52) which only have length dimension. if vibrations of the string correspond particles (namely bosons and fermions) and the strings have grassman dimensions, then as hawking claims it: "positive and negative ground state energy will cancel so exactly that there will be no infinities even of the smaller sort." (hawking 52) when one combines electromagnetic force with the strong and weak force, one still gets a consistent, finite answer from the theory, but when one takes gravity into play, one starts getting infinities. these infinities are the biggest obstacle to physicists who are trying to formulate ONE theory that explains everything in this universe, namely the TOE (theory of everything). string theory, however, manages to eliminate these infinities without much hassle like the old supergravity theories, thus making string theory the strongest candidate for TOE.
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