THE ELEGANT UNIVERSE PART 2: String’s the Thing

In order to solve some of the deepest mysteries of the universe, the rules that govern large objects like galaxies must be combined with the rules that govern small objects like subatomic particles.

Many physicists now believe that strings—miniscule vibrating strands of energy thought to make up all matter—hold the key to uniting the world of the large and the world of the small in a single theory.

In the 1960s, physicists caught a glimpse of what appeared to be strange, string-like objects hidden beneath the abstract symbols of a 200-year-old equation.

Meanwhile, mainstream science was embracing particles as points, not strings, and the Standard Model was born, uniting the strong force, the weak force, and electromagnetism.

By the 1970s, a few young physicists worked on taming the unruly equations of string theory and succeeded in describing how gravity works in the subatomic world, a key element missing from the Standard Model.

A revised version of string theory, free of mathematical inconsistencies, seemed capable of describing all the building blocks of nature, and it launched a hot new field of physics.

Despite our perception that we live in a universe with four dimensions—three spatial and one temporal—string theory demands that our universe has 11 dimensions.

By the mid-1980s physicists had developed five different versions of string theory, raising the question of whether it would prove to be a theory of everything or a theory of nothing.

taken from: http://www.pbs.org/wgbh/nova/elegant/program.html