Search For A Final Theory: A Holy Grail? : 13.7: Cosmos And Culture : NPR
The goal of elementary particle physics is to obtain a description of
matter in its most fundamental form. These indivisible bits of stuff
have certain properties, such as mass and electric charge, and can
interact via four forces: gravity, electromagnetism, and two that only
manifest themselves at nuclear distances, the strong and weak forces. A
Final Theory would unify these four forces into a single one, showing
that, at very high energies such as those prevalent near the Big Bang,
these four forces were one. As the universe expanded and cooled, this
force would gradually split, until it became the four forces we know
today: unification dissolves through cosmic history. At present, superstring theories
are the best candidates for such unification, although they remain far
from achieving this goal. Such theories actually go beyond the notion of
elementary particles: the fundamental entities are wiggling strings of
energy that move in nine spatial dimensions: as with guitar strings,
different modes of vibration carry different amounts of energy, each
identifiable with an elementary particle of matter.
