superstring theory

In physics and cosmology, a mathematical theory developed in the 1980s to explain the properties of elementary particles and the forces between them (in particular, gravity and the nuclear forces) in a way that combines relativity and quantum theory. In string theory, the fundamental objects in the universe are not pointlike particles but extremely small stringlike objects. These objects exist in a universe of ten dimensions, but since the earliest moments of the Big Bang six of these have been compacted or ‘rolled up’, so that now, only three space dimensions and one dimension of time are discernible.

There are many unresolved difficulties with superstring theory, but some physicists think it may be the ultimate ‘theory of everything’ that explains all aspects of the universe within one framework.