String theory, like quantum theory, is background dependent in that it relies on the existence of time and space. Strings vibrate in space over time and string theory does not describe what time ...

At the time, physicists found themselves facing a crisis: the two most important ideas of 20th century physics, relativity and quantum theory, were known to be fundamentally incompatible.

A novel theory of "wavy space-time" suggests the division between our best descriptions of the universe on its smallest and largest scales may be because gravity does not play by quantum rules.

For starters, LQG studies bits of space-time, whereas string theory investigates the behavior of objects within space-time. Specific technical problems separate the fields.

String theory postulates that there are an additional six dimensions, but they are so tightly curled in the fabric of space-time that they are beyond microscopic – so tiny that the size of one ...

But our world has four dimensions (three of space and one of time), leading string theorists to conclude that the missing six dimensions are tiny—coiled into microscopic shapes resembling loofahs.

String theory — the proposal that physics is based on two-dimensional entities ('strings') vibrating in ten-dimensional space-time — is viewed by many physicists as the most promising approach ...

And we expect it to be discovered, of course. NOVA: How far are we along the road to fully understanding string theory? Gross: String theory could be right and totally incomplete.

One of the problems of string theory is that five different versions of it exist! Four of these are theories with closed strings, which can be visualised with elastic bands that move in space-time.

In order for the math to work, string theory requires that there be 10 dimensions: nine of space and one of time.

Japanese physicists have created a string theory model that simulates the birth of the universe. In their model, the Big Bang was a "symmetry-breaking event" — a fluctuation that caused three ...