The authors state, “So though we don’t yet have a complete quantum theory of gravity, we do know that the origin of the universe was a quantum event.” Modern cosmology infers that there really was a “big bang,” and attempts to describe the state of the universe in its first nanoseconds of existence when it may have been as small as the Plank size: a billion-trillion-trillionth of a centimeter. M-theory allows for “ different universes with different apparent laws, depending on how the internal space is curled.”Īrtist’s conception of parallel universes The other dimensions are tightly “curled up” in the visible dimensions and invisible to us. Both require the existence of multiple dimensions of space-time (10 and 11, respectively), only four of which are observable, time being the fourth. String theory and M-theory are attempts to resolve the inconsistencies. Although special relativity and quantum theory are both very powerful in their respective domains, they appear logically inconsistent with one another. To the authors, “the universe doesn’t have just a single history, but every possible history, each with its own probability and our observations of its current state affect its past and determine the different histories of the universe.”įor the past century, scientists have attempted to articulate a single theory that encompasses both special relativity (which accurately describes observations of large systems like galaxies) and quantum physics (which describes events on an atomic or nuclear scale). In quantum theory, the unobserved past (like the future) is indefinite, and exists only as a spectrum of probabilities. The authors’ perception of reality is shaped by the assumptions of quantum physics as explained by Richard Feynman, whose “sum over histories” approach posits that any physical system has not one history but every possible history. These issues traditionally have been part of the realm of philosophy, but the authors assert “philosophy is dead.” The answers they give to those deep conundrums are suggested by recent developments in physics, particularly the hyper-exotic concepts of what has become known as M-theory (which introduced an eleventh dimension to the previously posited ten dimensions of string theory).

In The Grand Design, Stephen Hawking and Leonard Mlodinow address the questions of what the nature of reality is, and whether the universe needs a “creator” to make sense.

The great design stephen hawking