COSMOLOGY TODAY sounds more and more like theology. Or rather it should be cosmologies, which offer conflicting theories of how the universe was created that resemble the oldest creation myths in the world's great religions.
The latest comes from Neil Turok, of Cambridge University in Britain, and Princeton University cosmologist Paul Steinhardt, who have developed a cyclical model of creation and destruction of the universe.
Unlike the Big Bang theory, according to which the universe was created in one blow 15 billion years ago, the pair argue in the latest issue of Science that the universe has gone through cycles of creation and annihilation for eternity.
'We propose a cosmological model in which the universe undergoes an endless sequence of cosmic epochs which begin with a 'bang' and end in a 'crunch'. Each cycle includes a period of slow expansion, followed by contraction that produces the next cycle,' they write. 'The model [contains] an endless sequence of cycles . . . There is neither a beginning nor end of time, nor is there a need to define initial conditions.'
It is a highly controversial idea, which uses the latest fashionable string theory - a mathematical theory that aims to unify all the forces of nature but which is as yet highly theoretical and has no experimental backing.
The theory advanced by Dr Turok and Dr Steinhardt has several advantages over the Big Bang. For one, there is no need to ask what happened before the Big Bang. Their mathematical idea makes use of a fifth dimension in addition to the usual three dimensions of space and one of time.
They invoke weird mathematical entities called membranes - branes for short - which exist for all eternity. At any one time, there are two branes. When they collide, which happens regularly - cosmically speaking - worlds are made or destroyed. One such cosmic clash happened 15 billion years ago, resulting in the massive release of energy previously ascribed to the Big Bang.