Current Theories - Big Bang

The standard cosmology is the most reliably elucidated epoch spanning the epoch from about one hundredth of a second after the Big Bang through to the present day. The standard model for the evolution of the Universe in this epoch have faced many stringent observational tests.

Particle cosmology builds a picture of the universe prior to this at temperature regimes which still lie within known physics. For example, high energy particle acclerators at CERN and Fermilab allow us to test physical models for processes which would occur only 0.00000000001 seconds after the Big Bang. This area of cosmology is more speculative, as it involves at least some extrapolation, and often faces intractable calculational difficulties. Many cosmologists argue that reasonable extrapolations can be made to times as early as a grand unification phase transition.

Quantum cosmology considers questions about the origin of the Universe itself. This endeavours to describe quantum processes at the earliest times that we can conceive of a classical space-time, that is, the Planck epoch at 0.0000000000000000000000000000000000000000001 seconds. Given that we as yet do not have a fully self-consistent theory of quantum gravity, this area of cosmology is more speculative. source of energy, matter and the universe itself is the ultimate mystery of, well, the universe.

Based on a widespread afterglow called the cosmic microwave background (and other evidence), scientists think that the cosmos formed from a "Big Bang" -- an incomprehensible expansion of energy from an ultra-hot, ultra-dense state.

Describing time before the event, however, may be impossible.

Still, atom smasher searches for particles that formed shortly after the Big Bang could shed new light on the universe's mysterious existence -- and make it a bit less strange than it is today.

Caption: Illustration showing the creation and expansion of the universe. Credit: NASA

Article posted October 31, 2008.