Alternatives to the 'Big Bang Theory'?

Question

what are the leading alternative theories to the more popular "Big Bang Theory"?

Answer 1

Super-symmetry and string theory are other theories.

Some newer theories such as string theory do postulate extra dimensions, but as our three-dimensional universe expands, it does not need these extra dimensions to spread into.

TWO ALTERNATE THEORIES

1. The first, known as the pre-big bang scenario, combines T-duality with the better-known symmetry of time reversal, whereby the equations of physics work equally well when applied backward and forward in time. The combination gives rise to new possible cosmologies in which the universe, say, five seconds before the Big Bang expanded at the same pace as it did five seconds after the Big Bang. But the rate of change of the expansion was opposite at the two instants: if it was decelerating after the Big Bang, it was accelerating before. In short, the Big Bang may not have been the origin of the universe but simply a violent transition from acceleration to deceleration.

In the standard theory, acceleration occurs after the Big Bang because of an ad hoc inflation field. In the pre-big bang scenario, it occurs before the Big Bang as a natural outcome of the novel symmetries of string theory.

According to the scenario, the pre-bang universe was almost a perfect mirror image of the post-bang one. Infinitely long ago it was nearly empty, filled only with a tenuous, widely dispersed, chaotic gas of radiation and matter. The forces of nature, controlled by the dilaton field, were so feeble that particles in this gas barely interacted.

As time went on, the forces gained in strength and pulled matter together. Randomly, some regions accumulated matter at the expense of their surroundings. Eventually the density in these regions became so high that black holes started to form. Matter inside those regions was then cut off from the outside, breaking up the universe into disconnected pieces.

2. In a variant of this scenario, the collisions occur cyclically. Branes are domains or swaths of several spatial dimensions within a higher-dimensional spacee (extra dimensions and membranes). The everyday world we live in can be considered to be a three-brane.Two branes might hit, bounce off each other, move apart, pull each other together, hit again, and so on. In between collisions, the branes behave like Silly Putty, expanding as they recede and contracting somewhat as they come back together. During the turnaround, the expansion rate accelerates; indeed, the present accelerating expansion of the universe may augur another collision.

The cyclic model is based on the idea that our universe is a three-dimensional brane that bounds a four-dimensional space. Another brane--a parallel universe--resides a subsubatomic distance away. That universe is closer to you than your own skin, yet you can never see or touch it.

All the magic properties of quantum strings point in one direction: strings abhor infinity. They cannot collapse to an infinitesimal point, so they avoid the paradoxes that collapse entails. Their nonzero size and novel symmetries set upper bounds to physical quantities that increase without limit in conventional theories, and they set lower bounds to quantities that decrease.

String theorists expect that when one plays the history of the universe backward in time, the curvature of spacetime starts to increase. But instead of going all the way to infinity (at the traditional Big Bang singularity), it eventually hits a maximum and shrinks once more. Before string theory, physicists were hard-pressed to imagine any mechanism that could so cleanly eliminate the singularity.

These two branes act as if connected by a spring, which pulls the branes together when they are far apart and pushes them apart when they are close. Thus, they oscillate to and fro. Periodically the branes hit and rebound like cymbals. To those of us stuck inside one of the branes, the collision looks exactly like a big bang. The hot primordial soup was the energy dumped into the branes when they hit. The density fluctuations that seeded galaxies began as wrinkles in the branes.

Answer 2

I think that there is a semantics problem here. First off everyone in astrophysics believes that big bang theory describes everything from let's say 1 second after the initial 'bang' until now almost perfectly. The only debates are what happened in that first 10e-35 of a second after the bang. After that time the evolution of the universe is extremely well understood and stands up to a plethora of predictions.

Answer 3

All scientific proposals at this point have some version of the Big Bang. What is at issue are questions concerning the details of the expansion and how it got started. Theories involving branes or strings say that the expansion got stated through collisions of various sorts. Inflationary scenarios discuss the very early stages of the expansion. But we know that there is a universal expansion and that general relativity and known particle dynamics serve to explain what we see after very early times in that expansion. All of the current debate is about times before about 1 millisecond after the main expansion started.

Answer 4

CERN
http://public.web.cern.ch/Public/Welcome.html
European Laboratory for Particle Physics. Includes an introduction of the laboratory, information on experiments being conducted, publication archives, photos and press releases.
THEY WANT THE BIG BANG THEORY.
On the quest for neutrinos mass, the CERN Neutrino to Gran Sasso (CNGS) project will send a beam of high-energy neutrinos from CERN to the Italian Gran Sasso Laboratory, 730 km away through the Earth.
http://www.exploratorium.edu/origins/cern/index.html
Antimatter, the big bang and a particle that gives others mass

Answer 5

"STEVEN HAWKIN'S UNIVERSE" by PBS lists no less than 7 alternate theories. Recently, the Big Bang theory is in vogue, but this was not always so. Theories about the Universe are often accompanied by a religious fervor approaching fanaticism.

Answer 6

We are entities in a God's Dream?

Answer 7

There are none that are accepted by the scientific community, therefore, there are none.

Answer 8

the Bible

Answer 9

The bible.......