Big Bounce
It's a great question, just exactly the kind we like to ask:
Did our cosmos exist before the big bang?
According to the big bounce picture formulated by theoretical physicist Abhay Ashtekar and others, the cosmos grew from the collapse of a pre-existing universe. Will the same fate await us?It depends. We used to think that the universe was dominated by the gravity of its stars and other matter: either the universe is dense enough for gravity to halt the expansion from the big bang and pull everything back, or else it isn't, in which case the expansion would carry on forever. However, observations of distant supernovae in the past 10 years have challenged that view. They show not just that the universe is expanding, but also that the expansion is speeding up due to a mysterious repulsive force that cosmologists call "dark energy". So if the universe fails to contract, has it already bounced its last bounce?Perhaps not. Cosmologists are still very much in the dark about dark energy. Some theoretical models speculate that the nature of dark energy could change over time, switching from a repulsive to an attractive force that behaves much like gravity. If that happens, the universe will stop expanding and the galaxies will begin to rush together. A question mark also hangs over the universe's matter and energy density, which we have not measured with sufficient accuracy to be sure that the universe will not eventually stop expanding. If it turns out to be a smidgen greater than current observations, then it is a recipe for cosmic collapse.According to the big bounce, in both scenarios the universe will eventually collapse until it reaches the highest density allowed by the theory. At this point, the universe will rebound and begin expanding again - the ultimate in cosmic recycling.
It expands, it contracts. The universe is an accordion!
Or maybe accordion is the wrong analogy -- here's a picture of the cosmos in action:
The slinky is our universe. The stairs would then be...the context in which the universe exists. How big is the staircase, I wonder? Infinite?
More thoughts here.
Comments
Maybe the staircase is really an escalator...
Posted by: Chip Overclock | December 14, 2008 06:02 PM
The universe was not born from a single concentrated point of energy. It was born from an infinite vast expanse of gravitational field or say it philosophically or religiously from an infinite sourse of spirituality. When the current of gravitational wave or prime spirituality descended down
it started creating various regions below it, initially of course of region of gravitational force or pure spirituality. Thereafter when the current further descended down it started creating regions of electromagnetic forces and further regions of weak and strong nuclear forces. Gravitation force is present everywhere in the universe but the matter (Weak and strong nuclear force) and electromagnetic forces are not. When the process of creation is reversed back, weak and strong nuclear force merged into electromagnetice force and electromagnetic force ultimately merged into gravitational force. Then only gravitational force remains and no traces of matter or electromagnetic force. This is how the cycle of universe continues.
Posted by: a.k.satsangi | December 24, 2008 02:57 AM
You know, the Earth is unique, and if there's another planets with life, it's inhabitants will look not like us! and that is frightenning, I afraid if I would see one I will simply die away... are there any realistic idea about how they should look like?
Posted by: Jacob - Photostock Expert | January 14, 2009 04:07 AM