This is great Article. Now there is the Big Rip, or Big Collapse, or just a Big Fizzle as alternatives to expansion forever to absolute zero, or contraction back to a big Crunch, or the rubber band forever of expand and collapse back to a new big bang. Indeed, does Quintessence change with time, or does Quintessence become phantom energy that we use to open wormholes and travel through time? Are we ready for negative kinetic energy, where atoms lose energy by speeding up, or for a "standard model" of the universe that fits all the data, but which we must admit we have no hope of understanding, moving science from the current outward signs of faith to an inward and spiritual grace? enjoy!
http://www.nytimes.com/2004/02/17/science/space/17DARK.htmlFebruary 17, 2004 From Space, a New View of Doomsday
By DENNIS OVERBYE
<snip>Recent astronomical measurements, scientists say, cannot rule out the possibility that in a few billion years a mysterious force permeating space-time will be strong enough to blow everything apart, shred rocks, animals, molecules and finally even atoms in a last seemingly mad instant of cosmic self-abnegation.<snip>
Instead of slowing down from cosmic gravity, as cosmologists had presumed for a century, the galaxies started speeding up about five billion years ago, like a driver hitting the gas pedal after passing a tollbooth.
Dark energy sounded crazy at the time, but in the intervening years a cascade of observations have strengthened the case that something truly weird is going on in the sky. It has a name, but that belies the fact that nobody really knows what dark energy is.
In six years it has become one of the central and apparently unavoidable features of the cosmos, the surprise question mark at the top of everybody's list, undermining what physicists presumed they understood about space, time, gravity and the future of the universe.<snip>
The idea of an antigravitational force pervading the cosmos does sound like science fiction, but theorists have long known that certain energy fields would exert negative pressure that would in turn, according to Einstein's equations, produce negative gravity. Indeed, some kind of brief and violent antigravitational boost, called inflation, is thought by theorists to have fueled the Big Bang.<snip>
Another possibility comes from string theory, the putative theory of everything, which allows that space could be laced with other energy fields, associated with particles or forces as yet undiscovered. Those fields, collectively called quintessence, could have an antigravity effect. Quintessence could change with time — for example, getting weaker and eventually disappearing as the universe expanded and diluted the field — or could even change from a repulsive force to an attractive one, which could set off a big crunch.<snip>
Dr. Chris Pritchet of the University of Victoria, who is part of a collaboration using the Canada-France-Hawaii telescope on Mauna Kea to search for supernovas, said, "In many ways phantom energy is unphysical, but we're not ruling it out." <snip>