January 19, 2012

Cosmologists Forced to “In the Beginning”


The late astronomer Robert Jastrow detailed in his 1978 book God and the Astronomers how cosmologists were repulsed by the idea the universe had a beginning. He found it quizzical that they would have such an emotional reaction. They all realized that a beginning out of nothing was implausible without a Creator. Since then, various models allowing for an eternal universe brought secular cosmologists relief from their emotional pains. It now appears that relief was premature.

In New Scientist (01/11/2012), Lisa Grossman reported on ideas presented at a conference titled “State of the Universe” convened in honor of Stephen Hawking’s 70th birthday. Some birthday; he got “the worst presents ever,” she said: “two bold proposals posed serious threats to our existing understanding of the cosmos.” Of the two, the latter is most serious: a presentation showing reasons why “the universe is not eternal, resurrecting the thorny question of how to kick-start the cosmos without the hand of a supernatural creator.”

It is well-known that Hawking has preferred a self-existing universe. Grossman quotes him saying, “‘A point of creation would be a place where science broke down. One would have to appeal to religion and the hand of God,’ Hawking told the meeting, at the University of Cambridge, in a pre-recorded speech.”

In her article, “Why physicists can’t avoid a creation event,” Grossman explains that “For a while it looked like it might be possible to dodge this problem, by relying on models such as an eternally inflating or cyclic universe, both of which seemed to continue infinitely in the past as well as the future.” These models were consistent with the big bang, she notes. Unfortunately, “as cosmologist Alexander Vilenkin of Tufts University in Boston explained last week, that hope has been gradually fading and may now be dead.” Here are the models in brief and why they don’t work:


1.Eternal inflation: Built on Alan Guth’s 1981 inflation proposal, this model imagines bubble universes forming and inflating spontaneously forever. Vilenkin and Guth had debunked this idea as recently as 2003. The equations still require a boundary in the past.

2.Eternal cycles: A universe that bounces endlessly from expansion to contraction has a certain appeal to some, but it won’t work either. “Disorder increases with time,” Grossman explained. “So following each cycle, the universe must get more and more disordered.” Logically, then, if there had already been an infinite number of cycles, the universe would already been in a state of maximum disorder, even if the universe gets bigger with each bounce. Scratch that model.

3.Eternal egg: One last holdout was the “cosmic egg” model that has the universe hatching out of some eternally-existing static state. “Late last year Vilenkin and graduate student Audrey Mithani showed that the egg could not have existed forever after all, as quantum instabilities would force it to collapse after a finite amount of time (arxiv.org/abs/1110.4096).” No way could the egg be eternal.

The upshot of this is clear. No model of an eternal universe works. Vilenkin concluded, “All the evidence we have says that the universe had a beginning.” An editorial at New Scientist called this, “The Genesis Problem.”

Source

Read also: Vilenkin’s Verdict: “All the evidence we have says that the universe had a beginning.”