Before the Big Bang? (Origins)

by David Turell , Friday, August 12, 2016, 16:08 (2814 days ago) @ dhw

dhw; In any case I don't see how current theory about the course of events AFTER the BB can help us understand what happened BEFORE the BB,-http://www.scientificamerican.com/article/did-the-universe-boot-up-with-a-big-bounce/?WT.mc_id=SA_SPC_20160811-"Under those conditions Turok and Gielen found that the contracting universe would never actually become a singularity—essentially it would “tunnel through” the worrisome point by hopping from a state right before it to a state right after it. Although such sidestepping sounds like cheating, it is a proved phenomenon in quantum mechanics. Because particles do not exist in absolute states but rather hazes of probability there is a small but real chance they can “tunnel” through physical barriers to reach locations seemingly off-limits to them—the equivalent, on a microscopic scale, of walking through walls. -***-"Under those conditions Turok and Gielen found that the contracting universe would never actually become a singularity—essentially it would “tunnel through” the worrisome point by hopping from a state right before it to a state right after it. Although such sidestepping sounds like cheating, it is a proved phenomenon in quantum mechanics. Because particles do not exist in absolute states but rather hazes of probability there is a small but real chance they can “tunnel” through physical barriers to reach locations seemingly off-limits to them—the equivalent, on a microscopic scale, of walking through walls. “The fuzziness in space and time and the matter conspires to make it uncertain where the universe is at a given time,” Turok explains. “This allows the universe to pass through the singularity.”-***-"If the universe bounced once, a natural question is whether it will again. But not all bounce theories suggest we are destined to cycle forever through contractions and expansions—for example, even if our universe bounced before, we have no indication so far that it is heading for another contraction. The dark energy thought to make up the largest chunk of the cosmos' total mass-energy budget seems to be pulling our universe apart at an ever-accelerating rate. What is truly in store for the future is a very open question—about as open, in fact, as the issue of how it all got started.-***- “'I'm not happy that they do not admit that all their earlier papers should be disregarded,” says Stanford University physicist Renata Kallosh, who calculated errors in previously proposed bounce models. “They now make a new claim, and this new claim I don't believe.” Alan Guth, a pioneer of inflation based at Massachusetts Institute of Technology, agrees. “I'm still skeptical whether they have actually achieved a nonsingular solution,” he says. “I would like to wait and see how it develops. If they have succeeded in what they claim they've done, I do agree it's very important—even if it's not the best model for the history of the universe.”-"Some inflation researchers are more forgiving, though. “I think that this is a very intriguing line of research,” says Marc Kamionkowski of Johns Hopkins University. “The bounce scenarios, although not yet developed to the level that inflation has been developed, are promising, and it's imperative to try to develop them further. This paper provides an interesting mathematical result, in a toy model,” he adds, referring to the idealized universe the researchers worked with.-"Kallosh and others object to using quantum cosmology to describe a bounce, because the universe may not have been microscopically small at such a stage. “They have the collapse of a big universe—why should a big universe be different from what general relativity says?” Turok counters that any ultimate theory of the universe will have to incorporate quantum mechanics into general relativity, because the classical theory on its own is known to break down at certain extremes. “Nature is quantum,” he says. “We know that classical theories don't make any sense at a very basic level.”-"Turok and other critics of inflation have their own problems with the dominant theory. They charge that inflation requires unlikely circumstances to get started (a claim proponents disagree with) and that it does not resolve the specter of a singularity at the moment of the big bang itself. Furthermore, “inflation leads to this nightmare scenario of a multiverse,” Turok says, “which for some strange reason is surprisingly popular.”-"He suggests that the heated debate in the field and the heavy scrutiny new ideas receive will help scientists ultimately converge on a better theory of our origins. “People hold very strong opinions,” Turok says. “I freely admit I do and I freely admit my opinions aren't shared by 95 percent of cosmologists. I'm actually critical of all these theories, including the ones I invented. But today we have spectacular observations pointing us at incredible simplicity in the universe. To me that means that all of our existing theories are way too complicated. The observations are pointing at simplicity and it's our job to come up with a simple theory that will hopefully explain those.'”-Comment: Note the theory does not tell us 'how it all started'; back to 'why is there anything'. Only about five percent of cosmologists are in this camp. This model is a very simple universe, but the attempt to get rid of the singularity which is classical physics by using quantum mechanics may be a step in the right direction