Friday, March 30, 2012

When Absolutely Nothing Matters - Mukul Sharma


When Absolutely Nothing Matters
By: Mukul Sharma 
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If it’s true that a vacuum can create virtual particles, did our universe materialise out of nothing, asks MUKUL SHARMA
Nothing can come out of nothing — ex nihilo nihil — is something most people would agree with intuitively because it seems to pack such a punch of commonsense. In fact, the first thermodynamic law of energy conservation which underpins all of physics says basically the same thing — that matter (or energy) cannot be created or destroyed. The same argument has also frequently been invoked by detractors of the Big Bang theory to discredit it. How could all of space, time and matter, they ask, be created out of nothing unless some supernatural agency intervened.
However, all is not lost. That’s because funnily enough, other laws of modern physics do permit the creation of matter — albeit at a subatomic level — to take place spontaneously if it does so for a small enough period of time, so long as it vanishes back into the nothingness it sprang out of before that infinitesimally tiny bit of time expires.
Electrons, for instance, are allowed to pop in and out of existence and the fact that they do — all the time and everywhere in the vacuum of space — is something that has been experimentally verified thousands of times. They’re called “virtual particles” and form an integral part of physical equations and calculations because they produce effects that can be measured.
As the cosmologist Paul Davies puts it: “Even though we can’t see them, we know that these virtual particles are ‘really there’ in empty space because they leave a detectable trace of their activities.... These minute but significant alterations have been very accurately measured using spectroscopic techniques.”
So, what’s going on here? Something can come out of nothing? Physicists have now come to believe that empty space is never really empty and classify such phenomenon as “vacuum fluctuations” responsible for giving rise to virtual particles. That is, far from being empty with an absence of everything, even a perfect vacuum is filled with wave-like fields that fluctuate constantly, producing a multitude of ephemeral particles that continually arise out of nowhere, only to disappear into nowhere again.
This inevitably leads to the awesome conclusion that nothingness doesn’t exist and, back in 1948, the physicist Hendrik Cassimir virtually proved it. He found that if two metal plates in a vacuum were positioned extremely close to each other, maybe like only a hundred atoms apart, they were drawn together as if something was pushing them from the outside. And, indeed, there was as scientists soon found out: the vacuum fluctuations between the plates were too small compared to the vacuum fluctuations that existed outside of them and that was creating the attractive force. Apparently, nothingness was suddenly a force to reckon with.
Suddenly, other people began rethinking the Big Bang in a different way. Why, they wondered, couldn’t the first tiny bit of space, time and matter that initially came into being and became our entire universe later, itself be a massive vacuum fluctuation that began its existence as a virtual particle? It could of course, but there’s a small problem.
What came into existence in the Big Bang should in that case have lasted less than a trillion, trillion, trillionth of a second — if not less — and winked out immediately. But here it all is so many billions of years later and still going strong.
Some say the reason is because the infant universe went through a period of extreme inflation just after the Big Bang which ballooned out exponentially almost instantly causing the vacuum fluctuations to also behave in the same manner, thus stretching their timeline and lifetimes.
Others question the nature of time itself. Does a fraction of a second remain the same everywhere and mean the same thing to all observers? One day in the life of Brahma, for example, is said to equal some four billion years — which is how long the universe endures before it’s destroyed and recreated out of nothingness that doesn’t exist!