Monday, May 28, 2012

From nothing to something to nothing

By Mathew Goldstein

Why is the Earth 93 million miles from the Sun and the distance from Earth to Mars between 34 and 250 million miles? Questions like these, that seek the underlying purpose, are the sort of questions that theology falsely claims to answer. Such questions assume that there is a purpose behind everything and then assume that we can discern that purpose. But this flies in the face of all of the empirical evidence that there is no such purpose associated with everything and that, in any case, we have no way to discern any such purpose.

And so it is also with one of the favorite question of theists: Why is there something rather than nothing? There is no human focused, purpose based, explanation since humans are not the goal, and purpose is not the essential, or foundational, property of reality. So as long theists keep falsely insisting, a-priori, and contrary to the evidence we have, that the only "satisfactory" answers to the "why" questions must provide ultimate purpose from a human-centric perspective, they will continue to give priority to their own make-believe version of reality over the evidence.

We can fruitfully address the related "how" questions, such as what physical processes led to the Earth ending up in its present position. Most of theology, with it's insistence on finding the imaginary holy grail of the ultimate purpose, is non-productive. Unlike science, theology never has produced, and we have every reason to think cannot, and therefore never will produce, any knowledge.

Lawrence M. Krauss, in his new book, "A Universe from Nothing: Why There is Something Rather Than Nothing", advocates for the productive, empirical evidence first, skepticism based approach of science to resolve the mysteries of origins. He summarizes what we know, including what we know we don't know, about the origin of our universe, and he also discusses the possibility that there are mysteries about origins that we will never be able answer.

There is no way around the fact that the laws of physics are counter-intuitive and can only be understood by people who spend years learning the mathematics and studying the subject. So, for example, it turns out that empty space has gravitationally repulsive energy "... because it causes empty space to have "negative" pressure. As a result of this negative pressure, the universe actually does work on empty space as it expands". The end result is an initial period of inflation, after which "... one ends up with a universe full of stuff (matter and radiation), and the total Newtonian gravitational energy of that stuff will be as close as one can ever imagine to zero". Starting with "an infinitesimally small region of empty space" with a vacuum energy, we end up with an arbitrarily large and flat universe, without costing any energy. Our best measurements of our universe's curvature favor the conclusion that our universe is flat, exactly as predicated for a universe born from a tiny empty space.

The book has 11 chapters plus an epilogue. In chapter 9 he states: "Just as Darwin, albeit reluctantly, removed the need for divine intervention in the evolution of the modern world, teeming with diverse life throughout the planet ..., our current understanding of the universe, it's past, and it's future make it more plausible that "something" can arise out of nothing without the need for any divine guidance." But so far we have assumed a starting point of an infinitesimally tiny empty space. Where did that tiny empty space come from?

It turns out that everything happens that is not forbidden by the laws of physics. And according to the laws of physics, nothingness is an unstable condition, nothing always produces something. Not only can nothing become something, it is required to, but in a way that balances negative and positive energy so that they sum to zero.

At this point we encounter several of the big unresolved mysteries of cosmology. One question is what generated the asymmetry between matter and anti-matter? Dr. Krauss emphasizes that "independent of this uncertainty [regarding how our universe became dominated by matter], however, is the remarkable fact that a feature of the underlying laws of physics can allow quantum process to drive the universe away from a featureless state".

Another unresolved question is whether or not "small, possibly compact spaces ... themselves pop in and out existence?" And here Dr. Krauss follows the general principle that anything "not proscribed by the laws of physics must actually happen...". Citing Stephen Hawking, Dr. Krauss says "a quantum theory of gravity [which we currently do not have] allows for the creation, albeit perhaps momentarily, of space itself where none existed before." Furthermore, "a compact universe with zero total energy" could spontaneously appear and remain for a long time, without violating the Uncertainty Principle (a basic principle of quantum mechanics).

This suggests that our universe not only has total Newtonian gravitational energy of zero, and is therefore geometrically flat, but also has total energy, including the mass energy (e=mc2), of zero, and therefore our universe was initially geometrically closed. In other words, an initially tiny, closed universe can pop into existence, rapidly and exponentially expand (inflate) into an infinitely large flat universe, spontaneously, with impunity, carrying no net energy.

It is said that "out of nothing nothing comes". This has no foundation in science. Instead, the laws of physics imply there is a multiverse, with the other universes existing either in extra dimensions or in a context of eternal inflation within three dimensional space [the existence of extra dimensions is another unresolved question of cosmology]. The laws of nature in each universe may be set stochastically and randomly. It is even possible that there is no fundamental theory. It could be that "there is something simply because, if there was nothing, we wouldn't find ourselves living here." The question why is there something rather than nothing "... may be no more significant or profound than asking why some flowers are red and some are blue."

It may be that in the multiverse there are an infinite set of different laws of nature, or there may be a very restricted combination of laws that results in viable universes. Lawrence Krauss has clearly given considerable thought to the subject of origins, and he makes winning and important arguments on behalf of the conclusion in his epilogue that "I find oddly satisfying the conclusion that, in either scenario [infinite or restricted set of laws of nature], a seemingly omnipotent God would have no freedom in the creation of our universe. No doubt because it further suggests that God is unnecessary - or at best redundant."

This book received a strongly negative review in the NY Times. Having read the book, I can say that that negative book review was unfair. This is a very good book.

1 comment:

Gary Berg-Cross said...

There' a good hour long YouTube video of Krause giving an RDF sponsored talk on this which adds his sense of humor to these topics. Richard Dawkins provides the humorus intro. See http://www.youtube.com/watch?v=0ZiXC8Yh4T0

This was played at the recent Atheist Meetup in Rockville.