Over Christmas I finished the book "The Grand Design" by Stephen Hawking and Leonard Mlodinow. Hawking and Mlodinow claim at the beginning of the book that "philosophy is dead." They assert boldly that science is leading the way to find answers to questions regarding origins that were once the domain of philosophy: Why do we exist? Why is there something rather than nothing? and Why this particular set of laws and not some other? They conclude that God is no longer needed as an explanation. Hawking and Mlodinow believe that M-Theory is the best candidate for a unified theory of everything that can answer the questions of our existence.
Regarding the question of why there is something rather than nothing, the authors state in this oft quoted passage:
Because gravity shapes space and time, it allows space-time to be locally stable but globally unstable. On the scale of the entire universe, the positive energy of the matter can be balanced by the negative gravitational energy, and so there is no restriction on the creation of whole universes. Because there is a law like gravity, the universe can and will create itself from nothing in the manner described in Chapter 6. Spontaneous creation is the reason there is something rather than nothing, why the universe exists, why we exist. It is not necessary to invoke God to light the blue touch paper and set the universe going.
Luke, at Common Sense Atheism, reviewed The Grand Design and discusses an unfulfilling aspect of the book, noting that no where does it actually explain how something comes from nothing. When Hawking and Mlodinow describe the spontaneous creation of the universe, they describe it arising from "quantum fluctuations" which cause "microscopic" universes to arise and then either disappear or "expand in an inflationary manner." As Luke's review notes, this quantum vacuum is not "nothing" in the sense most of us conceptualize it.
I was interested that Hawking and Mlodinow acknowledge the strong anthropic principle, which "suggests that the fact that we exist imposes constraints not just on our environment but on the possible form and content of the laws of nature themselves." This brings up very real questions about how the universe managed to be so fit for life, given the great unlikelihood that chance alone could account for the necessary highly specified variables being in place, such as the strength of the strong nuclear force as well as the electromagnetic force, the number of space dimensions, and the cosmological constant. However, Hawking and Mlodinow state that if M-Theory is true, then the statistically unlikely becomes likely, as our universe is one of a multitude of universes that exist. They admit that work still needs to be done to substantiate M-Theory. However, they appear confident that it will prove to be the grand unifying theory of everything, which has been the holy grail of physicists since Einstein. It's fascinating to think we may be capable of understanding our origins. However, I was certainly not left feeling as if we understand them yet.
Some are quick to dismiss fine tuning as one of the stronger arguments in favor of intelligent design. However, Hawking and Mlodinow appear to concede that the fine tuning of the universe poses a difficulty for those seeking a naturalistic explanation of the universe, given the statistical improbability of it all. Of course, M-Theory potentially answers the challenge of fine tuning, but it still remains to be seen.
As always, I enjoyed Hawking's ability to explain technical concepts in easily accessible and entertaining ways. While the book may be premature in asserting M-theory to be the answer to life's deepest questions, it will at least serve to open the public up to M-theory as a possibility. (If they weren't already aware of it from the likes of Star Trek.)