Thursday, May 5, 2011

Hawking's Grand Design

I read Stephen Hawking’s most recent book, “The Grand Design” (co-authored by Leonard Mlodinow), and highly recommend it, particularly to those who have never read a Hawking non-fiction before.  My only negative comment is that the book is short.  Even a slow reader like me can complete it in just a few hours.  Hawking, the rock-star physicist that he is, always leaves me wanting more.

“The Grand Design” was not well-received by religious groups, as it points out that God is not necessary for the universe to exist.  This comes as no surprise, as religious groups are particularly displeased whenever arguments are based on observation and reason. 

Hawking methodically dances between philosophy and physics throughout the book’s eight chapters.  The ongoing theme throughout is that modern physics is difficult to appreciate by non-physicists (and physicists too) because it is not observable in our every day experience.  Modern physics hides from us well, in the extremely small, mind-bogglingly large, and blindingly fast.

Classical physics was far simpler to derive than quantum physics because we interact with it every day.  Someone who has never taken a physics course can appreciate the classical laws, whether it is through collisions in sport, vibrations of a string, or the path taken by a projectile.

If quantum physics does not sit well with you, you are not alone – in fact, you are in excellent company.  Albert Einstein was not comfortable with quantum physics, as it claims that there are infinite possible outcomes for any particular scenario (and God does not play Yahtzee). 

Though not noticeable on our scale, the randomness predicted by quantum physics can and has been observed on the microscopic scale.  As Hawking points out, no theories in history have been put to the test more than those of Heisenberg and Feynman.  Through decades of rigorous testing, quantum theories have never been disproven.

What really surprised me in “The Grand Design” was Hawking’s current view of a single unified theory for physics.  For decades, the goal for top physicists has been to connect Einstein’s general relativity and quantum physics into one single theory that explains everything in the universe.  Many have been trying to fit both concepts into what has been called ‘string theory’.  As complex as string theory is, Hawking explains now that the real picture is far more complex (oh, great).

String theory represents a potential unified theory for our particular universe.  Hawking believes that something called M-theory is what we should begin to ponder.  M-theory suggests that as a given scenario can take multiple possible paths, our universe is just one of many (M) possible universes, each with its own unique laws.  This notion is far from the one that leading physicists had been championing in recent years (that one unified theory will be soon be found). 

Hawking’s M-theory is somewhat of a back-to-the-drawing-board scenario for modern physics.  Upon reflection, this is just as well, as modern physics has come to a bit of a standstill as of late. 

Now, as if the mysteries of one universe were not enough to blow one’s mind, we are asked to consider those of many universes.  If you are curious, Hawking believes there are 500 of them.  So, even when a working unified theory is found for our universe, physicists will be asked to sharpen their pencils and move on (1 down, 499 to go).

Hawking’s most recent work, and M-theory in particular, gives much credence to a Christopher Hitchens quote: “Through advances in science, we find that we know less and less about more and more.”

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