Archive for September 4th, 2009
Having just done a post on quantum mechanics and particle physics, fields as distant from political science as one can imagine, and whose math I cannot grasp, I tried to resist the temptation to venture into modern physics yet again, but an article in Discover has me thinking.
Stephen Hawking is perhaps the best known physicist in the world, whose long term stature is still to be determined. Putting forth theories virtually untestable at the current time, he hasn’t had the practical impact of many other of the century’s physicists. His handicap — he has suffered from “Lou Gehrig’s Disease” or ALS since the early sixties — has been a blessing in disguise. It has turned his body useless, meaning he communicates with a sophisticated computer read out and voice, and he is permanently bound to a wheel chair. He is unable to enjoy life the way most people do, and unable to do his work and calculations in a manner typical for theoretical physics. Yet, as the article points out, this also has forced him to think differently, visualizing ideas in a geometric fashion, generating insights he probably would not have had if he handled the thinking in a usual way.
Alas, for nearly thirty years Hawking has been less relevant than famous. His major works were in the seventies, and while he still is active in science and culture (appearing on Star Trek and the Simpsons, for instance), his fame is more his image — the handicapped genius scientist — than recent output. Yet his new theory is fascinating. Not being a scientist or science writer, allow me to quote Discover, July/August 2009, p. 51:
“It is not the case that the past uniquely determines the present. Because the universe has many possible histories and just as many possible beginnings, the present state of the universe selects the past. ‘This means that the histories of the Universe depend upon what is being measured,’ Hawking wrote in a recent paper, ‘contrary to the usual idea that the Universe has an objective observer-indepent history.’ This idea could cut through some long standing scientific mysteries. One debate now roiling the physics community concerns string theory, currently the leading candidate for a so-called theory of everything. String theory holds that all the particles and forces in the universe can be explained as arising from the vibrations of vanishingly small strands of energy. But it has one huge problem: Its fundamental equations have a near infinite number of solutions, each corresponding to a unique universe. Hawking’s idea provides a natural context for string theory. All those universes might simply represent different possible histories of our universe. “
Think of the implications of this theory. Hawking, like most physicists, doesn’t really like it when one starts jumping from quantum weirdness to speculation about spirituality or the nature of life. I think the reason is less that they want to hold on to raw materialism, but more that such a move seems to ignore the absolute beauty and elegance of the equations and models which generate these theories. Those models, which I am unable to appreciate due to my lack of math skill, are elegant, complex and to those who understand them, aesthetically beautiful and dramatic. To jump to speculation about spirit or God, or something like that, well, that even seems to diminish the beauty of the theory.
Yet those of us who don’t get the math have to think in mundane terms about the meaning. The article notes that this theory may be testable, since the background micro-radiation from the universe’s early days may contain evidence of the existence of other quantum universes. If Hawking is right, then the present as a point in space time is not just a determined reality that must exist, but the actualization of a particular quantum probability that is not connected with any one particular past, or determinate of any one particular future. Clearly we are not constantly shifting pasts (at least in any way we notice) , so human existence probably deals with a narrow range of quantum fluctuation (as macro objects we do not experience the wildness of the micro quantum world), but yet that may be the nature of the universe(s).
Hawking is trying, with this theory, to overcome the need for the universe to begin with a singularity — an infinitely dense point. Singularities are mathematical possibilities in relativity, but seem impossible to imagine — how can a point be infinitely small and infinitely dense? Well, general relativity and quantum mechanics have fundamental disagreements, and thus one or both of them have errors. Hawking believes that if you apply quantum physics to the start of the universe, Heisenberg’s Uncertainty principle could mean that a singularity does not form, and the uncertainty fosters these multiple probable universes.
That would mean that consciousness exists at a point in space time, moving through it in ways that can vary. Herein is an opening for free will, and for speculation on why consciousness has that power. It opens up room for spirituality, even religion, and a recognition that the world may be a lot weirder than we realize. But for me, there is one reason why I find myself especially enticed by this theory. In a blog I wrote last year, on June 20, 2008, I speculated on this kind of possibility: Spinoza, Quantum Mechanics and Free Will.
On a different note, in an honors course I’m co-teaching with five other professors, we had a good discussion today about history, perspective, and truth. Is there one historical past we can “discover,” or a clear set of indisputable facts? Well, if Hawking is right there are probably an infinite number of probable pasts, and at any given point what we measure affects which past exists.
OK, I think I need a drink. This is starting to make my head hurt.