Thursday, May 21, 2009

Crazy Science

In his insightful book "The Trouble With Physics" Lee Smolin made the case that something has gone wrong with physics, the queen of science, over the last 40 years. In Smolin's view the last generation of effort in theoretical physics (at least those who study "fundamental physics") has stalled.

After centuries in which each generation uncovered some deeper and more elemental character of physical reality than the last (gravity, electromagnetism, statistical physics, relativity, quantum theory) the endeavor has lost its momentum. In the 40 years since the basic elements of the standard model of particle physics was put in place no deeper insight into the roots of the model have been discovered. Quantum Gravity, the holy grail of theoretical physics uniting the twin pillars of Einsteins' General Relativity and Quantum Mechanics, remains elusive. Despite its elegance and mathematical insights String Theory has not yet lived up to its promise of a theory of everything. The values of the 20 constants, which the standard model demands be put in by hand, remain unexplained by a deeper law.

For Smolin the requirement of invisible higher dimensions, which form the hallmark of string theory ,is part of this failure. If you need to invent invisible realities to make a theory work then, he argues, you are not explaining, you are explaining away. The same point can be made about the ideas of the multiverse - the universe of unobservable other universes - which are now a standard feature in many cosmological models.

These "crazy" ideas of modern physics (extra dimensions, extra universes) make many physicists nervous. They sound so much like plot devises from a Star Trek movie. Where are the close ties to experiment that form the hallmark of empirical investigation? Shouldn't physics and all of science be about the facts of this world, not the mathematical imaginings of some other possible worlds?

These conundrums are part of the dissatisfaction that have led some scientists to step entirely outside the box and ask what are we missing? What basic cherished principle are we holding onto and, in the process, holding ourselves back. It is from this vantage point that some are asking if the idea of physical law itself must be revised. It is from this vantage point that some are willing to ask what would Law without Law look like?

Tuesday, May 19, 2009

Law and Time: Who's on First?

So I am in the midst of the annual NASA grant writing binge which is my excuse for not writing more on my new favorite topic: Law without Law.

Over the next few weeks I will be writing a piece for DISCOVER magazine on this strange and, for me, revolutionary topic. As the comments to the last post artfully reveal this is really where the metaphysical rubber meets the empirical road. For today let me just give a little background. The term "Law without Law" originated, as far as I know, with the great American theoretical physicist John Wheeler. Wheeler was so far ahead of the curve in so many ways its hard to tabulate them all. He managed to be both radical, skeptical, hard headed and a dreamer all at the same time.

In his essay of the same name Wheeler asked about the interaction between quantum phenomena and observers and used a thought experiment involving a gravitationally lensed quasar to muse on the notion of "observer-participancy". In this wide ranging essay Wheeler seems to be arguing that reality is ongoing creative interaction between what he calls elementary phenomena (individual quantum processes) and observers (you and me). Only taken together as a whole, he says, does the world take the form we see. It may be essential here to emphasize the "we see" part because Wheeler never doubts there is a world out there but what he is asking about is the form of the world that humans are part of as observer-participants.

One could go on quite a while about this article which I recommend and ask if its crazy or sloppy or insightful. The point for this post is the conclusion that sits above his specific thinking about quantum mechanics: the so-called Laws of Physics, the timeless, eternal constraints which hover above and beyond this world, may be a fiction. Using the evolution as his example Wheeler asks

"Are the laws of physics immutable and eternal or are theses laws, like species, mutable and of a higgledy-pigglety origin"

Wheeler points to the origin of individual species as the result of countless blind accidents and then asks could the laws of this universe have emerged in the same way? Do they still emerge in the same way?

As a number of people have pointed out in the comments this, on face value, would seem impossible and, if it were possible, would challenge some of the most cherished assumptions of the scientific enterprise. Since I spent the last month reading and talking with scientists like Lee Smolin, Stuart Kauffman and Andy Albrecht on just this subject I will try and unpack the idea a bit more in the some of these posts (while still diverging every now then onto different subjects).


Check out the Wheeler article if you have time. It is long an technical in places and even has a strange shift in font (which comes I believe because it is actually 2 different pieces put together for the particular volume it was published in). I suggest starting on page 20 with the section called Law without Law.