The Difference Between Math and Physics

Recent headlines boast that string theory is finally testable.  If true, this would mark a significant turning point for the speculative theory.  Touted as a potential TOE, or theory of everything, string theory attempts to unite general relativity (our best theory of the very large) and quantum mechanics (our best theory of the very small).  The theory has been around for decades, but has yet to make a single, testable prediction.  The problem lies in the fact that string theory has so many independent constants, it can accommodate almost any empirical data.

Until now, argues Michael Duff of Imperial College, London.  According to a PhysOrg report, the insight came when Duff attended a “conference in Tasmania where a colleague was presenting the mathematical formulae that describe quantum entanglement: ‘I suddenly recognised his formulae as similar to some I had developed a few years earlier while using string theory to describe black holes. When I returned to the UK I checked my notebooks

What Explains the Direction of Time?

Why do we experience the world as unfolding in time?  And why does it unfold toward the future rather than the past?  One hint is provided by entropy: eggs break (but never un-break), we grow older (but never younger), ice melts when we add it to a pot of boiling water (but the boiling water never gets hotter while the chunk of ice gets bigger).  Yet entropy itself requires an explanation because both entropic and anti-entropic behavior are compatible with the fundamental laws of physics.  One solution was first explained in detail by David Albert, a philosopher at Columbia University, in his book, Time and Chance (2001).  According to Albert, it is the big bang, which provides a low-entropy boundary condition, that explains the direction of time (and all of its associated puzzles).  Now, Sean Carroll, a theoretical physicist at the California Institute of Technology has taken up Albert’s idea in his new book, From Eternity to Here.  In a recent interview in Scientific American, Carroll claims “just about everything about the arrow of time—what we would think of as “how time works,” the fact that the past is set in stone while the future can still be altered—is all because of entropy.”  Carroll’s book is intended for a popular audience, and would be a worthwhile investment for any philosopher curious about physics-based approaches to the metaphysics of time.

Related Articles:

The Experience of Time and Change

By Barry Dainton , University of Liverpool
(Vol. 3, June 2008)
Philosophy Compass

Time Travel: Double Your Fun

By Frank Arntzenius , Rutgers University
(Vol. 1, October 2006)
Philosophy Compass

The God particle! Or is it?

The search for the elusive Higgs-boson is the driving force between the fierce, but allegedly friendly, competition between the Large Hadron Collider at CERN and the Tevatron at Fermilab. Since CERN has decided at the beginning of the month that the LHC will run throughout the winter, an otherwise unusual practice because of the high energy consumption, it probably will win the race, or so they hope.

The reason why it is so important to win that race is that the Higgs boson plays a central role in the Standard Model of particle physics, but is the only particle in that same model that is not yet discovered. The discovery of the Higgs-boson would explain the existence of mass in the universe and the distribution of mass among the particles. It sounds like something of an ultimate explanation for the last open questions in physics.

But what happens then? String theorists argue that the smallest entities in the universe are strings which constitute the particles. In their view the Higgs-boson would not be the ultimate explanation. But should not the question be if we can “ultimately” explain something at all? The Higgs-boson is called the God particle. But what do we mean by that? That God has created that particle? That the Higgs-boson is God? That the existence of the particle proves God’s existence? That God is behind the Big Bang? And if it is discovered, does physics as a discipline all of a sudden stops, because everything is now explained. Of course not, is the obvious answer for most. But why is it then called the God particle? What is that supposed to be telling us?

For those interested in news updates about CERN from the Times, go here.

For an interesting article about science and its relation to religion, read the following:

Margaret Cavendish on the Relation between God and World

By Karen Detlefsen, University of Pennsylvania

(Vol. 4, May 2009)

Philosophy Compass

Extra Dimensions Restricted by Black Hole

If there are extra dimensions, they must be smaller than previously thought.

Though extra dimensions may sound like the stuff of science fiction, they are taken quite seriously by contemporary physicists and philosophers of physics. In addition to the three spatial dimensions we’re familiar with — up/down, left/right, forward/back — theories such as string theory postulate as many as 7 additional spatial dimensions. If such a theory were correct, the landscape of the three-dimensionalism / four-dimensionalism debate would need reformulation; perhaps objects are really perduring eleven-dimensional spacetime worms!