David Peat

60 From Certainty to Uncertaintytime. Maybe, he conjectured, magnetism and electrical attractioncould also be accounted for on the same basis. Possibly matter itself isno more than knots and concentrations in the fabric of space-time.Einstein worked on this approach until the end of his life. It was amagnificent vision save for one thing: it ignored the entire quantumworld. In their search for a fundamental level or principle, physicistshave not been able to discover any truly satisfying way of unifying thetwo great discoveries of the twentieth century—relativity and quantumtheory.The best minds of three generations of physicists have struggledwith the problem of unification. From time to time it looked as if abreakthrough was imminent, but then hope faded, and yet anotherapproach was abandoned.Postmodern PhysicsThe physicist Yoichiro Nambu, who developed the first string theory(precursor of “superstrings”), coined the term “postmodern physics”to express the current dilemma. Nambu suggests that the postmoderncondition applies not only to literary criticism but to physics. Up to theage of atoms it was always possible to test a scientific theory directly. Atheory makes certain predictions and allows calculations to be madethat can be tested directly through experiments and observations. Buta theory such as superstrings talks about quantum objects that exist ina multidimensional space and at incredibly short distances. Othergrand unified theories would require energies close to those experiencedduring the creation of the universe to test their predictions.Clearly there is no way in which these theories could ever be testeddirectly. Take the most powerful elementary particle accelerator knownto physics and blow it up to the size of the earth, or even the solarsystem, and the collisions and particles it produces would still not beremotely close to events discussed in these new grand theories.In other words, these theories are untestable in a direct way. Insteadthey are used to make inferences about other theories. Ratherthan physics producing a fundamental theory of reality that can be put