ALTHOUGH physicists were disappointed when the United States
Congress canceled their supercollider dream machine, they now have
other challenging frontiers.
Take, for example, the research typified by Piyare L. Jain's
quest to explore the origin of the universe. Working at the State
University of New York at Buffalo, Dr Jain recently reported major
progress. "We are approaching the point where we will be able to
re-create the Big Bang in the laboratory," he says.
Or consider the efforts of an international team working with
Germany's DESY particle-physics laboratory, which will fire up a
new experiment next month to probe deeply into the inner structure
of atomic building blocks: the proton and neutron that make up an
atom's nucleus. Among other matters, it should shed new light on
how protons and neutrons -- the so-called nucleons -- get their
spin. That's an abstract property that helps determine how the
larger material world is structured.
Physicists who had planned to work with the supercollider
haven't given up hope either. A new, albeit less powerful,
accelerator that member nations have agreed to build at the
European Center for Particle Physics (CERN) in Geneva may yet
achieve the supercollider's main goal of finding out why matter has
mass. American physicists are expecting Congress to decide later
this year whether to put up money to allow them to join the CERN
project. As physicist John Hauptman of Iowa State University at
Ames puts it: "We may live in exciting times yet."
The physicists' continuing hope in the face of disappointment
arises from the fact that they aren't interested in machinery for
its own sake. They want to elucidate matter's structure. That means
expanding their understanding of the basic particles that
constitute matter and of the forces that govern them. And that
means delving, by any methods available, ever deeper into the weird
world of things that are very small.
In what physicists call the current standard theory, the matter
particles consist of six quarks; three types of electrons; and
three massless, electrically uncharged particles called neutrinos.
Protons and neutrons that make up atomic nuclei are themselves
composed of two types of quarks, called up and down. The other
quarks only appear fleetingly in high-energy particle experiments.
All of the matter particles interact through forces carried by
yet other particles. The photon, for example, carries the
electromagnetic force. Protons and neutrons are bound together by a
so-called strong force. This force is carried by particles that
physicists whimsically call gluons.
The world of these particles is weird because, when you are
dealing with entities as small as atoms or smaller, things don't
happen the way they do in our familiar larger scale world. For
example, they obey an uncertainty rule that says the more precisely
you pin down the time interval when something happens, the less
certain you can be of the amount of energy involved. And the
conservation-of-energy law that says energy can't be created or
destroyed doesn't hold within that brief time period. So what
physicists call "virtual" versions of the basic particles can be
created using energy that isn't accounted for, provided the
particles disappear quickly enough to satisfy the uncertainty rule. …