EVERY time you turn on a light, use an electric motor, or watch
television, you benefit from 19th-century research into a basic
property of matter - the property of electric charge.
Michael Riordan likes to cite this fact to show why particle
physicists are excited about a new study of a basic material
property - the study of mass.
"We live in a century whose technologies are heavily dependent
on our detailed understanding of the behavior of electric charge
... and its associated field - the electromagnetic field" that
constitutes light and radio waves, he says. "Nobody could have
anticipated such an outcome ... in the 19th century."
With the particle accelerators, Dr. Riordan says, "we embark on
a new voyage to discover the nature and origin of mass, another key
property of matter, and to understand its associated field. Who can
anticipate what will emerge during the 21st century from the
knowledge this epochal voyage will provide?"
A particle physicist himself, Riordan currently is on leave from
Stanford University in California to serve as staff scientist for
the Universities Research Association Inc. in Washington. The
association has contracted with the United States Department of
Energy to build one of the 'ships" on which physicists plan to set
sail for this "epochal journey."
This is the Superconducting Supercollider (SSC) particle
accelerator, under construction near Waxahachie, Texas, about 40
kilometers (25 miles) south of Dallas. The second "ship" may be a
comparable machine proposed - but not yet authorized - for the
European Laboratory for Particle Physics (CERN) at Geneva. As now
planned, these machines would carry physicists' investigations into
an energy range where the secrets of this mysterious property
called mass should begin to reveal themselves.
Mass is the property that gives rise to gravity and to inertia -
the tendency of matter to resist acceleration. It is a familiar
property. Yet in spite of the deep insights physicists now have
into matter's underlying nature, they do not know why the basic
material particles have the particular masses they measure. They
cannot even explain how mass itself arises.
The leading speculation suggests that there is a new type of
energy-carrying field - called a Higg's field - that exists
everywhere. Roughly speaking, the strength with which particles
interact with this field determines their resistance to
acceleration and, hence, their mass. If one or more such fields
exist, they should have one or more new types of particle
associated with them. The new accelerators are designed to
concentrate enough energy in a small enough volume to create Higg's
The machines would do this by smashing together counter-rotating
beams of protons and antiprotons in head-on collisions. Antiprotons
and protons share most characteristics except they have opposite
Physicists specify particle energies in these colossal
collisions in terms of a unit they call an electron volt (eV). …