For well over a century, the lives of most people
in the developed countries were changed-more
often than not, improved-by the application of
discoveries in physics. Radio and television,
computers and the Internet, x-rays, and lasers are
only a few well-known examples. Some physicists
became celebrities because of their astonishing
discoveries and theories: Marie Curie
and Ernest Rutherford, for deciphering the mysterious
phenomena of radioactivity and transmutation,
and Albert Einstein and Stephen
Hawking, for overturning common-sense notions
of space, time, matter, and energy. Yet physics
itself, which should be a major part of the intellectual
heritage of all properly educated men
and women, is often regarded-wrongly-as
an esoteric subject, understood (at least in the
United States) by only a small elite. The sincere
and heroic efforts of educators and writers have
produced progress in teaching the public and
its political leaders what physics is all about,
but much more will be needed in the twenty-first
century.