This superb collection by the eminent physicist and critic John Ziman, opens with an album of portraits of scientists at work and at play, in which "plaster saints" are turned charmingly and thoughtfully into "living people." You'll find deft sketches of some of the more striking figures in the gallery of modern physics - Albert Einstein, Freeman Dyson, Lev Landau, Mark Azbel, Andrei Sakharov.

We then take a journey through the world depicted by contemporary scientists, how physicists make discoveries, and how they test each other's claims. Ziman says that what we know about the physical world - the product of the vast collective effort of scientists everywhere - is no more than a human representation of an accessible reality.

The basic lesson of these essays, "that you and I and the rest of us act on the understanding that we are all living in the same world" is a key to a general theory of scientific knowledge.

Ziman then travels with us on an even more delicate odyssey, into the personal as well as the professional minds and performances of scientists as they are pulled into competing directions. We discover that the path of discovery is strewn with complex human needs, the demands of the state, the desire for profits, the exercise of technical virtuosity.

Today, scientists are no longer lonely seekers after truth, but have emerged with multiple obligations as technical and military experts, entrepreneurs, managers, political advisers, publicists, and educators, as well as ordinary citizens.

The personal preferences of scientists are now transformed and often under the control of mammoth institutions - great universities, a tangle of granting agencies, huge defense establishments, and global corporations. Rarely do scientists work alone in isolated laboratories. They are linked together in intricate networks, busy with delicate instruments requiring armies of technicians and collaborators.

This is an essential guide for the initiated and the novice over the terrain of modern science and what it means to be a scientist today.