Issues

Lungs are very hard to image. Magnetic resonance imaging of inhaled noble gases optically pumped to high levels of nuclear polarization may offer the solution clinicians are looking for.

Several features of quantum chaos have been demonstrated in a system of sodium atoms interacting with a modulated standing wave of light. The system can be tuned continuously from a regime that can be described classically to one where a quantum description is necessary.

Medical and astronomical researchers have collaborated to apply sophisticated image processing techniques to detect microcalcifications in mammograms.

Eighty years after x rays were first used to determine the structures of well‐ordered crystals, coherent x‐ray beams are beginning to probe the atomic‐scale dynamics of random distributions of matter.

The breakup of the Soviet Union has led to welcome progress in nuclear disarmament but also to a worrisome vulnerability of the vast nuclear stockpiles accumulated there. The US has been working with Russia to tighten controls on fissile material that could be used in nuclear weapons.

Sometimes theory and experiment are both correct but do not agree with each other; sometimes a wrong theory agrees with experiment. One must therefore be careful not to jump to conclusions.

Physicists and friends celebrating Hans Bethe's scientific ingenuity and moral influence throughout his first 60 years at Cornell University.