The Global Tobacco Epidemic

Cigarette smoking has stopped declining in the U.S. and is rising in other parts of the world. Aggressive marketing and permissive regulations are largely to blame

Binary Neutron Stars

These paired stellar remnants supply exquisite confirmations of general relativity. Their inevitable collapse produces what may be the strongest explosions in the universe

Dendrimer Molecules

Chemists can now build fractal supermolecules.This new class of polymers promises to be valuable in biotechnology and environmental protection

The Ocean's Salt Fingers

A small-scale oddity in the way seawater mixes can have large-scale consequences for the structure of the ocean

The Silicon Microstrip Detector

Produced with the same tools used to create integrated circuits, these detectors recently helped to find the top quark and are central to other crucial experiments

The Atomic Intrigues of Niels Bohr

Did Bohr Share Nuclear Secrets?

Niels Bohr met with a Soviet agent in late 1945. Although some have accused Bohr of divulging nuclear secrets, a recently disclosed memo offers evidence to the contrary

What did Heisenberg Tell Bohr about the Bomb?

In 1941 Werner Heisenberg and Niels Bohr met privately in Copenhagen. Almost two years later at Los Alamos, Bohr showed a sketch of what he believed was Heisenberg's design for a nuclear weapon...

The Preservation of Past

Conservators are racing to save monuments threatened by development, pollution, looting and neglect. In the process, they are transforming the field of archaeology into a new science...