The Sciences
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
Stories by Hans A. Bethe
Space
How a Supernova Explodes
When a large star runs out of nuclear fuel, the core collapses in milliseconds. The subsequent "bounce" of the core generates a shock wave so intense that it blows off most of the star's mass...
The Sciences
Space-Based Ballistic-Missile Defense
President Reagan's "Star Wars" program seems unilkely ever to protect the entire nation against a nuclear attack. It would nonetheless trigger a major expansion of the arms race
Tech
Anti-Ballistic-Missile Systems
The U.S. is now building a "light" ABM system. The authors argue that offensive tactics and cheap penetration aids could nullify the effectiveness of this system and any other visualized so far...
The Sciences
What Holds the Nucleus Together?
Electrical forces bind the electron to the atom, but they cause nuclear particles to fly apart. The powerful cohesion of protons and neutrons must be explained by a wholly different phenomenon...
Tech
The Hydrogen Bomb: II
In which the technical and strategic discussion of last issue is continued, and a proposal is made for a first step toward the international control of atomic weapons
