Space & PhysicsFebruary 1, 1992
Why Only One Big Bang?
Stories by Geoffrey Burbidge
Space & PhysicsDecember 1, 1966
The Problem of the Quasi-Stellar Objects
The observational evidence on these strange celestial objects presents many mysteries. The central question is still whether they are at the edge of the universe or relatively close to us
Space & PhysicsAugust 1, 1966
The Origin of Cosmic Rays
What cosmic accelerators generate these fantastically energetic particles? Calculations suggest that most cosmic rays may come not from within our galaxy but from extragalactic radio sources
Space & PhysicsJune 1, 1961
Subdwarf Stars
Certain stars seem dimmer than normal stars having the same temperature. It now appears that they are not less luminous but are bluer because they are poorer in the heavier elements
Space & PhysicsNovember 1, 1958
Stellar Populations
Fifteen years ago Walter Baade observed that stars are divided into two populations. His concept opened up a broad field of study, and now astronomers classify stars into five populations instead of two
The SciencesApril 1, 1958
Anti-Matter
The discovery of the anti-proton and the anti-neutron raises the following question: Do anti-atoms made of these and other anti-particles exist in the universe?