Alfvén on cosmic rays, sunspots, antimatter

Plasma‐physics theories often have had little connection with reality, according to Hannes Alfvén. When we recently chatted with him in his office at the University of California in La Jolla (shortly before he left for his annual six‐month stay at the Royal Institute of Technology in Stockholm) Alfvén pointed out that two major confrontations between theory and experiment have occurred. One took place when controlled thermonuclear experiments began. “The result was catastrophic,” he said. The second confrontation came when space missions made the magnetosphere and interplanetary space accessible to physical instruments, and some cherished theories became ripe for revision. In the future, Alfvén believes, at least three “sacrosanct” astrophysics theories may be drastically revised.