Photo of Val L. Fitch

Val L. Fitch

  • National Medal of Science
  • Physical Sciences

For his pioneering experiments at the frontiers of physics, from his measurement of the properties of mu-mesons in nuclei to his co-discovery that nature violates a fundamental spacetime symmetry property; and for his leadership on National science policy.

Physicist Val L. Fitch helped shape our understanding of the universe. His study of the basic constituents and forces among subatomic particles led to a discovery that even now remains one of the profound mysteries of the early universe.

In experiments in 1964 at the Brookhaven National Laboratory on Long Island, Fitch and James Cronin found that matter and antimatter obeyed slightly different laws of physics. One of the possible consequences of this, experts say, is that if you could run the history of the universe (or any experiment) backward, the laws of physics may not be exactly the same. Their finding shook a principle that physicists ascribed to since Galileo.

The experiment also suggested a way in which matter and antimatter could have avoided mutual destruction in the early universe, leaving predominantly matter that could evolve into stars, galaxies and life. What we see in the universe is only matter, and Fitch’s discovery helps explain why it is that we don’t have galaxies made of antimatter.

By Jen Santisi