Starts With A Bang

Five Discoveries In Fundamental Physics That Came As Total Surprises

The Hubble eXtreme Deep Field, our deepest view of the Universe to date, which reveals galaxies from when the Universe was only 3-4% its current age. The fact that so much was revealed just by looking at a blank patch of sky for so long was one incredible surprise that didn't make the list. Image credit: NASA, ESA, H. Teplitz and M. Rafelski (IPAC/Caltech), A. Koekemoer (STScI), R. Windhorst (Arizona State University), and Z. Levay (STScI).

“On what can we now place our hopes of solving the many riddles which still exist as to the origin and composition of cosmic rays?” –Victor Francis Hess

It’s often said that advanced in physics aren’t met with “eureka!” but rather with “that’s funny,” but the truth is even stranger sometimes. Rather than the scientific method of: hypothesis, method, experiment, results, conclusion, revise, repeat, etc., many times throughout history, it’s been a series of surprise observations that have often led to our greatest leaps forward. When the speed of light was discovered not to differ when you moved with or against it, it was so revolutionary it was the only Nobel Prize ever awarded for a null result.

The Michelson interferometer (top) showed a negligible shift in light patterns (bottom, solid) as compared with what was expected if Galilean relativity were true (bottom, dotted). The speed of light was the same no matter which direction the interferometer was oriented, including with, perpendicular to, or against the Earth’s motion through space. Image credit: A. Michelson / Michelson & Morley.

When the gold foil experiment resulted in high-energy recoils, it surprised Rutherford so thoroughly it was the most incredible thing to ever happen to him in his life. The leftover glow from the Big Bang was discovered quite by accident; the neutrino was a crazy hypothesis that many abandoned; and the discovery of the muon, perhaps the most unexpected particle of all, literally was met with a cry of, “who ordered that?” from Nobel Laureate I.I. Rabi.

The first muon ever detected, along with other cosmic ray particles, was determined to be the same charge as the electron, but hundreds of times heavier, due to its speed and radius of curvature. Image credit: Paul Kunze, in Z. Phys. 83 (1933).

These five discoveries changed the course of physics forever, but they came as total surprises to practically everyone. Sometimes, the answer is in the place you least expect.