With a life focused on excellence, Nobel Prize-winning physicist Werner Karl Heisenberg (1901–1976) once got a “C” on his doctoral physics exam—because he hadn’t prepared well. That experience taught him the value of preparation and helped shape his path as a great learner.

“Every word or idea, even when it seems clear, has only a limited meaning,” he later explained.

Heisenberg, one of the greatest scientists of the 20th century, was born in Würzburg, Germany. He founded quantum mechanics, which replaced Newton’s classical physics and led to the discovery of different forms of hydrogen.

His most famous idea, the Uncertainty Principle, showed that the more exactly we measure one part of a tiny particle, the more uncertain another part becomes. In short, the act of measuring changes what we’re trying to observe.

“The more precisely the position is determined, the less precisely the momentum is known in this instant, and vice versa,” he wrote in 1927.

Inspired by Albert Einstein’s theory of relativity, Heisenberg worked with Niels Bohr in Copenhagen. “Every tool carries with it the spirit by which it had been created,” he once said. His groundbreaking ideas helped make possible the future development of computers, transistors, and communication technologies built on the strange truths of quantum physics.

Heisenberg once said, “What we observe is not nature itself, but nature exposed to our method of questioning.” That poetry reveals how science is wonder: the search for invisible truths while dancing with uncertainty.