Heinrich Hertz found his purpose in the invisible. Hertz—who originally wanted to study the more tangible, practical field of civil engineering—was eventually drawn to the theories of James Maxwell, which hypothesized that electromagnetic waves that move at the speed of light exist.

What was envisioned but not seen before sparked between two close-set brass globes, one rigged with a receiver and one with a transmitter. When electrified, they produced a visible vibrating line of light between them. Hertz thus discovered that the waves do indeed travel at the speed of light, as Maxwell surmised.

In 1930, thirty-six years after Hertz's death, the International Electrotechnical Commission designated the "hertz" as the number of cycles per second of a periodic occurrence. The hertz is used to measure everything from radio waves to CPUs.

While Hertz didn't put too much stock in his discoveries, dismissing the one he's most known for by saying, "It's of no use whatsoever," generations of scientists that followed built upon his work to create the wireless world we live in now. The Institute of Electrical and Electronics Engineers honors Hertz's life and legacy with the IEEE Heinrich Hertz Medal that is granted each year to "an individual for achievements which are theoretical or experimental in nature."

Hertz's short life kept him from seeing the fruits of his research and conducting more; he died at age 36 from an infection. But here are a few posthumous facts about Hertz that will surprise even someone who believes in what can't be seen.