The man adjusting the world's largest telescope had been driving mules up this same mountain just fifteen years earlier.

The Night Humason Found the Universe's Speed Limit

A Mule Driver Turned Astronomer Proved Galaxies Were Fleeing Earth

A former mule driver's telescope work proved the universe was expanding, reshaping cosmology forever.

The dome of Mount Wilson Observatory groaned open at dusk on September 14, 1929, revealing a California sky unmarred by the electric glow that would later consume Los Angeles. Milton Humason—a man who had never finished eighth grade—pressed his eye to the eyepiece of the 100-inch Hooker Telescope, the largest on Earth, and began the delicate work that would change humanity's understanding of the cosmos.

Humason had arrived at this mountain as a mule driver in 1908, hauling equipment up the treacherous trail for the observatory's construction. The astronomers noticed the quiet teamster lingering after his shifts, gazing at the instruments with hungry curiosity. By 1919, they had hired him as a janitor. By 1922, he was taking some of the most precise spectroscopic photographs in history.

That September night, Humason was photographing the spectrum of NGC 7619, a galaxy in Pegasus. The work required superhuman patience: exposures lasting entire nights, sometimes spanning multiple evenings, while he manually adjusted the telescope to compensate for Earth's rotation. A single sneeze could ruin forty hours of work.

What Humason captured was a telltale shift in the galaxy's light towar…

💡 Humason never earned a high school diploma, yet received an honorary doctorate from Lund University for his astronomical contributions—and personally discovered over 500 galaxies.