“Nature abhors a vacuum,” wrote Aristotle of Stagira—one of history’s greatest minds, and the first to approach the natural world in a systematic, organized way.
Aristotle (384–322 BC) had theories about everything he could think of, and he could think of a lot. “He’s said to be the last person to know everything there was to be known,” says John Jenkins, president and CEO.
Aristotle’s contributions to biology, physics, and logic laid the groundwork for the scientific method and the discipline of critical thinking. “He knew the Earth was round over 2,000 years ago,” notes director of operations Charlie Bryan. “There are people today who still don’t know that.”
Aristotle seemed to have an answer for everything. “Aristotle was a recognized genius,” says Bryan. “But if history teaches us anything, it’s that nobody is perfect—especially a genius.”
Aristotle insisted the Sun revolved around the Earth, that heavy objects fall faster than lighter ones, that men have more teeth than women, and that a vacuum—an empty space without air—was impossible.
For centuries, philosophers debated whether “nothingness” could exist at all. Aristotle argued that a vacuum was unnatural and that motion required a medium—something to move through. Without it, he reasoned, nothing could move.
“That’s not how we unlock nature’s secrets,” Jenkins says. “We test them. And if we’re lucky, we get surprising results.”
Those results would take nearly two millennia to arrive.
In 1643, Italian mathematician and instrument maker Evangelista Torricelli, a student of Galileo, built the first mercury barometer. In a letter the following year, he famously wrote, “We live submerged at the bottom of an ocean of air.”
Torricelli proved that air has weight and exerts pressure—evidence that shattered ancient notions of an impenetrable atmosphere. “When he showed it was possible, the race was on,” says Bryan.
A few years later, German inventor and Burgermeister, Otto von Guericke (1602–1686) took the next leap. In 1650, he built the first practical air vacuum pump—a device that used pistons and one-way valves to remove air from a sealed chamber.
“His early vacuum pumps are mechanical works of art,” says Jenkins. “We have several excellent examples on display in our galleries.”
Guericke soon discovered that removing air could have powerful effects. Using his mercury barometer, he became the first person to predict the weather from air pressure changes. But he wanted to prove something bigger: that a true vacuum could exist—and that the force of the atmosphere itself could be measured.
Guericke’s discovery set the stage for one of the grandest demonstrations in the history of science. “It’s probably the most dramatic end to an age-old controversy since Franklin introduced his lightning rod,” says Bryan.
On May 8, 1654, before an audience in Magdeburg, Germany, Guericke joined two hollow copper hemispheres together, pumped out the air inside, and harnessed sixteen horses—eight on each side—to pull them apart.
The horses pulled and strained, and yet, the spheres held firm. The pressure of Earth’s atmosphere was too strong to break. Only when Guericke opened the valve and let air rush back in did the hemispheres fall apart effortlessly.
He repeated the spectacle in 1663 before the court of Friedrich Wilhelm of Brandenburg, this time with twenty-four horses. The lesson was unmistakable: a vacuum could exist, and air pressure was a measurable, physical force.
Candles snuffed out, bells fell silent, and feathers floated freely inside his evacuated chambers, proving that air was essential for sound and fire, and that resistance—not weight—made things fall differently.
The discovery of the vacuum—or more precisely, the partial vacuum—opened new frontiers in physics, electricity, and optics.
“The vacuum was crucial to the development of everything from the combustion engine to the light bulb,” says Jenkins. “Our sincerest apologies to Mother Nature.”
Stay grounded.