The Ancient Greeks Had a Steam-Powered Device

Long before the steam-powered factories of the Industrial Revolution, a brilliant inventor in Roman Egypt named Hero of Alexandria was already harnessing the power of steam. Around 50 CE, he created a device known as the aeolipile, or "wind ball." It consisted of a hollow sphere mounted on pipes that led from a heated, sealed cauldron of water. As the water boiled, steam rushed into the sphere and jetted out of two L-shaped nozzles on opposite sides. This created thrust, causing the ball to spin rapidly on its axis.

While it was a mesmerizing sight, the aeolipile was never put to practical use as an engine. In a world with abundant slave labor, there was little economic incentive to develop labor-saving machinery. Furthermore, the metallurgy of the era was not advanced enough to create larger, high-pressure boilers that could perform meaningful work without exploding. The device was therefore treated as a fascinating novelty, a temple curiosity, or a clever way to demonstrate scientific principles to a small audience.

Despite its status as a mere curiosity, the aeolipile was a remarkable achievement. It stands as the earliest known example of a reaction engine, perfectly demonstrating the principle of jet propulsion that now powers rockets and modern aircraft. The invention proves that the basic concept of steam power was understood nearly two millennia before the right combination of scientific theory, materials science, and economic need would finally allow it to change the world.