Science – Life

Humans are an ingenious species. Though we’ve been on the planet for a relatively short amount of time (Earth is 4.5 billion years old), modern Homo sapiens have dreamed up and created some amazing, sometimes far-out, things. From the moment someone bashed a rock on the ground to make the first sharp-edged tool, to the debut of the wheel to the development of Mars rovers and the Internet, several key advancements stand out as particularly revolutionary. Here are our top picks for the most important inventions of all time, along with the science behind the invention and how they came about.

Before the invention of the wheel in 3500 B.C., humans were severely limited in how much stuff we could transport over land, and how far. Apparently the wheel itself wasn’t the most difficult part of “inventing the wheel.” When it came time to connect a non-moving platform to that rolling cylinder, things got tricky, according to David Anthony, a professor of anthropology at Hartwick College.

“The stroke of brilliance was the wheel-and-axle concept,” Anthony previously told Live Science. “But then making it was also difficult.” For instance, the holes at the center of the wheels and the ends of the fixed axles had to be nearly perfectly round and smooth, he said. The size of the axle was also a critical factor, as was its snugness inside the hole (not too tight, but not too loose, either).