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IntroductionHumans 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.
Live Science's Jeanna Bryner contributed to this countdown, which was originally published on March 6, 2012.
The wheelSlide 2 of 21
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).
The hard work paid off, big time. Wheeled carts facilitated agriculture and commerce by enabling the transportation of goods to and from markets, as well as easing the burdens of people traveling great distances. Now, wheels are vital to our way of life, found in everything from clocks to vehicles to turbines. [Read more about the invention of the wheel]
Next: The nailSlide 3 of 21
The nailSlide 4 of 21
Without nails, civilization would surely crumble. This key invention dates back more than 2,000 years to the Ancient Roman period, and became possible only after humans developed the ability to cast and shape metal. Previously, wood structures had to be built by interlocking adjacent boards geometrically a much more arduous construction process.
Until the 1790s and early 1800s, hand-wrought nails were the norm, with a blacksmith heating a square iron rod and then hammering it on four sides to create a point, according to the University of Vermont. Nail-making machines came online between the 1790s and the early 1800s. Technology for crafting nails continued to advance; After Henry Bessemer developed a process to mass-produce steel from iron, the iron nails of yesteryear slowly waned and by 1886, 10 percent of U.S. nails were created from soft steel wire, according to the University of Vermont. By 1913, 90 percent of nails produced in the U.S. were steel wire.
Meanwhile, the screw a stronger but harder-to-insert fastener is thought to have been invented by the Greek scholar Archimedes in the third century B.C.
Next: The compassSlide 5 of 21
The compassSlide 6 of 21
The compassAncient mariners navigated by the stars, but that method didn't work during the day or on cloudy nights, and so it was unsafe to voyage far from land.
The Chinese invented the first compass sometime between the 9th and 11th century; it was made of lodestone, a naturally-magnetized iron ore, the attractive properties of which they had been studying for centuries. (Pictured is a model of an ancient Chinese compass from the Han Dynasty; it is a south-indicating ladle, or sinan, made of polished lodestone.) Soon after, the technology passed to Europeans and Arabs through nautical contact. The compass enabled mariners to navigate safely far from land, increasing sea trade and contributing to the Age of Discovery.
Next: Printing PressSlide 7 of 21
The printing pressSlide 8 of 21