ORIGINAL: How Stuff Works
Circa 1510, Italian artist, architect, engineer and scientist Leonardo da Vinci (1452 – 1519).
Stock Montage/Getty Images
10- Ball Bearings
Wheel bearings made at Delphi’s Sandusky plant are seen at UAW Local 913 in Sandusky, Ohio.
J.D. Pooley/Getty Images
As an invention, the ball bearing doesn’t seem all that impressive, but much of modern technology depends on it. Ball bearings make it possible for drive shafts to rotate, for goods to roll along ramps in a factory or store, and for mechanical devices in general to operate. By placing a smoothly rolling sphere between moving surfaces, ball bearings eliminate friction. The idea can be traced back to the Roman Empire, but many historians believe that da Vinci’s notebooks contain the first practical designs. Many of the devices that he conceived depend on them and wouldn’t have operated without them. Of course, as with many of da Vinci’s ideas, the concept was never made widely known and the ball bearing had to be reinvented by someone else.
Synchronized Skydivers land at Justin Herman Plaza to celebrate the launch of the T-Mobile myTouch 3G phone with Google in San Francisco, Calif.
Michael Buckner/Getty Images for T-Mobile
The speed at which a body falls depends on two factors: the force of the gravity pulling it downward and the resistance of the atmosphere through which it is falling. If there were no atmosphere, a falling body would simply accelerate to higher and higher speeds until it hit a surface, but air tends to slow it down until it reaches its so-called terminal velocity. Different objects have different terminal velocities. The terminal velocity of a human being falling through the earth’s atmosphere — a skydiver with an unopened chute, for instance — is about 120 mph (193.1 kilometers per hour). That’s surprisingly slow, but still fast enough that a person falling from an airplane would make a pretty big splat upon hitting the ground. The idea of a parachute is to reduce a person’s terminal velocity and make a long fall survivable.
Da Vinci, who was fascinated by the idea of human flight, conceived his parachute as a way for people to drift gracefully through the air. Its pyramid-shaped framework was draped with cloth. As da Vinci wrote in his notebooks, it would allow a man “to throw himself down from any great height without suffering any injury.” Twenty-first century attempts to build the design suggest that it would have worked pretty much as da Vinci described.
Circa 1500, Sketches by the Florentine artist and engineer Leonardo da Vinci (1452-1519) showing his designs for the ornithopter and other flying devices.
Hulton Archive/Getty Images
Da Vinci was fascinated by birds. He watched them, sketched them and borrowed ideas from them for his inventions. One of the results of this fascination was the ornithopter, a device conceived by da Vinci that would theoretically have allowed humans to soar through the air like birds. While da Vinci’s parachute would have allowed a human being to jump off a cliff without being hurt, the ornithopter was actually a way for people to soar off the ground and into the air.
On paper, the ornithopter looks much more birdlike (or batlike) than present-day airplanes. Its wings are designed to flap as the pilot turns a crank. This invention demonstrates da Vinci’s strong grasp of aerodynamics and modern attempts to reproduce the ornithopter show that it could indeed have flown — that is, if it were already in the air. Taking off under the weak propulsion supplied by human muscles would have been much trickier.
The parachute and ornithopter were only two of the flying machines concocted by da Vinci in his notebooks. Others include a glider and his helicopter-like aerial screw, which we’ll talk about in a few pages.
7- Machine Gun
John Francis of California checks out a grenade machine gun at the Heckler & Koch booth at the National Shooting Sports Foundation’s 33rd annual Shooting, Hunting and Outdoor Trade (SHOT) Show in Las Vegas.
Ethan Miller/Getty Images
Da Vinci’s machine gun, or “33-barrelled organ,” wasn’t a machine gun in the modern sense. It couldn’t fire multiple bullets rapidly out of a single barrel. It could, however, deliver punishing volleys of gunfire at rapid intervals and, if it had been built, would have effectively mowed-down oncoming infantry.
The mechanism behind the machine gun is simple. Da Vinci proposed mounting 11 muskets side by side on a rectangular board, then attaching three such boards together in a triangular arrangement. By placing a shaft down the middle, the entire contraption could be rotated, so that one set of 11 guns could be fired while a second set cooled off and a third set was being reloaded. Then the entire mechanism could be rotated to bring the loaded set to the top where it could be fired again.
Though da Vinci noted time and again in his notebooks that he hated war and loathed the idea of creating killing machines like this one, he needed money to support his household and found it easy to convince his wealthy patrons that such machines would help them triumph over their enemies. Perhaps it was for the best that none of da Vinci’s war machines ever actually got built.
6- Diving Suit
Diver Bob Crawaford, in a 1950’s Mark-5 dive suit, waves to spectators outside the tank during the kick off of Diver’s Weekend at the Vancouver Aquarium Marine Science Centre in Vancouver, Canada.
Don MacKinnon/Getty Images
While living in Venice in the late 15th century, da Vinci devised a far-fetched idea for repelling invading ships: Send men to the bottom of the harbor in diving suits and let them cut holes in enemy hulls. Well, maybe that doesn’t sound so far-fetched any more. It’s fairly common now for frogmen with scuba gear to engage in underwater sabotage. In da Vinci’s time, however, the idea was unheard of. Da Vinci’s divers would have carried breathing hoses connected to a floating bell full of air, wearing facemasks with glass goggles that would help them see underwater. In another version of the concept, the divers would have breathed from wine bladders filled with air. In both versions, the men would carry a bottle to urinate in so that they could stay underwater indefinitely. Da Vinci’s design was not only feasible — it was practical!
These diving suits might actually have been constructed, except that the invaders they were intended to repel were driven away by the Venetian navy before underwater sabotage became necessary.
5- Armored Tank
A cutaway view of a 20th century model of a tank designed by da Vinci. The tank is constructed of wood on a round base topped by a cone shaped shell, with guns evenly spaced, emerging from the base.
Hulton Archive/Getty Images
While working for Ludovico Sforza, Duke of Milan, da Vinci proposed what may have been his ultimate war machine: the armored tank. Driven by the muscle power of eight men, the armored tank was a turtle-like moving shell with 36 guns poking out of its sides. It was operated by a system of gears propelled by cranks that turned a sequence of wheels. The eight men would have been protected by the outer shell so that they could have driven the tank at about walking speed right into the heat of battle without being hurt. The guns, firing in all directions, would have been devastating to enemy ranks.
The diagram of the armored tank in da Vinci’s notebooks contains a curious flaw: the gearing causes the front wheels to move in the opposite direction from the rear wheels. If built as shown, the tank would have been unable to move. Da Vinci was far too smart to make an error that trivial by accident, so historians have proposed a number of reasons why da Vinci would have made it deliberately. Maybe he didn’t really want the war machine to be built. Or maybe he was afraid that his diagram would fall into enemy hands, so he made the error to assure that nobody else could build the tank but him.
4- Self-Propelled Cart
A working model of Leonardo Da Vinci’s car is seen on display at the Museum of the History of Science in Florence, Italy.
Giuseppe Cacace/Getty Images
Da Vinci’s self-propelled cart can be looked at as history’s first car. In fact, because it has no driver, it can be looked at as history’s first robot vehicle, too.
The drawings that da Vinci made of the car in his notebooks don’t fully reveal the mechanism inside and modern engineers have had to guess at what made it go. The best guess is that it used a spring-driven mechanism similar to that in a clock. The “mainsprings” are contained inside drum-shaped casings and can be wound up by hand. As the springs uncoil, the cart is driven forward like a wind-up toy. The steering can be programmed through a series of blocks set among the gears, though the fact that the cart could only make right turns would have limited its usability.
Leonardo apparently considered his cart to be something of a toy, but it’s not hard to imagine that, had it actually been built, useful applications would have shortly followed.
3- City of the Future
When Leonardo was living in Milan around the year 1400, the Black Plague devastated Europe. Cities suffered far more than the countryside and da Vinci theorized that something about cities made them especially vulnerable to disease. This idea is surprisingly modern, given that the germ theory of disease didn’t become well established until the early 20th century. Da Vinci was inspired to draw out plans for one of his most ambitious inventions: A planned city, designed from the ground up to be sanitary and livable.
The result was a triumph of urban planning that unfortunately was never built. Da Vinci’s “ideal city” was divided into several levels, with everything thought to be unsanitary kept on the lowest level, and a network of canals available for rapid waste disposal. Water would have been distributed through buildings using a hydraulic system that prefigured modern plumbing. The resources needed to build such a city were well beyond da Vinci’s means, of course, and he never found a patron willing to foot the bill for constructing it.
2- Aerial Screw
A design for a ‘helical air screw’ – a helicopter-type flying machine, from the notebooks of Italian polymath Leonardo da Vinci.
Hulton Archive/Getty Images
If nothing else, da Vinci’s aerial screw is arguably one of the coolest designs that he ever sketched in his notebooks. Working much like a modern helicopter, this flying machine looks a lot like a giant whirling pinwheel. The “blades” of this helicopter were to have been made out of linen. When turned fast enough, they were intended to produce lift, the aeronautical phenomenon that makes airplanes and helicopters fly. Air pressure would have built up under each blade, forcing the flying machine into the sky.
At least that was the idea, anyway. Would the aerial screw actually have worked in practice? Probably not. And that’s a pity — it would have looked amazing in flight.
1- Robotic Knight
The anatomical analysis of the movements of the shoulder and the neck is a drawing made about 1509-1510 by Leonardo da Vinci.
If da Vinci’s self-propelled cart was the first working design for a robotic vehicle, then the robotic knight would have been the first humanoid robot, a real 15th century C-3PO. Da Vinci was fascinated by human anatomy and spent long hours dissecting corpses in order to figure out how the human body worked. This gave him an understanding of how muscles propelled bone. He reasoned that these same principles could be applied to a machine. Unlike most of da Vinci’s inventions, Leonard apparently actually built the robotic knight, though it was used primarily for entertainment at parties thrown by his wealthy patron Lodovico Sforza.
Da Vinci’s robot has not survived and no one knows exactly what it was capable of doing, but apparently it could walk, sit down and even work its jaw. It was driven by a system of pulleys and gears. In 2002, robotics expert Mark Rosheim used da Vinci’s notes to build a working model of da Vinci’s robotic knight and some of the concepts behind it have subsequently been used by Rosheim for the design of planetary exploration robots to be used by NASA. So after half a century of space exploration, da Vinci’s designs have finally made it into outer space.