Leonardo was one of the first to study friction in any systematic fashion. While he studied all kinds of friction, he drew a distinction between sliding and rolling friction.
He stated the basic laws of friction 200 years before Newton defined what force is. He stated that:
1) The area of the points of contact has no effect on friction.
2) If the load of an object is doubled, its friction will also be doubled
However, since Leonardo never published his theories, he got no credit for his work until several centuries after Newton published his work.
Leonardo was interested in many things, as most people know. So perhaps it will not surprise you to learn that geology was one of his interests.
At one point he lived in Milan, serving as the court artist to Ludovico Sforza. As this was close to the Alps, he often went walking in the mountains.
His notebooks detail how he explored a mountain cave and found massive fossil bones. His notebooks say he was famous for his interest in rocks and strange forms hidden within them. Which he then no doubt studied with the great care and astute mind with which he studied everything.
His research led him to the following conclusions:
Shells and fish bones must be the remains of animals that once swam in places that were once oceanic. So, therefore some parts of the Earth which were once covered by seas were no longer covered by seas. And therefore, the surface of the Earth must have changed over time.
Water is the most powerful natural force. Water has sculpted the largest features of Earth’s landscape over long periods of time
All this indicates that slow and relentless natural processes have shaped our planet.
If this sounds quite familiar, it is because geologists would come to realize it centuries later.
His geological discoveries led him to conclude that the Earth must be much older than the few thousand years the Bible seemed to imply and to conclude that natural geological forces, not divine ones, were responsible for the drastic geological changes he observed inferred must have taken place.
Credit for the invention of the first practical parachute typically goes to Sebastian Lenormand in 1783. However, Leonardo designed one much earlier.
He made a sketch of the invention, with this description: “If a man has a tent made of linen of which the apertures [openings] have all been stopped up, and it be twelve braccia (23 feet) across and twelve in depth, he will be able to throw himself down from any great height without suffering any injury”
Given it has a triangular, rather than rounded design, many questioned whether it would work. They questioned whether it would have enough air resistance to float. Or whether it’s linen covering over a wooden frame might be too heavy.
As is typical with his inventions, it was never built or tested during his lifetime. Given how many of his inventions later proved to work well, wasn’t this a shame?
However, in 2000, the daredevil Adrian Nichols constructed a parachute based on Leonardo’s design and tested it. Despite widespread skepticism, it worked and provided a safe landing!
Leonardo was, as is widely known, extremely far ahead of his time when it came to feats of engineering. But, did you know that he designed a robotic knight?
This was not his first robotic design. There was his self-propelled cart, which we will cover shortly. The robotic knight is massively impressive all the same.
No complete drawing of this device is known to exist. However, we have fragments dealing with different aspects of the knight. Here is what we do know:
It consisted of a suit of plate-mail containing gears and wheels connected to a pulley and cable system. By using this mechanism, the knight was said to be capable of sitting down, standing up, moving its head and lifting its visor.
No doubt his intimate understanding of how the human body worked and how muscles worked, helped him figure out how to create a method of emulating a limited subset of human motions.
In 2002, robotics expert Mark Rosheim used several different da Vinci drawings to build a prototype of the robotic knight. It was able to walk and wave. He noted that it was designed to be easily constructed, without a single unnecessary component.
Rosenheim has used some of the same concepts used by da Vinci to design his planetary exploration robots for NASA. So, da Vinci has, in a way, helped us to explore space! Not too bad for a 15th-century engineer…
It will surprise nobody that Leonardo was fascinated by virtually all aspects of the world around him, including the water. So, it should be no surprise that he might have tried to find a way to allow people to more easily navigate marine environments.
In 1500, when working in Venice, the “water-city”, Leonardo designed scuba gear to be used to allow sneak attacks on enemy ships from underwater. This was to be performed by allowing scuba-clad soldiers to cut holes in the bottom of enemy ships.
The leather suit was equipped with a mask like a bag that went over the head. Attached to the mask and around the nose area were two tubes that led to a cork diving bell which floated on the surface.
Air was provided by the opening of the tubes to the diver.
The mask was fitted with a valve-operated balloon that could be inflated or deflated thus allowing the diver to rise from the water more easily or more easily submerge himself.
Steel rings helped to reinforce the apparatus and to prevent the tubes from being crushed by water pressure.
Jacquie Cozens built a diving suit based on this design, using pig leather, bamboo tubes and a cork float. It worked quite well in shallow water.
This invention is widely described as an “automobile”, however, more recent scholarly work has revealed that it was intended as a cart devised for use in theatrical settings.
Two large central springs underneath the central horizontal cogwheels provided the motive power and caused the wheels to go into motion.
There was also another device which served as a remote handbrake.
The cart could go forward and could be programmed to steer either straight or at pre-set angles.
The size of this thing is certainly consistent with its use as a theatrical device. It was probably one meter by one meter and probably not even a meter high.
Regardless of its uses, this cart can be considered as one of the first automated mobile devices ever created.
In 2006, the Italian Institute and Museum of the History of Science built a model based on da Vinci’s design and it worked!
Below is a video showing a smaller version of the cart. It is in Italian, but you do not need to understand the dialogue to get some idea of how the cart might have worked.
That brings us to the end of this episode. I hope you enjoyed our brief coverage of some of the inventions and discoveries of the great da Vinci! We only had time to cover but a few and perhaps one day we will come back and cover some more.
But, for now, our brief tour of the genius of Leonardo da Vinci is over.
Next episode will be entitled “Life 3.0, A Slow Death” Part One. The first of a series of reviews covering the awful book “Life 3.0” and its arguments for Strong AI.
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