Leonardo Da Vinci’s Notes Show He Understood Gravity Long Before Newton

As the prototypical Renaissance man, Leonardo da Vinci was an artist, scientist, inventor and all-around genius who left a legacy of discovery and innovation that is still admired to this day. But if the authors of a newly released study are correct, da Vinci may have been even more wise and insightful than previously imagined.  According to these scholars, da Vinci left a series of notes and sketches in his collection of papers that proved he grasped the fundamental aspects of gravity centuries before Isaac Newton was even born.

In an article just published in the journal Leonardo, a team of academics led by California Institute of Technology (Caltech) aeronautics and medical engineering professor Mory Gharib introduced the results of their research into da Vinci’s gravitational theorizing. They explained how da Vinci’s drawings of a scientific experiment he imagined but didn’t perform piqued their interest and led them to discover how much he knew about gravity and about how it actually worked.

The sketches in question showed a water pitcher being moved through the air in a straight line, with sand-like particles falling out and falling to the ground along the way. In some sketches the water pitcher was being moved along at the same speed while in others it was being accelerated at a constant rate, with the sand particles falling out in each scenario.

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Da Vinci’s drawings of his pitcher experiment. (Morteza Gharib et al./MIT Press Direct)

In his notes, da Vinci tracked anticipated changes in the speed of the pitcher when it was accelerated, and also changes in the speed of the sand particles as they accelerated along their downward path. The latter move by da Vinci was incredibly important and groundbreaking, because it means he recognized the force of gravity as a constant force of acceleration. He knew that gravity would make a falling object go faster and faster, until it hit the ground and its motion was halted.

This was a great leap forward, and a vital first step on the way to understanding how gravity functioned and affected all physical objects everywhere.

But da Vinci’s genius didn’t stop there. He discovered something more specific in his experiments that took him another step closer to a fully developed theory of gravity.

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Da Vinci’s designs famously included machines designed to defeat gravity. (Public Domain)

Breaking a Real Da Vinci Code

Leonardo da Vinci’s drawings, which were published in a collection of his papers called the Codex Arundel, included triangles he generated from drawing lines that tracked the movements of the water pitcher and those of the various falling particles. Different shapes of triangles were produced depending on the changes in speed of the pitcher, and it was a drawing of one of these triangles—plus the accompanying inscription—that caught Mory Gharib’s attention in 2017, when he was using the Codex Arundel as a source material in a graduate course he was teaching.

"What caught my eye was when he wrote ‘ Equatione di Moti' [equalization or equivalence of motions] on the hypotenuse of one of his sketched triangles—the one that was an isosceles right triangle," he reported in a Caltech press release. "I became interested to see what Leonardo meant by that phrase."

To probe more deeply into da Vinci’s ideas and discoveries, Gharib recruited Caltech postdoctoral researcher Chris Roh (now an assistant professor at Cornell University) and Flavio Noca of the University of Applied Sciences and Arts Western Switzerland in Geneva to help him examine da Vinci’s drawings and notes more closely. Noca assisted with the translation of the Codex Arundel, and working together the team eventually discovered how far da Vinci had progressed in his understanding of gravity.

In addition to learning that he recognized it as an accelerating force, they also found out what da Vinci was referring to when he used the phrase Equatione di Moti'.

It seems that da Vinci had figured out that when the pitcher’s motion was accelerated to match the rate of gravitational acceleration applied to the particles, the shape that resulted would be a perfectly balanced equilateral or right isosceles triangle. This was significant, because it showed da Vinci had reached the stage where he was ready to calculate the gravitational constant, an all-important measure needed to create a more complete theory of gravity. He’d used geometrical reasoning to reach that stage, after which trying to determine the actual mathematical value would be the next step on the road to such a theory.

Unfortunately, da Vinci made some mistakes while attempting to calculate that constant, which the Caltech researchers were able to track in their decoding of his work. But even here his efforts were impressive, as he ended up with a figure that was about 97 percent accurate. All in all, this was an incredible effort, one that foreshadowed the work of other intellectual giants.

Leonardo Da Vinci, a Man 500 Years Ahead of His Time

Leonardo da Vinci died in 1518, which is 125 years before Isaac Newton was born and 169 years before Newton published Mathematical Principles of Natural Philosophy, which introduced his laws of universal gravitation . If mathematicians and scientists who lived in the years in between had only been aware of da Vinci’s discoveries (like Galileo, for example, who knew a thing or two about the subject), perhaps they could have built on his work and developed a complete theory of gravity long before Newton had a chance to do so. But it seems da Vinci’s work in this area was somehow overlooked.

"We don't know if da Vinci did further experiments or probed this question more deeply," Gharib said. "But the fact that he was grappling with this problem in this way—in the early 1500s—demonstrates just how far ahead his thinking was."

Far enough ahead that the fruits of his labor remained unrecognized and unappreciated until the 21 ^st century, more than 500 years after da Vinci came so close to uncovering the full truth.

Top image: Leonardo da Vinci and his sketches that hint at knowledge of gravity. Source: Caltech

By Nathan Falde