Leonardo Da Vinci understood concept of gravity 400 years before Einstein, new study reveals

Leonardo Da Vinci, often immediately associated with his masterpiece "Mona Lisa," is a pivotal figure in art. Not just art enthusiasts and historians, but everyone knows how great Da Vinci's artistic creations are. Recently, a lesser-known aspect of this renowned Italian artist's genius has come to light. A study titled, "Leonardo da Vinci’s Visualization of Gravity as a Form of Acceleration," published in the Leonardo Journal speaks about Da Vinci's knowledge of general relativity reflected in his sketches. More than four centuries before Albert Einstein introduced the "Equivalence Principle," Da Vinci had already grasped this concept.

As per a Caltech press release, in 2017, the study's lead author, Morteza Gharib was looking through the newly-released digitalized copies of Da Vinci's sketchbook "Codex Arundel." The notebook includes Da Vinci's analysis of flow dynamics, likely conducted between 1480 and 1518. Gharib noticed drawings of sand-like particles pouring from moving jars which led to the formation of a triangle. The phrase, "Equatione di Moti," written near the hypotenuse of one of the triangles intrigued Gharib and his colleagues. The researchers concluded that Da Vinci understood that once sand or water particles exited the jar, their acceleration downward was solely due to gravity. As per the study, Da Vinci found that the particles falling from a jar traced a vertical line if the jar moved at a constant rate and a slanted line (the hypotenuse of a triangle) if the jar accelerated constantly.

So, Da Vinci's finding that the accelerating jar and the particles falling in a slanting line formed an equilateral triangle could be one of the earliest hints of the equivalence principle. When Einstein formulated the "Equivalence Principle" in 1907, it was an extension of Isaac Newton's discovery of the universal law of gravitational attraction in 1687 and Galileo Galilei’s assertion of the law of freefall in 1604. However, the scientific world didn't realize that the legendary painter of "Mona Lisa" also hinted at the principle four centuries before Einstein. "We don't know if da Vinci did further experiments or probed this question more deeply. 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," stated Gharib who is a professor of aeronautics and medical engineering at Caltech.

The authors of this study noticed that Da Vinci had given up the attempt to deduce an equation based on his observation of the falling particles. To know why he didn't pioneer the equation of the "Equivalence Principle" the team simulated his experiment. "What we saw is that Leonardo wrestled with this, but he modeled it as the falling object's distance [from the object’s dropping point] was proportional to 2 to the t power [with t representing time] instead proportional to t squared. It's wrong, but we later found out that he used this sort of wrong equation in the correct way," explained co-author Chris Roh, a professor of biological and environmental engineering at Cornell University. Though Da Vinci's experiment didn't mark a groundbreaking discovery in history, it enlightened the world about his self-educated knowledge of science.