Pencil sketches by Leonardo da Vinci in the early 1500s suggest he understood gravity well before English mathematician Isaac Newton, who is accredited with the discovery in the late 1600s.
Researchers from the California Institute of Technology reanalyzed da Vinci’s notebooks, finding the famed Italian devised experiments to demonstrate that gravity is a form of acceleration.
And he modeled the gravitational constant with 97 percent accuracy.
The team believes that the only thing that hindered da Vinci’s experiments from definitively explaining gravity was the limited tools at his disposal – he lacked a means of precisely measuring time as objects fell.
The sketches show experiments to demonstrate that gravity is a form of acceleration. And Leonardo da Vinci modeled the gravitational constant with around 97 percent accuracy
Da Vinci, who lived from 1452 to 1519, was well ahead of the curve in exploring these concepts – so it may not be a surprise the famed polymath grasped the idea of gravity.
However, it was not until 1604 that Galileo Galilei suggested that the distance covered by a falling object was proportional to the square of the time elapsed.
And then, in the late 17th century, Newton expanded on that to develop a law of universal gravitation, describing how objects are attracted to one another.
The story goes that the apple fell on Newton’s head as he sat underneath the tree.
He then had a ‘eureka’ moment where he developed his theory of gravity after observing the fruit falling in the Summer of 1666.
Newton theorized that if an apple falls from a tree, gravity may extend even further – possibly as far as into space.
Mory Gharib first spotted da Vinci’s experiments in the Codex Arundel, a collection of papers written by da Vinci that cover science, art and personal topics.
‘What caught my eye was when he wrote ‘Equatione di Moti’ on the hypotenuse of one of his sketched triangles—the one that was an isosceles right triangle,’ said Gharib, lead author of the paper, in a statement.
‘I became interested to see what Leonardo meant by that phrase.’
Leonardo d Vinci was well ahead of the curve in exploring these concepts – so it may not be a surprise the famed polymath grasped the idea of gravity. The recent work suggests da Vinci understood gravity well before Isaac Newton (right), who is accredited for the discovery
Researchers from the California Institute of Technology reanalyzed da Vinci’s notebooks
The sketches show a water pitcher moving along a straight line parallel to the ground, pouring out water or sand.
Da Vinci’s notes clarify that when dumped out, the contents would not fall at a constant velocity but would accelerate.
He also wrote that the contents would stop accelerating horizontally because the pitcher no long influenced them – the ‘acceleration is purely downward due to gravity,’ according to the researchers.
‘If the pitcher moves at a constant speed, the line created by falling material is vertical, so no triangle forms,’ the researchers continued to explain.
‘If the pitcher accelerates at a constant rate, the line created by the collection of falling material makes a straight but slanted line, which then forms a triangle.
Da Vinci sought to describe that acceleration mathematically, which is seen in the sketches, but he did not quite hit the mark.
The researchers used computer modeling to run his water vase experiment and found where da Vinci went wrong
‘And, as da Vinci pointed out in a key diagram, if the pitcher’s motion is accelerated at the same rate that gravity accelerates the falling material, it creates an equilateral triangle.’
This is what Gharib initially noticed that da Vinci had highlighted with the note ‘Equatione di Moti,’ or ‘equalization (equivalence) of motions.
Da Vinci sought to describe that acceleration mathematically, which is seen in the sketches, but he did not quite hit the mark.
The researchers used computer modeling to run his water vase experiment and found where da Vinci went wrong.
Chris Roh, who was a postdoctoral researcher at Caltech at the time of the research, said: ‘What we saw is that Leonardo wrestled with this, but he modeled it as the falling object’s distance 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.’ In his notes, da Vinci illustrated an object falling for up to four intervals of time—a period through which graphs of both types of equations line up closely.
‘We don’t know if da Vinci did further experiments or probed this question more deeply,’ Gharib says. ‘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.’
