Isaac Newton is credited with first formulating a theory of gravitation in the second half of the 17th century – apparently inspired by an apple falling from a tree — but fundamental aspects of gravity’s pull were also recognized by Leonardo da Vinci more than a hundred years earlier, a new study explains.
The study analyzed diagrams in Leonardo’s now-digitized notebooks, including sketches of triangles showing the relationship between natural motion, directed motion and motion compensation – a realization that gravity is a type of acceleration.
In Leonardo’s case, this meant thinking of sand pouring out of a jar. What the polymath realized was that if the glass were pulled along a horizontal plane at the same speed as the force pulling the grains down, the sand would form the hypotenuse of a triangle. This knowledge of the change in velocity experienced by a falling object over time is a crucial step towards finding the gravitational constant on earth.
“About 500 years ago, Leonardo da Vinci attempted to unravel the mystery of gravity and its connection to acceleration through a series of ingenious experiments guided only by his imagination and masterful experimental techniques,” the researchers write in their published paper.
This gravitational constant was later used by Newton to define his laws of motion (including gravity) and by Albert Einstein in his theory of gravity general relativity. Leonardo knew he’d found something, but he wasn’t sure what it was.
Part of this uncertainty was due to Leonardo subscribing to Aristotle’s idea of continuous force called impulse, which fills projectiles and gives them an impetus to move against gravity. The principle of inertia – where objects just keep moving in one direction until they meet an opposing force – was not yet established in science at the time.
Gravity, on the other hand was explained by Aristotle as a tendency Materials arrange themselves in a natural order. In other words, gravity and flying projectiles have been explained by two very different theories.
While his calculations contained errors, replicas of Leonardo’s laboratory experiments showed that his algorithm calculated the elusive gravitational constant (“g”) with an accuracy of 97 percent compared to modern methods and equations.
“By developing a geometric equivalence approach to demonstrate the laws of motion, Leonardo showed a remarkable insight into the dynamics of falling objects by avoiding knowing the exact value of ‘g’ as long as we assume that ‘g’ represents velocity – or acceleration change” write the researchers.
“Had he performed the experiment he presents in his manuscript, he could have been the first human to knowingly produce a ‘g’ force effect without being in a state of free fall.”
The researchers were particularly impressed by the methods Leonardo had at his disposal at the time – especially geometry – and thus investigating something unknown. The same innovation can still be applied to science today.
Newton did not develop his law of universal gravitation himself: Galileo recognized the relationship between free fall motion and time in 1604, while Newton himself acknowledged the results of Bullialdus And Borelli in supporting his theories.
As it turns out, Leonardo da Vinci was also on the right track by identifying patterns in the way objects fall, which were later used to explain the movements of stars and planets – and are known to predict the existence of stars Neptune.
“We don’t know if [Leonardo] carried out further experiments or investigated this question in depth”, says Mechanical engineer Morteza Gharib from the California Institute of Technology.
“But the fact that he approached the problems in this way – in the early 1500s – shows how far ahead his thinking was.”
The research was published in Leonardo.