Half a millennium after Leonardo da Vinci explained gravity, engineers at the California Institute of Technology (Caltech) discovered that his understanding of the phenomenon – while not entirely accurate – was centuries ahead of his time. Despite limited tools, the great Italian thinker displayed ingenious problem-solving.

In an article just published in the journal Leonardo, the researchers draw upon a fresh look at one of da Vinci’s notebooks to show that the famed polymath had devised experiments to demonstrate that gravity is a form of acceleration and that he modeled the gravitational constant to around 97% accuracy.