Scientists say Olympic athlete Sha’Carri Richardson could technically "walk" on water

As the world's fastest sprinters gather in Paris for the 2024 Summer Olympics, all eyes are on athletes like Sha’Carri Richardson, the reigning women’s 100m world champion. While Richardson prepares to blaze across the track, a somewhat unusual scientific question has surfaced: could she, with her blistering speed, actually run on water?

To answer this, Nicole Sharp delves into the world of the basilisk lizard, affectionately dubbed the “Jesus Christ lizard” for its miraculous ability to run across water. When a basilisk lizard is chased by a predator, it bolts across the water’s surface, performing a seemingly impossible feat. These lightweight reptiles use a “slap-stroke-recover” motion to create enough lift and propulsion to keep them skittering across the water without sinking.

Biologists have discovered that the key to running on water is in the physics: the lizard’s feet slap the water hard and fast, creating pockets of air and pushing against the water with enough force to keep them from sinking.
Inspired by these little aquatic acrobats, scientists have pondered whether humans could pull off a similar stunt. A model developed by Harvard researchers calculated that an average human, with an average foot size, would need to slap the water at nearly 30 metres per second to stay afloat. That’s about 15 times more power than the fastest human can sustain.

But what if we bend the rules of gravity a teeny bit? A 2012 study by Italian physiologist Alberto Minetti tested this idea by simulating reduced gravity conditions with bungee harnesses and flippers. Under these conditions, participants could “run” on water at about 10% of Earth’s gravity, roughly the gravity on the Moon.
So, what about Sha’Carri Richardson? Let’s take this thought experiment to Titan, Saturn’s largest moon. With a gravity only 13.8% of Earth’s, Titan’s ethane and methane lakes provide a curious setting. Richardson, at 45 kg and with her world-class sprinting ability, would need to slap the surface of Titan’s lakes at about 9 metres per second. Given her top speed of 9.3 metres per second during her gold-medal run in 2023, she’s theoretically capable of dashing across Titan’s liquid ethane lakes!

While Sha’Carri Richardson won’t be running on water at the Paris Olympics, the science behind such a possibility offers a whimsical glimpse into the extraordinary capabilities of both nature and human imagination. So, as you watch her zoom across the track, remember: she might just have what it takes to walk on water — at least on Titan.