Can humans run on water? Scientists say yes, at least in environments of lower gravity.
On earth, only smaller insects and animals are capable of this feat, such as the water strider and basilisk lizard. Put a human on the moon or one of the moons of Jupiter, science says yup, man can probably run on water.
Scientists conducted a study on animals like the basilisk lizard and analyzed how it achieved this feat. Well by using its feet! The lizard strikes the surface with such force that it generates a hydrodynamic force on their legs which supports their weight.
For smaller insects, they are able to achieve this feat by leveraging on the surface tension of the water to support their weight.
Humans are far too big and heavy to support themselves running on water. We can only achieve this if we are in an environment of lower gravity and strapping on small fins on our feet.
The small fins increase the striking force with which the limbs hit the water. Reduced gravity (20% that of the Earth’s gravitational force) would reduce our body weight enabling one to run on water.
Scientists modeled their experiment with reference to the Basilisk lizard. They calculated a ratio between leg length and the effective radius of the feet and found it to be about 0.229. They replicated this result in the humans with fins, with a ratio of about 0.213.
The model determined that man would probably be able to run on water where g<2.16m/s2, creating an upper limit of 0.22gEarth.
By modeling the data, the scientists were able to identify 3 variables to make predictions from.
g = gravity
M = cylinder mass (assumed body shape of 2 legged entity to be a vertical cylinder)
Freq = minimum stride frequency to run on water.
From the above formula the scientists were able to determine the minimum stride frequency required to run on water and under what kind of gravitational environment that the body was subject to.
Get your fins ready and start walking on water!
Article Source: Humans Running in Place on Water at Simulated Reduced Gravity
Minetti AE, Ivanenko YP, Cappellini G, Dominici N, Lacquaniti F (2012) Humans Running in Place on Water at Simulated Reduced Gravity. PLOS ONE 7(7): e37300. https://doi.org/10.1371/journal.pone.0037300
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