Jul 17, 2024 05:22 PM
(This post was last modified: Jul 17, 2024 06:49 PM by C C.)
https://physicsworld.com/a/could-athlete...pic-sport/
EXCERPTS: The world’s best runners are gathering in Paris for the 2024 Summer Olympics. Sprinters vying for the title “world’s fastest” hope to chase records set by all-time greats such as Usain Bolt and Florence Griffith-Joyner, competing on a highly engineered athletic track. Across the Atlantic, however, a different type of sprinter is practising its craft daily, not on polymer-laced rubber, but on water.
Basilisk lizards – nicknamed “Jesus Christ lizards” for their ability to run on water – don’t run for accolades or titles; they’re just looking to escape predators. When threatened, these pint-sized powerhouses take a running start on land, then skitter across the water. At 100 grams, basilisk lizards are hardly heavyweights, but they’re much too heavy to be supported by surface tension.
The ability to run on water is one of the most impressive feats in the animal kingdom – a triumph of physics as much as biology. It’s a question that has intrigued researchers for many years, but there’s something else all good physicists will want to know: could humans moving at speed ever run on water?
[...] Although it was built for basilisk lizards, the model developed by Glasheen and McMahon at Harvard also tells us what it takes for a human to run on water. The idea is simple: to run on water, the total impulse from a slap and stroke must be greater than the impulse needed to support the runner’s mass. Impulse is simply a force multiplied by the time over which a force is applied – in this case, the time between steps. With a little algebra and some simple assumptions, you can determine the slap velocity needed, given the runner’s mass and foot area, as well as the time between steps and the depth the foot reaches.
In their original paper, Glasheen and McMahon calculate that an 80 kg human with an average foot size and a world-class sprinter’s stride rate would have to slap the water at a speed of nearly 30 metres per second to support themselves. Unfortunately, the power needed for a stroke at that speed is almost 15 times greater than a human’s maximum sustained output. In other words, no human can run on water – at least, not on Earth.
That’s the theory, but does it stack up in reality? To find out... (MORE - details)
The insane biology of the Jesus Christ Lizard ... https://youtu.be/UdUcRoQkiJ4
https://www.youtube-nocookie.com/embed/UdUcRoQkiJ4
EXCERPTS: The world’s best runners are gathering in Paris for the 2024 Summer Olympics. Sprinters vying for the title “world’s fastest” hope to chase records set by all-time greats such as Usain Bolt and Florence Griffith-Joyner, competing on a highly engineered athletic track. Across the Atlantic, however, a different type of sprinter is practising its craft daily, not on polymer-laced rubber, but on water.
Basilisk lizards – nicknamed “Jesus Christ lizards” for their ability to run on water – don’t run for accolades or titles; they’re just looking to escape predators. When threatened, these pint-sized powerhouses take a running start on land, then skitter across the water. At 100 grams, basilisk lizards are hardly heavyweights, but they’re much too heavy to be supported by surface tension.
The ability to run on water is one of the most impressive feats in the animal kingdom – a triumph of physics as much as biology. It’s a question that has intrigued researchers for many years, but there’s something else all good physicists will want to know: could humans moving at speed ever run on water?
[...] Although it was built for basilisk lizards, the model developed by Glasheen and McMahon at Harvard also tells us what it takes for a human to run on water. The idea is simple: to run on water, the total impulse from a slap and stroke must be greater than the impulse needed to support the runner’s mass. Impulse is simply a force multiplied by the time over which a force is applied – in this case, the time between steps. With a little algebra and some simple assumptions, you can determine the slap velocity needed, given the runner’s mass and foot area, as well as the time between steps and the depth the foot reaches.
In their original paper, Glasheen and McMahon calculate that an 80 kg human with an average foot size and a world-class sprinter’s stride rate would have to slap the water at a speed of nearly 30 metres per second to support themselves. Unfortunately, the power needed for a stroke at that speed is almost 15 times greater than a human’s maximum sustained output. In other words, no human can run on water – at least, not on Earth.
That’s the theory, but does it stack up in reality? To find out... (MORE - details)
The insane biology of the Jesus Christ Lizard ... https://youtu.be/UdUcRoQkiJ4
