Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: paul.fr on 18/05/2007 19:48:36
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When out trekking in the snow, you can wear snowshoes like tennis rackets that somehow prevent you sinking in to the snow.
If I had shoes big enough, in other words with a very large surface area would i be able to walk on water?
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It is not merely about being big enough, since water is a liquid and can flow over the shoes.
Certainly there is no reason why you could not wear floats on your feet to walk on water, but you would have to make sure that the floats were either seeled, or otherwise protected from having the water engulf it (e.g. very high sided).
I can imagine other ways of creating water shoes (e.g. some insects use the surface tension of water to keep them afloat, rather than buoyancy, and it is conceivable that an appropriately designed pair of water shoes might use a similar mechanism).
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The, so called 'Jesus Christ' lizard can run a long way on top of water. It does it by going fast enough to 'plane' on the water - just like a hydrofoil. Once it slows down, it sinks.
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How about shoes so that they are shaped like a boat?
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They would need to be big enough to provide lots of buoyancy (upthrust) if you ever wanted to stop.
I remember seeing a picture of some ancient character using shoes that looked like two canoes. Not very elegant.
It was amongst a lot of other pictures of whackey ideas.
A conventional kayak is much more practical ; it's more stable, faster and more controllable. 20,000 boatmen can't be wrong!
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How about shoes so that they are shaped like a boat?
The shape is not the issue, it is the buoyancy that matters.
In fact, the one thing you don't want it to be is shaped like a conventional boat. A boat is meant to be able to plough through the water, yet if you are walking on water, you don't need something that can plough through the water (because you will be picking your feet out of the water), but you will need a shape that will allow you to stand on one foot and remain stable (while you pick your other foot out of the water in order to step forward).