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Robots That Bounce on Water
inghamb87 writes "The way water striders walk on water was discovered years ago. The insect uses its long legs to help evenly distribute its tiny body weight. The weight is distributed over a large area so that the fragile skin formed by surface tension supports the bug on the water. However, the ability of water striders to jump onto water without sinking has baffled scientists, until now." If nothing less, you need to see the picture: it's awesome.
Well, if you don't mind the sources, check out this alternate coverage (with pictures):
Telegraph.co.uk article
ENN article
Misery loves company. Online misery loves unsuspecting random strangers.
This one is erroneous in at least one way. It suggests that tiny bubbles trapped in hairs on the bug's legs make it float. Tosh! The bubbles are too small to make it boyant. What the bubbles do is increase the surface area which, in turn, increases the amount of surface tension "skin" that the bug walks on and therefore the carrying capacity.
As most fly fishermen would tell you, surface tension is far stronger than you'd think. Hatching bugs struggle to get through the surface tension which keeps them under the surface. Once they break through they are able to sit and walk quite easily.
Engineering is the art of compromise.
with some surface-tension reducing soap
I'm gonna take a guess to say that you learned this from Mr. Wizard?
I remember this episode well - it is a simple but very awe-inspiring (at least from a geek's perspective) experiment. It goes like this:
1) Fill a cookie tray with water
2) Pepper the top of the water in order to *see* the movements of the surface tension
3) Carefully place a small amount of soap in the center of the tray
4) Watch the pepper scatter to the edges of the pan as the tension breaks
If you have a kid, then you need to go do this experiment with them NOW!
RIP Don Herbert - you are one of the main reasons that I am a geek today.
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See, my life just got better because I have a great excuse to karma whore. Yay nyud mirror
If you are about to mod me down, keep in mind that this post was most likely sarcastic.
The "robot" spreads its weight out using the whole length of its legs in contact with the water. That is nothing like a water strider.
A water strider walks on the **ends** of its legs (feet, if you will). For a far better description see http://www.livescience.com/animals/041103_water_strider.html.
The only similarity is that they both use surface tension.
Engineering is the art of compromise.