Water is wonderful, amazing and surprisingly unique in many, many ways. Most of these ways come back to the
hydrogen bonding between the different molecules including the feature pertinent to today’s FF – surface tension.
This is what we know as surface tension!
It must feel a bit like walking on a bouncy castle or trampoline.
There. Fun fact complete. You can go home now.
Firstly - Why don't they (water walking spiders, water strider insects and others) get their feet wet?
Secondly - How do they move (not just stand on water)
Thirdly - Are there other ways of walking on water
Finally can WE walk on water?
(if you are only interested in some of these questions the rest of the FF is colour coded, but do watch the videos, they are cool)
Getting your feet wet as a water walking insect or spider is dangerous - if you do that, then the water molecules adhere to you as well as each other and if you try to lift up your foot, it pulls the water surface up as well and the surface tension trys to pull it back down, making it very, very, hard for the creepy crawley to escape the water's wet grasp. So staying dry is essential. It ised to be thought (until very recently) that a waxy hydrophobic surface to their legs was solution of choice, but recently (2004) Chinese scientists discovered that water strider legs (water striders pictured above left are particularly good at walking on water) are covered in tiny hairs or micrositae which are in turn covered in tiny nanometre scaled grooves all of which capture tiny water repellant air bubbles around the legs preventing them getting wet and leading the insect to a watery grave.
I can imagine rowing/skating across a super-slippery flat pond surface, but what about the edges. Water forms a meniscus at the edge a little, but steep up slope. Ever walked up hill on ice? Let alone rowed on a slippery, flowing, felxible bouncy castle uphill? This isn't too much of a problem for the bigger water walkers/rowers. The water strider can move fast enough that its momentum can ski jump it up the meniscus on to dry land when it needs to. But what about the littler, slower insects? Things like the 3 mm long (and delightfully named) water treaders? |
"Surf's UP Dude!" (like literally!)
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The simple answer is:
No
Yes
Maybe
Well, under the right conditions.
To do this we would need to exert a very large,fast, downward force repeatedly with our feet to keep above water, unfortunately this needs about 15x more power than our leg muscles are capable of.
But couldn't we use big feet/fins like the lizard?
-Not easily - each fin would have to be an insanely unweildy 1 square metre. Nope, not practical.
HOWEVER In 2011, scientists in Italy wondered about whether we could do this feat if we weighed less due to less gravity. Putting volunteers in harnesses which mimicked reduced gravity, they then suspended them above massive barrels of water in special fins and told them to RUN!
And now we know. If they ever build a moon base, with a swimming pool, and you are very fit, and have fins. You WILL be able to run across the surface while keeping pretty much dry!
Disclaimer: If they build that moon base, with the pool. I want to run across it. I'll even bring my own fins. Not really a disclaimer. More a FF aspiration. Just sayin'