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The Chap
27 Feb 06,, 09:24
'just seen the stuninglyluuurly "Hero"

As sush (diib)

Is it indeed possible (as a chineese) chum claims for sombody to " walk on water "

In defence of the theory - as may be - hitting water hard is a brick wall.

These Shoulin (sp?) monks can break concrete with feet. You see where this is going ...

Thus, if they could pound their feet against the water hard enough for it to resist ...

'bit drunk, but I think, still one worthy of a head scratch

Officer of Engineers
27 Feb 06,, 12:41
It's called winter here.

Aryan
27 Feb 06,, 13:35
Its impossible for humans to walk on water, as water is a newtonian fluid, so its viscosity is unaffected by external forces.

If you want to walk over a swimming pool of a liquid, pick a non newtonian fluid thats viscosity increases with the application of stress.

Aryan
27 Feb 06,, 13:36
And alcohol and the internet aren't a good combination...take it from me :)

Officer of Engineers
27 Feb 06,, 14:25
Its impossible for humans to walk on water, as water is a newtonian fluid, so its viscosity is unaffected by external forces.

It's called winter.

sparten
27 Feb 06,, 14:35
While we are at that sir, did'nt the Mongols wait until winter to attack Russia, since the frozen rivers made acrossing easier.

Officer of Engineers
27 Feb 06,, 14:48
Which time?

THL
27 Feb 06,, 15:59
And alcohol and the internet aren't a good combination...take it from me :)
At least he was not drunk enough to actually try it

:)

sparten
27 Feb 06,, 16:25
Which time?
I was wrong in saying Russia, but did they not cross thge Danube when it was frozen?

Aryan
27 Feb 06,, 18:28
You were right, Mongols would time their invasions of Russia during winter so they could cross the frozen rivers easier on horseback.

Jay
27 Feb 06,, 18:59
may be you can try this stunt in dead sea?? :confused:

Aryan
27 Feb 06,, 19:45
You can float in the dead sea, but if you tried standing in it, you'd just fall into the water up to the point of your centre of gravity (assuming your density was less than the water).

Aryan
27 Feb 06,, 19:45
At least he was not drunk enough to actually try it

:)

Maybe he did...

THL
27 Feb 06,, 19:53
If you want to walk over a swimming pool of a liquid, pick a non newtonian fluid thats viscosity increases with the application of stress.
So, what then, like jello? :)

Aryan
27 Feb 06,, 20:00
I think jello viscosity decreases with application of force, but something like custard or thick enough corn starch is fine.

Karna
27 Feb 06,, 20:05
There's those lizards that skip on water.

But you'd have to be super fast.

Jay
28 Feb 06,, 22:04
Ive seen insects that float on water, they dont swim, they can walk on both land and water, I friggin forgot its name. It looks pretty much like a thin spider, any one from South India wudve seen it on Ponds and lakes.

Jay
28 Feb 06,, 22:07
Alright found it out....

http://images.livescience.com/images/041103_water_strider_A_01.jpg


The amazing water strider doesn't just walk on water. It skips across it with the grace of an Olympic skater and the power of a hockey player. The insect dances up and down to avoid being submerged by raindrops, and it can pack 15 times its body weight without sinking.

Until now, scientists thought this seemingly Biblical ability was due to a wax secreted on the insect's legs combined with surface tension, a property of water that makes its boundary behave something like stretched Saran Wrap for small things.

But new research finds the water strider's legs are covered with microscopic hairs that trap tiny air bubbles, allowing the insect to simply float.

The discovery was made by Xuefeng Gao and Lei Jiang of the Chinese Academy of Sciences and will be detailed in the Nov. 4 issue of the journal Nature.

The effect is like water off a duck's back, Lei told LiveScience.

The discovery could lead to new water-resistant textiles, the researchers say. "But our finding might be more helpful in designing innovative miniature aquatic devices with drag-reducing [properties] and fast propulsion," Lei said.

Microscopic images of the insect's legs revealed that the otherwise invisible hairs, called microsetae, are oriented in one direction and involve several layers. The needle-shaped microsetae are each less than 3 micrometers in diameter (a human hair is 80-100 micrometers wide).

The microsetae are scored with grooves measured in nanometers, even smaller units that represent billionths of a meter.

Air gets trapped in the spaces among the microsetae and nanogrooves to form an air cushion, which prevents the legs from getting wet, Lei explained. "Duck feathers are a similar matter, but they are not as effective as the striders’ legs to achieve super water-repellence."

Scientists call the hairy legs superhydrophobic.

To rule out wax and surface tension as a viable water-walking technique, the researchers created an artificial strider's leg and coated it with wax. It worked well enough to support a couch-potato strider, but "but not to enable it to glide or dart around rapidly on the surface."

Water striders flit about quickly by using their legs like oars, according to a discovery last year by MIT mathematician John Bush and colleagues. The MIT team used dye in lab water and high-speed video cameras to record vortices created as the striders strode.

It is critical that water striders legs not get wet, "in order to avoid penetrating the surface during their rowing stroke," said David Hu, who worked on the MIT research. "If they do happen to fall through, they must generate forces ten times their body weight to return to the surface."

In an email interview, Hu said today's result is "consistent with our 2003 study."

http://www.livescience.com/animalworld/041103_water_strider.html

http://www.fcps.k12.va.us/StratfordLandingES/Ecology/mpages/common_water_strider.htm

So what's the deal with the simple water spider? This eight-legged marvel speeds across the water fast enough to escape predators, find prey, and chase off intruding spiders. But how does it move? It must be pushing the water backwards, but what is doing the pushing?

That kind of question interests Vassar College biology professor Robert Suter. Shunning the glamorous study of elephants and Tyrannosaurus rexes, Suter is fascinated by the small. He started this Lilliputian quest by looking at spiders that ride strings of silk into the sky and found that, in a decent breeze, a single 10-centimeter strand of silk could lift a small spider.

Now Suter has turned his attention to a spider that doesn't fly. This one literally walks on water. The fisher spider (Dolomedes triton), a pond-dwelling species found in much of North America, is one of about 15 spiders that can turn this trick. Two groups of insects, including water striders, can do likewise.

Like a seven-year-old boy, it hates water
Surprisingly, Suter is not trying to figure out why the organisms don't drown. That clever feat is well understood to be a result of surface tension, a force between a liquid and solid materials that resist being wetted by that liquid.

In the presence of surface tension, a liquid "tries" to minimize its surface area. This explains why water beads up on a waxy surface -- because that the lowers the surface area of the droplet. Surface tension even explains why wet sand makes better sand castles.

Objects like waxes and glass that resist being wetted by water are called "hydrophobic." The hydrophobic legs of fisher spiders and other water-walking arthropods create so much surface tension that they barely touch the water. Yet because the animal has weight, its legs makes dimples where they do contact the water, but the animal still stays on top.

No friction, no movement?
But since the legs barely contact the water, there's very little friction, and here's the rub, or lack of it. Friction is the mechanism land creatures use to push themselves forward. But with so little friction, the spider can't push water backward to start the action-reaction equation.

It's a paradox: the same phenomenon that allows the spider to stay on the surface seems to prevent it from moving. Yet since the spider does move, there must be a flaw in the reasoning -- a fly in the ointment.

Using calculations and high-speed photography, Suter discovered that spiders "row" across the water by exerting force on the dimples of water under their legs. The dimple creates drag on the water, allowing the leg to push the water backward while barely touching it. In reaction, the spider moves forward. :)

Drag is the same mechanism that moves a rowboat, Suter points out: an oar pushes water backward, and the boat reacts by moving forward. Like somebody rowing a boat, fisher spiders lift their legs on the forward stroke. Otherwise, they'd push water in both directions, and would stay in one place.

However, while an oar can work at any depth, the spider's leg must be at the surface: a submerged leg would not create the dimple, and would move much less water.

Doin' the locomotion
A fisher spider in a real hurry doesn't bother to row, Suter says. It "gallops" across the water, actually lifting itself off the surface briefly while sprinting at up to 75 centimeters per second. Galloping is usually a response to a threat, and it does not use the "dimple" mechanism we described above. Rather, they do a kind of slapping stroke that certain lizards use. "Most of the propulsive parts of the legs are momentarily submerged during galloping," Suter says.

When they're feeling lazy, fisher spiders have other ways of getting around, Suter says. They may stand on tiptoe and sail downwind, or prostrate themselves and stick two legs aloft to catch the breeze.

Suter is to first to admit that the study of water spiders has virtually no practical applications. So why bother? Because these small organisms live in a world with different rules, and that alone makes them worth the effort. "I'm interested in the way organisms do things when they live in a different physical environment." Suter says. "The rules are different, and the smaller you get, the more different the rules become."

Small organisms have a high ratio of surface area to volume, making them more responsive to surface forces like surface tension and adhesion. As size increases, Suter notes, the surface area to volume ratio decreases, making large organisms more responsive to gravity and inertia.

The all-important ratio also explains why we couldn't walk on water, even if our feet were hydrophobic. With our much greater mass, the perimeter of our feet -- where all surface tension takes place -- would have to be huge.

However, Suter has calculated that surface tension would support a half-kilogram spider. That's a body as big as your fist. Think about that next time you're watching some quarter-sized water striders dance across a lake.
http://whyfiles.org/shorties/walk_on_water.html

http://www.fcps.k12.va.us/StratfordLandingES/Ecology/Insects/Common%20Water%20Strider/waterstrider.jpg

Karna
28 Feb 06,, 23:23
So yea, I guess if you had big balloons or some **** stuck to your hands and feet and you moved like a dog, sure, you can walk on water. :tongue: :biggrin:

Parihaka
28 Feb 06,, 23:49
http://www.benmorcombe.me.uk/uploaded_images/walkonwater-729272.jpg

Jay
01 Mar 06,, 01:18
So yea, I guess if you had big balloons or some **** stuck to your hands and feet and you moved like a dog, sure, you can walk on water. :tongue: :biggrin:

Not really, nothing is stuck on its leg. Read above, their legs have microsetae and nanogrooves.

So if you have nanogrooves and microfiber hair throughout your body, then you can walk/glide using that :tongue: You may look like an ape gone wrong, but who cares :biggrin:

The Chap
01 Mar 06,, 08:04
BUT is anyone aware of kungfu types being able to slap their feet down fast enough to treat water as a reactive solid. Surface tension does not really count. Neither do Colloids. :)

Parihaka
01 Mar 06,, 21:36
BUT is anyone aware of kungfu types being able to slap their feet down fast enough to treat water as a reactive solid. Surface tension does not really count. Neither do Colloids. :)
I'm aware that they believed that with proper training they'd be bullet-proof. Didn't work out that way though :rolleyes:

2DREZQ
12 Mar 06,, 01:54
Taken with a cellphone, so the resolution isn't the best...

Where they are standing, the water is 12-16 feet deep.

http://img.villagephotos.com/p/2003-1/86444/codysbuck2005.jpg

THL
13 Mar 06,, 12:01
Yyyeeeeeaaahh...and the boys stopping to pose for an apparent photo op while wading through the water dragging a dead deer relates to Walking ON Water how again? :confused:

Swift Sword
13 Mar 06,, 16:36
http://www.benmorcombe.me.uk/uploaded_images/walkonwater-729272.jpg

Hmm...so THATS how the Chinese intend to get all of those troops across the Taiwan Striats! :biggrin:

2DREZQ
13 Mar 06,, 16:45
Yyyeeeeeaaahh...and the boys stopping to pose for an apparent photo op while wading through the water dragging a dead deer relates to Walking ON Water how again? :confused:

Those are my boys (the one on the left is ex-USAF, the one on the right is future USMC.) are standing in 1/4" of water, on top of 4" of ice on 12 ' of water. The OAT was 57 degrees F. I figured that was enough of a tie-in to post a pic of one of my most prized memories.
We stir-fried the deer.

Parihaka
13 Mar 06,, 20:37
Hmm...so THATS how the Chinese intend to get all of those troops across the Taiwan Striats! :biggrin:
Shhhh, don't tell OoE, we're saving it as a surprise ;)

anand1266
19 Mar 06,, 15:11
guys if u hv seen the animation movie..INCREDIBLES....u will come to know how to walk / run on water....just like the little boy ( son of Mr.incredible) does by running very very very fastly on it :tongue:

The Chap
13 Jun 06,, 03:36
guys if u hv seen the animation movie..INCREDIBLES....u will come to know how to walk / run on water....just like the little boy ( son of Mr.incredible) does by running very very very fastly on it :tongue:

The above is EXACTLY what I'm on about.

Yes I did give it a go in Dubai but with hands allowed. In a (what else?) frantic attempt - with stung palms I may add - made 1/4 of the 28ft pool. On a gentlemans bet. Two of the other guys got futher. They were in good nik.

So could some super fit type, trained in this fiction, do it? :)

Mayhaps it would require an NBL player. Big feet: Can jump? ;)

ArmchairGeneral
13 Jun 06,, 04:43
The above is EXACTLY what I'm on about.

Yes I did give it a go in Dubai but with hands allowed. In a (what else?) frantic attempt - with stung palms I may add - made 1/4 of the 28ft pool. On a gentlemans bet. Two of the other guys got futher. They were in good nik.

So could some super fit type, trained in this fiction, do it? :)

Mayhaps it would require an NBL player. Big feet: Can jump? ;)
More like a midget with big feet. You want maximum surface area with mininum mass. There's a lizard that can do it. Has big splayed feet, I think they're webbed. Runs fast enough that it don't break through the surface tension, or something like that. So say a three foot40 lb midget with the muscle development of Bruce Lee multiplied times Arnold Swarzchenegger (and I'm proud to say that when I looked up the spelling of that, I was only off by 1 s), with webbed, size 17 feet might be able to do it. And with genetic engineering, who knows? Doesn't matter, though. In twenty years, I'll have taken over the world with genetically engineered fruit flies.

Jay
13 Jun 06,, 19:26
In twenty years, I'll have taken over the world with genetically engineered fruit flies.
a Genetically modified frog or lizard would feast on them :biggrin:

BMD
31 Jul 06,, 01:06
There's a lizard that can do it. Has big splayed feet, I think they're webbed. Runs fast enough that it don't break through the surface tension, or something like that.The lizard in question is called the "jesus lizard" for obvious reasons. Here's a pic: http://www.worth1000.com/entries/150500/150926wdFB_w.jpg
The reason is not surface tension, but purely a question of accellerating enough water downwards to equal gravity's pull on you. Newton's laws in other words: F=m*a


Yes I did give it a go in Dubai but with hands allowed. In a (what else?) frantic attempt - with stung palms I may add - made 1/4 of the 28ft pool. On a gentlemans bet. Two of the other guys got futher. They were in good nik. Hehe, should have been a priceless sight :-)

YellowFever
14 Aug 06,, 06:56
What???

Didn't you guys see movies like "Crouching Tiger, Hidden Dragon" and "Hero"?

They can do it, dammit!

Now if they can only make a CD player that lasts more than a few months...

Bill
17 Aug 06,, 08:25
Is it indeed possible (as a chineese) chum claims for sombody to " walk on water


LOL, Chriss Angel can do it.

ABW
09 Oct 06,, 23:42
It all depends on how much pull gravity has where you are. it is a very simple thing only forces not devine or mystical. but what do I know not tested.

Goatboy
10 Oct 06,, 20:26
What???

Didn't you guys see movies like "Crouching Tiger, Hidden Dragon" and "Hero"?

They can do it, dammit!

Now if they can only make a CD player that lasts more than a few months...

You forgot Remo Williams.