How do plants suck? / Did my school lie?

[hitch1978]

Fairly sure I know the answers, but here I go.....

When you look at a glass of water, the sides of the body of water turn up the glass due to surface tension. In plants, the stems contain cylinders so small that those 'lips' of water pull it up the stem, drawing water from the ground that the plant drinks.

The above is what my science teacher told me at school.

My question is - WTF?

[Sephus]

http://en.wikipedia.org/wiki/Capillary_action

[hitch1978]

TY Sephus.

My real question was 'where does the energy come from?' But I see it is a very limeted distance, and I get it. My misunderstanding came from the idea that with no energy a tube of the correct diameter could pull an indefinate amount of water an indefinite distance.

[tame_deuces]

Osmosis

[surftheiop]

ive allways wondered if it would be posible to get "free energy" using millions of very small tubes to move water up in elevation and then let it fall back down hydroelectric style. (even if the water could only be raised several inches it would style give energy without any input that i i can think of)

[kerowo]

I don't think capillary action shoots water out of the top of the thin tube, I think the water just reaches the top and stops.

[furyshade]

[ QUOTE ]
ive allways wondered if it would be posible to get "free energy" using millions of very small tubes to move water up in elevation and then let it fall back down hydroelectric style. (even if the water could only be raised several inches it would style give energy without any input that i i can think of)

[/ QUOTE ]
the question is how many tubes would it require and over what surface area? it would probably have the same problem as solar power, you would have to cover 1/3 of the country in tubes to power it.

an interesting idea i heard about was using waves as a power source, just having a giant paddle connected to electrodes, ever wave that hits it pushes it back and creates tremendous force

[surftheiop]

if you had something like a paper towel draped over and cylinder of tubes im pretty sure you would get water flowing up through the tubes, soaking in the the paper towel and then running down the sides.

Granted i know this isnt doing anything important but thats the concept im thinking of

[TomCowley]

I'd actually had that same idea, but.. before the water is free to fall, it has to be removed from the capillary. Guess how much energy that takes, relative to the potential energy of the water in the capillary.

[surftheiop]

yeah your probaly right, i might have to mess around with it someday just to prove it to myself