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Author Topic: Can A Water Arch Act Like A Lens ?  (Read 6322 times)

Offline neilep

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Can A Water Arch Act Like A Lens ?
« on: 09/10/2008 12:12:57 »
Hi all,
I'm Neil. Nice to meet ewe !


See this water arch ?




Nice eh ?


Would it be possible to bend a stream of water so that it acted like a lens ?..be it big or small..could it be done ?


Thanks


Neil
xx


 

Offline RD

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Can A Water Arch Act Like A Lens ?
« Reply #1 on: 09/10/2008 12:53:52 »
A droplet of water can be used as a magnifying lens...

Quote
a microscope is just a lens. You can see the principle quite easily by looking through a tiny drop of water. Try balancing a water droplet on a 2mm hole made in cardboard and looking through it. You'll have to get your eye very close - and the object you're looking at very close too - but it magnifies surprisingly well.

http://www.open2.net/sciencetechnologynature/worldaroundus/microscope.html
 

Offline lightarrow

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Can A Water Arch Act Like A Lens ?
« Reply #2 on: 09/10/2008 14:25:34 »
A droplet of water can be used as a magnifying lens...
...but a water arch can't (unless you mean a very tiny portion of it, as tiny as a droplet).
 

lyner

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Can A Water Arch Act Like A Lens ?
« Reply #3 on: 09/10/2008 14:30:55 »
An optical lens needs to have a flat surface. Lots of little droplets wouldn't produce a coherent image, I'm afraid.
The can produce a Rainbow, though.
 

Offline neilep

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Can A Water Arch Act Like A Lens ?
« Reply #4 on: 09/10/2008 16:43:39 »
A droplet of water can be used as a magnifying lens...

Quote
a microscope is just a lens. You can see the principle quite easily by looking through a tiny drop of water. Try balancing a water droplet on a 2mm hole made in cardboard and looking through it. You'll have to get your eye very close - and the object you're looking at very close too - but it magnifies surprisingly well.

http://www.open2.net/sciencetechnologynature/worldaroundus/microscope.html

Many Many thanks for this Rd..yes..I have witnessed this myself when caught in the rain whilst reading a magazine...thanks for the link too.
 

Offline neilep

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Can A Water Arch Act Like A Lens ?
« Reply #5 on: 09/10/2008 16:45:03 »
A droplet of water can be used as a magnifying lens...
...but a water arch can't (unless you mean a very tiny portion of it, as tiny as a droplet).

Thanks Lightarrow...yes, I meant a big arch or a small arch. I suppose I was hoping there might be a way to smooth the water out !
 

Offline neilep

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Can A Water Arch Act Like A Lens ?
« Reply #6 on: 09/10/2008 16:46:55 »
An optical lens needs to have a flat surface. Lots of little droplets wouldn't produce a coherent image, I'm afraid.
The can produce a Rainbow, though.


Thanks sophiecentaur. As mentioned above I was hoping there might be a way to smooth the water out.

I've just thought of two ways...ice ??..and what about in zero gravity if the water could be kept absolutely still  ?

*le sigh*..I luff rainbows !
 

lyner

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Can A Water Arch Act Like A Lens ?
« Reply #7 on: 09/10/2008 17:42:55 »
Quote
and what about in zero gravity if the water could be kept absolutely still
Unfortunately, surface tension would make the sheet of water break up into droplets after a very short time.

BUT  you could use a water arch as a lens to modify a beam of longer wavelength radiation - say @  500MHZ
 

Offline Make it Lady

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Can A Water Arch Act Like A Lens ?
« Reply #8 on: 09/10/2008 18:05:26 »
And if it doesn't work after you have fiddled with it you can make it go back to its refractory settings.....tee hee!
 

Offline Bored chemist

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Can A Water Arch Act Like A Lens ?
« Reply #9 on: 09/10/2008 18:45:32 »
You can use a jet of water like an optical fibre. If you pass a beam of light along a bent stream of water you bend the stream of light. Is that enough like a lens to count?
 

Offline RD

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Can A Water Arch Act Like A Lens ?
« Reply #10 on: 09/10/2008 21:19:42 »
I've just thought of two ways...ice ??..and what about in zero gravity if the water could be kept absolutely still  ?

An ice lens can be created by putting a loop of springy wire in a balloon then filling it with water...
http://www.open2.net/roughscience3/ice_lens.html

If you could spin a bucket if water at a constant rate (rather difficult) it would produce a concave surface which could act like a magnifying shaving mirror. The magnified reflection would be more obvious if the bucket was matt black, or if you used mercury...
http://www.space.com/scienceastronomy/astronomy/liquid_mirror_000924.html
 

lyner

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Can A Water Arch Act Like A Lens ?
« Reply #11 on: 10/10/2008 00:01:20 »
In the same way you could make a plano-concave lens (flat bottom. concave top) with the spinning bowl of water. But, concave lenses being what they are, you couldn't use it to focus light to form an image. You could use two small ones as spectacles of someone short sighted, though. You could only look down with these specs tho'.
 

Offline Bored chemist

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Can A Water Arch Act Like A Lens ?
« Reply #12 on: 10/10/2008 07:10:22 »
"But, concave lenses being what they are, you couldn't use it to focus light to form an image."
Usually, but in an atmosphere with a higher refractive inex than water, it would converge light to a focus. So it would work in a pool full of perchloroethylene for example.
 

lyner

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Can A Water Arch Act Like A Lens ?
« Reply #13 on: 10/10/2008 10:38:29 »
I think there is a problem with density there. The Cl2C=CCl2 would displace the water and form its own concave lens, underneath. The overall effect would, I think, be a concave lens again.
« Last Edit: 10/10/2008 10:52:54 by sophiecentaur »
 

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Can A Water Arch Act Like A Lens ?
« Reply #13 on: 10/10/2008 10:38:29 »

 

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