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Author Topic: Liquid Mirror Telescopes ?  (Read 4633 times)

Offline neilep

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Liquid Mirror Telescopes ?
« on: 21/02/2006 14:19:29 »
This is interesting, I never heard of a liquid mirror before.

 Can someone tell me how these things work ? what liquid do they use and how do you angle the thing ? or does the liquid part remain horizontal ?


Many Thanks

Neil


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Offline G-1 Theory

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Re: Liquid Mirror Telescopes ?
« Reply #1 on: 21/02/2006 14:35:46 »
Dear neilep;

   Iam going to make a guest on this one!!!!!

 The way that I would go about is;

I would start with a round pan about 2" deep and fill it with mercuy about 2/3 full and then put that pan in a housing of clear glass and then increse the air pressure in that housing to cause the mercuy to from into a concave mirror and keep it haorizonal and bring in the star light to it by other mirrors.
Edward E. Kerls


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Offline G-1 Theory

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Re: Liquid Mirror Telescopes ?
« Reply #3 on: 21/02/2006 15:34:33 »
Spinning it works for me too!!!!


"Learn the facts and go on from there, and never stop asking questions."

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Offline daveshorts

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Re: Liquid Mirror Telescopes ?
« Reply #4 on: 21/02/2006 17:51:45 »
The cunning of a liquid mirror is that if you spin a liquid the shape it will take up is a parabola - the ideal shape for a telescope mirror. This means that you can build very large, very perfect mirrors, very cheaply. Unfortunately there is a downside, you can only look straight up as the shape isn't correct in any other direction.
 

Offline neilep

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Re: Liquid Mirror Telescopes ?
« Reply #5 on: 21/02/2006 19:10:34 »
THANK YOU all for your answers.

Seems Newton proposed the idea all those billions of years ago !!...and there I was thinking it's a new thing !!..I'm so out of touch !!

Thank you all again.

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Offline Ray hinton

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Re: Liquid Mirror Telescopes ?
« Reply #6 on: 22/02/2006 01:26:45 »
oh so thats it,we go to all this trouble to find the information,you requested,and now your not bothered,you could have at least made the effort or pretence of building one,oh no,you just swan off down the pub,mines a charlie.


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Offline realmswalker

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Re: Liquid Mirror Telescopes ?
« Reply #7 on: 22/02/2006 02:53:31 »
quote:
Originally posted by daveshorts

The cunning of a liquid mirror is that if you spin a liquid the shape it will take up is a parabola - the ideal shape for a telescope mirror. This means that you can build very large, very perfect mirrors, very cheaply. Unfortunately there is a downside, you can only look straight up as the shape isn't correct in any other direction.


well...
what if you used a magnetic substance as the liquid in the mirror? Or some other sort of substance taht could bemanipulated by a differnt type of force (i can only think of magentism at the moment...)
you could use a magnetic attractioin above it at varying intensities depending on the varying angle to keep it perfect (with alot of calculation of corse)

could that work to solve that horizontal only problem?
 

Offline daveshorts

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Re: Liquid Mirror Telescopes ?
« Reply #8 on: 22/02/2006 09:47:03 »
It would theoretically be possible yes, although you would need some very sophisticated magnetic field shapes as you would have to counteract gravity as well, it would be difficult to get it as perfect. You also have the problem that there are no intrinsically ferromagnetic liquids. So you would have to suspend lumps of iron in a liquid, which would mean you would have problems with the liquid and the soilid seperating out under the forces you are applying.

Maybe an easier way of doing it would be to put the whole thing in space and accelerate it gently using a rocket to make artificial gravity, although you would probably run out of fuel too quickly.
 

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Re: Liquid Mirror Telescopes ?
« Reply #9 on: 22/02/2006 11:27:08 »
This liquid optics device is almost what Realmswalker was describing:-

""The interface between the oil and water will change shape depending on the voltage applied across the conical structure. At zero volts, the surface is flat, but at 40 volts, the surface of the oil is highly convex.""

http://www.theregister.com/2004/12/01/varioptics_liquid_lens/
« Last Edit: 22/02/2006 12:22:07 by ROBERT »
 

Offline Ray hinton

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Re: Liquid Mirror Telescopes ?
« Reply #10 on: 24/02/2006 12:31:08 »
forgive me for being a peasant,but using liquid in the first place,is this going to cause distortion as moisture in the atmosphere,does to telescopes that are earth bound,its a very unstable medium,and easily affected by vibration.
 

Offline realmswalker

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Re: Liquid Mirror Telescopes ?
« Reply #11 on: 01/03/2006 04:37:24 »
quote:
Originally posted by ROBERT

This liquid optics device is almost what Realmswalker was describing:-

""The interface between the oil and water will change shape depending on the voltage applied across the conical structure. At zero volts, the surface is flat, but at 40 volts, the surface of the oil is highly convex.""

http://www.theregister.com/2004/12/01/varioptics_liquid_lens/


well thats cool...my idea DOES work lol
 

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Re: Liquid Mirror Telescopes ?
« Reply #11 on: 01/03/2006 04:37:24 »

 

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