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Marbles, Refraction & Syrup


Stefan

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I was a little bored this afternoon and i just wanted to inform you about what i was doing. Immersing marbles in syrup... if you want to know why, continue reading :)

Ever had a badly damaged marble and wondered how it looks inside?? I will show a way to achieve this and i add some physics for better understanding for those who dont know about refraction yet.

1. First of all:Why do we see transparent things?

If something is transparent, why do we see it? Why do we see Glass and why can't we see air? Thats because of Refraction. This means the bending of an light beam when it hits a border between two Phases. When those two phases have the same so called "refractive index", the light beam will go through straight. If those refractive indices differ, the light beam will be bend. The refractive index of vacuum is set to 1, Air has 1,000292, Water 1,33 and Glass can have values between 1,45 … 2,14. Imagine an solid sphere with a refractive index of 1,33. If the surrounding medium is Air, it would almost look like a marble. But when you put that sphere into water, light would not be bend at the phase transition, so the object would be completely invisible. When you throw the sphere in, it would just look like it is disappearing. (Actually, such spheres exist and they are broadly used to fool people on the internet... check out this http://www.youtube.com/watch?v=vCeAfKCC2ng... the explanation is bullshit but the effect is real!)

2. what to do with this knowledge?

The idea was to search for a way to look into a damaged marble like this to determine if its worth polishing it.

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So you have to get a liquid which has the same refractive index like the marbles. Such a liquid will fill up those cracks and dents, letting pass the light straight through. Most of you will know the effect when rinse a damaged marble in water.

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But as said above, the refractive index of water is 1,33, the lowest value for glass is 1,45. So i searched for another liquid with an higher RI and tried out a lot of things like glycerine, different salt solutions, oil, but nothing seems to have an RI high enough. Today i stumbled over the fact that sugar solutions have a quite high RI. So i made a sugar syrup (as we chemists say: hot saturated aqueous α-D-Glucopyranosyl-β-D-fructofuranosid-solution :) ) and put that marble in. This is what i got.

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Its close, but not yet invisible. But i think its the best we can achieve with things we have around the house.... what was really suprising me is what happened when i took the marble out of the syrup. A perfect polished marble!

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3. conclusion:

i wanted to get the transparent glass invisible, putting it in syrup is the closest i got. Now i think its worth polishing, plus, the marble never tasted sweeter :D .

So long guys, i have to go now.... i should buy oil, salt and sugar before my darling asks me uncomfortable questions why we are out of those...

P.S.:Ever been told by someone that you're crazy giving away so much money for glass balls? Tell them the story of that guy immersing marbles in syrup! :confused-smileys-327:

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I do not think it will be invisible

The light refract alters as it passes through glass,into glass and through glass again, due to the damage on the outer area.

Those are miniature mountains all over the glass,each one with edges

I would think, polished, it would still not be invisible,again, as light is traveling through multiple layers of glass and then liquid

But, I will use a glass of sugar water next time i check instead of slobbering all over them :P

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I do not think it will be invisible

The light refract alters as it passes through glass,into glass and through glass again, due to the damage on the outer area.

Those are miniature mountains all over the glass,each one with edges

I would think, polished, it would still not be invisible,again, as light is traveling through multiple layers of glass and then liquid

But, I will use a glass of sugar water next time i check instead of slobbering all over them :P

I understand your point and i think you may be right but that can't stop me trying :D

I will try something different next week when im back at work... the sugar water still hasn't an RI high enough.... the problem ist that most liquids with a RI higher that 1,5 are toxic, carcinogenic, explosive or all together :D

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Stefan,

Not sure why you need to make a clear glass marble invisible to see what it would look like polished; after all, a "wet mint" marble in air is still very visible.

If you take a damaged marble and smooth out the damage, it will give you that polished look. After all, that's what polishing does. And you've found out that wetting the marble in air, preferably with a clear viscous solution, will do the trick.

(If you completely immerse the marble, what happens is that you lose the magnification caused by the different refractive indices between glass and air. In air, the curved glass surface bends the image of the interior of the marble which then appears magnified. You get the same loss of magnification when looking into a marble through a flat "facet" without the surface curvature.)

However, if you still want to immerse your marble in a clear liquid with a high refractive index, there are a couple here that are relatively safe: viz. silicone oil and glycerol.

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

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Stephan,

Roughly how much sugar did you add to the water? Is it a saturated solution?

All my best ... Danny

yes it is saturated

Stefan,

Not sure why you need to make a clear glass marble invisible to see what it would look like polished; after all, a "wet mint" marble in air is still very visible.

If you take a damaged marble and smooth out the damage, it will give you that polished look. After all, that's what polishing does. And you've found out that wetting the marble in air, preferably with a clear viscous solution, will do the trick.

(If you completely immerse the marble, what happens is that you lose the magnification caused by the different refractive indices between glass and air. In air, the curved glass surface bends the image of the interior of the marble which then appears magnified. You get the same loss of magnification when looking into a marble through a flat "facet" without the surface curvature.)

However, if you still want to immerse your marble in a clear liquid with a high refractive index, there are a couple here that are relatively safe: viz. silicone oil and glycerol.

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

well, i just love to do experiments :D the first idea was to see what a marble would look like when you can't see the surrounding glass. Never wondered what a glass of marbles would look like when you only see the colored glass? The fact that it looked polished when i took it out was just an side-effect :-)

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I understand your point and i think you may be right but that can't stop me trying :D

I will try something different next week when im back at work... the sugar water still hasn't an RI high enough.... the problem ist that most liquids with a RI higher that 1,5 are toxic, carcinogenic, explosive or all together :D

Well it never hurts to try :)

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Interesting experiment. I think any kid at some point probably tried the to achieve the same goal, except back then it made the most sense to try and bash the outside layers off to expose the cool design (or animals) inside. :)

Someday maybe one of the high end marble glass makers will find a medium to carry the inner pattern, that can later be dissolved (chemically or whatever) to leave just the inner pattern intact. Fragile and beautiful.

And then somebody might come up the idea of encasing that fragile and beautiful pattern in a durable layer of clear glass and here we are again.. (and the marbles keep on rolling)

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