Re: Forum Games: Solve the riddle

#273
Both rubies and the grit on most sandpaper are made primarily of aluminum oxide. Rubies are just large crystals of it with traces of chromium that give it its red color. Sapphires are also made of aluminum oxide, though they contain traces of iron or titanium which impart a blue color.

Admittedly, I did not know all that off the top of my head, but the idea that they were made of the same material occurred to me before I checked with google.
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"Quem notrum ignorare arbitraris, Catalina!" --Cicero

Re: Forum Games: Solve the riddle

#276
Joshanddrew is correct! Although I am not 100% convinced you knew that without googling the puzzle.. not many people will have provided the exact answer, especially since the word mineral is rarely used to describe this.

However, you get the point anyway and kudos if you did know it.

Score Table:

Cypher: 5
KarrothMelu: 3
Pupairo12: 2
Kick: 2
Spy: 2
Weresloth: 1
Scoobysnack: 1
Corbeil: 1
Malebolgia: 1
Andrew: 1
Maul: 1
Joshanddrew: 1

Riddle number 23:

If a cork is put into a glass of water, the cork will almost always drift to the side of the glass. There is one simple way, however, to get the cork to float in the center of the glass (the horizontal center, not the vertical).

Can you tell me what it is and why it happens?
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When people ask me plz because it's shorter than please, i feel inclined to respond no because it's shorter than yes...

Re: Forum Games: Solve the riddle

#277
I thought of two explanations to this, and I'm not sure which, if either, is right, but here goes.

Put a drop or two of soap in the water.

Water is very sticky, and has a high surface tension, so when water is sitting in a glass, it tries to pull itself into a sphere, and is a bit rounded on top (if the glass is too narrow, this effect is minimized and the water sticking to the sides of the glass will form a meniscus instead). When the cork is sitting on top, it doesn't get wet, it just sits on top of the water, because the water's surface tension is preventing it from breaking the surface. The soap, when added, binds the water to the cork, breaking the surface tension and causing the surface of the water to lay flat, letting the cork rest in the center.
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"Quem notrum ignorare arbitraris, Catalina!" --Cicero

Re: Forum Games: Solve the riddle

#278
You are thinking along the right lines, surface tension has nothing to do with it however, and no other materials apart from water, a glass and the cork are needed.

I might add; you can do this experiment twice at the same time, and get both results without adding any other type of material.
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When people ask me plz because it's shorter than please, i feel inclined to respond no because it's shorter than yes...
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