Why are ice cubes grey in the middle?

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In summary, an ice cube is less transparent in the center because the atoms are more tightly bonded there. This makes them less transparent to light.
  • #1
bobsmith76
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Do you see how the ice-cube is less transparent in the center in this image?

http://p.lefux.com/61/20091013/A10470000C/Crystal-LED-Ice-Cube-1-Gallay.jpg

This image doesn't capture exactly what I see in my cup but it gets my point across. Why is an ice cube less transparent in the center? I'm guess it's because the atoms are more tight bonded in the center. But if that's true then

1. why does that make them less transparent?
2. why are they more tightly bonded in the first place?

I put this question in general physics because it doesn't seem to deal with anyone area of physics except maybe classical physics.
 
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  • #2
Good question.
The outside freezes much faster than the inside and, the longer the freezing process, the larger the crystals that form. Also, any gas that comes out of the water near the outside will end up as bubbles near the centre, along with ice crystals.
So we have large crystals and possible bubbles in the middle.
Light gets internally reflected when it goes through a (nominally) transparent material if there are changes in refractive index. Light will be scattered and take a longer path on its way through this central part. It will be attenuated and images, seen through it will be diffused, giving a grey appearance..
 
  • #3
sophiecentaur said:
Good question.
The outside freezes much faster than the inside and, the longer the freezing process, the larger the crystals that form. Also, any gas that comes out of the water near the outside will end up as bubbles near the centre, along with ice crystals.
So we have large crystals and possible bubbles in the middle.
Light gets internally reflected when it goes through a (nominally) transparent material if there are changes in refractive index. Light will be scattered and take a longer path on its way through this central part. It will be attenuated and images, seen through it will be diffused, giving a grey appearance..

Thanks for the explanation, I feel more knowledgeable in this forum..:smile::smile::smile: thanks,,,
 
  • #4
It's just like a 'grey' cloud. Less light gets through.
 
  • #5
good question but even better answer. thanks for the help.
 

Related to Why are ice cubes grey in the middle?

1. Why do ice cubes have a grey color in the middle?

Ice cubes often have a grey color in the middle due to the presence of impurities in the water used to make them. These impurities can include minerals, gases, or even dust particles that get trapped in the ice as it freezes.

2. Is it safe to consume ice cubes with a grey color in the middle?

In most cases, yes, it is safe to consume ice cubes with a grey color in the middle. The impurities that cause the grey color are usually harmless and do not affect the taste or safety of the ice. However, if you are concerned, you can use filtered or distilled water to make your ice cubes.

3. Can I remove the grey color from my ice cubes?

No, the grey color in ice cubes is a result of impurities in the water and cannot be removed. However, you can prevent the grey color by using filtered or distilled water to make your ice cubes.

4. Why do some ice cubes have a clear center while others have a grey center?

The clarity of ice cubes depends on the freezing process. When water freezes slowly, impurities have time to settle at the center, resulting in a clear ice cube. But when water freezes quickly, the impurities get trapped and give the ice cube a grey color in the middle.

5. Can the grey color in ice cubes affect the taste of my drink?

In most cases, the grey color in ice cubes does not affect the taste of a drink. However, if the impurities present in the ice cubes have a strong taste or odor, it can potentially affect the flavor of your drink. It is best to use filtered or distilled water to avoid any unwanted flavors in your ice cubes.

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