A physics question

[Ed W]

Most materials have a crystalline structure, such as iron, diamond, or common table salt.  The carbon atoms in a diamond are much larger than the atoms in iron, yet the crystal structure of diamond allows light to pass through relatively unimpeded.  Why are other such structures opaque?
Photons are much, much smaller than any of these, so why do some materials block them and some do not?

Can you guess that we were really bored at work today?

[Red Arrow]

quote:Originally posted by Ed W

Most materials have a crystalline structure, such as iron, diamond, or common table salt.  The carbon atoms in a diamond are much larger than the atoms in iron, yet the crystal structure of diamond allows light to pass through relatively unimpeded.  Why are other such structures opaque?
Photons are much, much smaller than any of these, so why do some materials block them and some do not?



Can you guess that we were really bored at work today?

I couldn't find the answer to why light passes through a diamond. I did find that Iron (Fe) atoms have an atomic number of 26, making them bigger than carbon (C) atoms with an atomic number of 6.

[sgrizzle]

The size of the atoms does not change because carbon changes from coal to a diamond, it just means they are closer together.

Transparency is merely the inability of certain objects to absorb certain frequencies of light. A Ruby is red for exampe because it is filtering out the greens, blues, etc.

[izmophonik]

Rubys don't filter out light. They just don't reflect other light.  The spectrum where red lies is reflected the most therefore that is the color you generally see.

[PonderInc]

Since nobody wants to work on the Friday before Labor Day weekend...

Why is there a perfect hexagon circling over Saturn's north pole?



http://www.nasa.gov/mission_pages/cassini/media/cassini-20070327.html

[sauerkraut]

Rubys absorb lite and reflect the red hues. The color of a object depends on the color of light that falls upon it.