February 25, 2011 AT 11:31 am

What Makes Glass Transparent?

“I’m gonna pretend to be a photon…”

A neat explanation that gets into photodiodes and the energy gap.


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3 Comments

  1. These guys are absolutely brilliant. I think ive watched every sixtysymbols video.

  2. Good explanation, that made me think a bit… First thought was ‘so why is glass opaque to infra-red AND ultra-violet but NOT visible??’. He explains that you need high-energy photons to cause absorption but low-energy IR photons are absorbed too…

    Thinking a bit more: photons have to promote electrons between energy levels, so there must be available transitions between energy levels corresponding to IR and UV, but no transitions corresponding to visible photon energies.

    Does bonding change the available levels? I guess it often does as colour changes during reactions are common. Can anyone with a little more quantum chemistry knowledge elaborate?

    Great series of videos though – hard to top the periodic table of videos but these are doing a good job!

  3. Thanks for the discovery!

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