[TheForge] plastic forge? OT:

[peter fels]

On Jun 16, 2011, at 9:48 AM, Bruce Freeman wrote:

> Free electrons are involved in the absorption of light due to the fact
> that a photon of light will "promote" an electron from a lower- to a
> higher-energy state.  In pure elements, this is what gives rise to the
> absorbance spectra of the element (hydrogen, for example).  It is also
> the case for molecules.  The more possible energy states available for
> an electron to "reside" in, the more different possible transitions
> possible.  A photon of a particular energy corresponds to a 'color'.

Got it...thanks!
> 
> I don't see how running a current through a transparent material would
> have anything to do with color.  Salt water conducting electricity
> remains clear, but then electrons don't run through salt water -- ions
> do.  I would suppose it unusual for a transparent material to be able
> to conduct electricity.  Can you think of one?

Nope...other that possibly graphene ( but i may remember that wrong).
 Thought there was some work on using it for monitor display screens.
> 
> On Thu, Jun 16, 2011 at 12:38 PM, peter fels <artgawk at thegrid.net> wrote:
>> 
>>> 
>>> 
>>> 
>>> As you probably know, diamond is crystalline carbon, in which each
>>> atom is connected to four others in a tetrahedral configuration (i.e.,
>>> the OTHER four carbons are at the corners of a tetrahedron).  Very
>>> strong, very hard, no free electrons so completely transparent.
>>> 
>>> By contrast, graphite is crystalline carbon, in which each atom is
>>> connected to only three others in a hexagonal array (i.e., honeycomb
>>> or chickenwire shape).  This is even stronger than diamond within the
>>> plane.  However, the myriad of layers of carbon are only held together
>>> by their electronic interaction and whatever stuff that attracts to
>>> between the planes.  There are LOTS of loose electrons floating
>>> around, so virtually any wavelength of visible light can be absorbed,
>>> rendering the stuff black.
>>> 
>>>>>> How fascinating.
>> Bruce, do you know why free electrons absorb light?
>> Does this mean that running a small current through or across a transparent  material will male it opaque?
>>>>>> 
>>>>>>> 
>>>>>>> 
>> 
>> ______________________________________________________________
>> TheForge mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/theforge
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:TheForge at mailman.qth.net
>> 
>> TheForge mail list group photo site is
>> http://www.photoworks.com
>> Login: blacksmithblacksmith at hotmail.com
>> Password: anvil
>> 
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> 
> 
> 
> 
> -- 
> Bruce
> NJ
> ______________________________________________________________
> TheForge mailing list
> Home: http://mailman.qth.net/mailman/listinfo/theforge
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:TheForge at mailman.qth.net
> 
> TheForge mail list group photo site is
> http://www.photoworks.com
> Login: blacksmithblacksmith at hotmail.com
> Password: anvil
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html