Quote:
Originally Posted by Hengist
Yes I'm sure metal valves would help, but amazingly it seems that 'transparent aluminium' has already been invented!
"ALON® or Aluminum Oxynitride is an amazing and unique transparent advanced ceramic that is polycrystalline (made from powder) with a cubic spinel crystal structure. In the popular media and in the Star Trek community, it is commonly referred to as Transparent Aluminum. Surmet is the only company globally, that manufactures ALON®."
I can't find any mention of it's screening properties though. My gut feeling is that compounds of aluminium don't behave like the metal when it comes to RF. Does anyone know? (Bound to be too expensive anyway!).
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Screening happens through conductivity. Conductivity simply shorts electric field components. Conductivity allows alternating magnetic field components to create circulating eddy currents and the mag field from these currents cancels the arriving mag field on one side, and creates a reflection on the other.
No conductivity, no screening.
Metals have freely available electrons to do easy conductivity. In metal oxides, the electrons are a bit tied up and not available for conduction.
Of course, in Startrek, they only have to re-tune their transporter to emit a beam of Nurgulon particles (or some such) and they can convert any material into an electric conductor.
By the way, Faraday screens have slots to disrupt eddy currents, so they only stop electric fields, and let magnetic fields straight through, making them useless for radio screening. Doesn't stop lots of peple sticking the name Faraday in front when they really mean an ordinary screen. It's a bit like saying 'colander' when they mean 'saucepan'.
David