Re: Transparent Aluminum

Ken Macht ( macht@megabits.net )
Mon, 01 Feb 1999 20:42:06 -0500

Matthew Redmond wrote:

> This thread reminds me of that Star Trek movie when they go back to 198(5?).
> They needed transparent Aluminium to create a lightweight water container to
> transport some whales back to the future inside a klingon ship to save the
> future Earth from destruction caused by an alien probe trying to communicate
> With a story line like that it had to be a hit. :)

Correct. This concept sounded silly but it kicks over the question why is
transparent aluminium going to stay in Star Trek. Einstein's photoelectric
effect.

If a photon strikes an electron, the electron will absorb the photon and the
electron will change energy state (orbit). When it gives off the energy, it will
do so in the form of a photon. whatever the photons were from is now immaterial
for they and anything that they could be assembled into by our retinae are gone.
Elements with a lot of electrons not locked into stable orbits (that is
conductors like copper and aluminium) just can't pass light because of the very
mobile electrons bouncing in and out of various orbits. What solid substance can
we see through? Certain crystals. In crystals, the free electrons are shared by
adjacent atoms so the orbits are "full". It takes quite a packet of energy to
lift those electrons into higher orbits. Liquids like glass and water are
transparent because the molecules will bind into chains and the compaunds are
relatively stable from an elecgtron orbital point of view.

To make "transparent Aluminium", I should think that we need to make a compound
that corrals those pesky electrons. Hmmm, crystallised aluminium. Too fragile.
One blast from a Klingon disrupter and we're space flotsam. Bummer. So is the
poo-poo'ing of this idea. Somebody will get around the "no" of this.

Live long and prosper :)

Ken