On Fri, Sep 9, 2016 at 12:39 PM, Peter Cetinski <p...@pski.net> wrote:
> > > On Sep 9, 2016, at 10:55 AM, Doug Ingraham <d...@dustyoldcomputers.com> > wrote: > > > > Transparent aluminum exists. It is called sapphire. Sapphire is the > > crystalline form of aluminum oxide. If you recall, Apple was thinking of > > using it for the touch screen face of the iphone. > > > > Ah yes, but can you make in sheets 60 feet by 10 feet by 1 inch thick and > withstand the pressure of 18,000 cu ft of water? :) The answer is probably yes, but not for anything like a reasonable amount of money or in a reasonable amount of time. It would probably take a couple of years to grow a crystal that size. There was a company making the ovens used to make billets of sapphire about 18 inches in diameter and a foot tall from which they would cut out the pieces they would need with presumably a diamond saw. These billets would take something like a month to grow so you would need a lot of them to make your screens in the multi million quantities. And these billets had imperfections you had to work around. In 1986 it would probably have taken Mr Scotts technical know how. -- Doug Ingraham PDP-8 SN 1175
