Re: [CAD_CAM_EDM_DRO] re:re: flat glass

Jerry Kimberlin wrote:

> I think telescope glass is not anything like window glass. Good
> mirrors are made of fused quarts, if you can afford it.

AFIK, astronomical mirrors can be made from almost any glass. You kinda get what you pay for. Coefficient of expansion and stability
are critical. I think that the choice today is 'pyroceram' i.e. Corning ware.....

To demonstrate how easily glass deflects bounce a laser beam off the surface of a glass plate and then load the glass with your
finger. Doesn't take much pressure to show deflection.

Dave

> JerryK