On 2013-06-13, wrote:
On Jun 12, 5:30?pm, Ignoramus21475 ignoramus21...@NOSPAM.
21475.invalid wrote:

I did not start this bragging competition, and that's my excuse for
posting the following: I just bought two "optical flats", 28 inches
diameter, for $50 each plus auction buyer's premium. Then some company
guy told me, Igor, do you know what you bought, I said kinda sorta,
and he said, they cost a million dollars each, they had to grow the
glass in a special chamber.



I am gonna sell them, that's for sure. One optical flat lays on
styrofoam, and has some imperfections, the other one "Unertl" stays
vertically in a super heavy enclosure, shielded by a locking shield,
and looks perfect.

i


Do you know what material they are made of? Back in Washington State
I worked on the Battlepoint Observatory.
Their mirror is 27.5 inches in diameter and made of Zerodur, a
extremely low coef of expansion material. They got the blank from
Boeing , it was ground for some star wars project. So they built a
grinding machine to regrind it for a mirror.

See http://www.bpastro.org/index.php?pag...chie-telescope

And see http://www.bpastro.org/index.php?pag...d-of-directors for
the directors. You might contact Malcolm Saunders about selling the
flats. Ho might know someone who is looking for a large blank.

I am in a photo with John Rudolph on thils page.

http://www.bpastro.org/index.php?pag...chie-telescope


Dan

Dan, fascinating story, I might give them a holler.

i