Dawn of GPS and one weird giant telescope

From Modern Mechanix:
http://blog.modernmechanix.com/2009/...gating-system/
Never seen anything like this befo
http://blog.modernmechanix.com/2009/...que-in-design/

Pat

On 2009-03-05 09:25 "Pat Flannery" wrote:
Never seen anything like this befo
http://blog.modernmechanix.com/2009/...ique-in-design

Astoundingly, that telescope appears to still be around.
http://en.wikipedia.org/wiki/Archenhold_Observatory

It's one of the largest dozen or so refractors ever. I've looked through a
10" Cooke refractor at Mills Observatory in Scotland... But this is more
like 27-28 inches. Next time I have some time in Germany, I'm going to have
to get over to Treptow and check this place out!

-Dan

Daniel Birchall wrote:
It's one of the largest dozen or so refractors ever. I've looked through a
10" Cooke refractor at Mills Observatory in Scotland... But this is more
like 27-28 inches. Next time I have some time in Germany, I'm going to have
to get over to Treptow and check this place out!

Objective lens diameter was 26.8": http://tinyurl.com/allbpa
What I'm trying to figure out are two things:
1. How do you keep the thing aimed in one precise direction in even the
lightest of winds? You would think it would whip all over the place as
the tube above the guy wires flexed, particularly given it extremely
high f ratio...so that you would never be able to zero in on a star at
even low magnification.
2. How do you keep rain, dust, and pigeon poop off of the objective lens
given its completely exposed situation?
You might peer up the eyepiece someday and see fuzzy images of storks
building a nest on the front lens, like they do on the tops of chimneys.
This is _no_ way to make a large telescope.
It needed a dome over it.

Pat

Pat Flannery wrote:
2. How do you keep rain, dust, and pigeon poop off of the objective
lens given its completely exposed situation?

Graduate students.

rick jones
--
I don't interest myself in "why." I think more often in terms of
"when," sometimes "where;" always "how much." - Joubert
these opinions are mine, all mine; HP might not want them anyway...
feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH...

"Rick Jones" wrote:
Pat Flannery wrote:
2. How do you keep rain, dust, and pigeon poop off of the objective
lens given its completely exposed situation?

Graduate students.

It sounds good on paper, but aren't grad students generally known for living
in squalor? I fear they'd make a bad situation worse.

I know where there is a binder of rather (~30 years) old memos, including
things like "please remove your shoes before climbing into the telescope
tube." (Unwritten: "you d*mn dirty hippies!") Perhaps I should look into
transcribing some of the more choice ones...

--
Dan Birchall, Operator, UH 2.2-meter (88") Telescope
"Science is a wonderful thing if one does not have to
earn one's living at it." - Albert Einstein