Galileo and solar observing

While reading Willie R. Meghar's post (04 Jul 2006) on Solar Astronomy,
I started to wonder :

Do we know if Galileo looked at the sun using his early telescopes?
What kind of filters / shielding did he use to prevent eye damage?

Clear skies!

--
25° 45' S
28° 12' E
GMT+2

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Arnold wrote:
While reading Willie R. Meghar's post (04 Jul 2006) on Solar Astronomy,
I started to wonder :

Do we know if Galileo looked at the sun using his early telescopes?
What kind of filters / shielding did he use to prevent eye damage?



Hi:

None. He projected the image of the Sun onto a card. Galileo did go
blind in old age, but it was not because he looked at the unshielded
Sun.

Peace,
Rod Mollise
Author of _Choosing and Using a Schmidt Cassegrain Telescope_
and
_The Urban Astronomer's Guide_
http://skywatch.brainiac.com/astroland/index.htm
Like SCTs and MCTs?
Check-out sct-user, the mailing list for CAT fanciers:
http://groups.yahoo.com/group/sct-user

On 2006-07-07, Arnold wrote:

Do we know if Galileo looked at the sun using his early telescopes?
What kind of filters / shielding did he use to prevent eye damage?

Galileo famously observed the sun. He projected an image of the
sun onto a piece of paper for most of his observations, or
observed the sun directly when it was low on the horizon and
the light and heat were attenuated by the atmosphere. He
left a detailed description of his projection technique. By
plotting sunspots on the paper he could preserve an accurate
record of their positions. This allowed him to prove that
sunspots were not the silhouettes of satellites orbiting the
sun.

Bud

"William Hamblen" wrote in message
. ..
On 2006-07-07, Arnold wrote:

Do we know if Galileo looked at the sun using his early telescopes?
What kind of filters / shielding did he use to prevent eye damage?

Galileo famously observed the sun. He projected an image of the
sun onto a piece of paper for most of his observations, or
observed the sun directly when it was low on the horizon and
the light and heat were attenuated by the atmosphere. He
left a detailed description of his projection technique. By
plotting sunspots on the paper he could preserve an accurate
record of their positions. This allowed him to prove that
sunspots were not the silhouettes of satellites orbiting the
sun.

Bud

Mannnn...too bad he didn't clue into sunspot cycles. 400 years of records
would be astounding.

Funny how certain things take off and others don't.

William Hamblen wrote:
This allowed him to prove that
sunspots were not the silhouettes of satellites orbiting the
sun.

SunSeeker wrote:
Mannnn...too bad he didn't clue into sunspot cycles. 400 years of records
would be astounding.

Funny how certain things take off and others don't.

Ironically, it was a guy who was looking for an intra-Mercurial planet
that ended up discovering the sunspot cycle.

--
Brian Tung
The Astronomy Corner at http://astro.isi.edu/
Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/
The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/
My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.html

SunSeeker wrote:

Funny how certain things take off and others don't.







He (Galileo ) also made his own *sniper rifle* and used it out to almost
300 yards effectively........



--
AM

http://sctuser.home.comcast.net

CentOS 4.3 KDE 3.3

"SunSeeker" wrote in message
newsSFrg.122668$S61.47383@edtnps90...
Mannnn...too bad he didn't clue into sunspot cycles. 400 years of records
would be astounding.

Funny how certain things take off and others don't.

He also observed Neptune in 1612 and 1613. By chance, his first observation
was when Neptune started its retrograde motion and was stationary with
respect to the stars. Interestingly, the position he noted for Neptune was 7
arcminutes from the predicted position.

sun spots were one of his discoveries! Just too bad he didnt let the Pope
have a
look - straight thru!



Arnold wrote:

While reading Willie R. Meghar's post (04 Jul 2006) on Solar Astronomy,
I started to wonder :

Do we know if Galileo looked at the sun using his early telescopes?
What kind of filters / shielding did he use to prevent eye damage?

Clear skies!

--
25° 45' S
28° 12' E
GMT+2

Join the Planetary Society
http://www.planetary.org

Harry James wrote:
sun spots were one of his discoveries! Just too bad he didnt let the Pope
have a
look - straight thru!


Given later history, it was not one of Galileo's better moves to
pick a priority dispute about the discovery of sunpots - with a
Jesuit astronomer...


Bill Keel