RE: Urgent request.
For the benefit of Tony Moss, a search on http://bible.gospelcom.net/cgi-bin/bible in KJV for every thing beautiful yielded: He hath made every thing beautiful in his time: also he hath set the world in their heart, so that no man can find out the work that God maketh from the beginning to the end. ... Of course, the authorized version is always what the client wants. Whether the Bible is infallible or not, the customer certainly is. --Art Carlson
Re: a better eclipse filter
On Mon, 17 May 1999, John Carmichael wrote: Hi Ross: Getting a small, very long focal length lens (or mirror) to replace the pinhole can solve the problem, at the risk of introducing some image aberrations, including chromatic, visible at the edges of the solar disk. This was of course used to great effect on Kitt Peak in the wonderful solar telescope there that I visited a few months ago. The question is one of whether you or your astronomer friends knows of an optical system which produces the effect of a long focal length, but with a much shorter distance from the optical system to the focal plane. Sounds impossible to me, but I'll ask my astronomer friends. Take care, John Much easier than it sounds, John! It's called a telescope, or telephoto lens! Seriously, a simple telephoto lens is a basic Galillean telescope. Largish, long focal length positive objective lens, and a small, short focal length *negative* eyepiece lens. The long focal length is mostly consumed between the objective and the eyepiece. The rays coming out of the eye lens can be focussed on a card at any desired distance, giving a large, well focussed image. It will of course be dimmer than the direct sunlight, so you need to shade it like any other method. A small spotting 'scope, half a binocular, the finder scope from a larger instrument, or that spare telephoto lens all will work. Dave
Re: a better eclipse filter
John Carmichael wrote: Hi Ross: A little, off-the-wall, query. The larger the distance from the pinhole to the white sheet image of the sun, the larger the sun, but also the dimmer too. This is correct. The sun's image becomes quite dim at the long distance needed to see sunspots. This can be corrected by lowering the amount of ambient light as much as possible. Providing extra shade around the whole setup helps. ie. use a large piece of cardboard for the pinhole, or put the pinhole in the bottom of a box or tube. Why don't we re-invent the camera obscura? :-) - fernando Getting a small, very long focal length lens (or mirror) to replace the pinhole can solve the problem, at the risk of introducing some image aberrations, including chromatic, visible at the edges of the solar disk. This was of course used to great effect on Kitt Peak in the wonderful solar telescope there that I visited a few months ago. The question is one of whether you or your astronomer friends knows of an optical system which produces the effect of a long focal length, but with a much shorter distance from the optical system to the focal plane. Sounds impossible to me, but I'll ask my astronomer friends. Take care, John John Carmichael wrote: A bunch of us, including astronomers from Kitt Peak, traveled to southern Baja for the July 11, 1991 total eclipse. Thanks, Ross McCluney -- Fernando Cabral Padrao iX Sistemas Abertos mailto:[EMAIL PROTECTED] http://www.pix.com.br mailto:[EMAIL PROTECTED] Fone: +55 61 321-2433 Fax: +55 61 225-3082 15º 45' 04.9 S 47º 49' 58.6 W 19º 37' 57.0 S 45º 17' 13.6 W
Multiple sunsets
Regarding Fernando Cabral's multiple observation of sunsets at one setting I recently wrote to the Marine Observer (British Met. Office) concerning a meteorologist who claimed to have seen the sunset green flash three times at one setting by climbing to successive decks of an ocean weather ship as the sun sank. This elicitated the following note to the same journal (Marine Observer, April 1999) from Dr. R. J. Livesey, Director of the Aurora Section, British Astronomical Association, whose text I acknowledge: I was in Holyrood Park, Edinburgh, on the lower slopes of Arthur's Seat with a good clear sky. The sun was setting behind the top of David Hume tower block of Edinburgh University, which is about a mile away, when I saw a green flash. Realising the geometry of the situation I ran back up the slope until the sun was again visible above the tower block. Again as it set behind the building there was a green flash. I was able to repeat the phenomenon by a second run up the slope. One was required to move only so much as would bring the upper limb of the sun just above the tower block to cause a repeat as the sun sank down. -- Frank Evans
Re: Sundial for downed pilots
Art Carlson wrote: That's exactly what I had in mind. This is a rule that can be easily understood and remembered, as opposed to remember to ADD nine hours to the clock time for a three-quarter moon, if it is WANING. What I would like to figure out is the errors involved in both methods, given orbital parameters. [...] --Art Carlson Here are some rough parameters. The maximum deviation of the ecliptic from the equator is 23.5 degrees. In other words the maximum deviation of the point where the ecliptic meets the horizon from the true east or west compass point is 23.5 degrees. That's where my remarks about knowing the time of year and time of day comes in--it gives the information about this deviation. If you have a celestial planisphere, it probably has markings for the ecliptic and celestial latitude. Give it a good examination to get a feel for how the deviations behave over the course of a year and day. However, the moon does not lie precisely along the ecliptic, but can deviate from it by a maximum of about 5 degrees (I'm not certain of that max. deviation, and I don't have my books with me). Plus, there will be error in tracing out the ecliptic through the sky as I first suggested. In sum, the procedure I gave is pretty rough. Jim --- -- | Jim Cobb | 540 Arapeen Dr. #100 | [EMAIL PROTECTED] | | Parametric| Salt Lake City, UT | (801)-588-4632 | | Technology Corp. | 84108-1202 | Fax (801)-588-4650 | --- -- Through infinite mist, software reverberates In code possess'd of invisible folly. -- Curt Sampson
Re: Urgent request.
http://bible.gospelcom.net/cgi-bin/bible?language=Englishversion=KJVpassage=Ecclesiastes+3:11matchno=7 Ecclesiastes 3:11 (English-KJV) He hath made every thing beautiful in his time: also he hath set the world in their heart, so that no man can find out the work that God maketh from the beginning to the end. Jim --- -- | Jim Cobb | 540 Arapeen Dr. #100 | [EMAIL PROTECTED] | | Parametric| Salt Lake City, UT | (801)-588-4632 | | Technology Corp. | 84108-1202 | Fax (801)-588-4650 | --- -- I have an answering machine for my phone. Now when I'm not home and someone calls me up they hear a recording of a busy signal. -- Steven Wright Fellow Shadow Watchers, This is 100% on topic and somewhat urgent for me. The large bronze dial plate which I am about to engrave must bear the biblical inscription He hath made every thing beautiful in his time Can anyone give me 'chapter verse' for this please as I must be certain that I have it absolutely per the King James' version as erasers don't work on bronze :-) In particular does 'his' have a capital letter? Before now I've made a mistake in the workshop and found myself mentally reaching for 'undo'. If only it were possible! Many thanks in advance. Tony Moss
Re: a better eclipse filter
Hi Ross: A little, off-the-wall, query. The larger the distance from the pinhole to the white sheet image of the sun, the larger the sun, but also the dimmer too. This is correct. The sun's image becomes quite dim at the long distance needed to see sunspots. This can be corrected by lowering the amount of ambient light as much as possible. Providing extra shade around the whole setup helps. ie. use a large piece of cardboard for the pinhole, or put the pinhole in the bottom of a box or tube. Getting a small, very long focal length lens (or mirror) to replace the pinhole can solve the problem, at the risk of introducing some image aberrations, including chromatic, visible at the edges of the solar disk. This was of course used to great effect on Kitt Peak in the wonderful solar telescope there that I visited a few months ago. The question is one of whether you or your astronomer friends knows of an optical system which produces the effect of a long focal length, but with a much shorter distance from the optical system to the focal plane. Sounds impossible to me, but I'll ask my astronomer friends. Take care, John John Carmichael wrote: A bunch of us, including astronomers from Kitt Peak, traveled to southern Baja for the July 11, 1991 total eclipse. Thanks, Ross McCluney
Re: viewing an eclipse
Hello, All! Several years ago we were able to see a partial solar eclipse not too far away from local noon. Knowing the principal, I asked him whether he'd not like me to set up a viewing scheme for the grade school my children attended. He agreed, and I covered all the south-facing windows of a class-room (it was the music room) except for a pinhole in a piece of aluminum foil over one pane of one window. I put a sheet of white paper on a music stand some 6-8 metres away, and found a good-sized projected image of the sun on the sheet. One could distinguish a few spots. The children filed by slowly, all the time remaning somewhat awed. From time to time I moved the stand to keep pace with the sun's motion. It worked quite well. One unexpected benefit, for me who became dark-adapted in the unlighted room, was that this was, of course, a camera obscura. It was great fun to be able to see birds on the telephone wire outside -- upside down! I recommend the technique as one that is simple and very enjoyable. As I recall, the pinhole was only a couple of millimetres in diameter. John
Re: Urgent request.
ECCLESIASTES 3:11. John On Mon, 17 May 1999, Tony Moss wrote: Fellow Shadow Watchers, This is 100% on topic and somewhat urgent for me. The large bronze dial plate which I am about to engrave must bear the biblical inscription He hath made every thing beautiful in his time Can anyone give me 'chapter verse' for this please as I must be certain that I have it absolutely per the King James' version as erasers don't work on bronze :-) In particular does 'his' have a capital letter? Before now I've made a mistake in the workshop and found myself mentally reaching for 'undo'. If only it were possible! Many thanks in advance. Tony Moss
RE a better eclipse filter
My favorite way to show eclipses and sunspots is with a reflective pin hole camera. A small mirror, preferably front surface, about .25 to .5 inches in diameter mounted on a camera tripod. The light from the sun is reflected through a window into a darkened room onto a white wall or screen. Its often possible to get images of 3 feet or more in diameter. I haven't bothered to motorize the mirror so frequent adjustment is necessary. The later does, however, serve to demonstrate to non dialists that the sun moves across the sky:-) I often put an adjustable aperture on the screen side of the mirror to improve the resolution. Cheers, Professor John P.G.Shepherd Physics Department University of Wisconsin-River Falls 410 S. 3rd. St. River Falls,WI 54022 Phone (715)-425-3196, eve. (715)-425-6203 Fax (715)-425-0652 44.88 degrees N, 92.71 degrees W.
Re: Multiple sunsets
One can get a similar effect riding a large ferris wheel right at sunset. While not giving a full sunrise/sunset, it's still fun to watch the upper limb disappear and reappear :-) -Original Message- From: William P Thayer [mailto:[EMAIL PROTECTED] I also thought something I would like to ask the airplane pilots we have among us. Have any of you ever tried to take off immediately after the sunset, flying straight to the sun's azimuth, trying to see several sunsets in a raw?
Re: Urgent request.
Ecclesiastes. Chapter 3. Verse 11. The online versions I checked did not capilalise his. On Mon, 17 May 1999, Tony Moss wrote: Fellow Shadow Watchers, This is 100% on topic and somewhat urgent for me. The large bronze dial plate which I am about to engrave must bear the biblical inscription He hath made every thing beautiful in his time Can anyone give me 'chapter verse' for this please as I must be certain that I have it absolutely per the King James' version as erasers don't work on bronze :-) In particular does 'his' have a capital letter? Before now I've made a mistake in the workshop and found myself mentally reaching for 'undo'. If only it were possible! Many thanks in advance. Tony Moss === Richard B. LangleyE-mail: [EMAIL PROTECTED] Geodetic Research Laboratory Web: http://www.unb.ca/GGE/ Dept. of Geodesy and Geomatics EngineeringPhone:+1 506 453-5142 University of New Brunswick Fax: +1 506 453-4943 Fredericton, N.B., Canada E3B 5A3 Fredericton? Where's that? See: http://www.city.fredericton.nb.ca/ ===
solar filter sources
A page of solar filter sources is: http://umbra.gsfc.nasa.gov/eclipse/970309/text/filter-sources.html
books on atmospheric phonomena
There's a page of books on atmospheric phonomena at: http://www.treasure-troves.com/astro/AtmosphericPhenomena.html One book that I like is: Greenler, R., Rainbows, Halos, and Glories, Cambridge University Press, 1980.
Re: Urgent request.
Tony Moss asked (Snip) He hath made every thing beautiful in his time Can anyone give me 'chapter verse' for this please as I must be certain (Snip) King James version of Ecclesiastes Chapter 3 Verse 11 He hath made every thing beautiful in his time: also he hath set the world in their heart, so that no man can find out the work that God maketh from the beginning to the end Mike [EMAIL PROTECTED] 53.37N 3.02W
To those who needed info
Several months ago I volunteered to send out some jpg's of the inside covers of a book that I have. the pages are intitled Pocket Navigator and is a form of sundial, several asked for the pictures but for some unknowen reason I never sent them and I have lost the list of those that wanted them. If any of you are still interested please let me know Dave Carlson Redding, CA. USA P.S. The name of the book is Better ways of Pathfinding by Robert S. Owendoff
Urgent request.
Fellow Shadow Watchers, This is 100% on topic and somewhat urgent for me. The large bronze dial plate which I am about to engrave must bear the biblical inscription He hath made every thing beautiful in his time Can anyone give me 'chapter verse' for this please as I must be certain that I have it absolutely per the King James' version as erasers don't work on bronze :-) In particular does 'his' have a capital letter? Before now I've made a mistake in the workshop and found myself mentally reaching for 'undo'. If only it were possible! Many thanks in advance. Tony Moss
Re: Multiple sunset
I also thought something I would like to ask the airplane pilots we have among us. Have any of you ever tried to take off immediately after the sunset, flying straight to the sun's azimuth, trying to see several sunsets in a raw? One of the most famous pilots in the world included a version of this in his even more famous book. Antoine de Saint-Exupéry, in the Petit Prince, has his title character, the Little Prince, tell him how back on his home planet -- a very small place -- he watches as many sunsets as he wants, just by pushing his chair along... BT Bill Thayer LacusCurtius http://www.ukans.edu/history/index/europe/ancient_rome/E/Roman
