Re: Equatorial monument in Brazil
That's a horse of a different color. Then you have a geometrical image of the hole rather than a pinhole image of the sun. The lack of "perfection" remains, but is no longer so apparent. Now you might want to ask for how many days around the equinox the image stays "pretty much" on the line. The deviation will be largest near dawn and dusk. Let's use 7 AM and 5 PM as reference times and 65' as the height, so the horizontal projection distance is 65'/tan(15 deg) = 240'. An offset of a quarter diameter -- 2' -- should be quite noticeable. That corresponds to an angle of 2/240 = 8.3 mrad = 29 arc-min, nearly equal to the change of declination in one day. It is also nearly equal to the angular diameter of the sun, so the image will be rather washed out at that distance. All in all, you should be able to determine the exact day of the equinox. That's close enough to perfection to leave me impressed. I'd love to see it in action. --Art
Re: High Noon
Hi Mac et al, Following the previous discussion on this topic, I added High Noon to the draft second edition of the BSS Glossary. My understanding is that it derives from the term haute nones, i.e. the time during the period of nones when the sun is at its highest. Since nones is the early pm period, this makes it the same as our noon. By contrast, the term bas nones would be the time when the sun is lowest during nones, but luckily we have no equivalent modern term Low Noon as that would really confuse us all! Regards, John --- Now and then I run across the phrase High Noon. Can someone please tell me what that means? I didn't find it in John Davis' excellent glossary. Best wishes, Mac Oglesby - Dr J R Davis Flowton Dials N52d 08m: E1d 05m -
Re: Equatorial monument in Brazil
Josef, Art, and All, Yes, this was the monument I saw on the TV show. Thank you Josef for tracking down the link! It was very interesting to be able to see it from the air, to really see its scale and consider its functionas opposed to seeing it from plaza level forjust aminute or soduring a show about an unrelated subject. I am always excited when interesting solar devices pop up unexpectedlyon TV! As you view the photo on the website, the football stadium I mentioned is behind the cameraand to the right along the meridian, and the long street (it looks like it might actually be a very straight dirt road)extends to the left for quite some distance. I have no idea which is East or West...which way would be best when laying out a monument like thisdo you suppose? Would it be better to have the projected disc hit the visible lineon the plaza in the morning or in the afternoon, or does it matter? Art, I would love to see it in action as well...it would be interesting to see just how welltheprojected disc actuallyshows up, andhow dramatic the overall effect is. It would certainly be a special place to spend an equinox! Jim Tallman Sr. Designer FX Studios 513.829.1888
Message archive
I don't know how to find old messages for this list. I used to look at an archive on Yahoo Groups (http://groups.yahoo.com/group/sundial/messages/), but the last message there is from 2001/07/11. Where else can I look? Thanks in advance, Steve -
Re: Message archive
archive on Yahoo Groups (http://groups.yahoo.com/group/sundial/messages/), but the last message there is from 2001/07/11. Where else can I look? Thanks in advance, Steve - Steve, try www.astroarchive.com. Mac -
Failed mail
= transcript follows = TO: [EMAIL PROTECTED] [552 Message size exceeded available user storage] = Unsent message follows From [EMAIL PROTECTED] Fri Jun 28 13:04:23 2002 Received: from mail1.rrz.Uni-Koeln.DE ([134.95.100.208]) by mail2.stl-online.net with ESMTP (IOA-IPAD 3.0) id 3281200; Fri, 28 Jun 2002 13:04:23 -0500 Received: from mail1.rrz.Uni-Koeln.DE (localhost [127.0.0.1]) by mail1.rrz.Uni-Koeln.DE (8.12.3/8.12.2) with ESMTP id g5SGrCtD028938 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NOT) for [EMAIL PROTECTED]; Fri, 28 Jun 2002 18:53:13 +0200 (MEST) Received: (from [EMAIL PROTECTED]) by mail1.rrz.Uni-Koeln.DE (8.12.3/8.12.3/Submit) id g5SGrCxK028936 for sundial-out; Fri, 28 Jun 2002 18:53:12 +0200 (MEST) Received: from mailgate0.sover.net (mailgate0.sover.net [209.198.87.43]) by mail1.rrz.Uni-Koeln.DE (8.12.3/8.12.2) with ESMTP id g5SGrBtC028922 for sundial@rrz.uni-koeln.de; Fri, 28 Jun 2002 18:53:11 +0200 (MEST) Received: from [216.114.177.1] (dialup4318.wnskvtao.sover.net [216.114.177.1]) by mailgate0.sover.net (8.11.6/8.11.6) with ESMTP id g5SGr9329183 for sundial@rrz.uni-koeln.de; Fri, 28 Jun 2002 12:53:10 -0400 (EDT) Mime-Version: 1.0 X-Sender: [EMAIL PROTECTED] Message-Id: [EMAIL PROTECTED] In-Reply-To: [EMAIL PROTECTED] References: [EMAIL PROTECTED] Date: Fri, 28 Jun 2002 12:52:37 -0400 To: sundial@rrz.uni-koeln.de From: Mac Oglesby [EMAIL PROTECTED] Subject: Re: Message archive Content-Type: text/plain; charset=us-ascii ; format=flowed X-Virus-Scanned: by amavisd-milter (http://amavis.org/) X-Virus-Scanned: by amavisd-milter (http://amavis.org/) Sender: [EMAIL PROTECTED] Precedence: bulk Reply-To: sundial@rrz.uni-koeln.de I don't know how to find old messages for this list. I used to look at an archive on Yahoo Groups (http://groups.yahoo.com/group/sundial/messages/), but the last message there is from 2001/07/11. Where else can I look? Thanks in advance, Steve - Steve, try www.astroarchive.com. Mac -
Re: High Noon
Noon itself derives originally from nine or the ninth hour after sunrise (probaby 3pm :-) and not when it is apparently highest in the sky. Well... you asked, Mac! Maria Brandl Mallacoota So how and when did it get shifted from 3 pm to midday ? Richard. E-mail from: Richard Mallett, 27-Jun-2002 -
Re: Kitt Peak dial
Mac: You avoid design and surveying errors by using the Time Shadow Method for marking points, that's for sure. The biggest differences in point location were those points that were located in potholes in the asphalt or where the elevation changed. John John L. Carmichael Jr. Sundial Sculptures 925 E. Foothills Dr. Tucson Arizona 85718 USA Tel: 520-696-1709 Email: [EMAIL PROTECTED] Website: http://www.sundialsculptures.com - Original Message - From: Mac Oglesby [EMAIL PROTECTED] To: John Carmichael [EMAIL PROTECTED] Cc: Sundial list sundial@rrz.uni-koeln.de Sent: Thursday, June 27, 2002 6:03 PM Subject: Kitt Peak dial John, I've seen your juxtaposition of the computed and observed hour points at the Kitt Peak demonstration sundial. Congratulations on achieving such excellent results. After weeks of preparation followed by days spent on site, it must be extremely gratifying to you and the others involved to see that the dial turned out better than anyone dared hope. Most of us design and build a sundial, then spot check its accuracy, hoping for the best. You've enjoyed the unusual opportunity of doing all of the checking essentially during a single day. Few of us would have had the resolve to see a project such as this through. You and your coworkers must be very proud of its outcome. Best wishes, Mac Oglesby - -
Re: Message archive
Steve Lelievre wrote: I don't know how to find old messages for this list. I used to look at an archive on Yahoo Groups (http://groups.yahoo.com/group/sundial/messages/), but the last message there is from 2001/07/11. Connect to http://www.astroarchive.com/g/ Click on search on the left Type for instance camera obscura in the box search for Select Sundial in the box Select list Maria Brandl Mallacoota 37° 32' 60S 149° 45' 0E -
Re: High Noon
Richard: Noon itself derives originally from nine or the ninth hour after sunrise (probaby 3pm :-) and not when it is apparently highest in the sky. Richard Mallett asked: So how and when did it get shifted from 3 pm to midday ? Klaus Eichholz wrote: My answer is High noon is correlated with the temporal hour None used by the monks. But as the Benedict rules demanded to have no food before this time it changed more and more foward. The same thing happened with vesper. [EMAIL PROTECTED] wrote: ...My understanding is that it derives from the term haute nones, i.e. the time during the period of nones when the sun is at its highest. Since nones is the early pm period, this makes it the same as our noon. By contrast, the term bas nones would be the time when the sun is lowest during nones, but luckily we have no equivalent modern term Low Noon as that would really confuse us all! I will try a summary. The term nones is Latin and the way that the Romans divided up time is a subject in itself. Their way of reckoning was inherited by the Christians and is still part of the way religious name parts of their daily office or cycle of prayers. [As a child educated by nuns, I recall that the convent bell rang at noon when we then recited specific prayers. Of course the bells rang at twelve noon precisely or 'high noon' as opposed to early or later]. The matter of how the Roman/Christian church reckoning of time became what we use today is another subject but no mystery. I just do not know where to direct you to look, Richard. Try a web search. I am sure that when the reckoning of longitude came into the argument, high noon became crucial and on this group we can all relate to that. BTW I hope you have all had the opportunity to see the wonderful Charles Sturridge film Longitude based on Sobel's book. Maria Brandl Mallacoota 37° 32' 60S 149° 45' 0E -
