Re: Why are schools, across the world, 'banning' analemmatic sundials ?
And in Australia we can’t even purchase fire works that go off with a bang. And blow the letter box metal lid onto the roof. And who didn’t make a fire cracker gun out of a metal bicycle pump and marbles. But it was hard to get the wick to come out of the hole in the end of the pump. Regards, Roderick Wall. From: Roger Bailey Sent: Monday, May 28, 2012 1:56 PM To: Donald Christensen ; darkro...@aol.com Cc: sundial@uni-koeln.de Subject: Re: Why are schools, across the world,'banning' analemmatic sundials ? I was a free range kid, as were my kids. We created our own activities, took risks, and ended up learning from these experiences to accept personal responsibility and be creative. I ended up being a chemical engineer involved in research most of my life. As a kid, my personal chemistry set contained the forbidden stuff, strong oxidants, strong acids and bases, and poisonous chemicals. Explosives, rocket fuels, stink bombs etc where much more interesting the changing the colours of litmus paper. Our parents were generally unaware of our activities with minor exceptions. My father shut down our rocket society after a static test from a bedroom window. My mother objected to the escape of nine captured snakes into the house and neighbourhood. These were reasonable restrictions considering the situation. No rockets or snakes in the house? OK. Playgrounds with dangerous equipment like swings, slides, teeter totters, skipping ropes, analemmatic sundials are such trivial risks in comparison. Kids need to grow and develop. Give them space. Let them challenge themselves. Regards, Roger Bailey From: Donald Christensen Sent: Sunday, May 27, 2012 7:29 PM To: darkro...@aol.com Cc: sundial@uni-koeln.de Subject: Re: Why are schools, across the world,'banning' analemmatic sundials ? I was sickened how society prevents children from growing up or learning how to cope with life. That is until I read about Lenore Skenazy http://freerangekids.wordpress.com/ and Tim Gill http://rethinkingchildhood.com/ It looks like this will turn around. It may take a generation or 2 to do so. However, society is starting to figure out that the current idea is harmful to children. On Mon, May 28, 2012 at 11:44 AM, darkro...@aol.com wrote: Part of the problem seems to be that society is getting to a point where what ever happens there must be someone to blame. People just can't accept that stuff happens, get over it. It is true that if a child is over protected then they cannot learn how to effectively handle situations they face as they grow up. And with society looking for someone to blame for EVERYTHING that happens to them is proof that they have not learned the same thing. A child falls and skins a knee, the parents call the school and chew out the teacher for not watching their child. The sad thing is those of authority are too afraid of bad press of law suits that they may discipline the teacher. I don't know of any cases in the US where sundials are banned from schools but I have not looked either. It never crossed my mind that it would be a problem. -Original Message- From: Donald Christensen dchristensen...@gmail.com To: sundial sundial@uni-koeln.de Sent: Sun, May 27, 2012 8:29 pm Subject: Re: Why are schools, across the world, 'banning' analemmatic sundials ? I found an excellent book on the matter It shows how we are making the world more dangerous for children. Society protects them so much that we prevent them from learning how to cope in the stressful world. Children grow old. We can't prevent that. However we can prevent them from growing up. “Beautifully written [...] lays out very simply how we are absolutely screwing the development of children, given our complete paranoid fear of the world we live in.” Tanya Byron in the Browser. No Fear: Growing up in a risk averse society argues that childhood is being undermined by the growth of risk aversion. This restricts children’s play, limits their freedom of movement, corrodes their relationships with adults and constrains their exploration of physical, social and virtual worlds. http://rethinkingchildhood.com/no-fear/ On Sun, May 27, 2012 at 10:19 PM, Martina Addiscott martina.addisc...@gmail.com wrote: In message 20120517002755.K4ADT.56582.root@nschwwebs03p John Pickard john.pick...@bigpond.com wrote: Good morning Martina, I've been following the various replies, and I agree wholeheartedly with the sentiments expressed about stupid attempts to reduce risk to zero. We all have our favourite stories, but I think that these examples will top the list. I understand that one of the largest mining companies in the world (Rio Tinto Australia) is so concerned about risk that it has banned the use of scissors and electric staplers. I have never seen an electric stapler where you could hurt yourself unless you really wanted to. And
Re: Australia Meridian/Noon Mark Transit of Venus
Hi Ian, You may find something at this website: http://www.transitofvenus.com.au Someone there maybe able to help you. Roderick Wall. From: Ian Maddocks Sent: Sunday, May 27, 2012 1:18 AM To: sund...@rrz.uni-koeln.de Subject: Australia Meridian/Noon Mark Transit of Venus hi I will be on the east coast of Australia for the transit of Venus in a week's time (probably Brisbane but will have a hire car in case the weather forecast says move) and i was just wondering if there are any meridian lines in NSW or Queensland. I've googled all combinations of noon mark / meridian / nsw / queensland./ australia but can't see anything obvious.Does anyone know of any meridians that might show the transit? Thanks in advance Ian Maddocks UK --- https://lists.uni-koeln.de/mailman/listinfo/sundial No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1913 / Virus Database: 2425/5023 - Release Date: 05/26/12 - No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1913 / Virus Database: 2425/5023 - Release Date: 05/26/12 --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: about the pinhole diameter
Hi Ruden and Tom, The pinhole photography effect is interesting and would be fascinating to watch. Thanks for your help, Roderick Wall. -Original Message- From: ruben nohuitol Sent: Friday, February 17, 2012 10:28 AM To: sundial@uni-koeln.de Subject: about the pinhole diameter If it's usefull for you the pinhole of my analema (on the roof) is 3/16 which hapened to be very good. Let me tell you that, today, feb 16, even when is partially clouded, the sun beam went into the room, making a dark room photography effect, thus, even when the direct mark was 1 1/2 in the floor, the round spect formed for this spect, was fifteen inches, allow us to see the clouds around the sun, moving fast and fascinating. www.ruben.mx --- https://lists.uni-koeln.de/mailman/listinfo/sundial - No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1913 / Virus Database: 2112/4813 - Release Date: 02/16/12 - No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1913 / Virus Database: 2112/4814 - Release Date: 02/16/12 --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: A compact indoor sundial using a convex mirror on the north sideof the roof
Hi Tom, Thanks for your ‘inside small sundial’ information, and for the mirror links. It’s a great idea. I’ve found an Australian convex mirror manufacturer and have requested prices. It will be fun trying to project the beam across the room onto the far wall. Good luck with your NASS article and thanks, Roderick Wall. From: Tom Egan Sent: Thursday, February 16, 2012 5:02 PM To: R Wall ML emails ; sundial mailing list Subject: Re: A compact indoor sundial using a convex mirror on the north sideof the roof Good question. I found that a hemispherical (I put it in quotes because the mirror I use actually has an essentially ellipsoidal cross-section about the axis of rotation) mirror was needed to observe the entire day's travel of the sun in midsummer. There's an additional complexity: the axis must be tilted down in the amount of the site's latitude -- aligning it with the earth's spin axis -- if early a.m. and late p.m. solar az/els are to be observed. If I could have acquired a 4 pi steradian ball (btw, i used the word ball simply as shorthand for half spheroidal mirror etc. etc.) I wouldn't have had to worry about this. But it's an easy fix to just tilt the mirror's axis. I bought a 26 inch ball from TechnologyLK http://www.technologylk.com/__74/acrylic-dome-mirrors.html It is the acrylic 360 deg. full dome detection mirror with galvanized backing. It is weatherproof. I first tried a 10 inch Victorian gazing ball from the garden, but it couldn't reflect a bright enough beam. I needed a weatherproof plane mirror, too. I found Super #8 Nondirectional SS a highly polished corrosion resistant stainless steel from Mirrored Stainless Solutions http://www.mirroredstainlesssolutions.com/ . The have available for nominal price a 10 x 10 inch (or larger) sample. This was large enough for my project. Enjoy! On 2/15/2012 9:17 PM, R Wall ML emails wrote: Hi Tom, Your indoor sundial is a great idea. I’m now searching the internet for convex mirrors. I note that you have used a convex ball mirror, I guess that’s needed to cover 6am to 6pm? I’ve always wondered how to do that. Thanks for a great idea, Roderick Wall. From: Tom Egan Sent: Thursday, February 16, 2012 12:54 PM To: sundial mailing list Subject: A compact indoor sundial using a convex mirror on the north sideof the roof Dave Bell, in his 2/12/2012 response (appended) to Ruben's invitation to us to view his cosmic room, discusses ways to use flat mirrors -- one being effectively a reflective pinhole aperture -- to obtain a noon line throughout the year in a living room that is well north of the equator (at 37.3 deg.). I've developed an indoor sundial that uses a large convex mirror to capture the sun's position throughout the day and year. It allows a compact dial face, if desired, that can fit on a table-top. (For development purposes, I'm using a target the size of a piece of letter paper.) I presented a slide show on it at the 2011 NASS annual conference in Seattle WA. I'll summarize the description from an article that's in preparation: A sundial system based on a three-dimensional convex mirror can overcome many of the limitations of a plane mirror. The convexity provides a wide field of view, reducing the apparent arc of the sun’s travel throughout the day and year to no more than the width of the mirror. This, in turn, permits the dial face to be compact enough to fit on a table-top. A convex mirror, while creating a compact view of the world, is a virtual view. That is, additional components are required to turn the sun’s disk into a real image of a sun spot. This is accomplished by incorporating a pinhole “camera obscura” that projects the sun’s image onto the dial face, as for example, a piece of paper with drawn hour lines and seasonal markings. When the convex mirror is mounted above a window on any side of the building – even the north side – and above the roof line, the system can deliver the sun spot to the dial face inside the building. Being above the roof line provides the mirror with a view of the sun’s travels that is least shadowed by nearby structures and vegetation. Two flat mirrors at 45 degree angles are used to change the path of light that is reflected from the convex mirror from vertical to horizontal -- allowing perpendicular entry into the building through a window to avoid distortion -- and then again re-orienting the beam to vertical to allow a convenient and easy-to-read horizontal dial face. Figure 1 (attached) illustrates the concept. The photo shows a side view of the gazebo I'm using to develop the system. The convex mirror reflects the sunlight down to a flat mirror tilted approximately 45 degrees just outside the window. This flat mirror turns the sun beam from vertical to horizontal so it can penetrate the window glass. On the inside of the window, a mask with pinhole is affixed, creating the camera
Re: Equinoctial vs. Equatorial
Hi all, Does anyone know what material was used and how thick it is for the vertical section of the following “ The Tree of Sonius” sundial. I Rather like the style of this sundial. http://www.regiomontanus.at/bild40_e.htm Roderick Wall. - No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1913 / Virus Database: 2112/4810 - Release Date: 02/14/12 --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: From Mexico with love... Should we use a different title in the subject line?????
Hi all, Would it be better if a different title in the subject line is used. I almost deleted the your email without reading it. Others may have deleted it without reading it. Roderick. -Original Message- From: Dave Bell Sent: Monday, February 13, 2012 12:42 PM To: sundial@uni-koeln.de Subject: RE: From Mexico with love... Beautiful rooms and concepts, Ruben! A wonderful teaching facility. Your low latitude is certainly a help in fitting these dial displays to an interior. After viewing your pages, I once again looked at my living room with an eye towards a noon line, as I have a roof window well situated near the South wall, but due to its height (just over 10 feet) and my latitude (37.3°), the resulting analemma doesn't fit the living room at all. It's too far from the South wall in Summer, and extends well past the open floor space in Winter. However, it did get me to thinking again, and doing some calculations. If I designed the line for a more southern location, say 9° North, the total length of the analemma was much shorter, and the Summer end would extend South of the ceiling hole, quite close to my South wall. Moving my home 28° to the South isn't very practical, but it occurred to me that I could introduce a deviation in the incoming rays, and accomplish the same result! I thought of a prism, but the geometry isn't very good; finding the right prism (apex angle and refractive index) would be difficult and/or expensive, and I would have to deal with chromatic dispersion, as well. But a pair of mirrors, even first-surface mirrors, is much easier. If the first mirror (to the north of center) was blacked-out, with a small, pinhole reflective aperture, inclined vertically or slightly to the North, its reflected beam could fall on the second, larger, flat a few inches to the south, inclined 14° more to the north. The 14° apex angle of the pair would introduce a 28° deviation towards the south, independent of the exact inclination of the pair. (They would have to be accurately aligned East-West, of course.) Any inaccuracies in mirror angles and orientation would be hard to allow for in plotting the Noon analemma, but I could always fall back on the ancient empirical method of driving a tack at 12:00 local solar time, once a week! Something a little like the ASCII sketch below. Assume the light enters from above and to the right... | |\ | \ \ \ Dave -Original Message- On Behalf Of ruben nohuitol Hi friends, please look my cosmic room, my page is www.ruben.mx --- https://lists.uni-koeln.de/mailman/listinfo/sundial - No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1913 / Virus Database: 2112/4806 - Release Date: 02/12/12 - No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1913 / Virus Database: 2112/4806 - Release Date: 02/12/12 --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: 2 questions: declination animation
Hi Darek, Will this program run under Windows 7? Roderick Wall. -Original Message- From: Helmut Sonderegger (Tele2) Sent: Wednesday, January 11, 2012 8:41 PM To: sundial@uni-koeln.de Subject: Re: 2 questions: declination animation Hi Darek. a longer time ago, I also wrote such a software for reverse engineering. You can download this freeware from my homepage www.helson.at. There select Download software STUNDLIN Good success Helmut Am 11.01.2012 08:31, schrieb Shadows Pro: Hi Darek and all There is a feature in my program Shadows Pro to reverse engineer a vertical sundial from its picture. It does not correct aberrations due to the camera objective but if the picture is taken exactly in front, it works pretty well. You can see a screen copy on this page: www.shadowspro.com/en/gallery12.html Regards François www.shadowspro.com -Message d'origine- De : sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] De la part de Darek Oczki Envoyé : mercredi 11 janvier 2012 00:32 À : sundial@uni-koeln.de Objet : 2 questions: declination animation Dear Diallists I've got two practical questions: 1. Let's say I have a photograph of a sundial. I do not know where it was originally located. Is there a way to discover the values of the declination and latitude it was designed for? There are clear hour and declination lines on the dial. 2. A friend of mine is helping a student in an attampt to reconstruct an old missing dial. They need a software which allows to make an animation of a shadow's path over the dial. Is there anything that would help them? I would be most grateful for any suggestions. --- https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Proceedings for Future of UTC meeting
Hi Roser, You forget that some of us live in the southern hemisphere. Roderick Wall. -Original Message- From: Roser Raluy Sent: Saturday, December 24, 2011 10:35 PM To: Frank King Cc: sundial@uni-koeln.de Subject: Re: Proceedings for Future of UTC meeting I wish you all a happy winter solstice ( in that we agree, don't we?) full of sunshine for our minds, bodies and sundials. Roser Raluy 42º13'31''N 2º51'43''E 2011/12/24 Frank King frank.k...@cl.cam.ac.uk: Dear John, I like your story about the times quoted by the Darwin control tower. In some of my introductory talks about sundials I mention Unequal Hours, Babylonian Hours, Italian Hours and so on. Just when the audience thinks this is offering more choice than they can cope with, I explain that things are little better when you use clock time. Your story illustrates this nicely AND also illustrates the use of different levels of precision. I may plagiarise this next time I give such a talk! All the best Frank --- https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: paper sundial
Yes, I gave up after 3 minutes trying to get it to work, it needs to be made user friendly. I’ll go back and see if I can make it work. Roderick Wall. From: Thaddeus Weakley Sent: Saturday, December 17, 2011 2:00 AM To: Roger Bailey ; Fabio nonvedolora ; sundial@uni-koeln.de Subject: Re: paper sundial Thank you Fabio. I would second Roger's comments regarding the usability to a casual user. Like Roger I had to do a bit of hunting - trial and error, but once I found the way to enter location data, it worked very well. I share his concern that most wouldn't stick with it to figure it out and enjoy the reward of the final result. That's besides the issue that many general users of course wouldn't be aware that this would be needed in the first place for sundial layout and reading. Thank you again. Cheers, Thad Weakley From: Roger Bailey rtbai...@telus.net To: Fabio nonvedolora fabio.sav...@nonvedolora.it; sundial@uni-koeln.de Sent: Thursday, December 15, 2011 11:22:09 PM Subject: Re: paper sundial Thank you Fabio. I checked the link and found it quite useful but the use is not intuitive but subtle. A casual observer like me has no idea how to use the page to create a personal design. Many will click onto the link and then stall. It is not obvious how to get the program to respond. I found moving the cursor to the sunburst beside location data worked. There I could input my location. Look for the pointed finger cursor on the sunbursts. Entry your specific data to generate a design. Then click on the pdf drawing tab to see the design. It works like a charm as you said. Thanks for this gift for the members of the sundial list. Regards, Roger Bailey From: Fabio nonvedolora Sent: Thursday, December 15, 2011 3:09 AM To: sundial@uni-koeln.de Subject: paper sundial Hi all, news from the clouds. I’ve a toy for the end of the year. I don’t think this is the very last end of the year, like some Maya supposed, and this is a great year, it is better than 2012 :-) (like the same Maya didn’t know) so I hope you have fun with this new section of Sundial Atlas. You can reach ‘paper sundial’, a menu of Gnomolab, directly at this address: www.sundialatlas.eu/atlas.php?gnomolab=3 You will find 4 models, this number is growing and if you have other models to propose, I’ll be happy to develop them in Gnomolab. The models may be setted for any coordinates and other features, you will get a pdf as replay. The 3rd model is designed to be applied to glass windows (you may found the declination of the windows with Gnomolab). It has a small gnomonic hole you can do with a pin or a small nail, moreover this model may be customed with a photo (or a logo). I uploaded some sample photos but anyone may upload other photos (public or for personal use). Have fun, ciao, Fabio Fabio Savian Paderno Dugnano, Milan, Italy 45° 34' 10'' N, 9° 10' 9'' E, GMT+1 (DST +2) --- https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Lunar Eclipse of 2011 Dec 10
Hi all, I missed seeing the Lunar Eclipse, not because I forgot but because we had thunder storms, lighting and lots of clouds. Maybe if I watch the TV news tonight I might see it. Melbourne Australia. Roderick Wall. From: Brad Lufkin Sent: Thursday, December 08, 2011 6:05 PM To: Sundial Mailing List Subject: Lunar Eclipse of 2011 Dec 10 I thought some of you might be interested in the upcoming lunar eclipse on the 10th of this month. I've attached a diagram showing the regions of visibility of the eclipse. Brad --- https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: THE ANCIENT ISLAMIC SUNDIALS - A new book (in Italian)
Hi, Is there an electronic version where I can use Google Translate to translate it into English? Roderick Wall. From: Gianni Ferrari Sent: Thursday, December 08, 2011 6:06 AM To: LISTA INGLESE Subject: THE ANCIENT ISLAMIC SUNDIALS - A new book (in Italian) After a long time I finally finished a book dealing with the Islamic sundials : “LE MERIDIANE DELL’ANTICO ISLAM - Il tempo nella civiltà islamica - Caratteristiche, descrizione e calcolo dei quadranti e degli orologi solari islamici” THE SUNDIALS OF ANCIENT ISLAM - Time in Islamic civilization - Features, description and calculation of Islamic quadrants and sundials The book is written in Italian language and is the complete redesign of an essay on the same topic I wrote in 1998 (150 pg.) The present text has been completely rewritten and expanded on the basis both of new studies and new translations of Arabic astronomical manuscripts published in the last 20 years, both of books and articles on Arabic and Turks sundials, both of graphic results obtained with many original programs and of my efforts to translate into modern language the methods described by some Islamic astronomers who lived about 1000 years ago. The book has 560 pages and contains 442 footnotes, 560 figures in black and white, including 252 original drawings. The price is 35 € (about 47 $) plus a contribution for postage, currently very high (about 10 € for Europe and 15 € for America - 13 and 20 $ ) For those interested a PDF file (100 kB) with the index of the book and some information can be downloaded from http://dl.dropbox.com/u/6616660/MERIDIANE%20ISLAM_%20ENGL.pdf and a file with some pages of the book (1.3MB) from http://dl.dropbox.com/u/6616660/Gianni%20Ferrari%20MERIDIANE%20ISLAM_Alcune%20Pagine.pdf My best wishes Gianni Ferrari - Ing. Gianni Ferrari Lat.44;38,18.5N Long. 10;56,05.3E gfme...@gmail.com --- https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial
