What's New Under The Sun

Sunday, 02 April 2023 20:13

Suppose that you've purchased a commercial sundial and you want to make it work correctly for your latitude.  Further, you don't live on your time zone meridian, but are some kilometers/miles east or west of that longitude line.  Steve Lelievre has written a web app that allows you to build a wedge to hold the sundial.  You can use the calculator to simply make a latitude wedge...

Thursday, 30 March 2023 00:03

In the Swiss mountains near the resort of Zermatt just beneath the Matternhorn, Stir World reports that "famed luxury Swiss watchmaker Hublot announced Daniel Arsham as its new ambassador, with a compelling piece of temporary land art. Aptly titled "Light & Time", the work is a Hublot-inspired 20-metre sundial resting in the shadows of the Matterhorn mountain." This sculptural is billed as...

Monday, 16 January 2023 01:21

The NASS Conference comes early this year.  Register now for the 28th annual NASS Conference in Ann Arbor, Michigan June 8-11, 2023 KensingtonHotel, Ann Arbor Michigan Ann Arbor is best known as the home of the sprawling University of Michigan with its architecture, quadrangles, and bustling student life.  Yet, it also boasts of great art, science, and archeological...

Sunday, 18 December 2022 23:00

Sklar Bixby and Jeremy Meel, students at Santa Fe College in Florida took on a project to design and 3D-print a new sundial for the Kika Silva Pla Planetarium in Gainesville Florida (located on Santa Fe's Northwest Campus). Under the guidance of Dr. Philip Pinon, Sklar and Jeremy took on a semester long project as part of the Exploring Honors Mathematics class. They designed a horizontal sundial...

Saturday, 10 December 2022 17:41

Don Snyder, long time NASS member, sundial designer and conference organizer, died Nov. 21, 2022 at the age of 87. He organized two St. Louis conferences for NASS in 2008 and 2017. For the first St. Louis conference, Don worked closely with Michael Olsen of the Missouri Botanical Garden to have five sundials available for viewing, including the dedication of a dial donated by Ron Rinehard, the...

Thursday, 22 September 2022 20:41

The date is Sep. 22, 2022, the date of the fall equinox.  Although this is supposed to be the day of equal day and night, we know it's not exactly correct.  We measure daytime from sunrise to sunset, measured as the first and last light from the sun peaking over the horizon.  When we include sunrise and sunset plus atmospheric refration, at mid latitudes daylight wins by about 10...

Saturday, 27 August 2022 19:06

 Smithsonian Collection - Pocket sundial by Bourgaud of Nantes, 1660–1675. (MA.325565) From the National Museum of American History is an article about "How did a French pocket sundial end up buried in a field in Indiana?" published 20 July 2022 by Kidwell & Schechner.   It started in 1860 when Dr. Elisha Cannon, while plowing a field in Indiana, came...

Tuesday, 23 August 2022 14:17

The 2022 Sawyer Dialing Prize went to Frans Maes "for his creation of an introductory course on dialing, built on the idea of supervised self-study; for his successful multi-year running of that course in Europe; and for his inspiration of NASS’ development of a North American version.” Fred presented Frans with an award certification, the traditional cash prize of $250 and a custom made...

Tuesday, 09 August 2022 21:32

What makes a sundial?  Practically anything.  Sasch Stephens discusses how he became interested in dialing.  Since then he has turned many objects into solar time devices.  It takes some creative thinking to invision how a common object can become a working sundial.  One of the most recent projects turned a 54 x 28 foot south side of a building it into a giant sundial...

Sunday, 12 June 2022 22:00

Dr. Jeremy Robinson, (Naval Research Laboratory, Electronics Science and Technology Division) combined efforts with his father-in-law, Prof. Woodruff Sullivan (Univ. of Washington Dept. of Astronomy) to construct the World's Smallest Sundial. The competition was sponsored by Cadrans Solaires pour Tous and their record is being entered into the Guiness Book of World...

Saturday, 28 May 2022 17:28

Perhaps the smallest sundial goes to IBM with the printing of a sundial in a corner of a computer chip.  However it lacked a gnomon and could not really tell the time.  However, Chen Fong-shean, a Taiwanese miniature craftsman, was challenged by the French astronomical society to beat the Guiness World Record for smallest sundial held by an Italian.  The Italian dial created in...

Wednesday, 25 May 2022 14:42

NASS is saddened to report the passing of one of the UK’s pre-eminent sundial designer, Christopher St. J H Daniel who died on May 17, 2022. His works are to be found all over the UK, ranging from private commissions to major public works and to restorations and reconstruction of old and damaged sundials. After a 13-year career at sea, Christopher Daniel joined the staff of the National...

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The heart of the Cosmic Room is an unusual vertical meridian sundial created by sunlight passing through a slot on the roof above.  In winter the solar meridian transit is labeled  with a column of blue tiles and at the spring equinox the tiles change to orange.  The sign "Analemma 12:45" indicates civil time on the spring equinox when the sun is on the local meridian.  With the sun overhead, the beam of light follows the vertical set of tiles downward until it reaches the boundary between orange and blue tiles - the equinox has arrived.  Ruben Nohitol has been photographing this event for the last 16 years, every year since 2002.  From a ceiling hole Ruben marks the image of the sun at 12:45 on the floor with a small green circle.  He does this on dates throughout the year(s), not only creating a nice analemma, but does it with such precision that he is able to notice the slight shifts in solar equinox position through the leap year cycle of four years.

More impressive is the due west sunset on the equinox.   A beam of light streams though a hole in the western wall of his hacienda, across the living room,  through a square hole between rooms, across the Cosmic Room grazing past the vertical sundial and its tiles, and lands as a bright solar disk at the far end of the Cosmic Room on a vertical wood screen mounted on an exit doorway.   To add to the drama of the setting equinox sun, Ruben placed a model of the pyramid of El Cerrito on a shelf in the Cosmic Room blocking some of the sun's rays. The result is a shadow of the the pyramid against the solar disk, giving the illusion of thesun setting over the great pyramid.  You can see his vertical meridian and more at http://www.makeaholeinthewall.com and the sundial in operation at http://www.sundials.org/index.php/dial-links/videos/meridiane See his patience to photograph the real setting sun over the pyramid of El Cerrito in Queretaro, Mexico at http://www.sundials.org/index.php/dial-links/videos/analemmas-time-and-motion

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nass_news_2012_feb_ Nohuitol2_cosmic
[photo courtesy of Ruben Nohuitol]

Ruben Nohuitol of Queretaro, Mexico has a unique solarium or “cosmic room” to observe the rays of the sun throughout the year.  He has patiently constructed a wonderful time-lapse video following the sun every day at 12:45 pm.   His construction has a vertical meridiana beam of light descending and then ascending the wall as time passes throughout the year. A second sky-light gnomon creates a classical analemma on the floor.

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Time by Light of the Moon 2021
By the Light of the Moon
Photo by Dr. Jeff Kretsch

The analemmatic (human) sundial at Turner Farm Observatory Park in Great Falls, VA made by Eagle Scout candidate Kenny Dieffenderfer and Troop 1547 marked a unique place in sundialing history this July 23rd. The Analemma Society sponsors free Friday night public viewing of the heavens through telescopes at Turner Farm's Roll-Top Observatory. But just outside the Observatory on the sidewalk is Kenny's analemmatic dial. Could this dial tell correct time by the light of the moon?

On July 23rd this question was put to the test. It was almost exactly a full moon and the sky was clear. As can be seen in the accompanying photo taken by Dr. Jeff Kretsch at approximately 10:10pm EDT, the lunar shadow of a volunteer human gnomon cast a shadow of about 9:10pm standard moon civil time. How did this come about?

The important facts needed to make the analemmatic dial tell the correct "moon time" is knowing both the phase of the moon and the declination of the moon. On that night the moon was very close to being exactly a full moon and the declination of the moon was 25 degrees south of the equator. The maximum that the sun ever gets is 23.45 degrees south of the equator at the winter solstice. That means that (with practical precision) even though it was a late July night, the human gnomon must stand on the dial's zodiac walkway at the Dec-Jan winter solstice mark. 

If this were the sun, we apply a  plus 8 minute correction for the 77 deg west longitude of the observatory. The moon gets the same treatment. But what about the moon's phase and the "equation of time"? Here we find a fortunate coincidence: The moon was full moon at 10:37pm EDT on that Friday night, so by luck the moon was almost exactly opposite the sun. The moon's average full moon to full moon (a synodic month) is 29.53 days. Thus the average moon's lead or lag of a mythical full moon is about 49 minutes per day. Therefore the lunar phase correction is approximately 49 x 20/1440 = 0.68 minutes (41 seconds) ahead of the average full moon. Finally the sun's EOT for Friday July 23rd is approximately 6min 30 sec to be added to a dial's shadow to get civil time. But the moon opposite the sun has EOT in the opposite direction of minus 6min 30 sec. The net lunar correction is therefore +8.0 -.68 -6.5 = 50 sec, just less than one minute that needs to be added to that night's observation analemmatic shadow. One might say that the moon and sun were in perfect alignment!

 

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Spring Equinox 2020 Lowell ObservatoryHere in Great Falls Virginia on the day of the Spring Equinox, March 19th, it's a rainy day.  Perhaps that helps us want to stay inside with all of the travel and meetings restrictions imposed because of the Covid-19 virus.  However, astronomical events aren't deferred because of human and biological issues.  Late today the sun crosses the celestial equator and heralds in Spring.  You can observe this event remotely thanks to Lowell Observatory in Arizona.  Lowell Observatory will begin Live Streaming the event starting at 9pm EDT. "The spring equinox in 2020 occurs on Thursday, March 19 at 8:49pm MST/PDT (3:49am GMT), when the Earth's axis is exactly perpendicular to an imaginary line drawn between the Earth and Sun. On the equinox, the Sun rises due east, and it sets due west, no matter where you are on the Earth."

https://www.youtube.com/watch?v=LqP1Md85HHs&feature=youtu.be

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Dan-George Uza has prepared a calendar for 2018 "containing images of Romanian sundials and some daily astronomical information (the equation of time, the Sun's declination angle & zodiac sign, the Moon's phase & age etc.).... The calendar reflects the usual Romanian practice of starting weeks on Mondays, being the first working day, although orthodox religious calendars have reverted to starting weeks on Sundays due to religious reasons since 2011. The days of the week have been translated to their English counterparts for your convenience. Apart from the last two, which have different etymological background, they all closely follow the names of the ancient planets" Luni - Luna (Moon), Marti - Marţe (Mars), Miercuri - Mercury (Mercury), Joi - Joe/Jupiter (Jujpiter), Vineri - Venus (Venus) Sámbătă - from the Latin sa(m)bbatum meaning Sabbath, Duminica - from the Latin (dies) Dominica meaning day of the Lord. .... You may download the English version at the link below:"

https://goo.gl/FNafub

Dan explains  that the calendar " includes a brief introduction to the Romanian calendar, such as an explanation for the names of the days and months, the dates of national holidays etc. This is actually my second calendar. I did the first one last year inspired by Fabio Savian's French Republican Calendar. A big thanks goes to Patrick Powers who was kind enough to correct my spelling mistakes for this English edition."

"The  astronomical data was generated in Sun Ephemeris, Gian Casalegno's excellent software. The calendar is freeware so you may of course share it. It's intended for A3++ size paper (330x483mm) but I guess simple A3 will do."

"Have a Happy New Year or - as we like to say in Romanian - La Multi Ani!"

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Perryville Eclipse SundialPerryville Eclipse Sundial

In Perryville, Missouri, Perry County unveilled a sundial  commemprating the coming August 21st total solar eclipse. Mike Mohundro, Photojournalis for Hearland News (KFVS Channel 12) interviewed Trish Erzfeld, Perry Count Heritage Tourism Director, who said "We just wanted something after the eclipse is over with that the community can be proud of and reflect back on."  Mohundro went on to write "many organizations worked on this project together including Earthworks, the [North] American Sundial Society, St. Louis Stone Artist Abraham Mohler, Perry County and more."

The sundial, shown in a KFVS video and in the photo at right, is a horizontal white milk glass sundial now mounted on a large marble pedestal (watch the dial video at  http://www.kfvs12.com/story/35969739/perryville-to-commemorate-eclipse-with-sundial). 

On the pedestal are three plaques, one entitled "Time" explaining how to convert the sundial's solar time to civil time as told by watches and cellphones. "Not a lot of people know how to read a sundial," Erzfeld said. "It's a teaching tool as well as a historical marker here on out." The second plaque entitled "Eclipse" shows the date and time when the August 21st eclipse starts and stops as seen in Perryville said Don Snyder, local member of the North American Sundial Society.  The third plaque "Sundial" indicates who was involved in creating the dial.

Mohundro quotes Erzfeld saying "Education is been our main focus through this whole solar eclipse even... There's just so many things that play into the science of it and a sundial is one of those things that people can learn from."

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A sundial that only tells time during an eclipse?  Back in 2012 Bill Gottesman designed a peculiar dial to tell time by observing the angle between the cusps of the sun during the May 2012 eclipse.  Bill Gottesman is back at it with a more sophisticated version assisted by programmer Dan Axtell.  This time Bill and Dan give you an animated version of the cusp line, as well as detailed information of the line angle during the eclipse.  

This is for anywhere in North America that can see the partial or total eclipse.  Just enter your latitude and longitude and let the software create you a personal solar eclipse sundial. PLEASE DO NOT OBSERVE THE SUN DIRECTLY WITHOUT AN APPROVED SOLAR FILTER... OR, MAKE A SIMPLE PINHOLE CAMERA FROM A CARDBOARD BOX.

To make your solar eclipse sundial, go to www.eclipsesundial.com

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The North American Sundial Society will meet in St. Louis for their annual meeting and to observe the Great American Solar Eclipse on August 21, 2017.  Cities and towns across the US are planning events and raising awareness of both the beauty and hazards of the solar eclipse. For the last two years St. Louis groups have delivered more than 100 programs to area schools, libraries, cities, parks and businesses to raise awareness of this historic event which has not happened in St. Louis since the year 1442. 

Remember, except for the minute or two of totality, looking directly at the sun will do serious eye damage.  Use sun-safe eyeglasses (certified safe for solar viewing) available from many source (see links below or Amazon, etc.). Read about the Great American Eclipse coming near you:

St. Louis, IL: http://stlouiseclipse2017.org/

Other Cities: http://www.eclipse2017.org/2017/in_the_path.htm

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The 2017 August 21st solar eclipse will be commemorated by the US Postal Service with a unique thermochromic ink Forever Stamps: the stamp shows the total Eclipse of the Sun with its corona blocked by a black disk of the moon.  However, using the body heat of your thumb or fingers the eclipse image will reveal an underlying image of the moon. The image reverts back to the eclipse once it cools. Fred Espenak, "Mr. Eclipse" a retired NASA astrophysicist, took the photograph of both the eclipse (from Jalu, Libya on March 29, 2006) and the full moon.

The USPS  states that June 20, 1:30 p.m. MT will be theFirst-Day-of-Issue ceremony, taking place at the Art Museum of the University of Wyoming (UW) in Laramie. The University is celebrating the summer solstice on June 20. Prior to the stamp issuance, visitors are encouraged to arrive at UW's Art Museum's Rotunda at 11:30 a.m. to witness a unique architectural feature at noon when a single beam of sunlight shines from down on a silver dollar embedded in the floor, marking noon on the summer solstice,

The Total Eclipse of the Sun Forever Stamps may be pre-ordered at usps.com/shop in early June for delivery following the June 20 nationwide issuance.  The back of the stamp pane provides a map of the eclipse path and times it appears at cities across the US.

Back Panel of the Eclipse Stamp

Read more at: NASA Eclipse    and for observing tips  http://www.mreclipse.com/SEphoto/SEphoto.html

  1. Tour of Time
  2. Sundials and Timely Ceremonies
  3. ...until the last syllable of recorded time
  4. Greenwich Globe
  5. A History of the Sky
  6. Virtual Art for Inventor of Standard Time
  7. 2012 Transit of Venus
  8. Eclipse Sundial For May 20th, 2012