Digital Cube Beams Time Print
Posted: Friday, 28 March 2014 17:28
Voshart's Digital Cube

Chindōgu is the Japanese art of inventing ingenious things that are, well, Rube Goldberg.  Daniel Voshart from Toronto has designed a solar time-telling cube from 59 stacked millboard plates. [See: Voshart Cube ] The result is a digital sundial, though not as universal as those patented by Scharstein [USP 5,590,093] or Kellogg [USP 05,596,553] but still, it is an interesting dial.

The cube creates light tunnels, an extension of an idea perhaps from Jiyeon Song’s “One Day Poem Pavilion” [].  Voshart’s cube gives the digital hours from 8am to 6pm [the animated illustration above shows the concept from 10am-2pm] but only for about 15 days centered around a specific date, in the case of the prototype, designed around the birthday of his father.  According to Voshart, it only works within 100 miles of the designated location, and even then, only for a limited number of days when the sun’s declination track across the sky matches the computed tunnel angles within the cube. Voshart commented on his website, “I gave myself a month [to design the cube] and then I had to stop, otherwise it would have continued for the whole summer. I have a plan to do a giant one for Burning Man next year.”

The statement that the cube works only within 100 miles is slightly incorrect.  The cube works within a latitudinal band of +/- 50 miles, but the cube vs clock time can be replicated within each time zone around the earth.

The cube, if designed correctly, accounts for the longitude offset from the center of the time zone (4 minutes of time per degree of longitude) and the solar variation of meridian passage called the “equation of time” that can be calculated for a father’s birthday or any other day of the year.  We shall assume that Vorshart was clever enough to include both these corrections for his father’s birthday thus creating a sun clock that for a brief two weeks will tell quite accurate clock time.

Renaissance Dial - It's Academic Print
Posted: Tuesday, 04 March 2014 19:37
Telling Time with Precision
(By Permission - Bill Gottesman)

The Andalusia Star News reports that the Lurleen B. Wallace (LBW) Community College in Andalusia, Alabama, has a new timepiece that President Herb Riedel says, “… is a device used for practical purposes to keep time, but they also take on a symbolic meeting. For a college campus, I thought it would be very appropriate because it combines science and art.”

Indeed, the sundial is a large helical sundial, a modern “Renaissance” sundial designed by Bill Gottesman of Precision Sundials in Vermont. When the dial is adjusted for the day of the year it reflects a beam of light from mirrors sitting on the inclined gnomon back onto a helical band inscribed with hour and minute marks.  The dial is a precision instrument, telling civil time to an accuracy of less than one minute. While most sundials tell solar time marking noon as the moment the sun passes the meridian, the Renaissance helical dial is adjusted daily to show true clock time.  Several years ago at a North American Sundial Society conference where the helical dial was displayed, observers were able to tell time to 10 seconds.  This is rather remarkable since the sun's diameter (measured in time passage) is about two minutes and therefore requires the concave mirrors to reflect a converging beam that sharpen the sun's image, a sundial technique covered by US Patent 6,301,793.

President Riedel is proud to have this timepiece at LBW Community College saying, “It’s been my dream for many years to acquire this particular sundial, and it’s only been here in Andalusia that I was able to get one for LBW… I hope it will generate some thinking and learning, but I also hope that it will inspire people to think about who we are as humans in relation to the world, and that there are things greater than ourselves.”

The dial is made for the location of the College at 31o 19’ 19” North latitude, 86o 27’ 4” West longitude.  Other Renaissance sundials dot the academic landscape including the University of Maryland, Rockville campus in Maryland, University of Houston at Clear Lake, Texas, and Louisiana State University, Louisiana.

Sundials at STEM Festival Print
Posted: Sunday, 02 March 2014 19:09

Members of The North American Sundial Society and Analemma Society will be participating in the 3rd USA Science & Engineering Festival.  Mark your calendars for Saturday and Sunday April 26 and 27th at the Walter E. Washington Convention Center in Washington DC. This is a Science, Technology, Engineering and Mathematics (STEM) exposition.  In recognition of the Festival’s role in making STEM a national priority, Congress recently designated the last week in April as National Science Week.

NASS and the Analemma Society along with other expo presenters have more than 3,000 hands-on activities.  NASS and the Analemma Society will introduce students and families to a variety of sundials and offering hands-on activities to cut them out and test them using a solar heliograph. It's all free. Come and learn about Sundials – The World’s Oldest Clocks.

The Science & Engineering Festival will also have a Career Pavilion, Book Fair—complete with signings by well-known science authors. Bill Nye the science guy will be there as well as Mike Rowe (Dirty Jobs on Discover Channel), Nate Bell (Design Squad on PBS) and the cast and crew from TV shows like Big. Bang Theory, as part of over 100 live stage performances.

Founding Fathers Print
Posted: Thursday, 06 February 2014 22:33
Thomas Jefferson
by Rembrandt Peale-1800 
White House Historical Association

Fred Sawyer, President of the North American Sundial Society and editor of the Compendium sundial journal will present a lecture on "Gnomonic Tales of Thomas Jefferson (and other Founding Fathers)" on Thursday evening, April 10th at 7pm at the Great Falls Library, VA.  Reservations are required.  Contact the Fairfax County Libraries for more information.

The lecture will consider sundials in the lives of Thomas Jefferson and other prominent figures of early America such as George Washington and Benjamin Franklin.  Rather than serving simply as timekeeping devices, sundials will be seen as academic exercises, inspirations for poetry, symbols of an industrious new country, invitations to relaxation, and opportunities for invention.

Fred is a cofounder and the current president of the North American Sundial Society (NASS), and a vice president of the British Sundial Society.  He is also the editor of The Compendium, having been responsible for each of the 80 quarterly issues to date.  He has authored over 100 articles on gnomonics, and is a regular speaker at both NASS and BSS conferences.  His interests lie primarily in theory, historical techniques for drawing dials, and new dial forms (including his own wandering gnomon, equant, compressed gnomonic, Ptolemaic coordinate, Foster point, and other varieties).

In 2000, Fred and his family instituted the Sawyer Dialing Prize awarded each year at the NASS conference to an individual for accomplishments in, or contributions to, dialing or the dialing community.

Antique Sundial Treasures Print
Posted: Wednesday, 01 January 2014 12:51
Gallerie Delalande, Louvre de Antiquaires, Paris

The Galerie Delalande, Louvre des Antiquaires in Paris is presenting  an exhibition of 150 Pocket and Table Sundials.  The exhibit will continue until January 19th, 2014.  The gallery is now offering a book "Cadrans solaires / Sundials", written in French and English to illustrate these sundials:.

The Louvre des Antiquaires opened in 1978 and has a beautiful collection of astrolabes and nocturnals, globes and armillary spheres, octants, sundials and equinoctial rings and much more.  You can find photos of many of these dials following the link

Four Minutes Til Sunset Print
Posted: Wednesday, 20 November 2013 18:33

Eight years ago the University of Western Australia (UWA) commissioned a talented graduate, artist Shaun Tan, to create an impressionistic sundial for the 100th anniversary of UWA.  The fundamentals of the west-facing sundial were delineated by UWA Professor Peter Kovesi of the Geophysics and Image Analysis Group.

What Shaun artistically designed based on Professor Kovesi’s hour lines was carefully photographed, scanned and reproduced as a pixilated map that was turned into 337,600 glass chips (tessera) by artisan tiler Iain H. Middleton from V-vo Architectural Mosaics, with Ankit Gakhar, Darren Hay and Brody Osborne.  The mosaic suppliers Bisazza from Vicenza, Italy selected the colored glass to give Shaun Tan’s brilliance as well as accuracy.  They prepared 375 squares each containing 900 individual tessera and shipped them from Vicenza to Perth.  In all, UWA states that “To create the background, place the tiles, clean and detail, grout and polish has taken approximately 560 man-hours.”

The 4.56×8.0 m. sundial was unveiled in January 2013, mounted with precision on a west wall of the University Club building located on the UWA campus in Crawley, Perth. A star-shaped gnomon with an open annulus casts a spot of time on the wall.  During the course of the afternoon, the spot moves from the bottom of the wall to the top, recording Italian Hours until sunset, a common and practical way of measuring time used since the Arabic sundial of al-Shatir in 1371.  The final sunset line is a race between the gnomon shadow and a shadow from a further western building.  Watch the time-lapse video created by Nic Montagu to see which shadow wins the race.  The dial marks the annual limits of the sun’s shadow at the solstices (summer on the left hand and winter on the right hand side) and a middle line for the equinoxes.

Read the full details at:

VLA Sundial Memorial Print
Posted: Thursday, 31 October 2013 14:43
Bracewell Memorial Sundial at VLA
Photo Credit: NRAO/AUI/NSF

In 1961 Professor Ronald Bracewell at Stanford University created an X shaped array (called a “Chris-Cross array” for W.R. “Chris” Christiansen) using 32 10-foot diameter dish antennas to form a radio spectroheliograph nestled in the hills of Palo Alto, California.  The radio telescope, operating at a wavelength of 10 cm, produced daily maps of solar radio activity that NASA used during the Apollo moon landings.  Bracewell used the antenna piers as a novel “guest book,” handing visiting astronomers a hammer and chisel to carve their signatures into the concrete. He accumulated more than 200 of these signatures from many of the leading pioneers of radio astronomy.

Bracewell’s radio telescope, dismantled in the 1980’s, now has a second life as part of a sundial designed by Professor Woody Sullivan from the University of Washington. Dr. Sullivan is an avid dialist and member of the North American Sundial Society.  In 2012 donations from the Friends of the Bracewell Observatory Association, Associated Universities Inc., and the National Science Foundation provided funds to create a memorial to Dr. Bracewell who passed away in 2007.

The memorial is a horizontal gnomonic sundial at the entrance of the Very Large Array (VLA) of the National Radio Astronomy Observatory (NRAO) visitor center in New Mexico.  Ten of the 6-foot antenna piers with their historic signatures mark the hours.  They are positioned just northward of the winter solstice line.  As described by Dave Finley of the NRAO, “The central portion of the sundial is on a 46-by-35-foot concrete slab. Markers that indicate the time of day are embedded in the slab, where the shadow of a metal sphere mounted atop a post can fall on them. Visitors can walk around the sundial to find not only the time of day but the approximate time of the year. Other markers indicate important dates in the history of radio astronomy, and solar noon at other observatories. Unlike any other sundial, this one ... allows visitors to locate the approximate position in the sky of three celestial objects that played important roles in radio astronomy: two distant galaxies and the remains of an exploded star in our own Milky Way.”  Read more at:

9/11 Timeless Sundial Dedicated In Hampton, N.J. Print
Posted: Thursday, 12 September 2013 18:54

nass_news_2013_sep_hampton_dial-2nass_news_2013_sep_hampton_dial-1Tom Carpenter, a member of the Hampton fire company for 44 years, presented plans for a 9/11 memorial to the Borough Council at the beginning of 2012 and Councilman James Cregar began designing the memorial as a sundial using beams recovered from Ground Zero of the Twin Towers.

Last Saturday the beams, which had been transformed into a timeless sundial, was dedicated in a ceremony “… to the innocent victims of the attack on our country on September 11, 2001 and to all those who suffered responding to it.   By the Citizens of Hampton 9/11/2012”

Fire Company President Rob Walton, also a county Freeholder, served as master of ceremonies at the dedication.   Joining the volunteer firefighters were members of the Hampton Emergency Squad, some of whom went to Ground Zero immediately after the 9/11 Twin Towers attacks. Georgia Cudina of Lebanon Township assisted with the draping of the U.S. flag over the beam gnomon in memory of those who died, including her husband Richard who was among the many 2001 victims.

nass_news_2013_sep_hampton_dial-4Walton explained to an audience that overflowed into the nearby street that two bent pieces of steel from one of the towers make up the gnomon of the timeless sundial. Surrounding the gnomon there are no hour lines.  Rather, the dial base, shaped into a large Pentagon, has a floor of light and dark brick pavers creating the outline of the Twin Towers and the number 93 for the airline flight that crashed in Shanksville, Pennsylvania.  Within the outline of the Twin Towers are pavers with engraved names and remembrances. Four plaques on the memorial wall catch the morning gnomon shadows to remember that infamous day’s events:

“American Airlines Flight 11 Strikes North Tower at 8:46am"
“United Airlines Flight 175 Strikes South Tower at 9:03am”
“American Airlines Flight 77 Strikes The Pentagon at 9:37am”
“United Airlines Flight 93 Crashes in Shanksville, Pennsylvania at 10:03am”

nass_news_2013_sep_hampton_dial-3Keynote speaker Congressman Leonard Lance of Clinton Township noted that more than 700 New Jersey residents lost their lives in the 9/11 attack.  And Rob Walton said that the memorial should remind us all “to treasure time.”

Thanks to Tom Carpenter, Mayor James Cregar, Rob Walton, Rick Allen, and the committee of volunteers who worked so hard to create the memorial.  You can read about the dedication in Terry Wright’s article from the on-line Hunterdon-County-Democrat that includes many pictures of the dial and the ceremony. Visit

To raise funds, engraved bricks with names or short messages from the donors are still available - for details contact Tom Carpenter at 908-537-4521.

Bainbridge Island Equatorial Sundial Print
Posted: Saturday, 17 August 2013 21:55

The Battle Point Astronomical Association, founded in 1992, provides astronomical observing for science education and public enjoyment at Ritchie Observatory and Planetarium in Battle Point Park on Bainbridge Island, Washington.

The Association is designing a large equatorial sundial to excite curiosity and demonstrate the basic concepts of time and the motion of the earth.  A model of the sundial shows that it will be not only an accurate timepiece using an analemma shaped gnomon to tell civil time, but also will be a beautiful sculpture. “There currently is nothing like it on Bainbridge Island,” claims the Association.

The group has raised $13,000 towards the project's estimated cost of $30,000.  "Our community has a strong sense of stewardship of the public good. When you support the sundial, you’ll help create a significant and meaningful work of public art that will bring beauty as well as an appreciation of time and the day sky to the everyday life of our community.”  With your help the sundial will be installed in the Spring of 2014. Contributions for the sundial can be made at: BPAA Sundial Contribution at Indiegogo

In the video Professor Woody Sullivan, "Mr. Sundial", explains the enthusiasm for sundials in the Pacific Northwest and the goal to make Seattle the sundial capital of North America.  Contribute to the Battle Point Park Sundial and get a personal tour of the Seattle Sundial Trail from Professor Sullivan.

Read more at:

Oatlands Sundial on Endangered List Print
Posted: Wednesday, 14 August 2013 19:49


Photos Courtesy of Oatlands Historic House and Garden

Sitting peacefully in the garden of the Oatlands Historic House and Garden near Leesburg VA, is a beautiful, but sadly in need of repair sundial.  Each year the Virginia Association of Museums, comprising over 500 museums and historical sites within the state, receives nominations for conservation of Endangered Artifacts.  The Oatlands sundial is nominated to be considered for one of the Top 10 List of Endangered Artifacts for 2013. You can vote your concern for this sundial and donate to its restoration at:


Oatlands was an ante-bellum estate purchased as a “country home” by Edith and William Corcoran Eustis in 1903.  Edith collected artifacts from all over the world, including the sundial.  An early picture showed Edith standing in the garden with the sundial on its unmistakable pillar of pink marble balanced atop a large marble tortoise. See NASS sundial #255 (Virginia / Leesburg).  Unfortunately the dial is misaligned and the top marble plinth has come loose from the pillar.  The dial face and gnomon need restoration as well.

nass_news_2013_aug_Oatlands_fecitLori Kimball, Director of Programming and Education, provided NASS with detailed photos of the sundial showing the marks “FECIT” (Made by) with a symbol of a crown and the date 1717.  Analysis of the gnomon angle and dial face hour lines shows that the dial was designed for N 41 deg 54 min, the latitude of Rome.  This is consistent with Edith Eustis antique collecting from Italy and France.  But who made the sundial and is the date its true provenance?

Oatlands is raising funds to conduct a conservation assessment along with the sundial’s restoration. Kimball said she hoped the public would support Oatlands by voting to raise the visibility of the conservation work needed for the sundial.  Voting is open until the end of August.  The Virginia Association of Museums does not provide financial support - public donations such as yours are needed. The final Top 10  will be then selected by a panel of conservators and collections care professionals and announced mid-September.

Read:  Leesburg Today Oatlands Sundial on Endangered Artifacts List

A History of the Sky Print
Posted: Thursday, 25 July 2013 15:12

Kevin Murphy, artist and photographer, set up a time-lapse camera on the roof of the San Francisco Exploratorium to record the sky every 10 seconds, 24 hours per day for an entire year. The camera points due north at and elevation of 45 degrees, which means that you won’t see any dramatic sunrise or sunset, nor will you see a burning image of the sun. Even with the wide-angle lens, the sun is always kept just out of view. But what a wonderful view of the sky: Look closely at the video and you’ll see moving clouds, fog, rain, and differing colors of the sky.

Most stunning is the changing length of the day. Summer morning twilight begins about 4:10am (Pacific Standard Time) and evening twilight ends about 8:10pm, but you must be patient for the winter sky to appear. Winter morning twilight begins about 6:50am (PST) and evening twilight ends about 5:30pm. (There’s a small running clock in the bottom right corner to chart your progress). You’ll see the dramatic difference between summer and winter with days in darkness patiently waiting their turn at sunrise and conversely, the fast quenching of the blue sky into darkness well before the summer frames show any sign of paling.

Each frame is digitally photographed at 1024x768 pixels, that with compression, requires about half a terabyte storage per year. Kevin Murphy has been creative with the sky display: Thumbnail videos of each day of the year are collectively represented in a tiled mosaic 20 days wide by 18 days tall, showing 360 days of sky all at once. The images are arranged chronologically, and are synchronized by time of day, beginning before summer sunrise. Time is compressed in playback at 24 frames/second so that each second represents 4 minutes of time.

This is still a work still in progress: As the camera on the Exploratorium roof continues to collect images of the sky, they will be integrated into the daily montage. Therefore the video will vary from day to day, always displaying the most recent 365 days.

Visit for more information. Below is his video. It’s best played in full-screen HD resolution. Click the middle arrow to start, then click the bottom right frame box.

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