WoPSR​.net Offi­cial Time

This clock shows the offi­cial WoPSR​.net time. WoPSR.net’s offi­cial time is U.S. East­ern Time, or as it is more com­monly known, The World’s Best Time Zone. It auto­mat­i­cally updates for Day­light Sav­ing Time. It was scripted and assem­bled in Flash, with vec­tor and raster graphic ele­ments cre­ated in Illus­tra­tor and 3D Stu­dio Max. The code is orig­i­nal, but the move­ment of the hands is inspired by Microsoft’s Clock Side­bar Wid­get pack­aged with Win­dows Vista.

Astro­labe

Lat­i­tude: 38.905
Lon­gi­tude: –77.0162

This is v2.0 of the Astro­labe. v2.0 removes the hour, minute, and sec­ond hands which made the clock busier than it needs to be. v2.0 also redesigns the shape of the dragon hand, and cor­rects the shadow direc­tion to match the rest of the site.

This clock is based on the ancient astro­nom­i­cal instru­ment of the same name. It func­tions sim­i­larly to the Pražský orloj in Prague, Czech Repub­lic. It is an astro­nom­i­cal clock.

First, the image of the globe rotates so that observer’s lon­gi­tude is point­ing to 12 o’clock. There are two con­cen­tric cir­cles cen­tered over the pole. The smaller is the near tropic, and the larger is the equa­tor. The far tropic lies at the edge of the image of the globe. The near tropic is Can­cer in the North­ern Hemi­sphere and Capri­corn in the Southern.

Next, shaded areas over globe move to cor­rectly indi­cate the hori­zon, based on observer’s lat­i­tude. The gold line between the unshaded globe and the light blue region is the hori­zon (0° ele­va­tion), and the gold line between the light blue and dark blue shaded regions indi­cates astro­nom­i­cal twi­light (-18° elevation).

The large gold disc off­set from cen­ter is a depic­tion of the eclip­tic, pro­jected onto a plane through the oppo­site pole. It bears the sym­bols of the zodiac.

The large yel­low hand rep­re­sents the sun. The posi­tion of the sun is indi­cated by the inter­sec­tion of the outer edge of the eclip­tic disc with the line run­ning through the cen­ter of the long arm of the sun hand. The sun’s cur­rent posi­tion on the eclip­tic (“sun sign”) is indi­cated by the zodiac sym­bols. The sun hand moves slowly coun­ter­clock­wise (North­ern Hemi­sphere) or clock­wise (South­ern Hemi­sphere) around the eclip­tic. With respect to the eclip­tic, the sun hand makes one rev­o­lu­tion per year. The sun hand makes one rev­o­lu­tion around the globe each day. When the sun hand and eclip­tic indi­cate that the sun is in the dark blue region, it is night at the observer’s loca­tion. When the sun is indi­cated in the light blue region, it is astro­nom­i­cal twi­light. When the sun is in the unshaded region, it is above the hori­zon. When the sun is indi­cated directly over the hori­zon, it is sun­rise or sun­set. Sun­rise is to the left (right for South­ern Hemi­sphere), and sun­set to the right (left for South­ern Hemi­sphere). The sun hand moves clock­wise in the North­ern Hemi­sphere and coun­ter­clock­wise in the Southern.

The thin gold ring at the edge of the clock bears the names of the months. The posi­tion of the sun hand within the month indi­cates the cur­rent month and approx­i­mate date. The move­ment of the cal­en­dar ring approx­i­mately mir­rors the move­ment of the eclip­tic disc, but varies slightly with irreg­u­lar­i­ties in the Gre­go­rian cal­en­dar. The sun hand pro­gresses slowly coun­ter­clock­wise (North­ern Hemi­sphere) or clock­wise (South­ern Hemi­sphere) through the cal­en­dar ring once per year.

The equinoxes and sol­stices are indi­cated when the sun hand inter­sects the outer edge of the eclip­tic disc pre­cisely above the equa­tor (equinoxes) or one of the trop­ics (sol­stices). The sol­stice at the far tropic (outer edge of globe) will be the local win­ter sol­stice, and the sol­stice at the near tropic will be the local sum­mer solstice.

The light gray hand indi­cates the posi­tion of the Moon in the same way as the sun. How­ever, due to the ~5° incli­na­tion of the Moon’s orbit, the posi­tion of the moon only lies directly at the edge of the eclip­tic twice per year (see dis­cus­sion of dragon hand below). There­fore, there is a slight error in the Moon’s posi­tion that can­not eas­ily be depicted with clock-​​like graph­i­cal ele­ments. Moon’s posi­tion with respect to the sun, how­ever, is very accu­rate. Phase of the Moon is indi­cated by the crescent-​​shaped shaded region lying just out­side the cal­en­dar ring.

The short, blue, pointy hand is the dragon hand. It indi­cates the ascend­ing and descend­ing nodes of the Moon. These are the points at which the orbit of the Moon crosses the eclip­tic. The ascend­ing node is the node where the Moon is cross­ing the eclip­tic from celes­tial South to celes­tial North, and the descend­ing node is the oppo­site. These are the points where eclipses may occur. Eclipses are indi­cated by the sun hand, Moon hand, and dragon hand work­ing in con­junc­tion. An eclipse will occur when­ever the cen­ter lines of the sun and Moon hands coin­cide with one another while within the lit­tle win­dows of the dragon hand. A solar eclipse will occur (some­where on Earth) when the sun and Moon are at the same node (long hands coin­cide), and a lunar eclipse will occur when the sun and Moon are at oppo­site nodes (long hands oppo­site one another).

All astro­nom­i­cal cal­cu­la­tions are from Jean Meeus, Astro­nom­i­cal Algo­rithms (2d ed. 1998) (with cor­rec­tions through 2005). Globe map, tropic lines, equa­tor, hori­zon, and twi­light lines all drawn with Generic Map­ping Tools. Hands, cal­en­dar ring, and eclip­tic disc were drawn ini­tially in Auto­Cad and col­ored in Illus­tra­tor. Bezel and cover glass were cre­ated and ren­dered in 3D Stu­dio Max. Ele­ments were assem­bled in Illus­tra­tor and ani­mated in Flash. The Roman font is Engravers MT, and the zodiac font is Arial Uni­code MS. The look is inspired by Ulysse Nardin’s Astro­labium G. Galilei wrist­watch. Astro­labe uses the hostip​.info IP lookup API and data­base to find loca­tion based on IP address. If your IP is not in the data­base, Astro­labe will prompt you to go to hostip​.info to add it.

Flash and Illus­tra­tor are reg­is­tered trade­marks of Adobe Sys­tems, Inc.
3D Stu­dio Max and Auto­Cad are reg­is­tered trade­marks of Autodesk, Inc.
Win­dows Vista is a reg­is­tered trade­mark of Microsoft Corp.