UGears: Tellurion Mechanical Model (249pc)

The idea of a space-themed model has been “floating in the ether” atUgears for some time now. Every time we announce a new model, hopeful Ugearsfans will ask, “Is it an orrery?” From this shared desire a project wasborn. Our mission: to spread knowledge of space and time by helping peoplevisualize the movements of the planet we live on, and its closest satellite,the moon.

Ugears is proud to present the Mechanical Tellurion, an accurate wooden modelrepresentation of our corner of the universe. A tellurion (also spelledtellurian, tellurium, and sometimes called a loxocosm), is an ingeniousmechanism that depicts the cosmic dance between Sun, Earth and Moon. The causesof day and night, the phases of the moon, and the changing seasons are seen andunderstood according to the movements of this 3D puzzle. A tellurion (from theLatin tellus, meaning “earth”) is related to the orrery, which illustratesthe relative positions and motions of the planets and moons in the solar systemin a heliocentric model.

What is my place in the universe? Where am I going? We can't help you withthe metaphysical aspect of these questions, but this wooden puzzle will help youunderstand the voyages you make as a passenger on planet Earth, and yourinterconnected relationship with some of your nearest celestial neighbors. Weall experience the regular cycles of day and night, the phases of the moon, thechanging of the seasons and the passing of the years. But how many of us trulyunderstand these phenomena, or can explain what's behind the clocks andcalendars that rule our lives? Any child can tell you how old they are, but aska child how many times they've circled the sun, and you might get a puzzledlook, or an amusing range of answers: A hundred twenty-seven? Ten thousand?Once? Never?

Build the beguiling DIY wooden model Tellurion, enjoy showing it to yourfamily and friends, and you will all have a better understanding of the heavens,the seasons, and the concept of time itself. Turn the handle to set the closelycalibrated system of gears in motion. One turn of the handle = one rotation ofthe earth on its axis = one day. Point to a spot on Earth's surface, observethe spinning earth's position relative to the sun, and visualize sunrise andsunset, the passage of day into night. The Tellurion shows the phases of themoon are a function of the moon's position relative to the sun and earth. Whenrotating, the moon rises and falls slightly, thereby changing its trajectory.The earth's orbit around the sun, together with a correct depiction of the23.5 degree inclined orientation of the earth on its axis, shows why weexperience changing seasons (outside the equatorial regions). The Tellurioncharts the passage of the seasons, while also giving a handsome graphicrepresentation of the zodiac, showing the sign and constellation under which youwere born.

The Ugears Mechanical Tellurion can be manually adjusted or “tuned” toprovide an accurate depiction of the relative positions of the sun, earth, andmoon on any given day. When “tuning” the mechanism, set the pointer to themiddle of winter or summer on the seasons dial. The earth, on its tilted axis,can be rotated (using a gear under the phases of the moon) to have eitherhemisphere be farthest from the sun in the bleak midwinter, or closest to thesun in summer. Turn the handle the correct number of days forward or back, fromwhichever solstice is closest in time, to set the present day. After consultinga lunar calendar, use the upper gear disk to adjust the position of the moon toits correct phase. Your Tellurion is now “set.” With each passing day, givethe model one turn of the crank to chart the earth's progress around the sun,and the moon's lunar cycle as it orbits the earth.

As you study the movements of your Ugears model Tellurion, you will learnthat the full moon occurs when the moon is behind the earth, away from the sun.This is because the sun illuminates the entire surface of the moon that isvisible to us (the “bright side” of the moon). In contrast, when the moon isbetween the earth and the sun, the sun's rays illuminate that part of the moonthat is turned away from us (the “dark side” of the moon). We call thisphase the “new moon,” the period when the moon is not visible in the nightsky. In the intervals between these phases, the moon waxes and wanes, changingits apparent shape, depending on how much of the illuminated part we can observefrom the earth. The phases of the moon are just one of many somewhatcounterintuitive astronomic understandings that are easy to visualize with theUgears Tellurion 3D puzzle.

At Ugears, a rough approximation or “close enough,” isn't really ourstyle. In representing the orbital periods of our planet and the moon, ourdesign engineers have given the Mechanical Tellurion a sophisticated gear system(first worked out by Dutch mathematician Christiaan Huygens in the 17th C) tohave the most accurate approximations possible in a wooden mechanism at thisscale. The earth gearing has a 365.256 day orbital period, while the moon-earthgear system has an orbital period of 27.323, giving accuracies within onethousandth of a day.

The Ugears Mechanical Tellurion DIY model kit comes with 249 parts and israted “Medium,” with an estimated construction time of 5 hours. This 3Drepresentation of the earth's movements and its interplay with nearby celestialbodies will appeal to anyone interested in space, astronomy, skywatching, or tothose wanting to understand, or teach a child, the basic natural phenomena thatrule our lives: day/night, the seasons, the lunar cycle, and the construct oftime. The Tellurion is a great DIY project or gift idea for any hobbyist orbudding astronomer. We are pleased to finally bring this beautifultellurion/orrery 3D model to Ugears fans all around the world—the world wespin on together.

Specifications:

• Model size: 15.9×10.2×12 in (40.5×26×30.5 cm)
• Package size: 14.9×6.7×1.3 in (37.8×17×3.4 cm)
• Number of components: 249
• Estimated time for assembly: 5 hours
• Level: Medium