{"product_id":"planetary-epicycles-unisex-t-shirt-earth-and-mars-parchment","title":"Planetary Epicycles Unisex T-Shirt: Earth and Mars — Parchment","description":"\u003cp\u003e\u003cstrong\u003eThe planets’ real paths across the sky, drawn with two circles.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003ePlanet is Greek for wanderer. Against the stars, a planet drifts one way, stops, runs backwards for weeks or months, then turns forwards again. Ptolemy explained it with a small circle, the epicycle, riding on a large one. Later, Copernicus explained why it works: the small circle is the Earth’s own orbit, and seen from a moving Earth, every planet is two turning circles added together.\u003c\/p\u003e\n\u003cp\u003eEach loop is a retrograde, the moment the Earth overtakes the planet or the planet overtakes the Earth. The thin rings are the two circles that draw the pattern, and the colored stroke is the planet itself.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eEarth and Mars.\u003c\/strong\u003e Red Mars seen from blue-green Earth loops fifteen times in thirty-two years. Turn the question around, the Earth seen from Mars, and you get the same figure turned half a circle, looping at the same moments.\u003c\/p\u003e\n\u003ch3\u003eWho it’s for\u003c\/h3\u003e\n\u003cp\u003eThis is the real geometry of the night sky: the loops a planet traces as the Earth overtakes it, computed from each planet’s real orbital size and period. Made for astronomers, astrophysicists, physics teachers, planetarium people, stargazers with a telescope in the cupboard, and anyone who loves the history of science.\u003c\/p\u003e\n\u003cp\u003eMade to be noticed: a bold print in a relaxed unisex cut, for conferences, concerts, weekends, and anywhere a good conversation might start.\u003c\/p\u003e\n\u003ch3\u003eThe Unisex T-Shirt\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eLightweight polyester with a soft, cotton-like hand. Quick-drying, relaxed unisex fit: size down for a closer fit.\u003c\/li\u003e\n\u003cli\u003eWash by hand or on a gentle cycle. Hang to dry, no bleach, cool iron.\u003c\/li\u003e\n\u003cli\u003eNot quite the right fit? Tell us within 30 days and we’ll make it right.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eSize guide\u003c\/h3\u003e\u003cp\u003eMeasurements around the body, in cm (inches). Allow 1–3 cm either way.\u003c\/p\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSize\u003c\/th\u003e\n\u003cth\u003eLength\u003c\/th\u003e\n\u003cth\u003eChest\u003c\/th\u003e\n\u003cth\u003eSleeve\u003c\/th\u003e\n\u003cth\u003eShoulder\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eS\u003c\/td\u003e\n\u003ctd\u003e68 (26.8)\u003c\/td\u003e\n\u003ctd\u003e106 (41.7)\u003c\/td\u003e\n\u003ctd\u003e16.5 (6.5)\u003c\/td\u003e\n\u003ctd\u003e44 (17.3)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eM\u003c\/td\u003e\n\u003ctd\u003e70 (27.6)\u003c\/td\u003e\n\u003ctd\u003e110 (43.3)\u003c\/td\u003e\n\u003ctd\u003e17 (6.7)\u003c\/td\u003e\n\u003ctd\u003e45.5 (17.9)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eL\u003c\/td\u003e\n\u003ctd\u003e72 (28.3)\u003c\/td\u003e\n\u003ctd\u003e115 (45.3)\u003c\/td\u003e\n\u003ctd\u003e17.5 (6.9)\u003c\/td\u003e\n\u003ctd\u003e47.3 (18.6)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eXL\u003c\/td\u003e\n\u003ctd\u003e74 (29.1)\u003c\/td\u003e\n\u003ctd\u003e120 (47.2)\u003c\/td\u003e\n\u003ctd\u003e18 (7.1)\u003c\/td\u003e\n\u003ctd\u003e49.1 (19.3)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2XL\u003c\/td\u003e\n\u003ctd\u003e76 (29.9)\u003c\/td\u003e\n\u003ctd\u003e125 (49.2)\u003c\/td\u003e\n\u003ctd\u003e18.5 (7.3)\u003c\/td\u003e\n\u003ctd\u003e50.9 (20.0)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e\u003cem\u003eEvery Zenzicube design is grown from a real piece of mathematics. Find more in the \u003ca href=\"https:\/\/www.zenzicube.com\"\u003eMathematical Menagerie\u003c\/a\u003e.\u003c\/em\u003e\u003c\/p\u003e","brand":"Zenzicube","offers":[{"title":"S","offer_id":67833914785926,"sku":"ZZ1521223-V43032","price":58.0,"currency_code":"CAD","in_stock":true},{"title":"M","offer_id":67833914818694,"sku":"ZZ1521223-V43033","price":58.0,"currency_code":"CAD","in_stock":true},{"title":"L","offer_id":67833914851462,"sku":"ZZ1521223-V43034","price":58.0,"currency_code":"CAD","in_stock":true},{"title":"XL","offer_id":67833914884230,"sku":"ZZ1521223-V43035","price":58.0,"currency_code":"CAD","in_stock":true},{"title":"2XL","offer_id":67833914916998,"sku":"ZZ1521223-V43036","price":58.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0719\/2998\/7206\/files\/Planetary_Epicycles_T-Shirt_-_Earth_and_Mars_347ddcd3-5df5-4f16-a7b4-c415778c49f9.jpg?v=1793489693","url":"https:\/\/shop.zenzicube.com\/products\/planetary-epicycles-unisex-t-shirt-earth-and-mars-parchment","provider":"Zenzicube","version":"1.0","type":"link"}