{"product_id":"lenta-17-metres-per-second-physics-t-shirt","title":"Lenta – 17 Metres per Second Physics T-Shirt","description":"\u003cp\u003eLenta walks a beam of light on a leash, slowed to bicycle speed.\u003c\/p\u003e\u003ch3\u003eThe Physics\u003c\/h3\u003e\u003cp\u003eElectromagnetically induced transparency uses a control laser to make an opaque atomic cloud transparent over a narrow range of colours. Across that window the refractive index changes extremely steeply, so a light pulse's group velocity drops enormously.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003ev_g = c \/ (n + ω dn\/dω)\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003ev_g: group velocity (m\/s)\u003c\/li\u003e\n\u003cli\u003ec: speed of light (m\/s)\u003c\/li\u003e\n\u003cli\u003en: refractive index (dimensionless)\u003c\/li\u003e\n\u003cli\u003eω: angular frequency (rad\/s)\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eIn 1999 Hau, Harris, Dutton and Behroozi slowed light to 17 m\/s in ultracold sodium, about 18 million times slower than in vacuum; in 2001 light was stopped.\u003c\/p\u003e\u003ch3\u003eOn the shirt\u003c\/h3\u003e\u003cp\u003eFront: Lenta, the pixel-art character, with the title. Back: the group velocity formula, the EIT window, the 1999 result and the 2001 follow-up. Printed on a unisex tee.\u003c\/p\u003e","brand":"Printify","offers":[{"title":"S \/ White","offer_id":50936530075751,"sku":"26057014248093954612","price":29.99,"currency_code":"USD","in_stock":true},{"title":"S \/ Black","offer_id":50936530108519,"sku":"14011116729129400257","price":29.99,"currency_code":"USD","in_stock":true},{"title":"M \/ White","offer_id":50936530141287,"sku":"10966686505045946032","price":29.99,"currency_code":"USD","in_stock":true},{"title":"M \/ Black","offer_id":50936530174055,"sku":"26676234163350451279","price":29.99,"currency_code":"USD","in_stock":true},{"title":"L \/ White","offer_id":50936530206823,"sku":"21321212021970731696","price":29.99,"currency_code":"USD","in_stock":true},{"title":"L \/ Black","offer_id":50936530239591,"sku":"18924028024406616442","price":29.99,"currency_code":"USD","in_stock":true},{"title":"XL \/ White","offer_id":50936530272359,"sku":"30443582074747036194","price":29.99,"currency_code":"USD","in_stock":true},{"title":"XL \/ Black","offer_id":50936530305127,"sku":"11192849064819438221","price":29.99,"currency_code":"USD","in_stock":true},{"title":"2XL \/ White","offer_id":50936530337895,"sku":"11633554343710184744","price":29.99,"currency_code":"USD","in_stock":true},{"title":"2XL \/ Black","offer_id":50936530370663,"sku":"77126943544438317489","price":29.99,"currency_code":"USD","in_stock":true},{"title":"3XL \/ White","offer_id":50936530403431,"sku":"29669777385263859021","price":29.99,"currency_code":"USD","in_stock":true},{"title":"3XL \/ Black","offer_id":50936530436199,"sku":"47651260738557804973","price":29.99,"currency_code":"USD","in_stock":true},{"title":"4XL \/ White","offer_id":50936530468967,"sku":"25365606923862048302","price":29.99,"currency_code":"USD","in_stock":true},{"title":"4XL \/ Black","offer_id":50936530501735,"sku":"19403689367354696067","price":29.99,"currency_code":"USD","in_stock":true},{"title":"5XL \/ White","offer_id":50936530534503,"sku":"25940204800359221770","price":29.99,"currency_code":"USD","in_stock":true},{"title":"5XL \/ Black","offer_id":50936530567271,"sku":"13305588114234680607","price":29.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0596\/8746\/9159\/files\/slow-light-eit_front_16_white.png?v=1793595435","url":"https:\/\/pixelatedphysics.com\/hi\/products\/lenta-17-metres-per-second-physics-t-shirt","provider":"Pixelated Physics","version":"1.0","type":"link"}