{"product_id":"pressuria-lebedev","title":"Pressuria – Lebedev and the Pressure of Light \/ P = 2I\/c Physics Sticker","description":"\u003cp\u003ePressuria, a young armoured experimenter, sends a beam of light into a glass bell jar holding a tiny vane.\u003c\/p\u003e\u003ch3\u003eThe Physics\u003c\/h3\u003e\u003cp\u003eMaxwell predicted that light pushes. In 1900 Pyotr Lebedev measured it in Moscow, shining arc light onto thin metal vanes on a torsion balance in a high vacuum (Ann. Phys. 311, 433, 1901). The vacuum and fast reversals let him separate the true light pressure from radiometer gas effects. Nichols and Hull confirmed it in the US the same years.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eP = 2I\/c\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eP: radiation pressure on a perfect mirror (Pa)\u003c\/li\u003e\n\u003cli\u003eI: intensity of the light (W\/m²)\u003c\/li\u003e\n\u003cli\u003ec: speed of light (m\/s)\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eA perfect absorber feels half as much, P = I\/c. Sunlight at Earth gives only about 9 µPa on a mirror: solar sails rely on it.\u003c\/p\u003e\u003cp\u003e\u003cem\u003eHonest caveat:\u003c\/em\u003e The factor 2 applies only to perfect reflection at normal incidence.\u003c\/p\u003e\u003ch3\u003eOn the sticker\u003c\/h3\u003e\u003cp\u003ePressuria aims a bright beam from his hand at a small vane inside a glass bell jar. Printed text: \u003cstrong\u003ePRESSURIA\u003c\/strong\u003e with the line \u003cstrong\u003eP = 2I\/c\u003c\/strong\u003e. Pixel-art kiss-cut vinyl sticker, white, in 2″, 3″, 4″ and 6″ sizes.\u003c\/p\u003e","brand":"Printify","offers":[{"title":"2\" × 2\" \/ White","offer_id":50964117258343,"sku":"26120218102665256703","price":4.99,"currency_code":"USD","in_stock":true},{"title":"3\" × 3\" \/ White","offer_id":50964117291111,"sku":"17812001474050242758","price":6.99,"currency_code":"USD","in_stock":true},{"title":"4\" × 4\" \/ White","offer_id":50964117323879,"sku":"27948561114504700257","price":8.99,"currency_code":"USD","in_stock":true},{"title":"6\" × 6\" \/ White","offer_id":50964117356647,"sku":"20992746588327626477","price":11.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0596\/8746\/9159\/files\/10426684305257255518_1200.jpg?v=1793659979","url":"https:\/\/pixelatedphysics.com\/pl\/products\/pressuria-lebedev","provider":"Pixelated Physics","version":"1.0","type":"link"}