{"product_id":"the-42-bow-plate-024-physics-poster","title":"The 42° Bow – Plate 024 Physics Poster","description":"\u003cp\u003ePlate 24 speaks for itself: \u003cem\u003e“Every rainbow is a cone of 42 degrees around your shadow.”\u003c\/em\u003e\u003c\/p\u003e\u003ch3\u003eThe Physics\u003c\/h3\u003e\u003cp\u003eSunlight refracts into a raindrop, reflects once inside and refracts out. The deviation has a minimum, and light piles up there, so the primary bow sits about 42° from the antisolar point; two internal reflections give the secondary bow near 51°.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eD = 180° + 2θ_i − 4θ_r\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eD: deviation for one internal reflection, °\u003c\/li\u003e\n\u003cli\u003eθ_i: angle of incidence, °\u003c\/li\u003e\n\u003cli\u003eθ_r: angle of refraction, sin θ_i = n sin θ_r, °\u003c\/li\u003e\n\u003cli\u003en: refractive index of water, dimensionless\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003en = 1.333: primary 42°, secondary 51°. Descartes traces the rays, 1637.\u003c\/p\u003e\u003cp\u003e\u003cem\u003eHonest caveat:\u003c\/em\u003e The exact angle shifts slightly with colour, since n depends on wavelength.\u003c\/p\u003e\u003ch3\u003eSources\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eR. Descartes, Les Météores (1637), Discourse 8.\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eOn the poster\u003c\/h3\u003e\u003cp\u003ePlate 024, “The 42° Bow”: the pixel-art plate with its slogan “Every rainbow is a cone of 42 degrees around your shadow.”, the key equation and the facts panel shown above. Pixelated Physics. Physics. Personified.\u003c\/p\u003e","brand":"Printify","offers":[{"title":"9'' x 12\" (Vertical) \/ Matte","offer_id":50961827332199,"sku":"10463838147469945642","price":19.99,"currency_code":"USD","in_stock":true},{"title":"9'' x 12\" (Vertical) \/ Fine Art","offer_id":50961827364967,"sku":"10223994654047544512","price":29.99,"currency_code":"USD","in_stock":true},{"title":"9'' x 12\" (Vertical) \/ Semi Glossy","offer_id":50961827397735,"sku":"17192042163150402430","price":19.99,"currency_code":"USD","in_stock":true},{"title":"18″ x 24″ (Vertical) \/ Fine Art","offer_id":50961827430503,"sku":"22500668657482794684","price":44.99,"currency_code":"USD","in_stock":true},{"title":"18″ x 24″ (Vertical) \/ Semi Glossy","offer_id":50961827463271,"sku":"53299679525494128590","price":29.99,"currency_code":"USD","in_stock":true},{"title":"18″ x 24″ (Vertical) \/ Matte","offer_id":50961827496039,"sku":"17405102331626368554","price":29.99,"currency_code":"USD","in_stock":true},{"title":"36'' x 48\" (Vertical) \/ Matte","offer_id":50961827528807,"sku":"29816428398390236832","price":69.99,"currency_code":"USD","in_stock":true},{"title":"36'' x 48\" (Vertical) \/ Fine Art","offer_id":50961827561575,"sku":"32364414843192321491","price":119.99,"currency_code":"USD","in_stock":true},{"title":"36'' x 48\" (Vertical) \/ Semi Glossy","offer_id":50961827594343,"sku":"28635764986034189773","price":69.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0596\/8746\/9159\/files\/2501284080188383985_2048.jpg?v=1793633383","url":"https:\/\/pixelatedphysics.com\/hi\/products\/the-42-bow-plate-024-physics-poster","provider":"Pixelated Physics","version":"1.0","type":"link"}