{"product_id":"the-baryon-acoustic-ruler-plate-072-physics-poster","title":"The Baryon Acoustic Ruler – Plate 072 Physics Poster","description":"\u003cp\u003ePlate 72 speaks for itself: \u003cem\u003e“The first sound, now a 147 Mpc ruler.”\u003c\/em\u003e\u003c\/p\u003e\u003ch3\u003eThe Physics\u003c\/h3\u003e\u003cp\u003eSound waves in the early photon–baryon plasma travelled until the baryons were released at the drag epoch. That distance froze into galaxy clustering as a standard ruler.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003ec_s = c \/ √(3(1 + R))\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003ec_s: sound speed in the plasma, m s⁻¹\u003c\/li\u003e\n\u003cli\u003ec: speed of light, m s⁻¹\u003c\/li\u003e\n\u003cli\u003eR: 3ρ_b \/ 4ρ_γ, baryon-to-photon momentum ratio, dimensionless\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eThey froze in at the drag epoch. Comoving r_drag = 147.09 ± 0.26 Mpc (Planck 2018).\u003c\/p\u003e\u003ch3\u003eSources\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eD. J. Eisenstein et al., Astrophys. J. 633, 560 (2005).\u003c\/li\u003e\n\u003cli\u003ePlanck Collaboration, Astron. Astrophys. 641, A6 (2020).\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eOn the poster\u003c\/h3\u003e\u003cp\u003ePlate 072, “The Baryon Acoustic Ruler”: the pixel-art plate with its slogan “The first sound, now a 147 Mpc ruler.”, 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":50962644631655,"sku":"16407948239578395039","price":19.99,"currency_code":"USD","in_stock":true},{"title":"9'' x 12\" (Vertical) \/ Fine Art","offer_id":50962644664423,"sku":"31087258691069892569","price":29.99,"currency_code":"USD","in_stock":true},{"title":"9'' x 12\" (Vertical) \/ Semi Glossy","offer_id":50962644697191,"sku":"13076447615103664768","price":19.99,"currency_code":"USD","in_stock":true},{"title":"18″ x 24″ (Vertical) \/ Fine Art","offer_id":50962644729959,"sku":"23813144674286079761","price":44.99,"currency_code":"USD","in_stock":true},{"title":"18″ x 24″ (Vertical) \/ Semi Glossy","offer_id":50962644762727,"sku":"28366475620011065371","price":29.99,"currency_code":"USD","in_stock":true},{"title":"18″ x 24″ (Vertical) \/ Matte","offer_id":50962644795495,"sku":"25145169673732943181","price":29.99,"currency_code":"USD","in_stock":true},{"title":"36'' x 48\" (Vertical) \/ Matte","offer_id":50962644828263,"sku":"28829387921731749005","price":69.99,"currency_code":"USD","in_stock":true},{"title":"36'' x 48\" (Vertical) \/ Fine Art","offer_id":50962644861031,"sku":"83203463548795664740","price":119.99,"currency_code":"USD","in_stock":true},{"title":"36'' x 48\" (Vertical) \/ Semi Glossy","offer_id":50962644893799,"sku":"12670812508402599007","price":69.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0596\/8746\/9159\/files\/10067497680158636927_2048.jpg?v=1793635544","url":"https:\/\/pixelatedphysics.com\/it\/products\/the-baryon-acoustic-ruler-plate-072-physics-poster","provider":"Pixelated Physics","version":"1.0","type":"link"}