{"product_id":"the-poynting-flow-plate-019-physics-poster","title":"The Poynting Flow – Plate 019 Physics Poster","description":"\u003cp\u003ePlate 19 speaks for itself: \u003cem\u003e“The energy never travels along the wire.”\u003c\/em\u003e\u003c\/p\u003e\u003ch3\u003eThe Physics\u003c\/h3\u003e\u003cp\u003eIn a circuit, energy flows through the fields around the wires. The Poynting vector points from the battery through the space outside the wires and into the resistor from the side.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eS = (1\/μ₀) E × B\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eS: Poynting vector (energy flux), W m⁻²\u003c\/li\u003e\n\u003cli\u003eμ₀: vacuum permeability, N A⁻²\u003c\/li\u003e\n\u003cli\u003eE: electric field, V m⁻¹\u003c\/li\u003e\n\u003cli\u003eB: magnetic flux density, T\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eIt enters the resistor from the side. Poynting, 1884.\u003c\/p\u003e\u003cp\u003e\u003cem\u003eHonest caveat:\u003c\/em\u003e A little energy does enter a real wire: the heat lost to its resistance flows in radially through its surface, never along it.\u003c\/p\u003e\u003ch3\u003eSources\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eJ. H. Poynting, Phil. Trans. R. Soc. 175, 343 (1884).\u003c\/li\u003e\n\u003cli\u003eD. J. Griffiths, Introduction to Electrodynamics, 4th ed., §8.1.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eOn the poster\u003c\/h3\u003e\u003cp\u003ePlate 019, “The Poynting Flow”: the pixel-art plate with its slogan “The energy never travels along the wire.”, 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":50961793417319,"sku":"20576261578460070487","price":19.99,"currency_code":"USD","in_stock":true},{"title":"9'' x 12\" (Vertical) \/ Fine Art","offer_id":50961793450087,"sku":"19099421504714642965","price":29.99,"currency_code":"USD","in_stock":true},{"title":"9'' x 12\" (Vertical) \/ Semi Glossy","offer_id":50961793482855,"sku":"26938494730053461510","price":19.99,"currency_code":"USD","in_stock":true},{"title":"18″ x 24″ (Vertical) \/ Fine Art","offer_id":50961793515623,"sku":"17485502957521398284","price":44.99,"currency_code":"USD","in_stock":true},{"title":"18″ x 24″ (Vertical) \/ Semi Glossy","offer_id":50961793548391,"sku":"14683788662354779576","price":29.99,"currency_code":"USD","in_stock":true},{"title":"18″ x 24″ (Vertical) \/ Matte","offer_id":50961793581159,"sku":"21254943808502312682","price":29.99,"currency_code":"USD","in_stock":true},{"title":"36'' x 48\" (Vertical) \/ Matte","offer_id":50961793613927,"sku":"25445496851692363529","price":69.99,"currency_code":"USD","in_stock":true},{"title":"36'' x 48\" (Vertical) \/ Fine Art","offer_id":50961793646695,"sku":"11462084454871598513","price":119.99,"currency_code":"USD","in_stock":true},{"title":"36'' x 48\" (Vertical) \/ Semi Glossy","offer_id":50961793679463,"sku":"18364940863440239285","price":69.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0596\/8746\/9159\/files\/9470858522373225964_2048.jpg?v=1793633232","url":"https:\/\/pixelatedphysics.com\/ja\/products\/the-poynting-flow-plate-019-physics-poster","provider":"Pixelated Physics","version":"1.0","type":"link"}