{"id":223,"date":"2010-09-19T12:19:15","date_gmt":"2010-09-19T12:19:15","guid":{"rendered":"http:\/\/www.icmm.csic.es\/within-experimental-error\/?p=223"},"modified":"2020-03-21T11:03:54","modified_gmt":"2020-03-21T11:03:54","slug":"william-herschel","status":"publish","type":"post","link":"https:\/\/wp.icmm.csic.es\/within-experimental-error\/2010\/09\/19\/william-herschel\/","title":{"rendered":"William Herschel"},"content":{"rendered":"

\"\"<\/a><\/p>\n

Considered the father of modern Astronomy, discoverer of planet Uranus and of infrared radiation, Sir William Herschel (1738-1822) arrived to England from his homeland, Germany, as a multifaceted musician and composer. A virtuous of the oboe, the harpsichord, the organ, the violin and the cello and author of 24 symphonies and many concertos, Herschel was the head of the Bath orchestra, first organist at the St John the Baptist church in Halifax, first violin of the Newcastle orchestra and head of the Durham Militia band.<\/p>\n

As an astronomer, Herschel, that used to make his own lenses and telescopes, discovered Uranus and two of its moons, as well as two moons of Saturn. He also demonstrated that double stars are not an optical illusion, as it was believed. He also studied the Milky Way, deducing it is disc-shaped, and co-discovered Mars’ ice caps and their seasonal changes.<\/p>\n

Researching on the calorific power of sunlight, Herschel used a prism to disperse a sunlight beam and thermometers to check the heating produced by each color. Observing that thermometers got hotter going towards the red, Herschel was bold enough to place a thermometer beyond that color (despite statements from different sources, Herschel papers do not tell that he was measuring by chance the temperature of the room in that region, but rather that his curiosity and boldness made him check it). Seeing that beyond the red and the visible spectrum (\u00abprismatic spectrum\u00bb) there was an enhanced heating, Herschel deduced there had to be a form of invisible light with a large heating power (his \u00abcalorific rays\u00bb that we now call \u00abinfrared radiation\u00bb and that Herschel distinguished from the \u00abcolourific rays\u00bb).<\/p>\n

In what follows, sentences in boldface reflect the astonishment of this entry’s author:
\n“…it is evident that radiant heat is subject to the laws of refraction, and also to those of the different refrangibility of light. May not this lead us to surmise, that radiant heat consists of particles of light of a certain range of momenta<\/strong>, and which range may extend a little farther, on each side of refrangibility, than that of light? We have shewn, that in a gradual exposure of the thermometer to the rays of the prismatic spectrum, beginning from the violet, we come to the maximum of light, long before we come to that of heat, which lies at the other extreme. By several experiments, which time will not allow me now to report, it appears’ that the maximum of illumination has little more than half the heat of the full red rays; and, from other experiments, I likewise conclude, that the full red falls still short of the maximum of heat; which perhaps lies even a little beyond visible refraction. In this case, radiant heat will at least partly, if not chiefly, consist, if I may be permitted the expression, of invisible light<\/strong>“[1]<\/sup><\/a><\/p>\n

And would these rays be of a different nature from that of visible light? Herschel sensibly uses Okham’s Razor: “if we call light<\/em>, those rays which illuminate objects, and radiant heat<\/em>, those which heat bodies, it may be inquired, whether light be essentially different from radiant heat? In answer to which I would suggest, that we are not allowed, by the rules of philosophizing, to admit two different causes to explain certain effects, if they may be accounted for by one<\/strong>.”[2]<\/sup><\/a> For Herschel both types of rays have the same nature and their difference comes from their distinct perception due to the different interaction with the visual organs: eye \u00abadmits\u00bb sunlight beams contained in the \u00abprismatic spectrum\u00bb appearing as light and colors, while aqueous humour and the eye’s coatings, as other parts of the body, absorb the rays contained in the \u00abthermometric spectrum\u00bb beyond the \u00abprismatic\u00bb one, being thus not visible, but providing a heat feeling.<\/p>\n

After that, we can only take our hat off, with astonishment and admiration, to the genius and boldness of this great musician-scientist.<\/p>\n

Herschel was a member of the Royal Society and Astronomer of the King. Among many tributes (honoring him and his sister and collaborator, the soprano and astronomer Caroline Herschel), the European Space Agency named after him the Herschel Space Observatory<\/a>, an infrared and submillimetre telescope with the largest single mirror ever built for a space telescope (3.5 m). <\/p>\n

\"\"<\/a>
\nConsiderado el padre de la astronom\u00eda moderna, descubridor del planeta Urano y de la radiaci\u00f3n infrarroja, Sir William Herschel (1738-1822) lleg\u00f3 a Inglaterra desde su Alemania natal como m\u00fasico multinstrumentista y compositor. Un virtuoso del oboe, clavicordio, \u00f3rgano, viol\u00edn y chelo y autor de 24 sinfon\u00edas y numerosos conciertos, Herschel fue director de la orquesta de Bath, primer organista de la iglesia de San Juan Bautista de Halifax, primer violin de la orquesta de Newcastle y director de la banda militar de Durham.<\/p>\n

Como astr\u00f3nomo, Herschel, que fabricaba sus propias lentes y telescopios, descubri\u00f3 Urano y dos de sus lunas, as\u00ed como dos de las lunas de Saturno. Demostr\u00f3, adem\u00e1s, que las estrellas dobles no son un efecto \u00f3ptico, como se cre\u00eda. Tambi\u00e9n estudi\u00f3 la V\u00eda L\u00e1ctea, concluyendo su forma de disco, y codescubri\u00f3 los casquetes polares de Marte y sus variaciones estacionales. <\/p>\n

Investigando sobre el poder cal\u00f3rico de la luz solar, Herschel us\u00f3 un prisma para descomponer un rayo de sol y term\u00f3metros para observar el calentamiento que produc\u00eda cada color. Al observar que los term\u00f3metros se calentaban m\u00e1s al ir hacia el rojo, Herschel fue suficientemente atrevido como para colocar un term\u00f3metro a\u00fan m\u00e1s all\u00e1 (pese a lo que se dice en muchas fuentes, los art\u00edculos de Herschel, ver abajo, no relatan que estuviera midiendo por casualidad la temperatura de la habitaci\u00f3n en esa zona, sino que su curiosidad y atrevimiento le llevaron a hacer la comprobaci\u00f3n). Al observar que m\u00e1s all\u00e1 del rojo y del espectro visible (\u00abespectro prism\u00e1tico\u00bb) hab\u00eda un calentamiento mayor a\u00fan, Herschel concluy\u00f3 que deb\u00eda haber una forma de luz invisible y con gran poder cal\u00f3rico (los \u00abrayos calor\u00edficos\u00bb que hoy llamamos \u00abradiaci\u00f3n\u00a0 infrarroja\u00bb, y que Herschel distingui\u00f3 de los \u00abrayos color\u00edficos\u00bb).<\/p>\n

En lo que sigue, las negritas son del estupefacto redactor de esta entrada:<\/p>\n

\u00ab…it is evident that radiant heat is subject to the laws of refraction, and also to those of the different refrangibility of light. May not this lead us to surmise, that radiant heat consists of particles of light of a certain range of momenta<\/strong>, and which range may extend a little farther, on each side of refrangibility, than that of light? We have shewn, that in a gradual exposure of the thermometer to the rays of the prismatic spectrum, beginning from the violet, we come to the maximum of light, long before we come to that of heat, which lies at the other extreme. By several experiments, which time will not allow me now to report, it appears’ that the maximum of illumination has little more than half the heat of the full red rays; and, from other experiments, I likewise conclude, that the full red falls still short of the maximum of heat; which perhaps lies even a little beyond visible refraction. In this case, radiant heat will at least partly, if not chiefly, consist, if I may be permitted the expression, of invisible light<\/strong>\u00ab[1]<\/sup><\/a><\/p>\n

\u00bfY ser\u00e1n esos rayos de naturaleza distinta a la de la luz visible? Herschel usa muy atinadamente la navaja de Okham: \u00abif we call light<\/em>, those rays which illuminate objects, and radiant heat<\/em>, those which heat bodies, it may be inquired, whether light be essentially different from radiant heat? In answer to which I would suggest, that we are not allowed, by the rules of philosophizing, to admit two different causes to explain certain effects, if they may be accounted for by one<\/strong>.\u00bb[2]<\/sup><\/a> Para Herschel ambos tipos de rayos poseen la misma naturaleza y lo que cambia es su percepci\u00f3n debido a su distinta interacci\u00f3n con los \u00f3rganos de la visi\u00f3n: el ojo \u00abadmite\u00bb los rayos del sol contenidos en el \u00abespectro prism\u00e1tico\u00bb bajo la apariencia de luz y colores, mientras que el humor acuoso y los recubrimientos del ojo, como otras partes del cuerpo, absorben los rayos contenidos en el \u00abespectro termom\u00e9trico\u00bb m\u00e1s all\u00e1 del \u00abprism\u00e1tico\u00bb, no siendo as\u00ed visibles, pero dando sensaci\u00f3n de calor. <\/p>\n

Despu\u00e9s de lo cual no queda m\u00e1s que descubrirse, con asombro y admiraci\u00f3n, ante el genio y atrevimiento de este gran m\u00fasico-cient\u00edfico.<\/p>\n

Herschel fu\u00e9 miembro de la Royal Society y Astronomer of the King. Entre otros mucho homenajes (a \u00e9l y a su hermana y colaboradora, la soprano y astr\u00f3noma Caroline Herschel), la Agencia Espacial Europea di\u00f3 el nombre de este astr\u00f3nomo al Observatorio Espacial Herschel<\/a>, un telescopio de infrarrojos y longitudes de ondas submilim\u00e9tricas con el mayor espejo construido para un telescopio espacial (3,5 m). <\/p>\n

[1]<\/a> W. Herschel, Philosophical Transactions of the Royal Society of London, Vol. 90 (1800), pp. 255-283
\n[2]<\/a> W. Herschel, Philosophical Transactions of the Royal Society of London, Vol. 90 (1800), pp. 284-292<\/p>\n","protected":false},"excerpt":{"rendered":"

Considered the father of modern Astronomy, discoverer of planet Uranus and of infrared radiation, Sir William Herschel (1738-1822) arrived to England from his homeland, Germany, as a multifaceted musician and composer. A virtuous of the oboe, the harpsichord, the organ, …<\/span> Sigue leyendo →<\/span><\/a><\/p>\n","protected":false},"author":73,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0,"footnotes":""},"categories":[6],"tags":[],"class_list":["post-223","post","type-post","status-publish","format-standard","hentry","category-science-and-music"],"_links":{"self":[{"href":"https:\/\/wp.icmm.csic.es\/within-experimental-error\/wp-json\/wp\/v2\/posts\/223","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wp.icmm.csic.es\/within-experimental-error\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wp.icmm.csic.es\/within-experimental-error\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wp.icmm.csic.es\/within-experimental-error\/wp-json\/wp\/v2\/users\/73"}],"replies":[{"embeddable":true,"href":"https:\/\/wp.icmm.csic.es\/within-experimental-error\/wp-json\/wp\/v2\/comments?post=223"}],"version-history":[{"count":2,"href":"https:\/\/wp.icmm.csic.es\/within-experimental-error\/wp-json\/wp\/v2\/posts\/223\/revisions"}],"predecessor-version":[{"id":860,"href":"https:\/\/wp.icmm.csic.es\/within-experimental-error\/wp-json\/wp\/v2\/posts\/223\/revisions\/860"}],"wp:attachment":[{"href":"https:\/\/wp.icmm.csic.es\/within-experimental-error\/wp-json\/wp\/v2\/media?parent=223"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wp.icmm.csic.es\/within-experimental-error\/wp-json\/wp\/v2\/categories?post=223"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wp.icmm.csic.es\/within-experimental-error\/wp-json\/wp\/v2\/tags?post=223"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}