viernes, 22 de febrero de 2008

La invención del teléfono

El teléfono, último de los grandes inventos eléctricos simples, fue una consecuencia directa del telégrafo.
La prehistoria del teléfono se inició hacia 1854, cuando Boursel predijo que "el sonido podría transmitirse en breve por medio de la electricidad". El primero en construir un aparato a lo que sería el teléfono fue el alemán Johann Philipp Reis, que en 1861 diseñó uno destinado a transmitir sonidos musicales y dos años después mejoró sus dispositivos, consiguiendo, al parecer, difundir por los hilos cantos y palabras inteligibles. No se sabe si Reis produjo realmente la corriente "variable" necesaria para la transmisión de ondas sonoras, o si sólo se trató de un zumbido eléctrico provocado por la simple interrupción de contacto. Si fue lo primero, habría que reconocer que Reis fue el verdadero inventor del teléfono, quince años antes de que Bell y Gray dieran a conocer sus aparatos.
Aquel día, después de cinco años de experimentos, Bell transmitió la primera frase telefónica de la historia utilizando un transmisor de tipo químico. Sus palabras, fuera de programa, se harían posteriormente célebres en los anales de la historia de la ciencia.

El inventor, habiendo derramado ácido sobre su traje, lanzó este sencillo y urgido mensaje por el tubo a su ayudante que estaba en otra habitación: " Mr. Watson, venga aquí, le necesito. " Había nacido el teléfono y Bell se apresuró a patentarlo. Apenas dos horas después de que había concurrido a la oficina de patentes, hizo su entrada en ella Elisha Gray, de Ohio, que en un memorial describía un invento prácticamente igual al de Graham Bell. La estrecha llegada en esta carrera por obtener el teléfono tuvo que ser dirimida por los tribunales de justicia, que, tras largos alegatos, fallaron la causa en favor de Bell. Por sólo 120 minutos, Gray había perdido su oportunidad de pasar a la historia como un inventor célebre.

Tras ser perfeccionado por Edison, el teléfono experimentó un rápido desarrollo técnico, alcanzando en pocos años las proporciones de una amplia red de telecomunicaciones. En 1900, sólo la "Bell Telephone Company" contaba ya con más de un millón de abonados y cerca de dos millones de líneas que transmitían anualmente nada menos que 2 mil millones de conversaciones. Durante la década del veinte fue introducido el sistema automático y desde entonces hasta la fecha el teléfono ha tenido una difusión impresionante a través de todo el globo, hasta convertirse en uno de los aparatos más indispensables de uso cotidiano y a la vez en una especie de símbolo del febril mundo moderno.

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