Hearing the Field

2014 ◽  
Author(s):  
Peter Pesic
Keyword(s):  
Electromagnetic Induction ◽  
Mathematical Education ◽  
Web Browsers ◽  
Scientific Education ◽  
Ongoing Work ◽  
Royal Institution ◽  
Charles Wheatstone ◽  
Michael Faraday

The entwined stories of Charles Wheatstone and Michael Faraday interwove sound and electromagnetism, as had Hans Christian Ørsted’s original discoveries in that field. Though Faraday lacked mathematical education, his feeling for music complemented his visual and experimental turn of mind. Wheatstone also lacked scientific education but came from a family of instrument builders and invented a number of musical devices, including the concertina. Wheatstone extended Ernst Chladni’s work to investigate dynamic, transient vibrations of bodies, especially the transmission of sound along rods. In his lectures at the Royal Institution, Faraday demonstrated Wheatstone’s ongoing work, including some experiments involving Javanese instruments and guimbardes (“Jew’s harp”). This chapter discusses how their unusual collaboration led Wheatstone to discover telegraphy and Faraday to the intensive investigations of sound immediately preceding and preparing his discovery of electromagnetic induction, as indicated by his notebooks and letters. Throughout the book where various sound examples are referenced, please see http://mitpress.mit.edu/musicandmodernscience (please note that the sound examples should be viewed in Chrome or Safari Web browsers).

scholarly journals How the Telegraph and the Telephone Formed a Worldwide Wired Electromagnetic Environment

2022 ◽  
Vol 9 (1) ◽  
pp. 85-111
Author(s):  
M. A. Ian Baldwin
Keyword(s):  
19Th Century ◽  
Environmental Effects ◽  
Electromagnetic Induction ◽  
Human Beings ◽  
Electromagnetic Environment ◽  
Late 19Th Century ◽  
Technological Basis ◽  
Michael Faraday

The principle of electromagnetic induction was independently discovered by Michael Faraday (England) and Joseph Henry (USA) in 1831–32. The momentous discovery gave birth to numerous inventions that made civilization “modern,” beginning with the telegraph. First the telegraph and then the telephone required the installation of millions of miles of electric wire to cross continents and oceans in order to function as a global telecommunications system. These wires created a wholly new, anthropogenic electromagnetic environment, whose frequencies were orders of magnitude greater than those occurring naturally. Its effects on human beings, particularly inside cities, and the biosphere generally were unknown. Even now, more than a century later, the medical and environmental effects of this worldwide wired infrastructure are at best but partially understood. The telecommunications revolutions of the mid- and late 19th century were eagerly anticipated and implemented swiftly on an unprecedented scale, creating the technological basis for worldwide instantaneous communication. This paper describes the key discoveries that created the scientific and technical breakthroughs that allowed the first telecommunications revolutions to take place.

Dust Plate, Retina, Photograph: Imaging on Experimental Surfaces in Early Nineteenth-Century Physics

2015 ◽  
Vol 28 (3) ◽  
pp. 317-355 ◽  
Author(s):  
Chitra Ramalingam
Keyword(s):  
Nineteenth Century ◽  
Photographic Plate ◽  
Imaging Techniques ◽  
Metal Plate ◽  
Early Nineteenth Century ◽  
Epistemic Practices ◽  
Transient Phenomena ◽  
Charles Wheatstone ◽  
Michael Faraday ◽  
William Henry Fox Talbot

ArgumentThis article explores the entangled histories of three imaging techniques in early nineteenth-century British physical science, techniques in which a dynamic event (such as a sound vibration or an electric spark) was made to leave behind a fixed trace on a sensitive surface. Three categories of “sensitive surface” are examined in turn: first, a metal plate covered in fine dust; second, the retina of the human eye; and finally, a surface covered with a light-sensitive chemical emulsion (a photographic plate). For physicists Michael Faraday and Charles Wheatstone, and photographic pioneer William Henry Fox Talbot, transient phenomena could be studied through careful observation and manipulation of the patterns wrought on these different surfaces, and through an understanding of how the imaging process unfolded through time. This exposes the often-ignored materiality and temporality of epistemic practices around nineteenth-century scientific images said to be “drawn by nature.”

VI. Fifth letter on voltaic combinations, with some account of the effects of a large constant battery. Addressed to Michael Faraday, Esq. D. C. L. F. R. S., Fullerian Prof. Chem. Royal Institution, &c. &c. &c. By J. Frederic Daniell, Esq. F. R. S., Prof. Chem. in King's College, London

1839 ◽  
Vol 129 ◽  
pp. 89-95 ◽  
Keyword(s):  
Royal Society ◽  
Conducting Surface ◽  
Conducting Sphere ◽  
Active Point ◽  
King's College ◽  
Royal Institution ◽  
The Subject ◽  
Michael Faraday

My dear Faraday, In my last letter to you, which the Royal Society have done me the honour to publish in the Philosophical Transactions for 1838, I observed, that “the principal circumstance which might be supposed to limit the power of an active point within a conducting sphere, in any given electrolyte, is the resistance of that electrolyte, which increases in a certain ratio to its depth or thickness.” The superficial measure of the conducting sphere, and the distance of the generating metal, or the depth and resistance of the electrolyte, are, in fact, the variable conditions in a voltaic combination upon which its efficiency depends; and their relations require further investigation before we shall be able to determine what may be the proper proportions for the economical application of the power to useful purposes. I shall venture, therefore, to trouble you with the results of some further experiments upon the subject, and upon different combinations of the constant battery, before I proceed to communicate some observations upon Electrolysis, which I trust you will find not without interest, and to which, according to my plan, my attention has been lately exclusively directed. Looking, for a moment, upon the affinity which circulates in the battery as a radiant force, it seemed desirable to ascertain what would be the result of intercepting the rays by the conducting surface nearer to their centre than in the arrangements which have been previously described, as the relation of the generating and conducting metals to each other might be thereby more clearly ascertained.

scholarly journals Sixth letter on voltaic combinations, addressed to Michael Faraday, Esq., D. C. L., F. R. S., Fullerian Professor of Chemistry in the Royal Institution of Great Britain, &c., by John Frederic Daniell, Esq., Foreign Sec. R. S., Professor of Chemistry in King’s College, London

1843 ◽  
Vol 4 ◽  
pp. 384-384
Keyword(s):  
Great Britain ◽  
Electromotive Force ◽  
The Body ◽  
Theoretical Knowledge ◽  
King's College ◽  
The Arts ◽  
Royal Institution ◽  
The Law ◽  
Michael Faraday

The purport of this letter is to follow the consequences of the law of Ohm, and the expressions which result from it, relative to the electromotive force, and to the resistances in the course of a voltaic circuit; to apply this theory to the verification of the conclusions which the author had formerly deduced from his experiments; and to suggest additional experiments tending to remove some obsculities and ambiguities which existed in his former communications. In following out these principles, the author is led to offer various practical remarks on the different forms of voltaic batteries which have been proposed with a view either to the advancement of our theoretical knowledge of the science, or to the service of the arts. The author enters more particularly into an explanation of the principles on which the cylindric arrangement of the battery he has introduced is founded, which appear to him to have been greatly misunderstood. The formulæ and the calculations which form the body of this paper are not of a nature to admit of being reported in the present abstract.

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