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Description: | L.H.S.34. (old departmental catalogue number in aluminium paint). [ARTIF]ICIAL GLACIER [started] January 11. 1915 (written on an old torn label pinned to the side of the frame, removed). DES THOMSON,William,Lord,1st Baron Kelvin of Largs. after 1887 MANU Unsigned. after 1887 This experiment was used to show that small persistently applied forces are sufficient to produce unlimited changes in the shape of a substance over long periods of time. Kelvin used this model to show that it was possible for a homogeneous material to possess properties similar to the properties that he needed to assign to the luminiferous ether.
The ether was the substance invented by the Ancient Greeks in order to explain how the Gods could hear the music created by heavenly crystal spheres. The Greeks believed that the Earth was the centre of the universe and that each planet was fixed in an individual crystal sphere one inside the other, like a Russian doll. The spheres rotated at different speeds explaining why the planets moved independently of one another. The ether was, they argued, an imponderable (undetectable) substance that filled the space between the spheres.
By the 19th century the ether was being used by scientists to explain how light waves could be transmitted through the vacuum of space in the same way that sound waves are transmitted through air. Kelvin argued that the ether would have to be perfectly inelastic in order to explain how it could transmit vibrations of exceedingly small periodicity, i.e. light waves and yet at the same time it had to be sufficiently fluid in order to allow the Sun and the Earth and other forms of matter to move through it without resistance.
This experiment is closely related to GLAHM 113456, the pitch pool, devised by Kelvin for his Baltimore Lectures in 1884. The pitch glacier dates from 1887 and has been repeated many times. It relies on two seemingly mutually exclusive properties of Scotch cobbler's wax that mimic Kelvin?s ether. The wax, when dropped onto a hard surface will shatter like glass, demonstrating inelasticity. However, it will slowly flow like a viscous liquid under the influence of a persistent force such as gravity. The channel on this apparatus has a constriction in the form of two semicircular blocks of wood. The constriction creates eddies in the flow of the wax and was designed to illustrate turbulent flow in the ether.
Kelvin realised shortly after he had created this model that a luminiferous ether was not necessary for the transmission of electromagnetic waves and confessed to having suffered fifty years of ether dipsomania. Although the idea seems quaint now the ether, as a medium for the transmission of electromagnetic waves, persisted well into the 20th century. The notion of an imponderable medium like the ether has been considered recently as a mechanism for the transmission of gravity waves.
This demonstration, created by students, was first started in 1915. There is evidence that there was repeated use of the equipment . The wooden construction is identical to that of the original experiment GLAHM 113597. It also appears from the evidence of pencil lines that there were attempts to estimate the travel of the pitch or wax before it was poured | License: | http://www.hmag.gla.ac.uk/spirit/rights/ | Publisher: | Hunterian Museum and Art Gallery, University of Glasgow | Rights holder: | Hunterian Museum and Art Gallery, University of Glasgow | Subjects: | SCIENTIFIC COLLECTION : | Source: | Hunterian Museum | Creator: | Hunterian Museum and Art Gallery, University of Glasgow | Identifier: | http://www.huntsearch.gla.ac.uk/cgi-bin/... | Language: | en-GB | Go to resource |
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