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Six Lectures on Light - Delivered In The United States In 1872-1873 by John Tyndall
page 49 of 237 (20%)
theories, the scientific imagination must draw its materials from the
world of fact and experience. It was known long ago that sound is
conveyed in waves or pulses through the air; and no sooner was this
truth well housed in the mind than it became the basis of a theoretic
conception. It was supposed that light, like sound, might also be the
product of wave-motion. But what, in this case, could be the material
forming the waves? For the waves of sound we have the air of our
atmosphere; but the stretch of imagination which filled all space with
a _luminiferous ether_ trembling with the waves of light was so bold
as to shock cautious minds. In one of my latest conversations with Sir
David Brewster, he said to me that his chief objection to the
undulatory theory of light was, that he could not think the Creator
capable of so clumsy a contrivance as the filling of space with ether
to produce light. This, I may say, is very dangerous ground, and the
quarrel of science with Sir David, on this point as with many
estimable persons on other points, is, that they profess to know too
much about the mind of the Creator.

This conception of an ether was advocated, and successfully applied to
various phenomena of optics, by the illustrious astronomer, Huyghens.
He deduced from it the laws of reflection and refraction, and applied
it to explain the double refraction of Iceland spar. The theory was
espoused and defended by the celebrated mathematician, Euler. They
were, however, opposed by Newton, whose authority at the time bore
them down. Or shall we say it was authority merely? Not quite so.
Newton's preponderance was in some degree due to the fact that, though
Huyghens and Euler were right in the main, they did not possess
sufficient data to _prove_ themselves right. No human authority,
however high, can maintain itself against the voice of Nature speaking
through experiment. But the voice of Nature may be an uncertain voice,
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