Hippolyte Fizeau

Name: On the Effect of the Motion of a Body upon the Velocity with which it is traversed by Light
Author: Hippolyte Fizeau

On the Effect of the Motion of a Body upon the Velocity with which it is traversed by Light (1860)

Summary

“On the Effect of the Motion of a Body upon the Velocity with which it is traversed by Light”, published in 1860, is a work by Hippolyte Fizeau. It explores elements such as velocity, displacement and tubes.

Quotes from On the Effect of the Motion of a Body upon the Velocity with which it is traversed by Light (Hippolyte Fizeau)

Hippolyte Fizeau, On the Effect of the Motion of a Body upon the Velocity with which it is traversed by Light (1860)

“ After establishing the existence of the phænomenon of displacement, I endeavoured to estimate its magnitude with all possible exactitude. To avoid all possible sources of error, I varied the magnification of the bands, the velocity of the water, and even the nature of the divisions of the micrometer, so as to be unable to predict the magnitude of the displacements before measuring them. For in measuring small quantities, where our own power of estimating has to play a great part, the influence of any preconception is always to be feared ”

[↩︎]

Source: Wikisource

Hippolyte Fizeau, On the Effect of the Motion of a Body upon the Velocity with which it is traversed by Light (1860)

“ We owe to Arago a method of observation, founded on the phænomena of interference, which is well suited to render evident the smallest variation in the index of refraction of a body, and hence also the least change in the velocity with which the body is traversed by light; for, as is well known, this velocity is inversely proportional to the refracting index. Arago and Fresnel have both shown the extraordinary sensitiveness of this method by several very delicate observations, such as that on the difference of refraction between dry and moist air. ”

[↩︎]

Source: Wikisource

Hippolyte Fizeau, On the Effect of the Motion of a Body upon the Velocity with which it is traversed by Light (1860)

“ I conclude, then, that this hypothesis does not agree with experiment. We shall next see that, on the contrary, the third, or Fresnel's hypothesis, leads to a value of the displacement which differs very little from the result of observation.
We know that the ordinary phænomena of refraction are due to the fact that light is propagated with less velocity in the interior of a body than in a vacuum. Fresnel supposes that this change of velocity occurs because the density of the æther within a body is greater than that in a vacuum. ”

[↩︎]

Source: Wikisource

Hippolyte Fizeau, On the Effect of the Motion of a Body upon the Velocity with which it is traversed by Light (1860)

“ The greatest velocity at our command is unquestionably that of the earth in its orbit. At noon, during the period of the solstices, for instance, the direction of this motion is horizontal and from east to west; from this it follows that when a plate of glass receives a ray of light coming from the west, it ought to be considered as really moving to meet the ray with the immense velocity of 31,000 metres per second. ”

[↩︎]

Source: Wikisource

Hippolyte Fizeau, On the Effect of the Motion of a Body upon the Velocity with which it is traversed by Light (1860)

“ By causing the inclination of the glass to vary, the breadth of the bands may be varied at pleasure, and thus the magnitude most convenient for precisely observing their displacement may be readily given to them. ”

[↩︎]

Source: Wikisource

Hippolyte Fizeau, On the Effect of the Motion of a Body upon the Velocity with which it is traversed by Light (1860)

“ Of the several hypotheses which have been necessitated by the absence of any definite idea of the properties of luminiferous æther, and of its relations to ponderable matter, not one can be considered as established; they merely possess different degrees of probability. ”

[↩︎]

Source: Wikisource

Hippolyte Fizeau, On the Effect of the Motion of a Body upon the Velocity with which it is traversed by Light (1860)

“ In this manner a displacement due to motion would have been detected with certainty, even if it had been accompanied by an accidental displacement due, for instance, to some defect of symmetry in the diameters or orifices of the tubes, whence would result an unequal resistance to the passage of air, and consequently a difference of density. ”

[↩︎]

Source: Wikisource

Hippolyte Fizeau, On the Effect of the Motion of a Body upon the Velocity with which it is traversed by Light (1860)

“ It is assumed that when the body is put in motion, only a part of the interior æther is carried along with it, and that this part is that which causes the excess in the density of the interior over that of the surrounding æther ”

[↩︎]

Source: Wikisource

Hippolyte Fizeau, On the Effect of the Motion of a Body upon the Velocity with which it is traversed by Light (1860)

“ This inconvenience was made to disappear by placing a convergent lens behind the two slits; the bands were then observed at the point of concourse of the two rays, where the intensity of light was very considerable. ”

Hippolyte Fizeau

Summary

Quotes from On the Effect of the Motion of a Body upon the Velocity with which it is traversed by Light (Hippolyte Fizeau)

Common terms

Similar works

Get perspective with Kwize: daily news enlightened by great literature