Donor challenge: Your generous donation will be matched 2-to-1 right now. Your $5 becomes $15! Dear Internet Archive Supporter,. I ask only once a year. The Treatise on Light of Huygens has, however, withstood the test of time: and even now the exquisite skill with which he applied his. Treatise on Light In which are explained the causes of that which occurs in Christiaan Huygens. translated by Silvanus P. Thompson.
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And it apparently occurs against the particles of the air or others mingled with the ethereal particles and larger than they. But in order that it may not seem strange to suppose pn passage of waves in the interior of these bodies, I will first show that one may conceive it possible in more than one mode.
And it must not be thought that in this there is anything absurd or impossible, it being on the contrary quite credible that it is this infinite series of different sizes of corpuscles, having different degrees of velocity, of which Nature makes use to produce so many treahise effects. Bartholinus, and consequently much greater than trestise of Rock Crystal, or of glass, which is nearly 3 to 2. Now in the same time the piece A would have come to G along the straight line AG, equal and parallel to CB; and all the portion of wave AC would be at GB if the matter of the transparent cjristiaan transmitted the movement of the wave as quickly as the matter of the Ether.
This, moreover, necessarily follows from that which has been already demonstrated touching the small quantity of matter of which the bodies are built up. In which different velocity of light I shall show the cause of refraction to consist.
Jenniffer Baltzell rated it really liked it Jan 03, Another property, similar to this, is that the refractions are reciprocal between the rays entering into a transparent body and those which are leaving it. Huygens postulated guygens the great distance between the planets signified that God had not intended for beings on one to know about the beings on the others, and had not foreseen how much humans would advance in scientific knowledge. I found also the value of CG the semi-diameter parallel to the tangent ML to be 98, But, for the present, without yet deciding one or other, we will consider these spheroids only in those sections of them which make ellipses in the plane of this figure.
For one finds that the latter is really that which we feel and which we breathe, and which being removed from any place still leaves there the other kind of matter that serves to convey Light.
Let us also suppose that it is perpendicular to the Horizon, the llight B being nearer to the Earth than the portion A; and that because the vapours are less hindering at A than at B, the particular wave which comes from the point A spreads through a certain space AD while the particular wave which starts from the point B spreads through a shorter space BE; AD and BE treatisse parallel to the Horizon.
And this accords perfectly with experiment.
For supposing the same things as before, and that the ray makes with the same surface g G the angle RCG of 73 degrees 20 minutes, inclining to the same side as the crystal of which ray mention has been made above ; if one investigates, by the process above explained, the refraction CI, one will find that it makes exactly a straight line with RC, and that thus this ray is not deviated at all, conformably with experiment.
Whence one sees lighr the movement passes with an extreme velocity which is the greater, the greater the hardness of the substance of the spheres.
Huygens wrote that availability of water in liquid form was essential for life and that the properties of water must vary from planet to planet to suit the temperature range.
One can then in this way conceive of transparency in a solid without any treatiee that the ethereal matter which serves for light should pass through it, or that it should find pores in which to insinuate itself.
Treatise on Light / Christiaan Huygens
All this I have found as most probable for the mode in which the waves of light pass across transparent bodies. The OCR process results in too many typos and illegible characters. It is founded as is the preceding argument upon celestial observations, and proves not only that Light takes time for its passage, but also demonstrates how much time it takes, and that its velocity is even at least six times greater than that which I have just stated.
Want to Read Currently Reading Read. But the thing to be above all remarked in our treattise is that it does not require that the reflecting surface should be considered as a uniform plane, as has been supposed by all those who have treatiae to explain the effects of reflexion; but lightt an evenness livht as may be attained by the particles of the matter of the reflecting body being set near to one another; which particles are larger than those of the ethereal matter, as will appear by what we shall say in treating of the transparency and opacity of bodies.
Treatise on Light
The piece C of the wave AC, will in a certain space of time advance as far as the plane AB at B, following the straight line CB, huyges may be supposed to come from the luminous centre, and which in consequence is perpendicular to AC. Now there is no doubt at all that light also comes from the luminous body to our eyes by some movement impressed on the matter which huygenw between the two; since, as we have chrixtiaan seen, it cannot be by the transport of a body which passes from one to the other.
One sees also the reason for a noteworthy accident which happens in this refraction: His work included early telescopic studies of the rings of Saturn and the discovery of its moon Titan, the invention of the pendulum clock and other investigations in timekeeping.
Published January livht by Echo Library first published Let us pass now to the explanation of the effects of Refraction, assuming, as we have done, the passage of waves of light through transparent bodies, and the diminution of velocity which these same waves suffer in them.
The demonstration of this is, it will be seen, entirely similar to that of which we made use in explaining ordinary refraction. The effect is that objects seen through it, especially such as are placed right against it, appear double; and that a ray of sunlight, falling on one of its surfaces, parts itself into two rays and traverses the Crystal thus.
First, then, if the ethereal matter cannot penetrate transparent bodies at all, their own particles would be able to communicate successively the movement of the waves, the same as do those of the Ether, supposing that, like those, they are of a nature to act as a spring.
Now according to the explanation which has been given of the action of light, how the waves do not destroy nor interrupt one another when they cross one another, these effects liight I have just mentioned are easily conceived.
Now we see that water weighs only one fourteenth part as much as an tteatise portion of quicksilver: The double emission of waves of light, which I had imagined, became more probable to me after I had observed a certain phenomenon in the ordinary [Rock] Crystal, which occurs in hexagonal form, and which, because of this regularity, seems also to be composed of particles, of definite figure, and ranged in order. Eric Byrnes rated it really liked it Jun 04, We shall demonstrate hereafter that by this process the same penetrability may be inferred also as relating to opaque bodies.
It is again a general law in all other transparent bodies that treatixe ray which falls perpendicularly on their surface passes straight on without suffering refraction, and that an oblique ray is always refracted. As regards the different modes in which I have said the movements of Sound and of Light are communicated, one may sufficiently comprehend how this occurs in the case of Sound if one considers that the air is of such a nature that it can be compressed and reduced to a much smaller space than that which it ordinarily occupies.
Owing to the circumstance that the French word rayon possesses the double signification of ray of light and radius of a circle, he avoids its use in the latter sense and speaks always of the semi-diameter, not of the radius.
Christiaan Huygens – was a prominent physicist and astronomer.