Optics. An interference

you are: Optics

Arago and Frenel have checked up that will turn out if to turn one selenitovuju a plate on 45 °, and have seen all sets of strips at once. They have proved that the bunches polarised under right angles, not interferirujut. From here it is possible to draw only one logic conclusion that light represents cross-section fluctuations and that polarisation means restriction of these fluctuations in any plane.

There is also other obvious property of light - its colour. What physical properties allow light to create so fine sensations? Newton has received the basic answer to this question in the experiences with prisms in 1666, but did not publish any data on them up to 1672

Newton has been fascinated by colours of the spectrum created by a prism bought by it, and has spent some simple experiences with it in the house.

It has passed a sunlight beam through a small aperture in window shutters in a dark room and observed a spectrum created by a prism on the screen located opposite. He was rather surprised with that the length of a spectrum was approximately five times more than its width.

Then Newton has made that he named solving experiment. It has received a spectrum on the screen with an aperture, and, having passed through this aperture on other prism only a spectrum part, has found out that the second prism any more did not develop a bunch. Thus, Newton has shown that spectrum existence is property not prisms, and this world. From here he has concluded that this world consists of a set of colours with various ability to refraction. It has proved it, having collected dispersing light spread out in a spectrum by means of a lens: the turned out combination had white colour.

One more property of light has been established in the end of XVIII century - speed of its distribution; to those holes V was not confidence that light in general has izmerimuju speed. Galilej tried to measure it in well conceived, but unsuccessful experience in which participated he and its servant standing on considerable distance from it with lanterns. In their results, however, there was no coordination, and Galilej has concluded that the velocity of light is too great, that it was possible to measure it by such way. Human reactions are too slow, and the interval of distribution of light as we know now, was too small, that it was possible to measure it by means of rough devices at the time of Galilee.