Experimental demonstration of the general law of the interference of light. In making some experiments on the fringes of colours accompanying shadows, I have found so simple and so demonstrative a proof of the general law of the interference of two portions of light, which I have already endeavoured to establish, that I think it right to lay before the Royal Society, a short statement of the facts which appear to me so decisive.
Experimental demonstration of the general law of the interference of light. In making some experiments on the fringes of colours accompanying shadows, I have found so simple and so demonstrative a proof of the general law of the interference of two portions of light, which I have already endeavoured to establish, that I think it right to lay before the Royal Society, a short statement of the facts which appear to me so decisive.
In making some experiments on the fringes of colors accompanying shadows, I have found so simple and so demonstrative a proof of the general law of the interference of two portions of light, which I have already endeavored to establish, that I think it right to lay before the Royal Society a short statement of the facts which appear to me so decisive. Thomas Young, Bakerian Lecture, November 24, 1803 Interference defined In chapter 3, we framed the question, can we account for the behavior of light by supposing that light is wave motion of some kind? So far, the logic of our response has been of this form: we asked experimentally, do waves have property X that we know light possesses? For “property X ,” we took the existence of reflection the equality of the angles of reflection and incidence the existence of refraction, and Snell's law, in the sense that, in refraction, the ratio of sines is independent of the angle of incidence. Each time, we could answer, yes, waves do have this property X that we know light possesses. Beyond these tests, we found that the wave theory's prediction for the index of refraction – namely, a specific ratio of wave speeds – was resoundingly confirmed by Michelson's measurements of. Things are going well for a wave theory of light. The time has come to shift the perspective and to change the logic of the testing.
The following views regarding the mode of transmission of light are of so unorthodox a character that I set them down with some reluctance; but it seems to be generally admitted that the paradox of quantum theory cannot be resolved without doing violence to one or more of our cherished common notions.Some of the consequences of the theory that I am going to advance are repugnant to common sense, yet, searching in vain for an alternative and finding no physical fact of optics or of thermodynamics in opposition to the theory, I have come to regard it as a natural and indeed inevitable extension of Einstein's principle of relativity.Let me start with two statemefits which seem now to be well supported by experiment, although perhaps not entirely demonstrated.They are, however, the postulates upon which the following theory is built.
The double slit experiment was first conceived of by the English physician-physicist Thomas Young in 1801. It was the first demonstrative proof that light possesses a wave nature. In this experiment, light is made to pass through two very narrow slits that are spaced closely apart and a screen placed on the other side captures a pattern of alternating bright and dark stripes called fringes, formed as a result of the interference of ripples of light emanating from either slit. The relative positions and intensities of the fringes on the screen can be calculated by employing two assumptions that help simplify the geometry of the slit-screen arrangement. Firstly, the screen to slit distance is taken to be larger than the inter-slit distance (far field limit) and secondly, the inter-slit distance is taken to be larger than the wavelength of light. This conventional approach can account for the positions and intensities of the fringes located in the central portion of the screen with a fair degree of precision. It however, fails to account for those fringes located in the peripheral portions of the screen and also, is not applicable to the case wherein the screen to slit distance is made comparable to the inter-slit distance (near field limit). In this paper, the original analysis of Young’s Experiment is reformulated using an analytically derived hyperbola equation, which is formed from the locus of the points of intersections of two uniformly expanding circular wavefronts of light that emanate from either slit source. Additionally, the shape of the screen used to capture the interference pattern is varied (linear, semicircular, semielliptical) and the relative positions of the fringes is calculated for each case. This new approach bears the distinctive advantage that it is applicable in both the far field and the near field scenarios, and since no assumptions are made beyond the Huygens-Fresnel principle, it is therefore, a much more generalized approach. For these reasons, the author suggests that the new analysis ought to be introduced into the Wave Optics chapter of the undergraduate Physics curriculum.
Abstract The double slit experiment was the first demonstrative proof of the wave nature of light. It was expounded by the English physician-physicist Thomas Young in 1801 and it soon helped lay to rest the then raging Newton–Huygens debate on whether light consisted of a fast-moving stream of particles or a train of progressive waves in the ether medium. In the experiment, light is made to pass through two very narrow slits spaced closely apart. A screen placed on the other side captures a pattern of alternating bright and dark bands called fringes which are formed as a result of the phenomenon of interference. In prior work by the same author, it was shown that the conventional analysis of Young’s experiment that is used in many introductory physics textbooks, suffers from a number of limitations in regards to its ability to accurately predict the positions of these fringes on the distant screen. This was owing to the adoption of some needless and paradoxical assumptions to help simplify the geometry of the slit barrier-screen arrangement. In the new analysis however, all such approximations were discarded and a hyperbola theorem was forwarded which was then suitably applied to determine the exact fringe positions on screens of varied shapes (linear, semi-circular, semi-elliptical). This paper further builds on that work by laying down the mathematical framework necessary for counting fringes and then comparing their distributions on differently shaped screens, using MATLAB software package for numerical–graphical simulation. In addition, a pair of equivalent laws of proportionality are predicted that govern the distribution of fringes independent of the shape of the detection screen employed.
The subject of the following Memoir has been already touched on in a communication which I made to the Cambridge Philosophical Society, and which appears in the seventh volume of their Transactions, Art. IX. For the better understanding of what follows, it is desirable to state briefly the contents of that paper. Its object is to estimate the quantity of light which is received on a screen of unlimited dimensions, after passing through a certain aperture, or suffering reflection at two mirrors, as in the case of the interference experiment, so as to exhibit the appearance of bands.