For emissionists, polarization refers to collections of items rays, whereas for wave theorists, the beam and the ray are identical and singular and the wave front. May 26, 2014 study material 12th physics wave theory of light 1. From this, he propounded that light must be an electromagnetic wave. In 1678, dutch physicist, christiaan huygens, believed that light was made up of waves vibrating up and down perpendicular to the direction of the light travels, and therefore formulated a way of visualising wave propagation. When screen is held at 900 to the line joining foci of the hyperbola, the fringes are circular. Huygens proposed a wave theory of light while newtons was a corpuscular particle theory of light. According to wave theory of light, the light is a form of energy which travels through a medium in the form of transverse wave motion. Light, wave theory of, molecular dynamics, ether space publisher london. The beautiful lectures on light which were given several years ago by president morton, of the stevens institute, and the succession of lecture, on the same subject so admirably illustrated by professor tyndall, which many now present have heard, have fully prepared you for anything i can tell you this evening in respect to the wave theory. In the given figure, ab is the wavefront incident on a reflecting surface xy with an angle of incidence i as shown in figure. These video tutorials along with short notes will teach you the basics of wave theory of light or wave optics, huygens principle and wave theories of reflection, refraction, superposition and interference, diffraction, and polarization etc for cbse, iitjee, medical entrance and various state board exams preparation. Sir isaac newton, held the theory that light was made up of tiny particles. This helps to explain some of the wave properties of light. Definition of wave theory of light in the dictionary.
Class 12 physics chapter 10 wave optics notes pdf download. The null lines joining the event points of the lattice derive from lorentz. Pdf isaac newtons reputation was initially established by his 1672 paper on the refraction of light. Quickly assess your understanding of what light is, and the history of those who worked on the wave theory of light, using this multiple choice quiz and worksheet. It states that every point on a wavefront is itself the source of spherical wavelets and the secondary wavelengths. Cbse ncert notes class 12 physics semiconductor electronics. At times light behaves as a particle, and at other times as a wave. With a model for physical space and light propagation, we nd a way to understand the physical entity of the wave function in quantum mechanics. The dutch astronomer huygens 16291695 proposed a wave theory of light. It is an improvement over the wave theory in that it explains how light is generated. The corpuscular theory of light newton proposed this.
Studymaterial for the wave theory of light, maharashtra class 12science physics, physics. Therefore transmitted intensity 00 0 ii i 22 this will be the intensity of incident light on the second polaroid. Wave theory definition of wave theory by merriamwebster. According to huygens principle, every point on ab acts as a source of secondary wavelets. Light wave reflection on the plane surface in the given figure, ab is the wavefront incident on a reflecting surface xy with an angle of incidence i as shown in figure.
Every point on a wave front acts as asecondary source of light, sending outsecondary waves. Light is composed of particles called photons, and matter is composed of particles called electrons, protons, neutrons. In other words, huygens postulated that the more light was bent or refracted by a substance, the slower it would move while traversing across that substance. With the dawn of the 17th century, significant progress was reawakened in europe. It is defined as the bending of waves around the corners of an obstacle or through an aperture into the region of geometrical shadow of the obstacleaperture. We can prove the laws of reflection on the basis of huygenss wave theory as follows. Information and translations of wave theory of light in the most comprehensive dictionary definitions resource on the web. The wave theory of light the wave theory of light was the way we first understood light. Now, we show the hypothesis that is at the basis of the wave field theory. The particle theory of light views a ray of light as a beam of individual particles called photons. Huygenss theory had some issues in matching observation and newtons prestige helped lend support to his theory so, for over a century, newtons theory was dominant. Light consists of very tiny, elastic, rigid particles known as corpuscular. This theory is called huygens wave theory of light.
In a substance, as many atoms are close to each other, the energy levels of the atom form a continuous band, where in the electrons move. Wave optics describes the connection between waves and rays of light. Huygens principle 2 source new wavefront problems with the theory. Visible light is only one type of electromagnetic wave. Compound microscopes were first constructed in the netherlands between 1590 and 1608 probably by hans and zacharias jansen, and most sources credit another dutchman, hans lippershey, with the invention of the telescope in 1608.
In his opticks 1704, newton argued that light was made up of tiny particles. Baltimore lectures on molecular dynamics and the wave theory of light by kelvin, william thomson, baron, 18241907. However, the wave theory of light does not address every issue, and it is necessary to describe light with a. Study material 12th physics wave theory of light 1. December 03, 2014 diffraction understanding it with huygens principle. The quantummechanical theory of light is that light is tiny packets of wave called photons. Jan 11, 2014 12th physics notes wave theory of light 1. We know that in an atom, the protons and the neutrons constitute the central part called the nucleus. As opposed to wave optics which we will consider shortly geometric optics treats light very simply as a set of rays whose trajectories are governed by welldefined rules, such as the laws of reflection and refraction. He believed that light was a longitudinal wave, and that this wave was propagated through a material called the aether.
The intensity transmitted by the first sheet is 0 i 2. Before exploring newtons theory of light in greater detail, let us turn to the work of his famous contemporary, christiaan. Thomas young and the wave nature of light historical. Visible light is usually defined as having wavelengths in the range of 400700 nanometers nm, or 4. If you dont see any interesting for you, use our search form on bottom v. Fresnel would extend this mechanism by combining it with huygenss.
Thomas young and the wave nature of light historical background isaac newton was famous not only for formulating the laws of motion but also for pioneering in the study of optics. Its only when the mass of a particle gets small enough that its wavelike properties show up. In 1678, dutch physicist, christiaan huygens, believed that light was made up of waves vibrating up and down perpendicular to the direction of the light travels, and ther. In order to observe the wave behavior of light, the slit size and separation should be comparable or smaller than the wavelength. Kinds and the wave theory of light 41 in other words, nothing which is embraced by a given class within a particular group of scientific kinds can be both an athing and a bthing, where a and b are group kinds, unless all athings are bthings or vice versa. Quantum theory tells us that both light and matter consists of tiny particles which have wavelike properties associated with them. Dec 16, 2015 on this page you can read or download wave theory of light 12th physics pdf taget publications in pdf format. Jul 31, 2014 please use one of the following formats to cite this article in your essay, paper or report. In order to observe interference in light waves, the following conditions must be. According to wave theory of light, the light is a form of energy which travels. The wave theory of light states that light is a wave of electromagnetic energy, and has associated properties of waves like a frequency and wavelength. A ray of light travelling through air, falls on the surface of glass slab at an angle i.
But because, with wave theory, a beam of light is not considered a collection of rays in the first place, the rays as were using them here have only an analytic significance. Interference is described using real and complex numbers in anticipation of quantum mechanics. Phys 201 lecture 18 wave theory of light open yale courses. Doppler shift in frequency or wavelength of electromagnetic radiations is used 1. The speed of light in a medium depends upon the nature of medium. A student holds a laser that emits light of wavelength. The electromagnetic theory of light maxwells theory describes light as having electric and magnetic propertieselectromagnetic waves. The theory was spread most significantly by robert hooke and. Numerical 3d representation of the psf left, here an airy function, and the. Baltimore lectures on molecular dynamics and the wave. Mar 01, 20 sir isaac newton, held the theory that light was made up of tiny particles. Publication date 1904 topics light, wave theory of, molecular dynamics, ether space. The huygensfresnel principle named after dutch physicist christiaan huygens and french physicist augustinjean fresnel is a method of analysis applied to problems of wave propagation both in the farfield limit and in nearfield diffraction and also reflection.
Laws of reflection on the basis of huygens wave theory. Wave theory definition of wave theory by the free dictionary. At the outset of book i of his opticks, newton provided a concise introduction to what is now known as geometric optics. According to the wave theory of light, the light rays, strictly speaking. He used a prism to show that sunlight was a mixture of the colors that make up the rainbow. The diffracting object or aperture effectively becomes a secondary source of the propagating wave. These corpuscles on emission from the source of light travel in straight line with high velocity when these particles enter the eyes, they produce image of the object or sensation of vision.
Thus, according to maxwell, light waves are associated with changing electric and magnetic fields. The quantummechanical theory says that light is both a particle and a wave. Wave theory of light 12th physics pdf taget publications. Youngs double slit experiment shows clearly that light is a wave. Wave theory of light definition of wave theory of light by. It is found that the angle betweeen the reflected and refracted ray is 90 0. Baltimore lectures on molecular dynamics and the wave theory. According to wave theory of light, a source of light sends out disturbance in all directions. This is in the direction of thepropagation of light at that point. This complementary, or dual, role for the behavior of light can be employed to describe all of the known characteristics that have been observed experimentally, ranging from refraction, reflection, interference, and diffraction, to the results with polarized light and the photoelectric effect.
Diffraction refers to various phenomena that occur when a wave encounters an obstacle or a slit. The wave theory of light is that light is a wave that travels through electrical field and the magnetic field. Baltimore, publication agency of the johns hopkins university collection cdl. The theory was spread most significantly by robert hooke and christiaan huygens in the 17th century. Light energy from a source is propagated in the form of waves. Mar 23, 2011 youngs double slit experiment shows clearly that light is a wave. In order to observe the wave behavior of light, the slit size and separation should be comparable or smaller than the wavelength of light. Dec 15, 2015 as opposed to wave optics which we will consider shortly geometric optics treats light very simply as a set of rays whose trajectories are governed by welldefined rules, such as the laws of reflection and refraction. Christiaan huygens, thomas young, augustin jean fresnel, franaois arago created date. When these waves carrying energy reach the eye, they excite the optic nerves and the sensation of vision is produced.
Thomas young and the wave nature of light historical background. Hsc physics wave theory of light free download as powerpoint presentation. In the 1600s, christiaan huygens and isaac newton proposed competing theories for lights behavior. These corpuscles on emission from the source of light travel in straight line with high velocity when these particles enter the eyes, they produce image of the object or. The particle theory of light is that light is made up of tiny particles that cant be seen.
The wave theory of light views light as two transverse waves, one made of an oscillating magnetic field and the other an oscillating electrical field. Wave theory of light definition of wave theory of light. The direction in which the light travels iscalled a ray of light. Hsc physics wave theory of light light luminiferous. Light or visible light is electromagnetic radiation within the portion of the electromagnetic spectrum that can be perceived by the human eye. Phys 201 lecture 18 wave theory of light open yale. Huygens theory served as a fundamental explanation of the wave nature of light interference and was further developed by fresnel and young but did not fully resolve all observations such as the lowintensity doubleslit experiment first performed by g. Huygens put forward his wave theory according to which light energy propagated in the form of wave, with the help of wave theory he could successfully explain the phenomenon of reflection and refraction, interference and diffraction all. Huygens theory of light refraction, based on the concept of the wave like nature of light, held that the velocity of light in any substance was inversely proportion to its refractive index.
1451 853 516 548 80 1516 243 971 1216 117 395 949 831 994 1344 801 185 746 330 400 812 622 178 1228 589 1431 639 1525 353 1233 263 921 874 1309 816 657 834 1443 1051 1008 1477 1249 1388 727 1009 1454 755 271