Describe the six properties of electromagnetic waves and give everyday. Sample learning goals make waves with water, sound, and light and see how they are related. James clerk maxwells 1831 1879 theory of electromagnetism, however, showed that light was a wave in combined electric and magnetic. Light is electromagnetic radiation which is visible to the human eye. The disturbance or variation can be a change in pressure, electrical intensity or many other things, but there is always a transfer of energy. Giving it a name the luminiferous aether didnt help. Do energysaving lamps pose a risk to some groups of patients in. Adjust frequency and amplitude, and observe the effects. Waves a wave is a disturbance that pppg gropagates through space and time, usually with transferrance of energy. Even more important, though only touched on in this book, is the wave phenomenon of quantum mechanics, built into the fabric of our space and time. How does light, infrared and uv radiation interact with skin and eyes.
Objectives aims this chapter is essentially an introduction to the wave theory of light. Like all electromagnetic waves, light can travel through a vacuum. Introduction to waves interactive manipulate the size of the amplitude and the wavelength to visualize the. Introduction humans have interacted with some form of waves for a very long time, though of course they were not known as such. A physics revision video introducing the concepts of waves. These lessons focus on students collaboratively problem solving, discovering and investigating to find answers and solutions. Light is considered to be linearly polarized when it contains waves that only. Propagation of light through a slit demonstrates wave properties. The wavelength is the length from one peak to the next or from any point to the next matching point. Chapter 1 introduction to light and optical systems optical systems, which provide much convenience to our lives and industries, manipulate light to satisfy the particular requirements of end users. Conversely, radio waves are electromagnetic waves, like visible light, infrared, ultraviolet, xrays, and gamma rays. Introduction to light and electormagnetic waves exercises multiple choice identify the letter of the choice that best completes the statement or answers the question. Electromagnetic waves are ultimately produced by an accelerating charge.
Em waves is the em spectrum includes radio waves longest wave, microwaves, infrared, visible light, ultraviolet ray, xray, and gamma ray. All waves travel at a constant speed of 3 x 108 ms in vacuum. Tv, and cellular phone transmission, microwaves, visible light, infrared and ultraviolet light, radiation, x rays and gamma rays. The wavelength and frequency of electromagnetic waves vary from very long wavelengths to extremely short. Sir isaac newton believed that light was a stream of particles. Electromagnetic radiation is one of the many ways that energy travels through space. My text for physical science and engineering majors is simple nature. Electromagnetic waves are created by oscillating electric and magnetic fields. It comes from the greek word polos, for the axis of a spinning globe. Electromagnetic waves can be used in a variety of ways.
The transverse nature of light can be demonstrated through polarization. A radio detects a different portion of the spectrum, and an xray machine uses yet another portion. We use them to communicate, cook, and for medical purposes. In diffraction, waves bend when they pass around small obstacles and spread out when they pass through small openings. Introduction to electromagnetic theory electromagnetic radiation. Preface this book provides an introduction to the eld of optics from a physics perspective. At this stage you should get a basic understanding of the wave model of light, which involves the idea of light as a complex superposition of many component waves, or. The heat from a burning fire, the light from the sun, the xrays used by your doctor, as well as the energy used to cook food in a microwave are all forms of electromagnetic radiation. Electromagnetic waves and the electromagnetic spectrum.
James wood and kelsie jackson light and color why are some things seen as red while others are seen as blue. At this stage you should get a basic understanding of the wave model of light, which involves. Electromagnetic energy travels in waves and spans a broad spectrum from very long radio waves to very short gamma rays. The energy produced by this vibration travels in the form of electromagnetic waves. This phenomena is called the waveparticle nature of light or waveparticle duality. In this article, how a light wave behaves like a particle and a wave are explained. This is an introductory text intended for a oneyear introductory course of the type typically taken by biology majors, or for ap physics 1 and 2.
Speed of light depends on media medium speed ms refractive index vacuum 3 x 108 air 2. Interference of two one dimensional electromagnetic waves 3. There are familiar, everyday sorts of waves in water, ropes and springs. Waveparticle duality introduction light waves a level. Physics videos by eugene khutoryansky 1,110,756 views. We begin our study of waves in this first unit of physics 7c with an introduction to waves and then a thorough development of the harmonic plane wave model, which we will use extensively to model and understand a wide variety of wave phenomena. Balancing concise mathematical analysis with the realworld examples and practical applications that inspire students, this textbook provides a clear and approachable introduction to the physics of waves. At this stage you should get a basic understanding of the wave model of light, which involves the idea of light as a complex superposition of many component waves, or elementary waves, each with its own wavelength. For instance, why is the ocean blue while plants are often green.
Light waves vce the question of what is light was a matter of great debate during the 17th and 18th century. In this chapter, we briefly introduce aspects of light that are understood best when using wave models, as applied to geometrical and physical. Wave and particlelike behavior, and how to calculate the wavelength or frequency of a light wave. For end users and optical engineers, understanding optical systems is of fundamental importance for using, designing, or manufacturing optical systems. The wave nature of light was first illustrated through experiments. Radio and microwaves, light, and xrays are all electrical waves. The wave nature of light was first illustrated through experiments on diffraction and interference. Properties of light waves, particles and em spectrum interaction with matter absorption re.
So a ow of energy implies a ow of mass, which in turn implies nonzero momentum. The physics of waves version date february 15, 2015. This section introduces the properties of waves and wave motion. The amplitude is the height from the center line to the peak or to the trough. Properties of light university of maryland college of. Light can be represented as a transverse electromagnetic wave made up of mutually perpendicular, fluctuating electric and magnetic fields.
The higher the frequency, the more energy in the wave. Introduction to light electronic structure of atoms. Understanding the structure of the eye lessoneye structure and seeing lightnotes outline 1 eye structure and seeing light. Electromagnetic radiation is generated by the oscillation or acceleration of electrons or other electrically charged particles. Currently, people think that light has the attributes of a waveparticle duality. Some of these waves are compressional, and others are transverse. Introduction and types a wave is a transfer of energy through a medium from one point to another. The seismic waves that cause most damage to buildings are a kind of rolling waves. Mar 14, 2018 em waves do not require a medium to travel. Speed of light measured by fizeau and foucault between 1849 and 1862. A wave is a disturbance that carries energy from place to place. We deal with both normal and nonnormal angles of incidence. While a mechanical wave exists in a medium which on deformation is capable of producing elastic restoring forces waves ofproducing elastic restoring forces, waves of. Introduction electromagnetic radiation electromagnetic.
As shown below, an electromagnetic wave is a transverse wave consisting of mutually perpendicular oscillating electric and magnetic fields. Introduction to the electromagnetic spectrum science. Electromagnetic waves, the electromagnetic spectrum and. Humans have interacted with some form of waves for a very long time, though of course they were not known as such. In refraction, a wave bends when it enters a medium through which it has a different speed. The electromagnetic spectrum introductionvisible light 1 instructors guide to lab no. These rolling waves are a combination of compressional and transverse waves.
The electromagnetic spectrum is divided into five major types of radiation. There are less visible but equally pervasive sound waves and electromagnetic waves. In chemistry 111a you will be introduced to quantum mechanics, which is also sometimes called wave mechanics. Ordinary white light is made up of waves that fluctuate at all possible angles. Description make waves with a dripping faucet, audio speaker, or laser. The answer has to do with light and the way it interacts with objects. Produced by the motion of electrically charged particles also called electromagnetic radiation because they radiate from electrically charged particles light according to the wave theory, light consists of electromagnetic waves radiowaves microwaves infrared waves visible light ultraviolet light xrays gamma. Christian huygens proposed that light travelled as waves. The visible electromagnetic spectrum goal the goal is to introduce the visible electromagnetic spectrum to students through use of materials readily available to most high school science classes. For light electromagnetic waves the vectors are the electric and magnetic.
This is why sunlight can reach earth even if the outer space is basically a vacuum. In reflection, a wave encounters an obstacle and is reflected back. Some wave properties can be even more easily illustrated with microwaves than with light waves but microwave. Can fluorescent lamps affect people with skin conditions. In this lesson, youll learn about different kinds of light waves, how they work, and how they are used every day. Poster of em spectrum pdf right click and download. Diffraction of waves in everyday life and applications.
Speech and sound, for example, which enabled communication among ourselves and the creation of music, date from tens of thousands of years ago. Light waves can behave like particles photons and waves. Algebra and trig are used, and there are optional calculusbased sections. Light and sound during the study of light and sound waves students will develop their science skills through inquiry, prediction, observation, exploration, discussion and recording. A number of fundamental physical phenomena are describeable as waves. This led to the remarkable conclusion that light is an electromagnetic wave. Feb 02, 2016 introduction to light as known through the ages. This follows from the relativity fact that energy is equivalent to mass. Light waves can interfere with other light waves, canceling or amplifying them. The human eye can only detect only a small portion of this spectrum called visible light. It assumes that the student already has a basic background with complex numbers, vector. Since it travels at the speed of light, c 3 108 m s. Jul 12, 2011 light and the electromagnetic radiation spectrum. Introduction to light and electormagnetic waves exercises.
Nasa s scientific instruments use the full range of the electromagnetic spectrum to study the earth, the solar system, and the universe beyond. A wave is a disturbance that moves through space or matter. Introduction to the electromagnetic spectrum science mission. Your eye can detect only part of the light introduction the electromagnetic spectrum fig. And the speed at which these waves travel is the speed of light, c, and by c i mean three times 10 to the eight meters per second, because light is just and electromagnetic wave, light is a special example, one particular example of electromagnetic waves, but it is only. In this section we will familiarize ourselves with waves by concentrating on material waves. It focuses primarily on the wave and ray descriptions of light, but also includes a brief intro. The text is designed for upperlevel undergraduate students with a physics background. Can fluorescent lamps worsen health conditions not related to the skin. This chapter is essentially an introduction to the wave theory of light. Electromagnetic waves, the electromagnetic spectrum. Electromagnetics and applications mit opencourseware. Sound creates pressure variations waves in matter, such as air or water, or your eardrum. At this stage you should get a basic understanding of the wave model of light, which involves the idea of light as a complex superposition of many component waves, or elementary waves, each with its own wavelength, frequency, amplitude and phase.
Maxwells work thus unified the domain of electricity, magnetism and light. Hear the sound produced by the speaker, and discover what determines the color of light. Freegardes text on waves allows construction of a more cohesive physics curriculum, one with significant scaffolding, designed to revisit, reinforce and refine student understanding of core concepts, both within the bounds of this foundational course and, quite naturally, in subsequent courses that follow within the physics major. Speech and sound, for example, which enabled communication among ourselves. Cancellation and addition of diffracted waves results in striped pattern in contrast to what would be expected by particles. Daviddarom, wikimedia commons the beauty of a coral reef, the warm radiance of sunshine, the sting of sunburn, the xray revealing a broken bone, even microwave popcornall are brought to us by electromagnetic waves. Proved that light is an electromagnetic wave em waves carry energy through empty space and all. Electromagnetic waves and interference physics science. The nature of light as a wave a small disturbance in an electric field creates a small magnetic field, which in turn creates a small electric field, and so on light propagates itself by its bootstraps. Light, reflection, and color characteristics of light light is an electromagnetic wave.
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