Why does an electromagnetic wave referact while traveling through different mediums?
460834
I think you are asking about the change in direction or "bending" of a light ray when it is incident to a boundary between media at a nonperpendicular angle. What seems to me to be key to understanding this is the idea that you can think of a "wavefront" of a light beam, very much like a water wave, and that wavefront motion is always perpendicular to the wavefront (ref. 1 and following pages). Also you can think of the wavefronts as wheeled axles rolling from pavement onto grass, and turning the axle as first one wheel hits the grass, then the other. Each wheel slows down on reaching the grass (ref. 2). The first to reach it turns the axle and the second straightens it out. The result is that the axle and direction of motion have turned.
27171
Its actually derived from Maxwell's Wave Equations, see source. Its too complex and requires mathematic symbols, so I can't type it here.
565906
Electromagnetic radiation travels (propagates) by means of oscillating electromagnetic fields that pass through the air and the vacuum of space equally well, and does not require a medium of transport (such as the aether). When radio waves pass an electrical conductor, the oscillating electric or magnetic field (depending on the shape of the conductor) induces an alternating current and voltage in the conductor. This can be transformed into audio or other signals that carry information. The word 'radio' is used to describe this phenomenon, and television, radio, radar, and cell phone transmissions are all classed as radio frequency emissions.
684467
In electrodynamics, polarization (also spelled polarisation) is the property of electromagnetic waves that describes the direction of their transverse electric field. Electromagnetic waves, such as light, exhibit polarization, unlike more familiar wave phenomena such as waves on water or sound waves. Electromagnetic waves are three-dimensional, and it is their vector nature that gives rise to the phenomenon of polarization.\n\nThe polarization of an electromagnetic wave is defined as the orientation of the electric field vector. Recall that the electric field vector is perpendicular to both the direction of travel and the magnetic field vector. The polarization is described by the geometric figure traced by the electric field vector upon a stationary plane perpendicular to the direction of propagation, as the wave travels through that plane. An electromagnetic wave is frequently composed of (or can be broken down into) two orthogonal components
217609
light intensity is maximum at the source and dies down over distance, this can be explained with wave theory of light. so a medium in which light travels faster is where light looses intensity faster. but that is relative to another medium. because in any medium light is the fastest travelling thing. it may not be 'c' but fastest possible. \nso i conclude nothing :D
278787
in waves, therefore, in order to be transmitted it requires some medium to transmit the waves in. That's why sound can't travel through a vacuum such as outer space, for example
745636
The main concept to understand is that of a carrier wave.  The radio wave is that.  A radio wave is electro-magnetic radiation, which, unlike other waves, is not a vibration within a medium, like sound waves for example, which are the propagation of alternating high and low pressure within the air, or other fluid media.  Electro-magnetic waves are a self propagating electro-magnetic effect which can travel even in a vacuum.  Electro-magnetic radiation is a pulsing stream of energy where the pulses are at a constant frequency.  What we perceive as different phenomenon are in fact the same electromagnetic radiation but at different frequencies.  Microwaves, Radio, Ultra-violet, Visible Light, and Infra-red, are all electro-magnetic radiation moving down the scale from high to low frequency.\n\nThe radio transmitter sends out radio waves at a specific frequency or band of frequencies.  The aerial of the receiver develops tiny electric currents in it as the radio wave flows past it.  These are pulsing currents at the same frequency as the radio wave, but these pulses are not in themselves the content of speech or music.  This content, or signal, is carried in the wave, hence the concept of the carrier wave.\n\nIt is easier to understand Amplitude Modulation or AM radio so I will restrict myself to that.  If you imagine a radio wave as a very long string with the pulses like beads on it, all spaced at precise intervals, then imagine that the beads slowly getter bigger and smaller along its length.  Each bead is a packet of energy in the wave and all occur at the same frequency, but where the beads get bigger there is more energy in the packet.  It only takes a little more imagination now to see how the pattern of a sound wave can be represented by the bulging out of the beads, and their getting smaller.  This is called the amplitude.\n\nLooking at it in practical terms, at the transmitter end sound is converted in the microphone into a corresponding pattern of changes in the current flowing through the microphone.  That is your signal.  That signal which is at a low electrical power, is used to create the same pattern but in a circuit of much higher electrical power - that is what an amplifier does.  The device used to transfer the pattern is called a transistor, which uses the low powered circuit to control the flow in the high powered circuit.\n\nThe amplified signal is fed to the transmitter aerial, so now that pattern of electrical energy, identical to the pattern of the sound picked up by the microphone, comes out of the aerial as radio waves, with the pattern held in the varying amplitude of the radio wave.\n\nNow comes a trick to follow.  If there are thousands of transmitters all radiating radio waves all over the place, how come your radio only picks up the one signal.  This is where the tuner comes in.  The principle of radio tuning depends on the opposite properties of coils and capacitors.  I don't know if you know what these are, but it doesn't matter if you don't.  Both of these devices have a special kind of resistance to electricity known as impedance.  Impedance only operates where the current is varying.  The voltages and currents in our radio Ariel will be varying at exactly the same frequency as each radio wave it is exposed to, so if we pass that current through either a coil or a capacitor there will be an impedance in the circuit.  Now the impedance of the coil increases as the frequency gets higher and the impedance of the capacitor gets higher as the frequency gets lower.  An AM tuning circuit simply passes the signal current through both a coil and a capacitor at the same time, and the capacitor is a mechanically variable one, so by turning a knob you can increase or decrease the capacitance.  The trick here is that as the capacitance changes the circuit will show least impedance to a specific frequency compared with all the others, so provided the frequencies are not too close, as the law requ
1124513
an optical medium is the medium through which light travels.\nin scientific words optical medium is a medium through which light undergoes REFLECTION and REFRACTION from one medium to another.such as glass,water,layers of atmosphere,air,and many more(but not those media which absorbs the light)\nthere are two types of optical medium-:\n\nOPTICAL RARER MEDIUM\na medium in which the speed of light is more is known as optically rarer medium.\n\nOPTICAL DENSER MEDIUM\na medium in which the speed of light is slow is known as optically denser medium.
260953
Not at all.\n\nSound and light are two totally diiferent types of waves.\n\nSonic wave is a disturbance in a medium (in our situation most commonly air).\n\nLight is electromagnetic wave and needs no medium.
509957
Electromagnetic radiations or waves are propagating in space. Electromagnetic waves have electric and magnetic components, the electric field and the magnetic field oscillate at right angles to each other and to the direction of propagation.\nAs any other waves e.m. waves are characterized with  frequency (number of vibrations in one second), wavelenght (the distance from one crest to the next crest in the sinus wave) and radiant energy. \nThe range of the e.m. waves is called the electromagnetic spectrum. The highest frecvency and energy / the lowest wavelenght e.m. radiations are gamma rays (are shorter than the size of the nucleus in the atom) then X rays, ultraviolet radiations, visible light, infrared radiation (heat radiation), microwaves, and radiowaves which has the lowest frequency and longest wavelenght (can be several km long). We can see only the visible light, the other e.m. radiations are invisible to us. But they can have an effect on our organism. They have a lot of technical, medical and other use.\n\nfor more see >>\nhttp://en.wikipedia.org/wiki/Electromagnetic_radiation
1006021
There are two models of electromagnetic waves:  the wave model and the photon model (proposed by Einstein --> photoelectric effect... leading to quantum mechanics).  The wave model is based on a simple equation of propagation : v=f(lambda), however, there are more sophisticated equations for modelling transmition and propagation of waves based on simple harmonic motion etc... The photon model works via the principle of energy:  E(gama)= hf, where h is Planck's constant.  So, it is important to understand that radio waves and photons are 2 differnt perspectives of radiation occurring at frequencies many orders of magnitudes apart.
438842
Like light rays radio waves are reflected refracted and diffracted and absorbed by materials. At certain angle of reflection radio waves are also polarized.\n\nSince it is an E.M wave it travels in vacuum or air with velocity C.\n\nThey are reflected by metals, but absorbed by many substances like wall. The absorption depends upon the thickness of the material.Usually the thicknes of a wall is such as to absorb radio waves. \n\nBecause of long wavelength it can bend across obstacles, and even small cleavage in a wall can fill a room with radio waves.
425519
there are basically 2 parallel mediums of propagation. air and the outer liquid hemisphere. i expect to see interference also as there will be addition of waveforms.
994799
REFRACTION IS THE PHENOMENA\n\nWhen light travels from one medium to another, it bends. In other words, it changes direction and moves at different speeds in different mediums. This property of light is called “refraction”. \nWe also know that white light is made up of different colours. Different colors of light have different frequencies. Except in vacuum and air, they travel at different speeds in different mediums.\nIf you were to allow a beam of light to pass through a simple prism, it will bend when it enters the prism, when it leaves the prism it bends again. The different colours of the white light travel with different speeds inside the prism. The slanted surfaces of the prism makes the different colours emerge separately, thus in addition to bending light as a whole, a prism separates white light into its component colors. This splitting of light into its component colours is called dispersion, where prism is a dispersing element.\nThis is exactly what happens when the sun rays hit droplets of water. When the sunlight strikes a raindrop, the light is refracted (bent) because the light is moving from one medium(air) to another( water). Drops of rainwater can disperse light in the same way as a prism.. When the light comes out of the water droplet, the sun's rays (white light)have now been split into their component wavelengths (colors). In this way, each individual raindrop behaves just like a prism, dispersing white sunlight into its seven component colors and a rainbow is formed. \nThe rainbow we see is thus a result of many, many raindrops bending the sun's rays.
1018708
Light waves are electromagnetic energy, which can be transported across a medium. If it helps, light waves can be thought of as photons, massless particles that fly through space. No medium is required for transport.\n\nSound waves however are a disturbance OF the medium, as ocean waves are a disturbance of the water. Your eye and ear are very different in how they operate, one being capable of detecting electromagnetic energy, the other acoustic energy.
616403
In both cases, information (music, voice, video, whatever) is carried in radio waves (electromagnetic waves).  Think of waves on the beach.  They can differ in the height (amplitude) of the waves, and in the frequency of the waves (how close the waves are to each other).\n\nIn amplitude modulation (AM) ... the information is carried in the changes (modulation) of the amplitude of the radio waves.  All the waves from a particular radio source (e.g. a radio station) all have the same frequency, but different amplitude.\n\nIn frequency modulation (FM) ... the information is carried in the changes (modulation) of the frequency of the radio waves.   All the waves from a certain radio source have the same amplitude, but different frequency.
289035
Because mediums are what the waves move through.