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(Physics) A wavefront is an imaginary surface joining all points in space that are reached at the same instant by a wave propagating through a medium. Let's try some examples. When a rock is tossed into a calm lake, a surface disturbance radiates from the point where the rock broke the water. The leading edge of all of that wave forms a circle, and that circle is the wavefront for that event. It is moving outward at a constant speed in all directions. Note that it's two-dimensional (2D). Want 3D? You got it. In a burst of chemical energy, a star shell explodes at a fireworks display. The light moves away from the origin in all directions at the same speed - the speed of light. And the 3D surface of this wavefront is a sphere, and it is expands around the origin at the speed of light. Pick an arbitrary distance, say, 1 kilometer. Anyone at a distance of 1 km from the event in any direction will find that the wavefront reaches him at the same instant of time as anyone else in any direction who is that 1 km from the event. Even someone in an airplane that is 1 km away will be on the wavefront for an instant - that same instant as any other observers 1 km away. Note that the sound will arrive later - but it, too, radiates forming a spherical wavefront. Our observers at 1 km distance from the event all experience the arrival of the sound wave at the same time. [Note: Yes, the speed of light is a constant, and it appears to "slow down" when it moves through air of different densities and different humidities, etc., etc., etc. We'll save the splitting of hairs for a question on microtomes or the like. Same with sound. It's velocity will vary a bit through air because of the differential properties of the medium and over the distance through which it travels in said medium.]
Wiki User
∙ 16y ago
Wiki User
∙ 13y agoA wavefront is an imaginary surface representing corresponding points of a wave that vibrate in unison.
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What are some examples of xray waves?
The sun's rays are an example of a ray. The sun is the starting point or the point of origin and its rays of light extend indefinitely in our solar system. You can also get science assignment help for any topic.
What is path difference of waves?
The Path DifferenceTwo-point source interference occurs when waves from one source meet up with waves from another source. If the source of waves produces circular waves, then the circular wavefronts will meet within the medium to produce a pattern. The pattern is characterized by a collection of nodes and antinodes that lie along nearly straight lines referred to as antinodal lines and nodal lines. If the wave sources have identical frequencies, then there will be an antinodal line in the exact center of the pattern and an alternating series of nodal and antinodal lines to the left and the right of the central antinodal line. As discussed in http://wiki.answers.com/u12l3a.cfm, each line in the pattern is assigned a name (e.g., first antinodal line) and an order number (represented by the symbol m). A representative two-point source interference pattern with accompanying order numbers (m values) is shown below.
What is a good sound insulater?
There are a number of good ways to insulate from sound. Headphones use a number of different polymers in solid or foam forms. Some modern recording studios are soundproofed by expensive materials which are good at dissipating sound energy in the audible spectrum, but the traditional approach is instead to disperse the sound. Using the egg-box shape (I've heard egg boxes can themselves be quite good, but don't rely on that) crates an uneven surface on the wall. Wavefronts therefore do not "push" the wall in a single force as they would if it was flat and face on to a source of sound, but instead hit different points of the surface at different times and scatter in a pseudo-random manner. This significantly reduces the sound heard on the other side of the wall. Also, make sure no sources of sound are touching the wall and that nobody who might be bothered by the sound is on the floor below
Which statement best explains why the direction of some seismic waves change sharply as the waves travel through the earth?
As you go deeper within the Earth, the density and rigidity of the constituent material varies. This affects the speed of the seismic waves, and hence causes them to refract (much light how a light beam refracts when it goes from air to a glass block).
What are the differences between Fresnel and Fraunhofer diffraction?
FRESENEL DIFFRACTIO1) Both the incident and diffracted wavefronts are spherical or cylindrical.2) the source must be close to he obstacle.FRAUNHOFFER DIFFRACTION1) Both the incident and diffracted wavefronts are plane wavefonts.2) the source must be infinite distance from the obstacle.
What has the author Orestes Nicholas Stavroudis written?
Orestes Nicholas Stavroudis has written: 'The optics of rays, wavefronts, and caustics' -- subject(s): Mathematical physics, Geometrical optics
What causes Doppler effect?
Take a car for example. When the car is moving to the left, each successive wave is emitted from a position further to the left than the previous wave. So for an observer in front (left) of the car, each wave takes slightly less time to reach him than the previous wave. The waves "bunch together", so the time between arrival of successive wavefronts is reduced, giving them a higher frequency. For an observer in back (right) of the car, each wave takes a slightly longer time to reach him than the previous wave. The waves "stretch apart", so the time between the arrival of successive wavefronts is increased slightly, giving them a lower frequency.
What are some examples of xray waves?
The sun's rays are an example of a ray. The sun is the starting point or the point of origin and its rays of light extend indefinitely in our solar system. You can also get science assignment help for any topic.
Is there any particle faster than light particles?
If relativity theory is correct (and as far as we know, it is), no signal can overtake light in a vacuum; thus no real, observable particles can travel faster than c = 299792458 m/s.In matter, though, the speed of light can be reduced (this is just refraction). In these media, it is possible for particles to overtake the slowed light without breaking the universal speed limit of c. When charged particles travelling through a medium exceed the artificially slowed speed of light, wavefronts of electromagnetic radiation analogous to a sonic boom are produced. The resulting radiation is known as Cherenkov radiation (see related links).
Can light travel in straight lines or can it bend?
Light always travels in straight lines . But we can use prisms and the phenomenon of total internal reflection to make it bent. Except that we find is actually doesn't when we observe at long distances. It's conventionally called 'curved space time'. But also diffraction, i.e. in the atmosphere. In fact common understanding is poor, as light travels as wavefronts expanding spherically from the source. When we add 'time' we get what is termed the 'light cone', the fundamental basis of causality. We can make it 'curve' at will in the same way via local rotations of axis from particles on the causal wavefront plane. Look up 'GRIN lenses', and 'Huygens Construction'.
What is path difference of waves?
The Path DifferenceTwo-point source interference occurs when waves from one source meet up with waves from another source. If the source of waves produces circular waves, then the circular wavefronts will meet within the medium to produce a pattern. The pattern is characterized by a collection of nodes and antinodes that lie along nearly straight lines referred to as antinodal lines and nodal lines. If the wave sources have identical frequencies, then there will be an antinodal line in the exact center of the pattern and an alternating series of nodal and antinodal lines to the left and the right of the central antinodal line. As discussed in http://wiki.answers.com/u12l3a.cfm, each line in the pattern is assigned a name (e.g., first antinodal line) and an order number (represented by the symbol m). A representative two-point source interference pattern with accompanying order numbers (m values) is shown below.
What is a good sound insulater?
There are a number of good ways to insulate from sound. Headphones use a number of different polymers in solid or foam forms. Some modern recording studios are soundproofed by expensive materials which are good at dissipating sound energy in the audible spectrum, but the traditional approach is instead to disperse the sound. Using the egg-box shape (I've heard egg boxes can themselves be quite good, but don't rely on that) crates an uneven surface on the wall. Wavefronts therefore do not "push" the wall in a single force as they would if it was flat and face on to a source of sound, but instead hit different points of the surface at different times and scatter in a pseudo-random manner. This significantly reduces the sound heard on the other side of the wall. Also, make sure no sources of sound are touching the wall and that nobody who might be bothered by the sound is on the floor below
Why does a convex lens converge the rays that fall on it and a concave lens diverge the rays that fall on it?
Better to understand how the shapes of the wavefronts of light change when they pass through the lens(concave or convex) in terms of Huygens Principle? The simple answer is that light travels in a straight line in any given medium. A medium could be anything light can pass through like air, vacuum, water, glass, plastic. Each medium has its own 'refractive index' which is a physical property of the material that varies the speed of light within a medium. Light travels slower in glass than it does in air for example. Light bending or refraction occurs as light passes the boundary of one medium into another. When viewing light from an object through a lens, that light passes from the object through air to the lens material and back into the air before reaching they observers eye.Light rays entering the front convex or concave surface of a lens are refracted (bent) by the refractive index of the lens to a new path through the lens material. As light leaves the lens material it is bent again as it reenters the air. The extent that light rays bend depends on the lens material and the curvature of the lens surfaces. Light entering a convex lens is refracted toward a focal point on the other side of the lens. Light at the edges bends more than light passing through the center of the lens, however all rays converge at the focal point. If an observer were to place their eye just in front of the focal point the image would appear larger and in the same orientation. If an observer places their eye beyond the focal point the image appears inverted.Light entering a concave lens is refracted away from a focal point making the image appear smaller.
Which statement best explains why the direction of some seismic waves change sharply as the waves travel through the earth?
As you go deeper within the Earth, the density and rigidity of the constituent material varies. This affects the speed of the seismic waves, and hence causes them to refract (much light how a light beam refracts when it goes from air to a glass block).
What is the meaning of laser?
The word laser is an acronym , the letters standing for Light Amplification by Stimulated Emission of Radiation. Lasers work as a result of resonant effects. The output of a laser is a coherent electromagnetic field. In a coherent beam of electromagnetic energy, all the waves have the same frequency and phase.The acronym laser stands for "light amplification by stimulated emission of radiation." Lasers work as a result of resonant effects. The output of a laser is a coherent electromagnetic field. In a coherent beam of electromagnetic energy, all the waves have the same frequency and phase.In a basic laser, a chamber called a cavity is designed to internally reflect infrared (IR), visible-light, or ultraviolet (UV) waves so they reinforce each other. The cavity can contain gases, liquids, or solids. The choice of cavity material determines the wavelength of the output. At each end of the cavity, there is a mirror. One mirror is totally reflective, allowing none of the energy to pass through; the other mirror is partially reflective, allowing approximately 5 percent of the energy to pass through. Energy is introduced into the cavity from an external source; this is called pumping.As a result of pumping, an electromagnetic field appears inside the laser cavity at the natural (resonant) frequency of the atoms of the material that fills the cavity. The waves reflect back and forth between the mirrors. The length of the cavity is such that the reflected and re-reflected wavefronts reinforce each other in phase at the natural frequency of the cavity substance. Electromagnetic waves at this resonant frequency emerge from the end of the cavity having the partially-reflective mirror. The output may appear as a continuous beam, or as a series of brief, intense pulses.The ruby laser, a simple and common type, has a rod-shaped cavity made of a mixture of solid aluminum oxide and chromium. The output is in pulses that last approximately 500 microseconds each. Pumping is done by means of a helical flash tube wrapped around the rod. The output is in the red visible range.The helium-neon laser is another popular type, favored by electronics hobbyists because of its moderate cost. As its name implies, it has a cavity filled with helium and neon gases. The output of the device is bright crimson. Other gases can be used instead of helium and neon, producing beams of different wavelengths. Argon produces a laser with blue visible output. A mixture of nitrogen, carbon dioxide, and helium produces IR output.Lasers are one of the most significant inventions developed during the 20th century. They have found a tremendous variety of uses in electronics, computer hardware, medicine, and experimental science.
