Prove laser is monochromatic???? How?
817252
Abstract: When an image, which is an object of reading and which is recorded on a photographic film, is to be registered at a reading position of a film scanner by an operator, following processes are repeated: results of a CCD sensor picking-up the reading position and periphery thereof are fetched; a moving speed V of the photographic film is computed; if the moving speed V is greater than or equal to a reference value, results of pick-up are displayed on a CRT as a high-speed, monochromatic dynamic image; and if the moving speed is less than the reference value, the results of pick-up are displayed on the CRT as a highly-detailed, color dynamic image. In this way, a dynamic image display mode is automatically switched in accordance with changes in the moving speed v during a registration operation, and registration of the image can be carried out quickly and accurately. \nClaim: What is claimed is:\n\n1. An image position confirming device comprising: a pick-up sensor which picks-up a region within a predetermined pick-up range including an image reading position at whichan image, which is recorded on an original medium, is to be registered in order to read the image, and a peripheral region of the image reading position, the peripheral region surrounding the image reading position; a display section for displaying theregion including the image reading position and the peripheral region; and a display control section for, when the image recorded on the original medium is to be registered at the image reading position in order to read the image, displaying, as adynamic image, on the display section images which are obtained by the pick-up sensor picking up the region including the image reading position and the peripheral region, wherein, when the image recorded on the original medium is being moved, by movingthe original medium, to the image reading position at which the image is to be registered, a moving state of the original medium is detected, and a dynamic image display mode is selected based on the detected moving state of the original medium, thedynamic image display mode being selected from among a plurality of dynamic image display modes which are stored in advance, and the dynamic image is displayed on the display section in accordance with the selected dynamic image display mode.\n\n2. An image position confirming device according to claim 1, wherein the plurality of dynamic image display modes include a high speed display mode which displays the picked-up image as a dynamic image which follows, at high speed, changes in astate of the region within the predetermined pick-up range, and a highly-detailed display mode which displays the results of the pick-up as a dynamic image which shows in great detail a state of the region within the predetermined pick-up range.\n\n3. An image position confirming device according to claim 2, wherein the pick-up sensor outputs the results of the pick-up at a predetermined period, the high speed display mode is a display mode which displays the results of the pick-up as adynamic image by displaying an image, in data expressing the picked-up image, only data of one pixel group among a first pixel group or a second pixel group which are determined such that pixels forming each pixel group are substantially uniformlydistributed in the region within the pick-up range, and by updating display of the image at the predetermined period, and the highly-detailed display mode is a display mode which displays the results of the pick-up as a dynamic image by displaying theimage by using both the data of the first pixel group and the data of the second pixel group, and by alternately updating, at the predetermined period, between display corresponding to the first pixel group and display corresponding to the second pixelgroup.\n\n4. An image position confirming device according to claim 1, wherein the plurality of dynamic image display modes include a monochrome display mode which displays the
138258
try these sites: http://www.phy.ornl.gov/astrophysics/data/cf88/\n\nhttp://www.llnl.gov/science_on_lasers/07AstSpace/AS-F_Ther.html\n\nhttp://arxiv.org/abs/astro-ph/9801028\n\nI hope this helps....\n\nDon
983322
frequency = C / wavelength.  c is speed of light
448202
If you shine a white light through a prism, the light is refracted and you get a rainbow. Thats how you can see the different wavelengths in white light.
904518
Light Amplification (by) Stimulated Emission (of) Radiation\n\nMany different types:\n\nRuby rod laser - basically a polished rod of aluminium oxide/chromium oxide (synthetic tuby), surrounded by apowerful flashtube.  - Visible Red\n\nNitrogen laser, co2 laser (gas lasers) fairly efficient by laser standards, inivisble output but can be strong enough to cut metal\n\nsemiconductor - both invisible and red - cheap for low power\n\ndpss  -  diode pumped solid state - these lasers use a "pump" diode which is usually 808nm, tis goes into a sliver of something called vanadate which take in light at 808bm (almost invisible Infra Red) and re-emit it at 1064nM (Invisible. It is then put through a crystal of KTP which halves the wavelength (doubling the frequency) and re-emits at 532nM - bright green
702843
Fringe width β= λD/d\nIf the wavelength is decreased,  the fringe width also decreases.\nSo, if you consider any order fringe, say 5th order, it would form at a lesser distance from the centre as compared to the previous case(i.e.when red light was used)
614312
Its all to do with the reflection orf light on concave and convex mirrored surfaces.\n\nSee this web page app. half way down for a more detailed explanation.\n\nhttp://www.mic-d.com/curriculum/lightandcolor/reflection.html
27389
The basic physics behind a laser was thought up by Einstein (that guy was everywhere!) but the first ones were not actually built until the middle of the 20th century.\n\nLaser is an acronym for Light Amplification via Stimulated Emission of Radiation. "Radiation" just means light, and "Stimulated Emission" is a property of some gases because of Quantum Mechanics.\n\nIn QM we know that electrons can only be in certain "orbit" in an atom, more properly called energy levels. When an electron makes a quantum leap from one energy level to another lower level (assuming there is a lower level) It will release a photon (sort of a piece of light) with a very specific frequency. (Frequency and wavelegth are inversely proportion, so one frequency corresponds to one wavelength.)\n\nFor example in hydrogen if an electron in the second lowest energy level drops down to the very lowest level it will emit a photon with a wavelength of 656.3 nanometers, which turns out to be reddish light. From the third lowest to the lowest the photon wavelength is 486.1 nm, which is blue green.\n\nThe point being that an atom can emit light only in very precise frequencies, and not any old frequency.\n\nEinstein developed the concept of "stimulated emission" which is a much more complicated consequence of Quantum Mechanics. It says that if a photon with a transition wavelengh passes close to an excited atom, it will "stimulate" the excited atom to also emit at that frequency.\n\nSo in the hydrogen example, lets say the electron is in the 3rd level. If it were to drop to the lowest level the photon would be 486 nm. While the electron is just hanging around on the third level, if some random photon comes flying past with a wavelength of 486 nm this will stimulate the electron to drop and emit its own photon of that frequency. From the outside it looks like one photon went past an atom and then there were two photons.\n\nTherefore the idea in a laser is to get a lot of atoms into an excited state - which is hard, they would rather be in their ground state - and then wait for one of the atoms to emit a photon. This will prompt more atoms to emit photons, and all those will prompt even more to emit photons, etc. etc. The result being "light amplification via the process stimulated emission."\n\nThe benefits of a laser include the light being all very nearly at one wavelength, and all the light being in phase.\n\nFor a CO2 laser the output light has a wavelength of 10,600 nm, which is in the infrared part of the spectrum and not visible to the human eye. The gas inside a CO2 laser consists of, well, CO2 and also Nitrogen and Helium. The transitions are not simple atomic ones as in the example of hydrogen I gave, but molecular transitons of the CO2 molecule. The basic physics is the same, though.\n\nThese other gases are needed as part of the difficult process of getting a lot of the CO2 molecules into an excited state and keep them there long enough so that they will emit photons via the stimulated emission process.
710202
You are right! Atomic structure has everything to do with what wavelengths are absorbed, and which ones are reflected. I works with light, and it works with radio waves... Thats how they make stealth aircraft. Funny thing about copper... when powdered and burned, it makes a pretty green color!
871410
Colorimetry is a specrophotometric determination but as the name suggests it revolves around the forming colour so the visible part of the EM spectrum. It is usually made using simple instruments usually visual comparison to standards or simple filter spectrophotomers. The vavelength discrimination is thes machines is somewhat poor and deviations from Beer's law (abs proportional to cocnc) can occur. Despite this, these techniques are widely used very successfully in routine chemical analysis.\n\nSpectrophotometry is available across most of the EM spectrum form gamma rays to IR. The better instruments have much better sources and monochromators to produce "single" wavelength radiation. Generally the detection equipment is superior as well. Also being a spectrophotomer the source, monochromator sample and detector is "in line". You might also want to check fluometry is you want to go further.
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A laser (from the acronym Light Amplification by Stimulated Emission of Radiation) is an optical source that emits photons in a coherent beam. Laser light is typically near-monochromatic, i.e. consisting of a single wavelength or color, and emitted in a narrow beam. This is in contrast to common light sources, such as the incandescent light bulb, which emit incoherent photons in almost all directions, usually over a wide spectrum of wavelengths.\n\nhttp://en.wikipedia.org/wiki/Laser\nhttp://www.howstuffworks.com/laser.htm
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the wavelength is half...\n\nvavelength and frequency are inversely proportional
806627
This is partially true, partially false.\n\nWith regards to purple, most people would agree that purple light is always some mixture of reddish and bluish light.   I.e. you can imagine two knobs, one raising and lowering the red and the other raising and lowering the blue, and you can get many shades of purple.  There may be other hues added in as well, but there is *always* red and blue (if not, we rarely call it purple).\n\nIn other words, if we didn't have the word "purple" in our language, we would probably call it something like "reddish blue" or "bluish red".\n\nBut we cannot do the same with red and green.   We have a very hard time imagining, or pointing to, a color that is "reddish green".  If given only a red and a green knob, the result will be make the color more or less neutral (gray or white).\n\nLikewise with blue and yellow.  (Some people will respond that green is bluish yellow, but that's because many people are used to mixing pigments on paper ... we're talking about mixing lights.)\n\nThese two pairs,  red-green and blue-yellow, are *fundamental* pairs.  We call them "oppositional".  (There is also a third opponent pair ... light-dark ... but as we're just talking about color here, we can ignore that one for the moment.)  This is called the "opponent theory" of color vision and is associated with Ewald Hering.\n\nSo in that sense we can call these four colors "fundamental" hues"  because all color we see can be mixed using knobs of these four colors.\n\nPeople will also wonder about the red-green-blue primaries, and the fact that we know we have red, green, blue photoreceptors in our eyes.  These would also seem to be fundamental hues (as evidenced by the computer monitor on which you are reading these words ... that monitor is able to simulate a wide range of colors using just red, green, and blue).\n\nThese two theories ... the "opponent theory" and the "trichromatic theory" competed for a long time until we found a way to reconcile them.  Basically, we have three types of photoreceptors, but they are wired in a way in our retina, that by the time signals are travelling down our optic nerve, the red-green are antagonistic signals as are yellow-blue.
310583
It's just a light thing.  I've studied this for art more than for science...um, red light is the shortest wavelenth, so it's the first to be filtered out by distance.  If they're far enough away, only the blues and purple wavelengths make it to your eyes.
750681
A photon with a wavelength of about 650 nm
128889
Here ya go!\n\nhttp://science.howstuffworks.com/laser.htm
1135249
The proof is red-shift.\n\nAs things recede from each other at a high fraction of c (speed of light), the waves stretch out; visible light takes on a higher red content.  The SPEED of light remains the same, but the frequency changes.\n\nConversely, when things approach each other, they blue-shift; the light becomes more blue.