If slits in a light polarizer are spaced at 500 nano-meters, will only red light be polarized but not blue?
409747
Better make it 480 nano-meters to avoide spectrum spill over from the blue frequency.
744886
Not significantly. If the space is a vacuum, not at all, but if there is gas in the space, the infrared will be refracting from the gas to some extent, and if the gas is vibrating too there might be a slight change in the refractive property of the gas. As for interfere, in the sense of a detectable difference? probably not.
670589
Forever and ever.\nIt may get dimmer, but that is from the spreading of the light.  The photons will travel until they collide with something.
1110039
Yes, you need a carefully set up arrangement with coherent monchromatic light to see it clearly.\n\nAbsurdly, the Poisson spot was named because Poisson said it was plainly absurd and could not occur. He claimed this predictions of Fresnel's theory of light basically proved Fresnel completely wrong. But it was Poisson who was wrong. Yet Poisson who was remembered.\n\nThere is a lesson there. Just not a good one.
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.
446565
Actually it's the other way around, the red is what is reflected and most of the rest is absorbed.  It has to do with the different wavelenths being absorbed by different atoms on the surface.  Some atoms or atomic bonds will reflect certain energies and absorb others.\n\nOr they can absorb energy and re-emit it as a lower energy photon which can also happen.
498079
nothing stupid about the question. \n\nthe refractive index depends on the wavelength. this is given by Cauchy or Sellmeier equations.\n\nif you want the equation the link is : -\n\nhttp://en.wikipedia.org/wiki/Sellmeier_equation\n\nthe refractive index decreases with increasing wavelength.\n\nnow the wavelength of various components are ; -\n\nColor    Wavelength (nm)\n\nRed       780 - 622 \nOrange    622 - 597\nYellow    597 - 577\nGreen     577 - 492\nBlue      492 - 455\nViolet    455 - 390\n\nclearly red which has a higher wavelength will have lesser refractive index and hence will bend lesser than violet which has higher refractive index and bends more..\n\nother useful links are-\n\nhttp://en.wikipedia.org/wiki/Refractive_index\n\nhttp://csep10.phys.utk.edu/astr162/lect/light/dispersion.html\n\nhttp://en.wikipedia.org/wiki/Dispersion_(optics)\n\ni hope this will help :)
269019
The speed of light is the ratio of electric permitivity to magnetic susceptibility. So prisms, lenses, Pockel cells. Maybe those magnetic seals. An ion filter that blocks electric DC fields, but not alternating.
75862
prism. \n\n(polarizer - phase shift; lens - angle of relection,refraction; analyzer - phase)
771806
Yes, the refractive index of glass varies with wavelength. If it didn't, a prism wouldn't disperse light into a spectrum.\n\nThe index of refraction is always higher for shorter wavelengths. I'm not sure why; maybe it takes more time for a higher energy photon to be absorbed and re-emitted? The result is that blue light is refracted more than red light. Numbers for a typical crown glass (Bk7) are 1.5143 at 656.3nm and 1.5267 at 435.8nm.
36159
As mechanical engineer this is out of my normal field but felt you deserved an answer of some sort.\n\n"Because of diffraction effects caused by slits or apertures in optical measurement systems, the radiation energy which is directed towards a particular region on a sample will be spread over a larger area than desirable. By employing an apodizing filter in the radiation path in such system, diffraction tails of the system will be reduced. The apodizing filter preferably has a pattern of alternating high transmittance areas and substantially opaque areas where the locally averaged transmittance function is an apodizing function. In the preferred embodiment, the locally averaged transmittance function varies smoothly and monotonically from the periphery to the center of the filter"\n\nI see the theory here, also found on on using an apodizing mirror to stabalise images in a telescope\n\n"I built and used an apodizing screen for my 6" f/8 scope many years \nago. I made it by layering several layers of window screen, each one \nwith a circular cutout of different diameter. The result was an aperture \nmask with a step-wise approximation to a smooth apodizing function. It \nwas claimed to improve contrast for planetary viewing. Anyway, my \nexperience was that it seemed to make the image more stable but if it \nimproved contrast, I couldn't see it. If you do this on-axis, the \ndownside is that your diagonal mirror will now become more of a factor \nin the contrast equation. The bottom line is I wouldn't recommend it."\n\nAlso "An excellent reference for all sorts of technical techniques is\n>"Procedures in Experimental Physics" (also printed under the title\n>"Physical Laboratory Practice") by John Strong.  I don't recall the\n>publisher, but it came out in the 30's.  The bad news it that it's been\n>out of print for decades (and some SOB stole the copy I got from my\n>father!); the good news is that an outfit called Lindsay is reprinting it\n>in paperback.  (Don't have their name/address here in the office; I'll try\n>to remember to look it up tonight.)\n>\n>                            Dr. Kurt Hillig\n\nEvery ATM should have a copy of this great book. Lots of stuff on\nmirror making, figuring, special laps,making flats, prism ,etc.\nThere is nice modifed Draper machine ( upper disk also powered)\nand a homemade diamond cutting wheel to cut small glass blocks.\n( I would like to build this one someday ) A great section on\nkinematical mechanical construction. Yeah this a mid 30,s book but the \ninfo\nstill can be used. No I don't work for Lindsay Publications,<G>\n\nBob Pfaff\n\n\n This book, in paperback form, can be ordered from\n      http://www.amazon.com, on the Web. It can also be ordered\n      through your local bookstore. Amazon prices it at $23.95, and\n      provides the following information:\n\n      Published by Lindsey Publications\n      Publication date: June 1986\n      ISBN: 0917914562"\n\nSorry couldn't find any really decent expplanations, but at least you've got a starting point.
762017
The width pf  entrance slit to the grating has nothing to do with the diffraction. The slit is only there so you can image it over and over again on your detector in different wavelengths. \n\nIt is the distance between the rulings on the grating (and some other things;  see below) that determines the angle of diffraction.  \n\nIt sounds to me like you are looking for a grating equation; the relationship between the line separation of the grating, the angle of incidence, angle of diffraction, order of the diffraction and the wavelength of the incident wave.\n\nhttp://www.tau.ac.il/~phchlab/experiments/hydrogen/diffraction_gratings.htm
322625
polarization is a way of filtering out all light except for the light that oscilates in a certain direction.  Light from the sun oscilates in all directions, but when it is reflected from a surface, it tends to oscillate very heavily in a single direction, which makes it amenable to filtering by polarlized lenses.  Sub glasses are therefore designed to minimize glare from reflected surfaces.  Some model cars also have polarized windshields for exactly the same reason - to minimize glare from sunlight bouncing off surfaces - like the hoods of other cars.  If you look through two polarized lenses, if the polarization of the two is parallel then most light passes through - but if they are perpendicular, then most light is blocked.  You are seeing light from the inside of a car that is passing through two polarized layers - that of the windshield and that of your glasses, and it is likely that the relative angle of alingment of the polarization between the two is somewhere between 0 and 90 degrees.  \n\nHere is something to try - next time you see a display of polarized sunglasses - hold one pair before your eyes - rotate the subglasses - and look at all the other polarized subglasses on the rack as you do so - you'll be amazed to see how all the glasses on the rack turn from clear to opaque as you rotate the pair in your hand
38745
I'm pretty sure that the red light would go faster than the blue.\n\nThe speed of light is NOT constant.  It is only constant in a vacuum.  In other media, the speed is retarded.  The refractive index is a measure of the degree to which light is slowed when it enters a non-vacuum medium.  The more light is refracted, the more it is being slowed by the medium.  Since red light is refracted the least, I think that's indicative of red light being least slowed by the medium transition.
575845
It is due to refraction, not diffraction.  Red is not bent the most in a prism, violet is bent the most.  \n\nWhen the sun is on the horizon, its light has to travel through many miles of atmosphere before it gets to our eye.  Since the blue end of the spectrum is bent the most through refraction, it is completely scattered away by the time the light gets to us.  Therefore, the only colors left are the red and orange.\n\nThis is the same reason the sky is blue (no it is not blue because of the reflection of the oceans!)  The blue end of the spectrum is scattered the most, thus illuminating the sky more than the other colors.  Actually, since violet is bent more than blue, the sky is actually more a violet color, but our eyes are more sensitive to blue, so we see a blue sky.
65636
You're right, Red+Blue=Violet.  The light doesn't have to interfere.  You don't have violet cones in your eye (you have 3 that are more or less maximally receptive at red, green, and blue)... your brain interprets equal amounts of blue and red neurons firing as the color violet.  It also interprets equal amounts of red and green light as yellow.  \n\nNow you should wonder what happens when light of 400nm hits your eye.  You don't have violet cones, but this light is not in an energy eigenstate, so you can express it as a linear combination of red and blue wavelengths... the result is that 400nm light will excite red and blue cones in equal amounts so you view it as violet.
635627
How about a polarized lens