why does UV light make white things glow?
959790
Ultraviolet (UV) light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than soft X-rays\nThe conventional black light(UV Rays are called Black light) design is just a fluorescent lamp with a couple of important modifications. Fluorescent lamps generate light by passing electricity through a tube filled with inert gas and a small amount of mercury. \nThe first thing most people notice when you switch on a black light is that some of their clothing glows. This is because most laundry detergents contain phosphors to make whites appear brighter in sunlight. Sunlight contains UV light that makes the whites glow "brighter than white." Dark clothes don't glow because the dark pigments absorb the UV light.\nThere are a lot of everyday materials that fluoresce, or glow, when placed under a black light. A black light gives off highly energetic ultraviolet light. You can't see this part of the spectrum, which is how 'black lights' got their name. Fluorescent substances absorb the ultraviolet light and then re-emit it almost instantaneously. Some energy gets lost in the process, so the emitted light has a longer wavelength than the absorbed radiation, which makes this light visible and causes the material to appear to 'glow'. \nFluorescent molecules tend to have rigid structures and delocalized electrons. Examples of common materials that contain fluorescent molecules include: \n\nWhite paper is treated with fluorescent compounds to help it appear brighter and therefore whiter. \n\n some other things to glow under UV light are\nClub Soda or Tonic Water\nThe bitter flavoring of tonic water is due to the presence of quinine, which glows blue-white when placed under a black light. \n\nBody Fluids\nMany body fluids contain fluorescent molecules. Forensic scientists use ultraviolet lights at crime scenes to find blood, urine, or semen (all fluorescent).\n\nVitamins\nVitamin A and the B vitamins thiamine, niacin, and riboflavin are strongly fluorescent. Try crushing a vitamin B-12 tablet and dissolving it in vinegar. The solution will glow bright yellow under under a black light.\n\nChlorophyll\nChlorophyll makes plants green, but it fluoresces a blood red color. Grind some spinach or swiss chard in a small amount of alcohol (e.g., vodka or everclear) and pour it through a coffee filter to get chlorophyll extract (you keep the part that stays on the filter, not the liquid). You can see the red glow using a black light or even a strong fluorescent bulb, such as an overhead projector lamp, which (you guessed it) gives off ultraviolet light.\n\nAntifreeze\nManufacturers purposedly include fluorescent additives in antifreeze fluid so that black lights can be used to find antifreeze splashes to help invesitagors reconstruct automobile accident scenes.\n\nLaundry Detergents\nSome of the whiteners in detergent work by making your clothing a bit fluorescent. Even though clothing is rinsed after washing, residues on white clothing cause it to glow bluish-white under a black light. Blueing agents and softening agents often contain fluorescent dyes, too. The presence of these molecules sometimes causes white clothing to appear blue in photographs.\n\nTooth Whiteners\nWhiteners and some enamels contain compounds that glow blue to keep teeth from appearing yellow.\n\nPostage Stamps\nStamps are printed with inks that contain fluorescent dyes.\n\nJellyfish\nIf you have a jellyfish handy, see what it looks like under a black light in a darkened room. Some of the proteins within a jellyfish are intensely fluorescent.\n\nSome Minerals and Gems\nFluorescent rocks include fluorite, calcite, gypsum, ruby, talc, opal, agate, quartz, and amber. Minerals and gemstones are most commonly made fluorescent or phosphorescent due to the presence of impurities. The Hope Diamond, which is blue, phosphoresces red for several seconds after exposure to shortwave ultraviolet light.
429574
gas emitting visible light as a result of being heated
594651
Its a high frequency low wavelength light.can you see UV? no right? so it appears black.. also its monochomatic that you dont see the tinge of other light or colour...
166740
I guess u need a UV light
1141579
A number of colours are sensitive to UV - usually when you don't want them to be. They will fade or degrade under UV light. Many organic pigments are like this - particularly some of the organic red pigments.\n\nA few compounds fluoresce under UV - the "dayglow" type dyes and pigment, some stilbenes (compounds like Tinopal which are used as optical brighteners), fluoroscene, some of the rhodamines. They all look impresssive under UV.
153150
the white is because of the lights reflection off of the ice crystals.  When it melts there are no more crystals to reflect.
422778
The UV light has a cycle time that is faster than your eye can detect. Your computer monitor also has a refresh time, again, way too fast for you to see. But if the 2 times line up, it looks like your computer screen is flashing and you can just barely detect it. Highly annoying! Get a regular light bulb lamp for your computer room and leave the flourescent off- that should take care of it.
693112
I don't think it's very nice to call someone an idiot for asking a reasonable question.  \n\nBut the two answers you have already are correct, it's the sun light reflecting off the moon that causes it to "glow".
228557
The ultraviolet (UV) makes your skin brown.\nThe UV comes from the sun.\nThe air wordks as a filter for UV.\nIn the mountains a lot of the filter is gone.\nThe snow reflects the UV.\nSo by both facts more UV than normal reaches your skin.\nAttention: many UV can make you blind. So wear sunglasses that really absorb UV!
374484
Since the UV light has particular wavelength and energy, the atoms in the florescent material absorbs that energy and goes to excited state from ground state. but it nomore stable in the excited state. so it emits an energy with is in the range of visible region with some particular wavelength and returns to ground state. the wavelength corresponding colour is visible to us....
1004069
Ignore the above answers they are all horribly wrong. This is a chemistry question.\n\nColors in chemistry are due to two main phenomena. \n\n1. Light Absorption\n2. Charge Transfer\n\n\nFor the first case an electron can be promoted to a higher energy state by absorbing light energy. White light consists of wavelengths (about) 400-800 nanometers. Wavelength is inversly related to frequency which is related to the energy of light. The photonic energy of the light from certain wavelengths is absorbed to promote an electron. The rest of the light is transmitted. This transmitted light is what we see. But also keep in mind that the eye works strangely and we see mixed colors a little different.. I dont know why but just keep it in mind.\n\nThe second phenomena is charge transfer. This occurs when  an electron is transferred from one atom to to another. An example is KMnO4 (which has no d electrons) but is purple! This is because a electron is transferred from the oxygen to the manganese. \n\nAnd there are some other mechanisms for which colors are produced. One of the latest is now understood by a physics professor at ucla. Hes been studying how sound can interact with a bubble to produce light.
607087
The color of a substance is based on the light that it emits, typically after absorbing photons from an external source.  The movement of electrons from one energy level to another is what is typically responsible for the light we see.  If you ionize a substance, you affect the energy levels that are available to an electron to be excited to, or relax down to, and hence you affect its color.
730478
White light is a combination of many wavelengths of the visible light spectrum.  As these wavelengths pass through water droplets suspended in the air, they are refracted at different angles.  Because of the angle of refraction, and because each wavelength of light is bent at a different, specific angle, the result is the division or sorting of light into wavelengths, which the human eye then perceives as color.\n\n:) Hope this helps!
467638
Glow-in-the-dark stuff contains phosphor. \n\nI'd be bluffing like crazy if I tried to explain it.\n\nHere's a better link :)\n\nhttp://science.howstuffworks.com/question388.htm
280135
Both reasons are correct.  The UV rays have less "stuff" to travel through in the air and atmosphere, so they have a stronger effect.\n\nAlso the snow does have a reflective and intensifying quality that it passes to the UV rays.
6778
A black light emits light in the ultraviolet range with a wavelength not visible to the naked eye; thus black light (yes, the lamp filament may also emit a visable glow).\n\nWhen ultraviolet light photons (which have a very short energetic and penetrating wave length - where X-rays are even shorter and more penetrating) strike the surface of certain materials, electrons absorb the photon's energy and are knocked out of their low energy electron shells to higher energy shells.  When the electrons fall back to lower energy states, the absorbed energy is released emitting a characteristic phosphoresence color.  This often can be used to identify certain minerals that exhibit crystaline structure.
214199
Yes. You need proof? UV is a radiation. Radiation is the travel or emission of waves.\nYou can see it in a magnetic spectrum. High frequency and low wavelength are those ionizing radiation. High wavelenth and low frequency are those non-ionizing radiation. \nPenetration of these waves are dependent on their frequencies. High frequencies are able to tranmsmit objects. \nUV is found in part with white light. White light is found at the mid part of the spectrum. UV is in part with white light but its on the ionizing side.\nMeaning, UV have higher frequency and lower wavelength that the white light, and it is more penetrating than the white light. \nHope I answered your question.