Their research was published last week in IEEE Transactions on Image Processing. Researchers at Fudan University have developed a sophisticated way to construct digital fingerprints that encode secret messages into these spiral points. Take a look at your fingers and note the continuous lines that occasionally swirl into a spiral. But what if there’s another way to use fingerprints-one that could even help a criminal achieve their ill-intentioned goals? In an interesting twist, researchers in China have described a way to use fingerprints to encode secret messages. Learn more →Īnalyzing fingerprints found at the scene of the crime is a classic way to identify a criminal who has accidentally left behind his or her unique signature.
#How to encode a message into laser light pdf#
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#How to encode a message into laser light full#
Enjoy more free content and benefits by creating an account Saving articles to read later requires an IEEE Spectrum account The Institute content is only available for members Downloading full PDF issues is exclusive for IEEE Members Access to Spectrum's Digital Edition is exclusive for IEEE Members Following topics is a feature exclusive for IEEE Members Adding your response to an article requires an IEEE Spectrum account Create an account to access more content and features on IEEE Spectrum, including the ability to save articles to read later, download Spectrum Collections, and participate in conversations with readers and editors. Physics, President and creator of PhysLink.Close Stay ahead of the latest technology trends. This also happens to your white shirts when you walk under a 'dark UV lamp' in a disco bar or in one of those stores that sell glow in the dark stuff.Īnswered by: Anton Skorucak, M.S.
This happens because the UV excites blue dyes in the paper (the paper manufacturers put blue dyes in all papers to make them appear more 'white'). However if you put a piece of paper in its path the paper will glow blue. This beam, say at 244 nm or 300 nm, can not be seen at all with a human eye. Usually a frequency-doubled argon gas is used to produce a continuous wave beam of UV light. However, one can make 'pure' UV of a single wavelength using a laser. So when you turn them on they glow white or pink. The trouble is that these lamps also produce a certain visible light content. The Sun is a strong UV emitter but only near UV reaches the surface of the Earth because the ozone in the atmosphere absorbs all wavelengths below 290 nm.Īrtificially, UV light is usually produced with mercury-vapour and deuterium lamps. So called near UV is in the range 400-300 nm, far UV is in the range 300-200 nm, and extreme or vacuum UV is anything below 200 nm. Typically anything with a wavelength between 4 nm and 400 nm (nm = nanometer = 10 -9 m) is called UV light. Ultraviolet (UV) light is basically light that has a shorter wavelength (and higher frequency) than visible light. They can also be madeĪrtificially.just visit the nearest tanning bed for all the UV rays you want.Īnswered by: Paul Walorski, B.A. Sunburn, deterioration of some materials, and other effects. Upper atomosphere's ozone layer to different extents. You don't need to make it artificially, since the Sun emits UV rays that penetrate the In this scenario, however, UV light is being emitted, not received. Part of the electromagnetic spectrum if you and the source of UV radiation are receding fromĮach other at a high enough velocity to red-shift high frequency UV waves into the visible Sensitive to UV convert it into a form that we can see. Is there any way to see ultra violet light, or make it? Asked by: Alex Reinischīy definition, ultraviolet light is 'beyond violet light' and the visible spectrum that canīe detected by the human eye.
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