News tagged with visible light
Proposed gamma-ray laser could emit 'nuclear light'
(PhysOrg.com) -- Building a nuclear gamma-ray laser has been a challenge for scientists for a long time, but a new proposal for such a device has overcome some of the most difficult problems. In the new study, Eugene Tkalya ...
May 02, 2011 |
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Invisibility carpet cloak can hide objects from visible light
(PhysOrg.com) -- Most of the invisibility cloaks that have been demonstrated to date conceal objects at frequencies that are not detectable by the human eye. Designing invisibility cloaks that can conceal ...
Jun 15, 2011 |
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Plasmonic device converts light into electricity
(PhysOrg.com) -- While the most common device for converting light into electricity may be photovoltaic (PV) solar cells, a variety of other devices can perform the same light-to-electricity conversion, such ...
Nov 09, 2011 |
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Nano-LEDs emit full visible spectrum of light
(PhysOrg.com) -- Physicists from Taiwan have designed and fabricated nano-sized light-emitting diodes (LEDs) that emit light spanning the entire visible spectrum. Although the tiny full-color LEDs aren't intended ...
Jun 17, 2011 |
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Cantilever bends repeatedly under light exposure for continuous energy generation
(PhysOrg.com) -- With the goal to enable small electronic devices to harvest their own energy, researchers have designed a device that can convert light and thermal energy into electricity. When exposed to ...
Oct 05, 2010 |
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Improving on the amazing: Scientists seek new conductors for metamaterials
(Phys.org) -- Scientists at the U.S. Department of Energy’s Ames Laboratory have designed a method to evaluate different conductors for use in metamaterial structures, which are engineered to exhibit ...
Apr 24, 2012 |
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A breakthrough in superlens development: Cheap, simple lens to let us see a single virus
A superlens would let you see a virus in a drop of blood and open the door to better and cheaper electronics. It might, says Durdu Guney, make ultra-high-resolution microscopes as commonplace as cameras in ...
Jan 09, 2012 |
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'Darkest' world enlightens astronomers about mysterious light-gobbling planet
(PhysOrg.com) -- A giant Jupiter-like gas planet has been revealed to be the most light-thirsty object in the known universe -- a finding that may help astronomers better understand a mysterious characteristic ...
Sep 27, 2011 |
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Infrared Nanotube Films Offer Advantages for Solar Cells and More
(PhysOrg.com) -- Researchers have already known that carbon nanotube thin films have mechanical and conductive advantages that could make them useful as electrodes in solar cells, solid state lighting, and ...
Mar 11, 2009 |
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Will carbon nanotubes replace indium tin oxide?
(PhysOrg.com) -- Up until now, George Grüner tells PhysOrg.com, most of the studies regarding the properties - and uses - of carbon nanotubes have been restricted to the visible spectral range. “We, however, were interested in the ...
Nanotechnology / Nanomaterials
Mar 09, 2009 |
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Novel negative-index metamaterial that responds to visible light designed
A group of scientists led by researchers from the California Institute of Technology has engineered a type of artificial optical material—a metamaterial—with a particular three-dimensional structure such that ...
Apr 22, 2010 |
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New lens doubles the resolution of conventional microscopes
(PhysOrg.com) -- Conventional lenses can resolve structures around 200 nanometers (nm) in size, but scientists in Europe have for the first time developed a lens capable of achieving optical resolution of ...
Mar 25, 2011 |
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New approach to invisibility cloaking gets much closer to the science-fiction version
The idea of being able to become invisible, especially by simply covering up a person or an object with a special cloak, has a perennial appeal in science-fiction and fantasy literature. In recent years, researchers ...
Jan 25, 2011 |
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A single cell endoscope: Researchers use nanophotonics for optical look inside living cells
(PhysOrg.com) -- An endoscope that can provide high-resolution optical images of the interior of a single living cell, or precisely deliver genes, proteins, therapeutic drugs or other cargo without injuring ...
Dec 20, 2011 |
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Chinese scientists create metamaterial black hole
(PhysOrg.com) -- Two physicists in China have used metamaterials to create the first artificial electromagnetic black hole. The scientists, Qiang Cheng and Tie Jun Cui from the Southeast University in Nanjing, ...
Oct 16, 2009 |
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Visible spectrum
The visible spectrum is the portion of the electromagnetic spectrum that is visible to (can be detected by) the human eye. Electromagnetic radiation in this range of wavelengths is called visible light or simply light. A typical human eye will respond to wavelengths from about 380 to 750 nm. In terms of frequency, this corresponds to a band in the vicinity of 790–400 terahertz. A light-adapted eye generally has its maximum sensitivity at around 555 nm (540 THz), in the green region of the optical spectrum (see: luminosity function). The spectrum does not, however, contain all the colors that the human eyes and brain can distinguish. Unsaturated colors such as pink, and purple colors such as magenta are absent, for example, because they can only be made by a mix of multiple wavelengths.
Visible wavelengths also pass through the "optical window," the region of the electromagnetic spectrum that passes largely unattenuated through the Earth's atmosphere. (Blue light scatters more than red light, which is why the sky appears blue.) The human eye's response is defined by subjective testing (see CIE), but atmospheric windows are defined by physical measurement.
The "visible window" is so called because it overlaps the human visible response spectrum. The near infrared (NIR) windows lie just out of human response window, and the Medium Wavelength IR (MWIR) and Long Wavelength or Far Infrared (LWIR or FIR) are far beyond the human response region.
Many species can see wavelengths that fall outside the "visible spectrum". Bees and many other insects can see light in the ultraviolet, which helps them find nectar in flowers. Plant species that depend on insect pollination may owe reproductive success to their appearance in ultraviolet light, rather than how colorful they appear to us. Birds too can see into the ultraviolet (300-400 nm), and some have sex-dependent markings on their plumage, which are only visible in the ultraviolet range.
For more information about Visible spectrum, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
