NounSingular spectrum spectrum (plural spectra or spectrums)
Derived termsRelated termsFrom Wiktionary under the GNU Free Documentation License. A spectrum (plural spectra or spectrums) is a condition that is not limited to a specific set of values but can vary infinitely within a continuum. The word saw its first scientific use within the field of optics to describe the rainbow of colors in visible light when separated using a prism; it has since been applied by analogy to many fields other than optics. Thus, one might talk about the spectrum of political opinion, or the spectrum of activity of a drug, or the autism spectrum. In these uses, values within a spectrum may not be associated with precisely quantifiable numbers or definitions. Such uses imply a broad range of conditions or behaviors grouped together and studied under a single title for ease of discussion. In most modern usages of spectrum there is a unifying theme between extremes at either end. Some older usages of the word did not have a unifying theme, but they led to modern ones through a sequence of events set out below. Modern usages in mathematics did evolve from a unifying theme, but this may be difficult to recognize. OriginsIn Latin spectrum means "image" or "apparition", including the meaning "spectre". Spectral evidence is testimony about what was done by spectres of persons not present physically, or hearsay evidence about what ghosts or apparitions of Satan said. It was used to convict a number of persons of witchcraft at Salem, Massachusetts in the late 17th century. From Wikipedia under the
GNU Free Documentation License What if you could see a different part of the electromagnetic spectrum other than the visable? Q. Imagine being able to see in a different part of the electromagnetic spectrum other than visable. If you were using X-ray; what would it be like to see those waves? How would your perception of your world be different than it is now? Would there be advantages and/or disadvantages? Do not confuse being able to see with that kind of vision (which is NOT what the question is ansking) with being able to see things giving off the electromagnetic radiation you've chosen. For example, being able to see in x-ray part of the electromagnetic spectrum doesn't mean you have x-ray vision. Asked by dave b - Fri Jun 22 14:58:51 2007 - - 1 Answers - 0 Comments A. The part of the specturm to which our eyes are sensitive is the part that is abundant as reflected light from the sun, and is also not emitted to any significant degree by anything else. Being able to see infrared or lower energy light would be confusing, as many objects emit this kind of light, and seeing anything higher wavelength would not be useful as our atmosphere blocks most of it out. Essentially, the wavelengths that we can see developed out of the fact that it provided the most useful sensory information for us to process as a means of seeing. We also have to consider how artificial color is in a sense. Red is only red because that is what we call that particular wavelength when we observe it. If we could see other wavelengths,… [cont.] Answered by Arkalius - Fri Jun 22 15:28:53 2007 What is the tool used in photography that is like a ruler showing the colors of the spectrum? Q. I have sometimes seen a tool in photographs that looks like a ruler covered in the colors of the spectrum. I assumed it was used to process colors consistently, or to show relationships between colors. What is that tool called? Where can I get one? Asked by grad_researcher_1977 - Thu Jul 5 14:58:14 2007 - - 3 Answers - 0 Comments A. Depending on what you saw, if it looked like a ruler with graduations-- it was a Kelvin scale. If it was any other type of chart with patches of color, it was a target. Kelvin measured 'black body radiation' and assigned grades to the color of visible light in ratio to his scale. Thus, a 'black body' emitting low levels of radiation appears black. The same black body, when heated to more than 5500K the same 'black body' would emit nearly 'white light' radiation. Above 6000k, the same body would generate blue spectral wavelengths. Though this scale is used to measure radiation, it has become a standard measuring scale for any devices producing or capturing light, such as light bulbs and cameras. This is known as color temperature. … [cont.] Answered by Otto P - Thu Jul 5 16:40:42 2007 How did Bohr's 4 postulates explain observations and mesasurements of the hydrogen gas spectrum?
Q. I know what Bohr's four postulates are, but I'm not familiar with the measurements of the hydrogen gas spectrum, so I don't really know how they affected them.. Can anyone tell me? How did the four postulates explain observations and measurements of the (hydrogen) gas spectrum? Asked by Caitu - Sat Jul 19 03:30:05 2008 - - 1 Answers - 0 Comments A. When an electron of the hydrogen atom is excited from one level to another, then as a consequence of Bohr's postulate a specific amount of energy would be needed. That is because, the electrons in different orbits possess energy in discrete values. so when the electron is excited it gains some energy to go to a higher level. When it comes back to a level below the excited level, either the same one from which it was excited or to some other lower level, it releases energy, because to remain in the lower level it doesnot require so much energy as was required while it was in a higher level. so it releases the extra energy as radiations having energy equal to the difference in the two energy levels (the higher and the lower energy level).… [cont.] Answered by velocitycric17 - Sat Jul 19 03:59:44 2008 From Yahoo Answer Search: "spectrum"  news.google.com Le Mars Daily Sentinel Mirrors are another interesting item with prisms and colors and all sorts of different ways of managing the variances of the light spectrum (visible and ... news.google.com PitchEngine (press release) 08.16.2009 The Spectrum Services Group has chosen to go pink in the fight against breast cancer and announced their selection of a charitable organization ... and more » news.google.com Meriden Record-Journal There's also a summer intern, 19-year-old Matthew Radler, the first of many on the autism spectrum who will take on the responsibility of running the farm. ... and more » From Google News Search: "spectrum"  inuktun.com 155px x 250px | 9.10kB [source page] Can be used to supplement other crawler systems The control unit for the Spectrum 60 and Spectrum 90 cameras  electronictheatre.co.uk 500px x 352px | 60.70kB [source page] Click to enlarge Sequel to the award winning squad based real time tactical combat game Full Spectrum Warrior Ten Hammers improves on the ground breaking and  abrsm.org 512px x 772px | 137.90kB [source page] Spectrum for Cello composers From left to right Rhian Samuel Gavin Bryars Nicola LeFanu Jonathan Dove Sally Beamish Giles Swayne Richard Causton Alissa Firsova Pianist Thalia Myers with cellists Raphael Wallfisch Steven Isserlis Alice Neary Andrea Hess Gemma Rosefield Denis Vigay Hannah Lloyd Sebastian Comberti and seated at front From Yahoo Image Search: "spectrum"  psfk.com Nicko Margolies hu, 20 Aug 2009 08:30:15 GM It may not look like much, but that little box could be the answer to long distance Wi-Fi connectivity, possibly from a mile away. Yesterday, at the SIGCOMM.  cityweekly.net unknown hu, 13 Aug 2009 05:00:00 GM According to GLAADblogger, The . Spectrum. recently turned down the wedding announcement of a gay couple who legally married in California during that short window in which same-sex couples could marry there. Remember the Cali Supreme ...  openleft.com Paul Rosenberg Sat, 08 Aug 2009 15:30:00 GM Proof that these questions are relatively similar in measuring an ideological . spectrum. comes from comparing the basically symmetrical curve that Sides comes up with against the following curve that measures net support for seven ... From Google Blog Search: "spectrum" |
