The light should be thin and preferbly adjustable in length and width.
122400
My son has a cheap red laser pointer (well under $10)\nwhich has a few "lenses" that he can screw on the\nfront to make different patterns.\n\nI don't know if these things are strictly "lenses",\nbut they distort/focus/shape the laser dot to\nlook like a star, a line, or a couple of other\npatterns.\n\nIn any case, one causes the laser pointer to produce a\n"line" rather than a "dot", and that seems like it would\nsatisfy some of your needs.  The width isn't readily\nadjustable, but the the length would be (by covering\npart of the "line" just past the light source).
445996
Try an incandescent light bulb; Wikipedia says argon is used in them.
514865
Measure them with an accurate measuring device.
565860
yes good lighting and a chair the right height to the computer desk and a beake every other 20 minutes looking around the room and rubbing the neck
198390
You need a parabolic 5-inch reflector which you can get from headlight (but not a sealed beam) or a large flashlight. Or you can use a 5-inch convex lens like the ones used for close-up work (try a hobby shop). You will also need a very small source of light. A flashlight bulb should do. The light source should be positioned at the focal point of the reflector or lens. Since the lens/reflector will not be perfect and the light source will not be a true point, the beam will not be perfectly parallel.\nThe sun IS a near-perfect parallel light source in the context of a 5-inch viewing field. Maybe that's what you meant. I can't see it being used by your construction.
540683
Compact Fluorescent Lamps\n\n  ************************************************************************\n  *                  COMPACT FLUORESCENT LIGHT BULBS                     *\n  *                                                                      *\n  *                       **** Version 1.10 ****                         *\n  *                                                                      *\n  *                      Copyright (C) 1996, 1999                        *\n  *                        Samuel M. Goldwasser                          *\n  *                        Donald L. Klipstein                           *\n  *                                                                      *\n  *        Corrections or suggestions to: sam@stdavids.marconimed.com    *\n  *                                       don@misty.com                  *\n  *                                                                      *\n  *                     --- All Rights Reserved ---                      *\n  *                                                                      *\n  *    Reproduction of this document in whole or in part is permitted    *\n  *    if both of the following conditions are satisfied:                *\n  *                                                                      *\n  *     1. This notice is included in its entirety at the beginning.     *\n  *     2. There is no charge except to cover the costs of copying.      *\n  *                                                                      *\n  ************************************************************************\n\n...\n\n8.  Like other fluorescents, operation at cold temperatures (under around\n    50 degrees F) may cause reduced light output or erratic operation.\n    Some models work fairly well down to about 35 degrees F, others may\n    get noticeably dim below 60 degrees F.  The optimum temperature range\n    of a particular lamp may vary with burning position, generally\n    preferring cooler temperatures if operated base-down.\n    Compact fluorescents may also not like excessive heat.  Some ballasts\n    are unreliable in ambient temperatures much over 120 degrees F.  This\n    is sometimes a problem in enclosed or recessed ceiling fixtures if\n    heat in the fixture builds up.
645015
turn off lights... use a flashlight for sun. see how the opposite side is dark but the front is light.
672898
maybe a lightweight..good luck shorty!
284148
1. a candle and a match, or anything that can produce light. The light can then fill the room.\n2. 7 or should I say SEVEN without the S it's EVEN.
54038
try http://www.audigys.gr  .I know they sell some good lighting lamps and effects from Element Labs. They have a bendable tube (clear in color) which when attaching a power source in it's side gets the tube lighten up in any color you choose! It is also ideal for creating any shape you like! Best news is that it's not expensive stuff.\nAudigys are in Athens, Greece but they are able to handle foreign orders very well and are very friendly people.
378381
The distance from lamp to P is r = √[h^2+s^2], where s = dist from center to P (10m).  The illumination is inversely proportional to r^2, and directly proportional to cos(theta), where theta is going to be arctan(s/h).  So the formula is\n\nI(h) = cos(arctan(s/h))/(r^2+s^2)\n\nBy drawing a right triangle with legs l and h, you can find that cos(arctan(l/h)) = h/√[h^2+s^2] so the formula is then\n\nI(h) = h/(h^2+s^2)^(3/2)  this is the function to maximize w.r.t. h, the independent variable. \n\nTo maximize, differentiate and set to zero, you will get h = s/√2, and you can check it by putting into the formula h = (s/√2)+∆ and h = (s/√2)-∆ where ∆ is a small deviation.
174749
A photodiode will allow current to pass proportional the amount of light incident upon it.
66087
I guess u need a UV light
86958
It will be used in reference to a prism.\n\norange light has more wavelength thanx yellow.
38748
Tightening the string (or making it shorter, or a smaller diameter).
556781
That depends on what you call lighting the room. It is plausible I suppose, but I doubt a 3 cm circle of light would have enough light to do it. In order to get normal light for a mid sized room you will need 2400 lumens or more in that 3cm. That is at least 3 light bulbs.  \n\nMirrors are prefectly suitible way of spreading the light. They don't have to be perfect reflectors either. Concave mirrors would probably work better than flat as they would direct the light to the next mirror better.
332804
reduce your light on the screen if no change see an optician they will advise you