How does Glowing work?
814295
Phosphorescence is a process in which the energy absorbed (light) by a substance is released in the form of light at a different wavelength. The strength of the light diminishes over time and eventually fades out as the absorbed energy dissipates. \n\nNow let's look at fluorescence in posters or other items. A "black light", which is really just a bulb that illuminates mostly in the blue and ultraviolet and will cause a picture or item painted with fluorescent materials to “glow” in the dark. Those items absorb the short-wavelength blue light, and re-radiate the energy at the longer green and yellow wavelengths. Without fluorescence, the posters would appear as blue as the rest of the room would appear under the “black light”, rather than colored. This is the mechanism used for 'glow in the dark' materials which are 'charged' by exposure to light which is the energy source absorbed and re-emitted by the item without fading! As soon as the light is turned off the posters or items cease to emit light.
818868
I suspect this refers to how flourescent light bulbs generate a quasi-continuous spectrum as opposed to the discrete emission lines like other self respecting plasma discharge tubes.  \n\nHere is a website that has several pages on Flourescent Lamps:\n\nhttp://home.howstuffworks.com/fluorescent-lamp.htm\n\nThe first two or three are the ones useful to you.  Also there are several links on the last page under More Great Links that will help you in your researches.  Happy hunting!\n\nBTW: This reeks of an intro science class lab write-up question.  TAs at help desks or profs during office hours can help a great deal more effectively than something like yahoo answers, if you want to truly understand.
1046132
A star produces it's own light, a planet does not, it merely reflects the light of the star. Because a star producing it's own light, it will glow brightly, dim, then glow again........this is the twinkling effect, much like the flame from a match, or any burning fire. :)
465942
I don't know but if you make one you can use those glow necklaces (hot glued on) in several rows to make the body glow...how cute would that be????
827893
It works on photo electricprinciple.\n\nBasic is a light source and a reflective surface(mirror).\n\nCircuit either stay normaly open or shute but when the beam is broken it provides a signal which in turn operates a system, say bell or a motor, that can open a door.
223171
The same way all lasers work.Light energy is bounced back and forth within the structure of a certain material (rubies work) until the atoms are "pumped" into an excited state.  When the atoms of the material are excited enough, they emit light of only one wavelength (coherent light).\nCoreherent light will travel out whatever size aperature the device has, and not be inclined to spread and dissipate the way full spectrum light does.
313639
Nothing.\nUnless they are connected to a power source...\nThen power is teransferred to the other.\nThe spark you see is the power jumping the last few microns to make the connection.
1121249
Fireflies produce light via a chemical reaction consisting of Luciferin (a substrate) combined with Luciferase (an enzyme), ATP (adenosine triphosphate) and oxygen. When these components are added, light is produced. \nThere are several theories on how fireflies control the "on" and "off" of their photic organs. However, the exact mechanism(s) has yet to be worked out. The "Oxygen Control Theory" is based on the firefly turning on and off its light by controlling the oxygen supply to the photic organ for use in the chemical reaction. The "Neural Activation Theory" hypothesizes that fireflies have neural control of structures called "tracheal end cells" which, upon stimulation, may release a messenger molecule in the photic organ which initiates the activation of the chemical reaction. Regardless of how fireflies control the "on" and "off" of their bioluminescence, the production of light in the above manner is very efficient. I think fireflies, or "lightning bugs" are amazing...another little demonstration of God's wild imagination.
159810
Don't be ridiculous, radioactive stuff doesn't glow. However, Hollywood screenwriters think it does. \n\nIn some instances high-energy radioactive particles will cause other stuff to glow, but that's an exception, not the rule. On old radium watch dials the radioactivity from the radium would cause zinc sulfide to fluoresce, but you cannot see the radioactive particles themselves. Radium by itself will not "glow green" and you cannot see electrons or alpha particles unless they react with something (e.g. the phosphor screens in oscilloscopes).
46196
I hope you don't take this to be something of a cop-out answer. Light is itself an electromagnetic field that is carrying energy through space -- commonly called an electromagnetic wave or 'light'. It is this wave that really makes things visible.\n\nConversely, if you have no electromagnetic wave or one of an invisible wavelength, (at least to the human eye) then it won't bounce off of the object or if it does it won't be visible when it reaches you.\n\nThe visible properties of an object are determined by how EM waves interact with the electrons near the surface of an object. These interactions are what make shiny things shiny (for instance).
157911
use a blacK light and see what happens
1091509
The short answer to your question is: chemicals.\n\nSome insects glow all over, and some only in certain places. Some glow all the time, and some only in bursts or flashes. In any event, the glowing is caused by the oxidation of luciferin by luciferase. In English, a specific chemical (called "luciferin" by early physiologists because it could "ignite," so to speak, to make light... "lucifer," get it?) is chemically changed ("oxidized;" electrons are removed from it resulting in its acquiring a positive charge) by a special enzyme ("luciferase;" an enzyme is a special kind of protein that speeds up chemical reactions). Chemical reactions can be of two basic types, one kind requires energy, and the other kind gives off energy. This luciferase-luciferin reaction is of the "energy-giving-off" variety. By "energy given off" scientists mean to say that some form of energy can be detected. The are more than a few forms of energy: heat is probably the most common kind of energy given off by a chemical reaction, but light (radiant energy) is also seen in many reactions. Incidentally, the luciferase-luciferin reaction also gives of heat energy, but it is negligible (98% of the energy is given off as light). \n\nIn lightning bugs, this reaction occurs in special cells on the ventral side (belly) of the posterior (rear end) abdomen (last segment of the insect). The special cells are probably derived from fat cells, and are sandwiched between a reflective layer of cells inside and a transparent cuticle ("skin," sort of) outside. These cells are under the control of the nervous system, which will supply the additional materials necessary to the cells to effect the chemical reaction, stuff like the enzyme itself, oxygen, blood, adrenaline and other compounds. Without some kind of control, the organs would flash all the time or simply stay lit, but you've probably noticed that fireflies only flash at night, dusk being the most popular time.
55361
In flourescent lights electricity passes through a gas (i.e Neon)to create the light. This is much more efficient as very little heat is produced. Unlike incadescent ones,which create a lot of heat.
1057725
As electricity flows into certain atoms (which make up LEDs), energy is transferred to the electrons in the atoms.  Those electrons absorb energy and rise to a higher excited state.  At some later point in time, those electrons fall to a lower energy state.  The difference in energy between the higher state and the lower state is emitted as a photon.  The amount of energy in the photon determines the color.
674006
By tube lamps I will make the assumption you are talking about Neon tubes.  Generally, Neon tubes are a combination of Neon and Helium with a small amount of Mercury in them.  The inside of the class is coated with white phosphor.  \n\nThe basis of operation is a high voltage transformer is used to cause the Neon gas to rise in energy level to the point it forms a plasma.  This is kind of like a spark that causes  the neon to suddenly glow, the energy emitted by the Neon is then absorbed by the phosphorous and re-emitted as a blueish white light.\n\nTo get the process started requires a higher amount of current then is available from the transformer and in older lamps a capacitor is used as a starter.  This capacitor charges up and then provides the current to get the Neon to start to glow originally.\n\nGenerally, the Neon lamps will only rise to the energy level in the presence of this high voltage from the transformer; however, I have seen cases in which either lightning or High energy radio waves can raise the energy level enough to cause them to begin to glow at a low level.  Generally the wires that are connected to the ends act as antennas and external energy radiated can be enough to cause the Neon to glow.\n\nIn failing neon tubes sometimes a conducting track begins to form on the inside of the lamp moving the conductor ends closer together, if the capacitors are not discharged it is possible that you might see a glow a second or two after the power has been shut off.  The you have another case in which the tube is already failed in that the anodes in the ends of the lamp tubes have broken down and the Neon does not rise in level required to glow.  And though they look like the power is off it is still on only there is not enough power reaching the gas in the tube to cause it to glow.  However, due to random heating or metallic vapor in the tube it is possible that the tubes will start to glow once in a while.\n\nDave Cooke
530435
Get a glowing splint (piece of wood that is still burning out). \n\nPlace near the oxygen and it will glow brighter as it uses the oxygen to burn more.\n\nPlace near the hydrogen and you will hear a 'pop' sound. \n\nHope that helps! :)
185051
They tend to be either vibrating models (vibrating pillows) or strobe.  Like the doorbell/telephone, strobe lights work very well in this application.