Light

Question: Light.....? For the past several days and sometime in my life i've always wondered about heaven. everything from the name to its stories. And then something really struck me. have you ever wondered why is heaven is referred to as the light. you know "come into the light" , movies, dreams, and other things have a "light at the end of the tunnel", well my question is, is there some meaning of this? maybe reoccuring dreams of light shining and theres always someone there means something. maybe we have the science to say that light has other identities.or other meaning to mankind. ? i don't know but, this is really fascinating.. just go outside on a bright shiny day and stare at the sun and you'll feel some tranquility for those few seconds.

Answer: Perhaps it has to do with the idea that God is the light. On the first day of creation, God made light. The opening of Genesis tells the biblical story of creation and how it was completed. The first verse of Genesis 1 begins with a description of how God created Heaven and Earth. The text thus begins by establishing a series of dualisms - heaven and earth, light and dark, day and night, etc. So, in the beginning of God's creation...when the earth was without form and empty..., God said, "Let there be light". In the beginning, Heaven was the light and the Earth was empty and dark until God spoke and said, "Let there be light". We associate light with God and Heaven - safety, profound peace and enlightenment - and perhaps our subconscious knows we could be going home to God when we are called by the light.

Question: What type of lighting should I get for taking photos in a room with no natural light, such as a basement? I am getting ready to finish my basement and will be designing an area with backdrops, etc. so that I can take pictures of my son. I have a decent camera for a point and shoot (Canon A630)...and am hoping to start taking some portrait shots of my 1 year old. Since the basement has little to no natural light, I am wondering what type of lighting I should install in order to get quality photos. Do I need to invest in lighting specifically geared towards photography or can I re-create that type of lighting by finishing out the area with a certain type of light? I don't know much about the different types of photography lighting available, but I can use some of the advanced options on my camera. I am definitely still an amatuer in photography, but I am hoping to improve. Any advice or tips would be greatly appreciated!

Answer: You didn't say whether your camera was digital or uses film. If it uses film, the "color" of the artificial light and the amount of it will be more important than if it's a digital camera. For indoor "portrait" photography, generally the lights are set up in a particular way, generally one on each side of the front of the subject and angling down, and possibly one shining on the hair from above. You can make the shadows and even tones be any way that looks good to you, but it's best to read about what creates what effect before you try to photograph a child. In fact, if your one year old is walking, you probably will do better to take the photos outdoors, or at least have the area well and evenly lit so that you can follow him/her all around! You might want to check out some of the info on the page on photography at my site: http://glassattic.com/polymer/photography.htm ... it has lots of tips about doing all kinds of photography with artificial or natural light, as well as various good links on general photography, you can check out. I'd recommend buying a book on "photographing people" too because so much of the info will be condensed there, along with visual examples... Kodak or some other company used to put out some good ones on various topics, including that one. In fact, it's probably at the library too, along with others. Good luck! Diane B.

Question: How do Light dependent resistors work in automatic street lights? I understand that as the light intensity increases the resistance decreases and vice versa in an LDR. But I don't know why, shouldn't it be the other way around because in the morning when there is high light intensity shouldn't it there be high resistance to prevent any current to light up the bulb. And at night when there is low light intensity the resistance decreases to allow more current to light up the bulb. Thanks!

Answer: By allowing the resistance of the LDR to decrease, this allows the extra current to operate a relay which will cut off the supply to the bulb. Once the resistance increases on the approach of darkness there is insufficient current for the relay to operate and the connection to the bulb will be re-instated. Nowadays, instead of using mechanical relays a solid state (transistors, etc) circuit is used.

Question: How much light is required for java moss to thrive? I know java moss is the kind of plant that you can just leave in water and it will grow, but I'm wondering what kind of light it thrives under. It is a low-light plant - does that mean it CAN survive with very little light, or does it mean that it THRIVES under very little light? (ie, is it possible for java moss to suffer because it is getting too much light?) So basically, the more light the better?

Answer: i use on my planted tank 20 g. 6500K lighting from corallife which is very good on my plants and java moss. Also i use a turbo co2 system. It will make your java moss grow crazy of course. But i have had them in low lighting. there is a fine line as it can grow dark and brown. so you should look into a 6500K bulb... it was about 10 dollars.

Question: What happens to light after passing through a pane of glass? Please read this before answering... I understand that visible light is transparent through glass, where as ultraviolet and infrared are not, and I understand how that works. I also understand that because of absorption and remission of light slows the light down as it's passing through the glass. What I don't understand is, what happens after the light has already passed through the glass? Does it resume its' previous speed, or does it maintain the speed the glass created until the lights' energy is absorbed completely?

Answer: Good job on spelling infRared correctly... Drives me nuts. Ultraviolet can pass through glass, unless it has a UV coating to reflect it. Visible light either is absorbed by a surface and emitted back as heat (infrared) or reflected back as visible light. When you look through a window and see what's inside, that is the visible light coming back out. The speed of light is constant in space, and is somewhat slower in air. It's speed is dependent upon the medium through which it is CURRENTLY traveling, not the one it just went through. Most glass has a reflectivity for infrared pretty close to 100%. I am a certified thermal inspector and will gladly post pictures of the sky, houses, etc if you have specific needs relative to IR.

Question: What type of light bulb produces the clearest light? I'm really sick of the yellow tint that incandescent and compact fluorescent bulbs have, and am looking for something that produces clear white light. LED lights are clear, but a bulb full of those is really expensive. Does anyone know about halide lights, or another type of light?

Answer: Halogen give off very white light.

Question: What happens to light passing through even thin clouds of dust? A) The light that passes though them is blue shifted due to the cloud's approach. B) Its motion causes all light to be red shifted as it passes through these clouds. C) Its motion causes the light of stars beyond to twinkle. D) It dims and reddens the light of all more distant stars. E) Even a little can completely block all light, such as the Horsehead Nebula.

Answer: D) It dims and reddens the light of all more distant stars. The reason is that all wavelengths are absorbed, but blue light more than red light for a given thickness of dust.

Question: Why does my recessed light continually turn on and off on it's own? I have a recessed light on a 20 amp circuit. It is on a three outlet switch in a bathroom. I have the ceiling light, vent fan and recessed light on the same switch. Does the light have a heat overload sensor on it to keep it from getting too hot? The fan and ceiling light stay on while the recessed light will stay on and then go off. After a short time it will come back on. When it kicks off I have tried flipping the breaker and the switch, but it still takes time for it to come back on. Any ideas?

Answer: Most Recessed lights contain a heat sensor that turns off the lamp when overheated. It could be that you just have a bulb that exceeds the rating for your fixture. Never install a 110 watt bulb in a recessed can light. Most of the time they're rated for around a 60 watt bulb. This could be a fire hazard if you continue to overheat the fixture so take precautions to be sure you have the appropriate lamp. When you remove the bulb there will usually be a label inside the fixture telling you not to exceed a certain wattage on the lamp (bulb).

Question: What are the light intensities of each wavelength of sunlight? I, like many others at the moment, have been set a peice of work to plan an investigation into how light intensity of a bulb emmitting similar light to sunlight (specialist bulb for growing plants) changes at its different wavelengths. I would very much appreciate it if someone could find for me a table or graph with a number of wavelengths in nm, and their corresponding intensities in kW/m2/s or similar, for sunlight. Also, if anyone has any more general tips for how to conduct the experiment, I would be very pleased to hear them. My plan so far is simply to use filters to get light of a specific wavelengths and then use a multimeter to measure the resistance of an LDR near to the light, as an indication of light intensity of that wavelength. Most important thing though, is to get a table/graph of some preknown values. Thanks very much.

Answer: You can find many graphs by a google images search for solar spectrum.

Question: How to get more light out of recessed lighting? I have 6 recessed lights in my basement with white solid (not baffle) trims that are sized for R30 with no space on the sides. I would like for these lights to give off more lighting. I have video taped my daughter walking her first steps and other firsts, (we hang out here most of the time) and it's a bit dark. So, I'm thinking I need more light to get better video/photos. Will replacing the baffles (or whatever you call them) give me more light? If so, will reflective be better than step baffle, etc?

Answer: WITHOUT KNOWING THE SIZE OF THE MAX BLUB U CAN USE IN THESE FIXTURES WHICH U MAY WANT TO CHECK, THERE IS ALSO A HEIGHT ADJUSTMENT WING NUT INSIDE AFTER REMOVING THE BLUB WHICH WILL ALLOW U TO LOWER THE BLUB FOR BETTER LIGHT SPRAY. SEE IF THAT WILL WORK. ALSO MAKE SURE U ARE USING THE PROPER FLOOD BLUBS IN THE FIXTURE.

Question: How to install a light switch and additional ceiling lights? I have a ceiling light with a pull chain in my attic. I want to add two additional ceiling lights with pull chains. I also want to add a switch so all three come on at once. I believe to do this, I can take the wire leading to the first light, wire the black and white to the switch, and the grown as well. Then run a new wire to the first light, and then to each subsequent light. Am I over simplifying?

Answer: You basically have it. You keep the black wire black and the white wire white splicing a connection at each box. The black wire is supposed to be the "hot" side so your switch will be a break in the black wire and your white will just be connected without the switch. Do a google on "residential wiring" or "home wiring" there are many sources with pictures and advice.

Question: Can one light bulb in a series of eight recessed lights cause a dimmer switch to stop working? I built a bulkhead above my kitchen counters and installed recessed lighting that runs off of an on/off switch with a dimmer control. After the first light bulb burned out, the dimmer function stopped working. Now they will only turn on and off, but not dim. Is this because of the burned out light bulb or is something wrong with the switch?

Answer: If the lights are wired in series none of them should work at all if one is burned out or missing. If they are actually wired in parallel the dimmer should still be working.

Question: What is the best light to grow a plant indoors? I have a ficus tree in my living room that i am afraid is not getting enough light. What kind of light can i use to give it an extra boost? I want a light i can get easily from like home depot or something, nothing too fancy or expensive. Maybe a compact fluorescent light? Halogen light? My ficus needs you!

Answer: What makes you think it is not getting enough light? Is it exhibiting any signs of low light? Natural light is the best. Otherwise you will have to light it from above... with a full spectrum fluorescent bulb.

Question: What can I do about fluorescent lights that sometimes take hours to light? We have a set of fluorescent lights in our kitchen. When we throw the switch: Sometimes they immediately light up. Sometimes they light up after a time. Sometimes they never light up at all. It seems they are taking longer and longer to light up. What should I do to have them light up when I turn them on?

Answer: some flourescent lights have a small aluninum starter. they wear out. pull off the cover and see if it has one. they are pretty cheap.

Question: What is the internal storage drive light and why is it flashing? I have a toshiba satellite lap top. On the right front at the very edge are 5 little lights. 1 is ac power light, 2 is on/off light, 3 is low battery light,4 is internal storage drive light,5 is memory card reader light. My question is what is INTERNAL STORAGE DRIVE LIGHT and why is it blinking? Please help!

Answer: To build on the above answer, during normal use, that light should flash occasionally as you're using the computer, showing that something is being read from or written to the disk. If the light stays solidly on, it means that your disk is in constant use, which either indicates you're copying many large files (normal) or somethings abnormally doing a lot of disk activity that may be slowing down your computer.

Question: What would cause a light fixture to be brighter at times and noticeably not as bright other times? I have a light fixture (a 5 light bulb ceiling hanging dining thing) that seems as bright as a light fixture should be sometimes and dim as if it were on a dimmer set to 50% other times. I can physically see the light bulbs and they are all lit. They're just your stereotypical style light bulb at an average wattage. the light bulbs are 12W

Answer: Could be 2 things: 1) small power surges of electricity 2) the bulbs are getting ready to blow and are burning irregularly because of that. You can have the power company put a surge meter on your line for a week or so to see if the power is surging, If so, the fix is on them. or you can change the 5 bulbs with new ones and see if that remedies the problem. If it doesn't, its a power surge problem coming from your transformer.