x__heavenly__x Posted May 6, 2004 Share Posted May 6, 2004 I raised this Question to my Physics teacher and he thought it was OK. However I like to share it here. IMAGINE: A 5 inch sphere covered with a perfect reflecting meterial inside(if there is such a thing!). And there is a pin hole in the sphere through which light or laser is blasted with pretty high illumination. and the pin hole is closed in apropriate time so that the light remains inside. SO: 1.Will the light remain inside? 2.What will happen when we open it in a dark room? 3.Will the light fade away(it shouldnt though)? 4.Can it be used as a reservoir. Link to comment Share on other sites More sharing options...
alext87 Posted May 6, 2004 Share Posted May 6, 2004 This may be true but i think that you would have to have a vacuum in the sphere. However with light you also always get some heat therefore the reservoir would lose heat energy and therefore the light inside would slowly run out. This means that it may work but only for a small period of time. A similar idea has already been done with 'slow glass' so that the light is directed into a type of glass which slows down the speed of light to about 1cm/yr this means that the light can be stored for a few years - not 100% sure though. Link to comment Share on other sites More sharing options...
aommaster Posted May 6, 2004 Share Posted May 6, 2004 One thing. I don't think you would be able to see the light, therefore, prove that it works, because if u did, then, the energy would be lost. That should already answer the question about the dark room. If it is 100% reflective inside, then, it would appear black in a dark room! {edit} Correct me if i am wrong guys. I am just putting my knowledge to test here Link to comment Share on other sites More sharing options...
fafalone Posted May 6, 2004 Share Posted May 6, 2004 The problem arises with getting light in without it very nearly instantly escaping. Link to comment Share on other sites More sharing options...
Cap'n Refsmmat Posted May 6, 2004 Share Posted May 6, 2004 Close the hole before it reflects back. Link to comment Share on other sites More sharing options...
fafalone Posted May 6, 2004 Share Posted May 6, 2004 When you invent a mechanism that closes at a good fraction of the speed of light, be sure to let the world know. Link to comment Share on other sites More sharing options...
x__heavenly__x Posted May 6, 2004 Author Share Posted May 6, 2004 actualy closing the hole is easy if u have the surrounding environment full of the same light so that same comes out that goes in and wen u close it, there is somethng inside. And yes heat can be a problem...but we do have supercooled reflectors!? Link to comment Share on other sites More sharing options...
Tesseract Posted May 6, 2004 Share Posted May 6, 2004 You should patent this, before someone else thinks of it. Anyway you could build the light projecting device right into the reflective surface you you wouldnt need and hole. Link to comment Share on other sites More sharing options...
Ms. DNA Posted May 6, 2004 Share Posted May 6, 2004 A similar idea has already been done with 'slow glass' so that the light is directed into a type of glass which slows down the speed of light to about 1cm/yr this means that the light can be stored for a few years - not 100% sure though. I read a science fiction story using this "slow glass" a couple of months ago; maybe later when I have more time I can post the URL. Link to comment Share on other sites More sharing options...
Glider Posted May 7, 2004 Share Posted May 7, 2004 Close the hole before it reflects back. That's a bit like a bomb disposal engineer saying "I'll put me tin hat on if it stars exploding" Link to comment Share on other sites More sharing options...
aommaster Posted May 7, 2004 Share Posted May 7, 2004 4.Can it be used as a reservoir. well it can't if u think about it. The second u start to use up the energy, then, it disappears. This is all according to the law of conservation of energy! Link to comment Share on other sites More sharing options...
swansont Posted May 7, 2004 Share Posted May 7, 2004 There is no such thing as a perfect reflector, so any pulse will quickly dissipate. Even .999n goes to zero when n=ct/L gets large. (L is the size of the device, c is the speed of light) In one dimension, using two mirrors (typically confocal), you can do this - if you keep adding light the power grows much higher than in the incident beem. It's called a "power buildup cavity." Link to comment Share on other sites More sharing options...
Sayonara Posted May 7, 2004 Share Posted May 7, 2004 well it can't if u think about it. The second u start to use up the energy, then, it disappears. This is all according to the law of conservation of energy! Errr... that's what reservoirs are for. Link to comment Share on other sites More sharing options...
x__heavenly__x Posted May 7, 2004 Author Share Posted May 7, 2004 well using the light-slow-down-crystal insted of air in the cavity can do something?? like it will take years for it to reflect and light dosnt die away. Link to comment Share on other sites More sharing options...
swansont Posted May 7, 2004 Share Posted May 7, 2004 well using the light-slow-down-crystal insted of air in the cavity can do something??like it will take years for it to reflect and light dosnt die away. I'd like to see a reference for the "slow glass." I know that people have slowed or "trapped" light using coherence properties of vapors, and electromagnetically induced transparency. But 1 cm/year in a solid? I need a cite. But, in addition to there being no perfect reflectors, it's also true that nothing is 100% transparent - light will get absorbed. Link to comment Share on other sites More sharing options...
Guest vishnu_einstein Posted May 7, 2004 Share Posted May 7, 2004 a very good idea of traping light! u can trap the light inside,but what is the use.because i can always produce photons at the cost of some energy(because there is no conservation law for number of photons).then why should u go for storing the photons. there is major problem in this.you may not trap the light for long time because of lot of technical problems.it is easy to store it as electrical energy. Link to comment Share on other sites More sharing options...
x__heavenly__x Posted May 7, 2004 Author Share Posted May 7, 2004 How about storing messages in the spheres...like light pulses and then transporting it somewhere else to retrieve the data. Maybe just an expariment, you know something interesting might pop up. Link to comment Share on other sites More sharing options...
aommaster Posted May 7, 2004 Share Posted May 7, 2004 Errr... that's what reservoirs are for. But isn't a reservoir a thing to store something for later use? Link to comment Share on other sites More sharing options...
Sayonara Posted May 7, 2004 Share Posted May 7, 2004 Yes. You can't have your cake and eat it. Link to comment Share on other sites More sharing options...
aommaster Posted May 7, 2004 Share Posted May 7, 2004 so, if you use the energy stored into the reservoir, you basically use the energy from the light, decreasing it. This leads us back to: well it can't if u think about it. The second u start to use up the energy, then, it disappears. This is all according to the law of conservation of energy! Link to comment Share on other sites More sharing options...
Sayonara Posted May 7, 2004 Share Posted May 7, 2004 Yes, which is true. But you said "well it can't [be used as a reservoir]", whereas what you were describing sounded pretty much like a reservoir. Link to comment Share on other sites More sharing options...
Bryn Posted May 7, 2004 Share Posted May 7, 2004 If this is possible is there a finite amount of light you can put into a finite amount of space or is the amount of light you can store infinite? Link to comment Share on other sites More sharing options...
aommaster Posted May 7, 2004 Share Posted May 7, 2004 Well, we first have to answer the question "Does light have mass?" Then work out from there! Yes, which is true. But you said "well it can't [be used as a reservoir]", whereas what you were describing sounded pretty much like a reservoir. Ok sorry! MY bad! Link to comment Share on other sites More sharing options...
Bryn Posted May 7, 2004 Share Posted May 7, 2004 light doesn't have mass afaik, otherwise it would be incapable of moving at the speed of light. Link to comment Share on other sites More sharing options...
Dave Posted May 7, 2004 Share Posted May 7, 2004 light doesn't have mass afaik, otherwise it would be incapable of moving at the speed of light. A bit more accurately put, photons have no mass. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now