cedsci Posted June 27, 2011 Share Posted June 27, 2011 Well I didn't know where to post it but I was asking myself a question today. I'm in no way qualified to attend to a debate about it and my question might be very dumb but well I doubt so. So my question is : Why the light doesn't make sound ? Meaning," A sonic boom is the sound associated with the shock waves created by the supersonic flight of an aircraft. " I know the phenomen goes for everything going faster than the speed of the sound. The light being waaaaay faster , why doesn't it apply to it ? Wich makes me think that light is not material ? (I've heard it was, that's why i'm asking ) thanks Link to comment Share on other sites More sharing options...
rktpro Posted June 27, 2011 Share Posted June 27, 2011 Well I didn't know where to post it but I was asking myself a question today. I'm in no way qualified to attend to a debate about it and my question might be very dumb but well I doubt so. So my question is : Why the light doesn't make sound ? Meaning," A sonic boom is the sound associated with the shock waves created by the supersonic flight of an aircraft. " I know the phenomen goes for everything going faster than the speed of the sound. The light being waaaaay faster , why doesn't it apply to it ? Wich makes me think that light is not material ? (I've heard it was, that's why i'm asking ) thanks Sonic Boom is created due to breakage of the sound barrier. Sound waves are produced at this point. But, breaking the light barrier is theoretically impossible. Link to comment Share on other sites More sharing options...
cedsci Posted June 27, 2011 Author Share Posted June 27, 2011 (edited) that's not what I said . light is breaking sound barrier. so it should make a sonic boom.. why there isn't sonic booms all around us therefor ? Edited June 27, 2011 by cedsci Link to comment Share on other sites More sharing options...
boxerfangg Posted June 27, 2011 Share Posted June 27, 2011 for something to make a sonic boom it has to accelerate up to and through the "sound barrier". light does not accelerate...it starts at the "speed of light" and continues to "travel" at the same constant speed. Source: http://www.theforumsite.com/forum.php?p=1496762 Link to comment Share on other sites More sharing options...
cedsci Posted June 27, 2011 Author Share Posted June 27, 2011 (edited) okay thanks a lot. tho now I'm wondering if it's possible to start at a speed different from 0 lol Edited June 27, 2011 by cedsci Link to comment Share on other sites More sharing options...
swansont Posted June 27, 2011 Share Posted June 27, 2011 Light isn't displacing atoms as it passes through a medium. 2 Link to comment Share on other sites More sharing options...
Leader Bee Posted June 27, 2011 Share Posted June 27, 2011 Light isn't displacing atoms as it passes through a medium. For reflective surfaces that bounce light away how does this work? How does this fit in with Newtons 3rd law? Link to comment Share on other sites More sharing options...
Fuzzwood Posted June 27, 2011 Share Posted June 27, 2011 That works by absorbing and re-emitting the proton, depending on the refractive index of the material. Link to comment Share on other sites More sharing options...
swansont Posted June 27, 2011 Share Posted June 27, 2011 Reflection isn't passing through, and the mirror will recoil from conservation of momentum, in accordance with Newton's third law. 1 Link to comment Share on other sites More sharing options...
Leader Bee Posted June 27, 2011 Share Posted June 27, 2011 (edited) @ Fuzzwood Is this what is known as "Linear Absorption" and applies to any elctromagnetic radiation, not just Photons and the visible EM spectrum? Further to that, does that mean radio/microwave/gamma waves/x-rays are all photon emitters? Edited June 27, 2011 by Leader Bee Link to comment Share on other sites More sharing options...
J.C.MacSwell Posted June 27, 2011 Share Posted June 27, 2011 @ Fuzzwood Is this what is known as "Linear Absorption" and applies to any elctromagnetic radiation, not just Photons and the visible EM spectrum? Further to that, does that mean radio/microwave/gamma waves/x-rays are all photon emitters? They are all photons. If you bounce (or absorb) them off something hard enough, you should hear the result. Link to comment Share on other sites More sharing options...
Klaynos Posted June 27, 2011 Share Posted June 27, 2011 We have laser pulses that have a repetition rate of ~0.5Hz or ~1Hz depending on the beam path. If you place something in the beam you can often hear that. It depends greatly on the intensity though, so I've either got to pick a tight focus or a part of the beam before much splitting has occurred. It's actually alerted me a few times when I've walked into the lab when other people have been using the kit and I've heard that something in their alignment is clipping a mount. It always makes people think you're slightly odd to be trying to fault fix an optics experiment by listening carefully... Link to comment Share on other sites More sharing options...
swansont Posted June 27, 2011 Share Posted June 27, 2011 We have laser pulses that have a repetition rate of ~0.5Hz or ~1Hz depending on the beam path. If you place something in the beam you can often hear that. It depends greatly on the intensity though, so I've either got to pick a tight focus or a part of the beam before much splitting has occurred. It's actually alerted me a few times when I've walked into the lab when other people have been using the kit and I've heard that something in their alignment is clipping a mount. It always makes people think you're slightly odd to be trying to fault fix an optics experiment by listening carefully... I was thinking about things like this after my last response — if there is absorption you can get sound, because the energy is being deposited. But that isn't the case for transmission. Link to comment Share on other sites More sharing options...
Hal. Posted June 27, 2011 Share Posted June 27, 2011 Somebody , who will remain nameless because the night is young and we all would like to get things done before the sun shines again in this part of Europe , previously said that light does not accelerate from below the sonic boom speed to above the sonic boom speed . Let's say I have a torch and soon after I press the electric switch to let the current flow the filament emits light . Is the light just being redirected from somewhere else where it is being stored ? Link to comment Share on other sites More sharing options...
cedsci Posted June 27, 2011 Author Share Posted June 27, 2011 (edited) okay thanks for the answers even if I don't understand everything because it's a bit complicated for me. I'm not a scientist so I use only my intuitive judgement. So ok but I still have some thought that I can't explain why and i would like to understand Speed does not makes sonic boom because isn't subject to acceleration /decelerration. Speed of light = x in the air and y in the water for example. So it passes from x to y without any decc/ acc right ?I can understand just with a yes lol Edited June 27, 2011 by cedsci Link to comment Share on other sites More sharing options...
boxerfangg Posted June 28, 2011 Share Posted June 28, 2011 okay thanks for the answers even if I don't understand everything because it's a bit complicated for me. I'm not a scientist so I use only my intuitive judgement. So ok but I still have some thought that I can't explain why and i would like to understand Speed does not makes sonic boom because isn't subject to acceleration /decelerration. Speed of light = x in the air and y in the water for example. So it passes from x to y without any decc/ acc right ?I can understand just with a yes lol yes, the speed of light is a constant 299,792,458 m/s Link to comment Share on other sites More sharing options...
rktpro Posted June 28, 2011 Share Posted June 28, 2011 Somebody , who will remain nameless because the night is young and we all would like to get things done before the sun shines again in this part of Europe , previously said that light does not accelerate from below the sonic boom speed to above the sonic boom speed . Let's say I have a torch and soon after I press the electric switch to let the current flow the filament emits light . Is the light just being redirected from somewhere else where it is being stored ? You misunderstood that guy! What has been said is an object can cross the speed of sound, but not the speed of light. It is been converted from heat energy. Link to comment Share on other sites More sharing options...
Hal. Posted June 28, 2011 Share Posted June 28, 2011 (edited) The speed of light is a variable , under certain circumstances it is a constant . The constant in vacuum of 299 792 458 m/s is under certain circumstances . I'd love to trace the origin of light from a filament of a bulb and go through what material the light is travelling in and what it's speed is . It's great when you don't know how things work sometimes , it allows interesting questions to be asked . Like , Let's ask these physicists to give us an example of circumstances of how light could travel at 25 000 m/s , And , if they are not too busy , maybe another of 600 000 000 m/s . Is the speed of light in vacuum the fastest light can travel ? Edited June 28, 2011 by Hal. 1 Link to comment Share on other sites More sharing options...
Klaynos Posted June 28, 2011 Share Posted June 28, 2011 The speed of light is a variable , under certain circumstances it is a constant . The constant in vacuum of 299 792 458 m/s is under certain circumstances . I'd love to trace the origin of light from a filament of a bulb and go through what material the light is travelling in and what it's speed is . It's great when you don't know how things work sometimes , it allows interesting questions to be asked . Like , Let's ask these physicists to give us an example of circumstances of how light could travel at 25 000 m/s , And , if they are not too busy , maybe another of 600 000 000 m/s . Is the speed of light in vacuum the fastest light can travel ? Photons and all massless particles travel at c (3x108). When it appears light is travelling slower this is due to absorption and re-emission, which takes a small amount of time, the number of events and the time this takes dictates the speed that the light appears to travel and is quantified by the refractive index (n) or a material. Link to comment Share on other sites More sharing options...
swansont Posted June 28, 2011 Share Posted June 28, 2011 Let's say I have a torch and soon after I press the electric switch to let the current flow the filament emits light . Is the light just being redirected from somewhere else where it is being stored ? No. Photons can be created and destroyed. Collisions of electrons in the filament are causing the creation of photons. The photons are traveling at c (technically c/n) when they are created. 1 Link to comment Share on other sites More sharing options...
Hal. Posted June 28, 2011 Share Posted June 28, 2011 ......................... Photons can be created and destroyed............................................ I once heard photons being described as little pieces of energy . I suspect your statement is not being contrary to conservation of energy principles . ....... Collisions of electrons in the filament are causing the creation of photons....... Overall does this then mean that energy is changing from the form of kinetic energy due to motion of the electrons , into the form of photons ? Link to comment Share on other sites More sharing options...
swansont Posted June 28, 2011 Share Posted June 28, 2011 I once heard photons being described as little pieces of energy . I suspect your statement is not being contrary to conservation of energy principles . They have energy. No, it's not contrary to conservation of energy. Overall does this then mean that energy is changing from the form of kinetic energy due to motion of the electrons , into the form of photons ? Yes. Left to itself, the object cools down because of the radiation it has emitted. Or you drive current through it, and the P=IV=I^2R resistive losses are ultimately in the form of the photons because the filament heats up. Link to comment Share on other sites More sharing options...
preciseenergy Posted July 7, 2011 Share Posted July 7, 2011 I think it is a bit complicated for me to say that.....have no clear idea dude!! Link to comment Share on other sites More sharing options...
gulshan Posted July 24, 2011 Share Posted July 24, 2011 light travels as electromagnetic waves and does not need any mediumm to travel through. sound is produced when the particles of medium get oscillated but when there is no medium htere is no sound Link to comment Share on other sites More sharing options...
AlwaysCurious Posted June 5, 2012 Share Posted June 5, 2012 Hi, im just a yound kid of age 16 who found this web by accident and saw this topic. At the start, the people were arguing about why light could not be used to produce sound. Is it correct for me to say that light and sound are 2 different types of waves, so they could not be converted from one form to another? Although the law of conversation of energy states that energy can converted from one form to another, shouldn't the difference in the way energy is "carried" between the 2 waves make it not possible to make light into sound? Im just a young kid curious about this, please help. ^^ Link to comment Share on other sites More sharing options...
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