Shygirl Posted August 10, 2007 Posted August 10, 2007 is sound energy? if yes.. what kind? are ocean waves energy? what kind? is light energy? "i know yes" what kind? is heat energy? if yes what kind? does light cool or heat up? is light a solid? what happens to light when it hits somthing? they say the faster somthing goes the more mass it gains... is this true? or is it.. the more mass it has the faster it goes.... why is this? does the mass fuel it? does light age? does gravity affect light? what color is a mirror? white? "it bounces light right..?" is sound energy? if you go swimming...and you dive 8 feet down... its a sunny day and the sun still shines on you..... you do down 40 feet... its dark... the water molecules stop the light? sound can travel through water... waves can move through water... but light doesnt have the energy to move through water?
Klaynos Posted August 10, 2007 Posted August 10, 2007 This looks a bit like homework, but it's the summer, so I'll reply as if it was and if it isn't answer better later one... OK, the first 4 questions are basically "are waves energy", so what do you think, are they? Do things get hot in the sun? No light is not a solid, a solid is a macroscopic idea, the word "light" can be applied to a single photon. This is quite complicated and depends on what it hits, if it is homework what is your education level, if not I'll get back to you OK, relativity, to an observer, 2 objects that when they are stationary have the same mass, when they are moving with 2 differnent speeds relative to the observer the faster one will appear to have a greater mass. This a result of the 2 postulates of special relativity, thta the physical laws are the same everywhere and that c is invariant. What is there to age it? How could it age? Can any subatomic particle age? Have a look on wikipedia at gravitational lensing. What is colour? There are difference between the way most coloured thing reflects and the way most mirror things refelects.... See first comment. Sound and waves both use the water as a propagation material, and therefore their absorption is significantly lower than that of light through water.
timo Posted August 10, 2007 Posted August 10, 2007 is sound energy? if yes.. what kind? No, but sound is directed motion of moelcules (air, water or whatever the sound travels through). Motion of molecules is kinetic energy. are ocean waves energy? what kind? No, but they are quite similar to sound in also being directed motion of molecules. They also have energy. Quite a lot, actually. There's attempts to harness the energy of ocean waves comercially. is light energy? "i know yes" what kind? Light is not energy. is heat energy? if yes what kind? Dunno, but it's related for sure. does light cool or heat up? Depends. For everyday-physics I'd say test it on a nice summer day. In more advanced applications light can also cool down -> laser cooling. is light a solid? No. what happens to light when it hits somthing? The electrically charged constituents of something react with the light or not. they say the faster somthing goes the more mass it gains... is this true? Depends on your definition of mass and the something. "No" imho is the better choice, the "yes" crowd uses a definition of mass that I simply call energy. or is it.. the more mass it has the faster it goes.... why is this? does the mass fuel it? A biker can overtake a car in a traffic jam. does light age? Yes, that's why you should take important photos at a studio of a professional photographer. does gravity affect light? Yes -> Gravitational lensing. what color is a mirror? white? "it bounces light right..?" dunno is sound energy? Depends on the band. if you go swimming...and you dive 8 feet down... its a sunny day and the sun still shines on you..... you do down 40 feet... its dark... the water molecules stop the light? Yes. sound can travel through water... waves can move through water... but light doesnt have the energy to move through water? Neither of the three waves has an infinite range and neither is completely stopped, they dimish gradually.
RyanJ Posted August 10, 2007 Posted August 10, 2007 is sound energy? if yes.. what kind? I'd have to say no, not directly but it can be used as an energy source. As Atheist points out a sound wave is just the air moving and therefore it has kinetic energy. There are however uses for it as an energy source in chemical reactions and in physics. Sonochemistry and Sonofusion. are ocean waves energy? what kind? Not directly. See above. is light energy? "i know yes" what kind? Light (in particle form anyway) is considered to be composed of a stream of particles called photons. These are defined as being as being light quanta which again are defined as being indivisible units of energy. therefore I'd have to say that light would be classed as energy. is heat energy? if yes what kind? A tough one. Seeing as heat is simply the measure of how fast a particle "vibrates" its sort of difficult to specify it as an energy source. does light cool or heat up? Both. See Atheist's post. is light a solid? Nope. It isn't. what happens to light when it hits somthing? Depending on what the substance is any number of things can happen. For example all elements in a gaseous state absorb photons with different wavelengths, this is done by electrons absorbing the photon and rising to a higher energy level in the molecule. This is used in spectroscopy to identify compounds and such. There are other things that can happen however. they say the faster somthing goes the more mass it gains... is this true? or is it.. the more mass it has the faster it goes.... why is this? does the mass fuel it? It depends I guess but I'd say no. From a relativistic point of view however it makes things awkward as I understand it. Energy has a rest mass of 0 meaning that you can't gain mass directly from it however from an external observers point of view the relativistic mass will be seen to increase. does light age? Nope. As you get closer and closer to the speed of light time is slowed down for you relative to everything else (time is shown to progress more slowly for toe object travelling at near light speed than those who aren't.). Imagine that every particle in the universe were wearing a watch. As something moves closer and closer to the speed of light an outside observer looking at watch of the particle would see it tick every more slowly until at the speed of light it would stop altogether. Light lives the eternal dream never to grow old (again this is from a relativistic point of view, the particle its self doesn't observer this effect and instead sees every other particles clock as speeding up while its remains the same). does gravity affect light? Yes it does. Gravitational lensing is a great example. what color is a mirror? white? "it bounces light right..?" I don't see the point in this question. is sound energy? You asked this question already. if you go swimming...and you dive 8 feet down... its a sunny day and the sun still shines on you..... you do down 40 feet... its dark... the water molecules stop the light? Yes. More and more of the photons have collided with water molecules and so there are less and less as you go deeper, leading to the gradual decrease in ligt intensity. sound can travel through water... waves can move through water... but light doesnt have the energy to move through water? I don't really understand this question.
someguy Posted August 10, 2007 Posted August 10, 2007 is sound energy? if yes.. what kind? are ocean waves energy? what kind? these are both the same. you just can't hear waves because they are at such low frequency. the type of energy is motion. motion of things that are connected. molecules move around freely but they are still bonded together despite this (like one molecule will move and another would replace it so ultimately the bond is never broken). is light energy? "i know yes" what kind? this is a complicated question, and i would feel like saying "light" kind. maybe also like a wave through space-time.. but i think they once thought that and don't anymore. it is also regarded as a particle, but it is massless and therefore can move at the speed of light. is heat energy? if yes what kind? motion of particles within a body. does light cool or heat up? no light is not made of particles with mass it has no temperature, though it has the capacity to heat things up. is light a solid? no what happens to light when it hits somthing? it depends what it hits, sometimes it gets absorbed by the thing sometimes it reflects off of it. they say the faster somthing goes the more mass it gains... is this true? or is it.. the more mass it has the faster it goes.... why is this? does the mass fuel it? all of the universe is made of energy. motion is energy, mass is energy. to increase the speed of an object with mass adds more energy to that system and causes it to increase in mass. does light age? no from light's perspective it already is where it is going. does gravity affect light? yes, gravity is a curve in space-time and light is affected by the curve. what color is a mirror? white? "it bounces light right..?" silver. i'm not sure why exactly a white object reflects all light and mixes it all up so that it looks white but a metallic or silver object keeps it organized so that it looks on the way out the same as it did on the way in. is sound energy? everything is energy. if you go swimming...and you dive 8 feet down... its a sunny day and the sun still shines on you..... you do down 40 feet... its dark... the water molecules stop the light? yes. so does air, i would guess even glass at some point if it were thick enough would stop light from passing through. i think every material at some thickness would stop light from passing through. sound can travel through water... waves can move through water... but light doesnt have the energy to move through water? waves, most of them, the common ones, are caused by the wind blowing so their energy is constantly being fed. the tsunami was a huge wave caused by a shift of the earth underneath it pretty much all at once. the tsunami eventually subsided, even if there was no land this would have eventually happened (it did go around the world a few times or at least once i think though, it's just it was really weak by the time it got to america). since moving the water requires energy if you only give the wave a set amount of energy in one go, eventually all that energy will be used up on moving the water and the wave will die out. light dies out for a different reason but they both can't move through water forever.
Shygirl Posted August 10, 2007 Author Posted August 10, 2007 lol its summer vacation im going into 9th grade.. so dont think its homework... just a bunch of questions on my mind.. and now i know so thanks lol im smarter!
iNow Posted August 10, 2007 Posted August 10, 2007 It would probably be beneficial for those discussing this to first agree on a definition of energy. You can see, after just a handfull of posts, great amounts of disagreement on the specific questions, much of which I think would be ameliorated by first agreeing on a definition.
Shygirl Posted August 10, 2007 Author Posted August 10, 2007 isnt a photon somthing you could in theory phisically touch??? if not... then how do you know it exists? if it doesnt exist... then.. ow my brain
swansont Posted August 10, 2007 Posted August 10, 2007 isnt a photon somthing you could in theory phisically touch??? if not... then how do you know it exists? if it doesnt exist... then.. ow my brain Now we have to define what it means to touch something. Photons can interact with your skin. They can also pass right through you (think x-rays). A photon is a quantized bit of an electromagnetic vibration/oscillation. One of the earliest bits of evidence they exist, as opposed to just having waves, is the photoelectric effect, in which light of sufficient frequency can ionize an atom and cause an electron to be ejected. The ability to ionize doesn't depend on the intensity, though (that changes only the number of electrons ejected) This isn't consistent with a wave, but is consistent with a localized interaction, as with a particle.
someguy Posted August 10, 2007 Posted August 10, 2007 you can't see or touch gravity, yet you know that it exists. you don't always need to see or touch or use any sense to know that something exists. from doing experiments and observations and tests and asking the right questions you can deduce that something must exist with certain properties. so you take those properties, and give them a name. and now that thing exists to us. like a photon. or an atom. but sometimes we figure out we were slightly wrong about part of the definition or that thing becomes part of a larger definition because of new observations we make with better tools or whatever. so we are never really certain exactly what everything is. but the more we know, the more things tie in together nicely, the more we can be sure of how accurate we are. besides, our senses are kind of tricky and do not truly display the outside world as it is. the outside world exists just as it is without the existence of human senses. so in a way anything that you say about the outside world that you used your senses to described is not a natural fact of the object. it is a fact of how that object reacts to our senses. a wave in the water is just the same as any other sound. your ears are not designed to transform that low of vibrations into sound. this can be a difficult thought to get your head around. so sound and color are fabrications of your brain. but the photon, the wavelength of light, and wavelength of sound parts are all facts of the universe its only the actual sound part and color part that your mind invents.
Cap'n Refsmmat Posted August 10, 2007 Posted August 10, 2007 isnt a photon somthing you could in theory phisically touch??? if not... then how do you know it exists? if it doesnt exist... then.. ow my brain Photons are interacting with you all the time - it's how you see. It's not quite "touching," though. Photons can be absorbed by other particles (like the ones that make up the inside of your eyeball) and give their energy to whatever it is that absorbs them.
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