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Post by silverdragon on May 31, 2015 9:12:27 GMT
Can sound travel at the speed of light?... Why yes it can... BTW, I read the article, my head hurts. physicsworld.com/cws/article/news/2005/nov/01/could-sound-move-at-the-speed-of-lightReason my head hurts?.. I think I understand whats going on there, and it makes sense. But the speed of sound..... Well, perhaps not, perhaps we found the "minimum" speed and we aint found the upper speed yet?... And just what is sound?.. the sound we here is not what Bats hear, and if they can hear it, its sound isnt it?... |
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Post by OziRiS on May 31, 2015 21:54:56 GMT
Well, a quick google for "what is sound?" produces this answer:
"vibrations that travel through the air or another medium and can be heard when they reach a person's or animal's ear"
By that definition, if no living being would be able to hear it, it's not sound, but that seems a little iffy to me.
Send vibrations through a medium at the same wavelength as visible light and no known living being would be able to hear it, but that doesn't make it any less "sound", does it? If it does, what do we call it then?
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Post by watcher56 on Jun 1, 2015 2:38:33 GMT
Mechanical vibrations at a frequency higher than can be heard are referred to as "Ultrasonic". Google says "ultrasound" is anything above 20 KHz. No upper limit given other than "up to several gigahertz". Since sound travels much slower than does light, getting it to a wavelength on par with visible light may not be as far out as it first seems.
Anyone want to do the math to determine what frequency of ultrasound has the same wavelength as red light (650 nm)?
Looks like about 530 MHz.
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Post by the light works on Jun 1, 2015 4:40:48 GMT
so they are changing both the medium and the frequency of the signal to accomplish it. this is nothing new. Alexander Graham bell accomplished that technology.
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Post by OziRiS on Jun 1, 2015 6:38:57 GMT
Mechanical vibrations at a frequency higher than can be heard are referred to as "Ultrasonic". Google says "ultrasound" is anything above 20 KHz. No upper limit given other than "up to several gigahertz". Since sound travels much slower than does light, getting it to a wavelength on par with visible light may not be as far out as it first seems. Anyone want to do the math to determine what frequency of ultrasound has the same wavelength as red light (650 nm)? Looks like about 530 MHz. Not even close! Scale that up about a million times and you're in the ballpark. Red light is in the 484–508 THz range. en.wikipedia.org/wiki/Visible_spectrumIf red light was only in the 530 MHz range it would interfere with a lot of UHF radio traffic, which it doesn't do. |
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Post by silverdragon on Jun 1, 2015 6:45:01 GMT
We dealt with that one a while back and the results are still to argumentative than clear, if a tree falls.
If sound is produced in a room that is sound proof, and then you remove the only thing in that room that can "hear" that sound, then some people say its no longer sound.
Impossible.
So can we see sound or hear light?...
I see no reason.
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Post by OziRiS on Jun 1, 2015 6:50:59 GMT
We dealt with that one a while back and the results are still to argumentative than clear, if a tree falls. If sound is produced in a room that is sound proof, and then you remove the only thing in that room that can "hear" that sound, then some people say its no longer sound. Impossible. So can we see sound or hear light?... I see no reason. The "if a tree falls" thing is an old philosophical question that was posed long before anyone knew of the physical properties of sound. We now know how and why sound works and (unless you believe the idea that reality only exists when someone observes it, as some quantum physicists like to argue) we can comfortably say that yes, sound does exist, even when no one is around to hear it. At least there's not much evidence to the contrary. If you produce sound in a sound proof room and remove the only thing in that room that can "hear" it, the vibrations are still made. Whether you want to define those vibrations as sound or not is more of a semantics question than one of physics. It's still there and it hasn't changed its properties, so you can call it sound, molecular vibrations or a cocker spaniel for all I care, but it doesn't change anything. It's still the same physical reaction to energy input from a vibrating medium into the molecules surrounding it. |
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Post by silverdragon on Jun 1, 2015 7:43:33 GMT
We dealt with that one a while back and the results are still to argumentative than clear, if a tree falls. If sound is produced in a room that is sound proof, and then you remove the only thing in that room that can "hear" that sound, then some people say its no longer sound. Impossible. So can we see sound or hear light?... I see no reason. The "if a tree falls" thing is an old philosophical question that was posed long before anyone knew of the physical properties of sound. We now know how and why sound works and (unless you believe the idea that reality only exists when someone observes it, as some quantum physicists like to argue) we can comfortably say that yes, sound does exist, even when no one is around to hear it. At least there's not much evidence to the contrary. If you produce sound in a sound proof room and remove the only thing in that room that can "hear" it, the vibrations are still made. Whether you want to define those vibrations as sound or not is more of a semantics question than one of physics. It's still there and it hasn't changed its properties, so you can call it sound, molecular vibrations or a cocker spaniel for all I care, but it doesn't change anything. It's still the same physical reaction to energy input from a vibrating medium into the molecules surrounding it. I think you missed the point, we are arguing the same point that it was sound when it started despite what others may say. But, if it was then altered.... If the wavelength was speeded up, at what pint does it stop being sound on the EMS and start being LIGHT.... Can the frequency of sound be raised so high it becomes light?... And yes I realise you may have to put a lot more energy into it to get that to happen?... |
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Post by silverdragon on Jun 1, 2015 7:46:17 GMT
Additional, I change sound into light every single day of my life, and then back again.
I live with a Fibre Optic Network, where sound files are changed into flashing lights to transmit them over great distances down fibre optic cables, then back into sound waves again...
Its called Television here,......
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Post by OziRiS on Jun 1, 2015 8:24:26 GMT
Sound into light? Won't happen.
Sound can't create photons, the fundamental particle that carries light.
When it comes right down to it, sound files don't contain sound either. They contain data that tells your computer (or TV or whatever other device you're using) how to translate that into vibrations in your speakers, which then produce the sound by vibrating the air inside and around them. If there are no speakers, there's nothing to vibrate the air and there's no sound.
Sound isn't made through the creation of high energy particles, like light is. It's made by vibrating already existing particles. If you place your speakers in a vacuum, no sound would be produced because there wouldn't be any (or at least not enough) particles/molecules to vibrate. Light, on the other hand, is a particle in itself and as such is perfectly fine with existing in a vacuum. It doesn't need anything else around it to exist, except space.
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Post by silverdragon on Jun 1, 2015 8:52:04 GMT
My argument is not of the nature of what sound is, its more on the nature of what produces sound.
If something that vibrates al low frequency and produces sound can be speeded up so fast that it produces sound "at the speed of light", is that still sound, or, is it light.....
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Post by OziRiS on Jun 1, 2015 9:13:47 GMT
My argument is not of the nature of what sound is, its more on the nature of what produces sound. If something that vibrates al low frequency and produces sound can be speeded up so fast that it produces sound "at the speed of light", is that still sound, or, is it light..... Unless you put enough energy into the system for it to produce a photon, what comes out of it will never be light. If it produces a photon, and therefore becomes light, it's no longer sound. |
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Post by watcher56 on Jun 2, 2015 0:42:23 GMT
Mechanical vibrations at a frequency higher than can be heard are referred to as "Ultrasonic". Google says "ultrasound" is anything above 20 KHz. No upper limit given other than "up to several gigahertz". Since sound travels much slower than does light, getting it to a wavelength on par with visible light may not be as far out as it first seems. Anyone want to do the math to determine what frequency of ultrasound has the same wavelength as red light (650 nm)? Looks like about 530 MHz. Not even close! Scale that up about a million times and you're in the ballpark. Red light is in the 484–508 THz range. en.wikipedia.org/wiki/Visible_spectrumIf red light was only in the 530 MHz range it would interfere with a lot of UHF radio traffic, which it doesn't do. Never said red light was at 530 MHz. I said red light has a wavelength (in free space) of about 650 nm. Then I went on to say that ultrasound at a frequency of 530 MHz in air has the same wavelength (650 nm). |
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Post by OziRiS on Jun 2, 2015 6:04:58 GMT
Not even close! Scale that up about a million times and you're in the ballpark. Red light is in the 484–508 THz range. en.wikipedia.org/wiki/Visible_spectrumIf red light was only in the 530 MHz range it would interfere with a lot of UHF radio traffic, which it doesn't do. Never said red light was at 530 MHz. I said red light has a wavelength (in free space) of about 650 nm. Then I went on to say that ultrasound at a frequency of 530 MHz in air has the same wavelength (650 nm). Okay. Misunderstanding on my part. Quick question: I know how to calculate the wavelength of an electromagnetic wave, so when I use that calculation, I come to the conclusion that a frequency of 530 MHz has a wavelength of about 0.5 meters or about 1.8 feet. I also understand that sound isn't an electromagnetic wave, so the same calculation can't be used. It's a mechanical wave that moves at around 330 m/s in air and not the 300,000 m/s that an electromagnetic wave moves at. So, what's the calculation you used to find the wavelength of sound? ADDENDUM: Could you perhaps also explain why you believe the wavelengths have any impact on sound's ability to move at or beyond the speed of light? As far as I know, wavelength isn't a measure of speed, just a measure of distance. |
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Post by silverdragon on Jun 2, 2015 8:17:58 GMT
Ok, now I need help, and maybe someone can do it in a way that I may understand.
So, Light (maybe its red) travels at a "speed" of 530 MHZ....
Is that wrong?...
If anything else is travelling at 530 MHZ, does that make it light?... or can "other things" vibrate at that speed as well?...
If I got a quartz crystal to vibrate at 530mhz, will it start to glow slightly red?....
I get a feeling my understanding of physics has hit a wall (you heard the splut right?..)
I may be confuzzded here.
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Post by OziRiS on Jun 2, 2015 11:06:20 GMT
Ok, now I need help, and maybe someone can do it in a way that I may understand. So, Light (maybe its red) travels at a "speed" of 530 MHZ.... Is that wrong?... Yes, that's wrong. Light (or, to be more scientific about it, an electromagnetic wave) travels at roughly 300,000 km/s or 186,000 miles per second and it doesn't matter what color that light is. From low infrared light to high energy gamma rays, they all travel at the same speed. Frequency tells you nothing about the speed at which something moves. It just tells you how many times per second it oscillates/vibrates. Wavelength is a physical measurement between two full oscillations/vibrations in a wave. Apparently, red light and 530 MHz ultrasound (meaning sound waves that oscillate 530 million times per second) has the same wavelength, meaning that the physical distance between oscillations is the same. But that doesn't mean they move at the same speed. Actually, the reason for them having the same wavelength IS the difference in speed. Because sound moves MUCH slower than light, at around 330-340 m/s in air, the 530 MHz sound wave isn't stretched as much as a 530 MHz electromagnetic (radio) wave, so the distance between oscillations becomes smaller. For example, in one second, a red light wave (depending on the hue of red) will oscillate 484–508 trillion times and travel 300,000,000 meters (like any other color of light). In that same second, a 530 MHz sound wave going through regular atmospheric air will oscillate 530 million times, but will only travel 330-340 meters. This means that the sound wave will have to pack its 530 million oscillations into a much shorter distance than the light wave, making the distance between oscillations the same for both. If the 530 MHz sound wave had travelled at the speed of light (effectively making it a radio wave instead of a sound wave), the distance between oscillations would have been 0.566 meters/1.857 feet. To understand the relationship between speed, frequency and wavelength, imagine a slinky spring. Take one end of the slinky in each hand and grab the middle of the spring with your fingertips. You now have one second to pull the spring as far apart as possible, allowing the coils to slip through your fingertips as the spring stretches. One second and then you have to stop pulling. At that stop, the amount of coils you've managed to pull out is the frequency (coils per second) and the physical distance between each coil is the wavelength. The speed is how far apart your hands have come in that second, regardless of how many coils you've pulled out and how far apart they are. Increase the speed without increasing the frequency (pull longer in that second, but pull out the same amount of coils) and the wavelength gets longer, because there's more space between coils. Increase the frequency without increasing the speed (pull out more coils, but over the same distance) and the wavelength gets shorter, because there are more coils crammed into the same amount of space and thus less space between coils. Double both the speed and the frequency at the same time (pull twice as long and pull out twice as many coils) and the wavelength will be the same. If anything else is travelling at 530 MHZ, does that make it light?... or can "other things" vibrate at that speed as well?... If I got a quartz crystal to vibrate at 530mhz, will it start to glow slightly red?.... Again, frequency is a measure of how many oscillations/vibrations are made per second, not speed. Nothing is "travelling at 530 MHz". It's just vibrating/oscillating at 530 MHz, regardless of how far it travels in a given amount of time. It doesn't mater if it travels 3 feet or 3,000 feet in that second, it still makes 530 million oscillations over that distance. If it only travels 3 feet in that second, the oscillations are very close together and the wavelength is therefore very short. If it travels 3,000 feet in that second, the oscillations are further apart and the wavelength becomes longer. Sound is a mechanical wave, meaning that it works by means of particle-to-particle interaction. There has to be a source of vibration and particles around it (air, water, metal and so on) in order to create sound. The source vibrates and the particles are "bumped into each other". There's a really good explanation of how it works here: www.physicsclassroom.com/class/sound/Lesson-1/Sound-is-a-Mechanical-WaveLight, on the other hand, is an electromagnetic wave, carried by particles called photons that are created when an atom's electrons are excited into a higher energy state (via direct heating or friction for instance) and then drops back down to their ground state, releasing the excess energy as photons of light. Sound doesn't come from the creation of particles. It comes from the manipulation of particles that already exist, so sound can never produce photons of light. Neither can vibrating something at a specific frequency. The vibrations can cause friction that will add energy to the electrons of the atoms, causing them to spit out photons of light, but the vibration in and of itself won't do it. |
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Post by watcher56 on Jun 2, 2015 16:10:51 GMT
Never said red light was at 530 MHz. I said red light has a wavelength (in free space) of about 650 nm. Then I went on to say that ultrasound at a frequency of 530 MHz in air has the same wavelength (650 nm). Okay. Misunderstanding on my part. Quick question: I know how to calculate the wavelength of an electromagnetic wave, so when I use that calculation, I come to the conclusion that a frequency of 530 MHz has a wavelength of about 0.5 meters or about 1.8 feet. I also understand that sound isn't an electromagnetic wave, so the same calculation can't be used. It's a mechanical wave that moves at around 330 m/s in air and not the 300,000 m/s that an electromagnetic wave moves at. So, what's the calculation you used to find the wavelength of sound? ADDENDUM: Could you perhaps also explain why you believe the wavelengths have any impact on sound's ability to move at or beyond the speed of light? As far as I know, wavelength isn't a measure of speed, just a measure of distance. Same calculation, just use 330/freq(hz) instead of 300/freq(Mhz). For the physical wavelength of sound in air at 530 Mhz, that comes out to be 330/530000000 = 623 nm. I actually used the calculator here: www.sengpielaudio.com/calculator-waves.htm . b). Don't think it does. I really did not get anything out of the referenced article. Only thing I can guess is that they are using a strange definition of 'group velocity' - kind of like the old story of how a water wave can appear to move along the shoreline at a much faster rate than the wave is actually moving. Perhaps our resident Electrical Engineer, GTCGreg, could comment on how 'group velocity' is different than wave velocity. |
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Post by OziRiS on Jun 2, 2015 17:09:59 GMT
Okay. Misunderstanding on my part. Quick question: I know how to calculate the wavelength of an electromagnetic wave, so when I use that calculation, I come to the conclusion that a frequency of 530 MHz has a wavelength of about 0.5 meters or about 1.8 feet. I also understand that sound isn't an electromagnetic wave, so the same calculation can't be used. It's a mechanical wave that moves at around 330 m/s in air and not the 300,000 m/s that an electromagnetic wave moves at. So, what's the calculation you used to find the wavelength of sound? ADDENDUM: Could you perhaps also explain why you believe the wavelengths have any impact on sound's ability to move at or beyond the speed of light? As far as I know, wavelength isn't a measure of speed, just a measure of distance. Same calculation, just use 330/freq(hz) instead of 300/freq(Mhz). For the physical wavelength of sound in air at 530 Mhz, that comes out to be 330/530000000 = 623 nm. I actually used the calculator here: www.sengpielaudio.com/calculator-waves.htm . I figured it out on my own before you had a chance to answer. I had to understand it myself in order to write the above explanation for SD, so I've learned quite a lot today  b). Don't think it does. I really did not get anything out of the referenced article. Only thing I can guess is that they are using a strange definition of 'group velocity' - kind of like the old story of how a water wave can appear to move along the shoreline at a much faster rate than the wave is actually moving. Perhaps our resident Electrical Engineer, GTCGreg, could comment on how 'group velocity' is different than wave velocity. I think you're right on both counts there, so let's hope GTCGreg finds this interesting enough to chime in. wvengineer might also be helpful at this point. |
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Post by silverdragon on Jun 3, 2015 6:06:09 GMT
Hence the confusion, the vibration per second rate, doesnt that get used in mas spectrometry to indicate what something is?...
If it vibrates at xyz per second is gold, etc?...
And that is why we come here isnt it?...
My thanks to everyone again, I learn more on how the universe works by coming here than I do anywhere else, because this makes me ask questions.
And answers them as well.
I am reading through the lengthy reply above, I am getting it, and why the heck didnt I see it that way before.
But again, I still have questions...
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Post by OziRiS on Jun 3, 2015 10:45:21 GMT
Hence the confusion, the vibration per second rate, doesnt that get used in mas spectrometry to indicate what something is?... If it vibrates at xyz per second is gold, etc?... Again, I had to do a little research on that, because it sounded right at first, but then there was something in the back of my memory that told me it wasn't. I just couldn't get that memory to the front of my brain to figure out what was wrong about it, so I found these: Here's one of your local boy, Brian Cox, explaining how we know what stars are made of. I think this is what you're confusing for having something to do with frequency, which, granted, it by definition does, because each color of light has its own frequency, but they measure the frequency of the "missing colors" and that doesn't have anything to do with the frequency the indiviudal atoms vibrate at. I think that's where the confusion kicked in for both of us on that one. Give it a look. He keeps it really short, sweet and simple. Mass spectrometry is, as the name suggests, a way to measure the mass of particles. Since we already know the atomic mass of every known particle, breaking a compound apart into its basic elements and finding out the mass of individual particles in it allows us to figure out what it's made of, which in turn can tell us what it is, since we know what the chemical compositions of most common compounds are. There's a really good and simple explanation here: www.chemguide.co.uk/analysis/masspec/howitworks.htmlAnd that is why we come here isnt it?... My thanks to everyone again, I learn more on how the universe works by coming here than I do anywhere else, because this makes me ask questions. And answers them as well. I am reading through the lengthy reply above, I am getting it, and why the heck didnt I see it that way before. But again, I still have questions... And I love your questions, because they make me think, so don't hesitate to keep 'em coming! |
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