poptart said:
Such compelling evidence dashes me!
Re-read what Professor X said. He kinda agrees with me (though his wording is a little muddled).
Poptart, if this is causing you stress, maybe you should find another topic to join in on. No sense getting upset.
I'll post some more when I have the time. Its late, I'm tired.
Professor X said:
wakibaki said:
Well put, and point taken. I guess I look at it like a person of one faith learning about and educating themselves in another faith. This doesn't typically cause him/her to lose their faith, but rather it allows them to better understand people who they don't necessarily agree with. I bring up religion because it would take a fair amount of faith to believe that every one of us, as well as every scientist is wrong, and the truth is a theory John created in grade school. (Mods, I'm using religion simply as a metaphorical example, and not speaking about any certain ones specifically)
MJL21193 said:
Such compelling evidence dashes me!
Re-read what Professor X said. He kinda agrees with me (though his wording is a little muddled).
Poptart, if this is causing you stress, maybe you should find another topic to join in on. No sense getting upset.
I'll post some more when I have the time. Its late, I'm tired.
John, to be totally honest I read what "Professor X" wrote as blatantly saying that you are incorrect in your theory. (now I'm having an open mind to what "Professor X" is saying) He is basically breaking down a sound wave traveling through water for you. By explaining how the rarefactions of an audio waveform cause molecular displacement in one area which that in turn causes the compressions of an audio waveform in another. These compressions are surrounded by the rarefactions that are displacing water molecules into them causing, you guessed it, compression. If sound traveled through water the way you say it does then you would honestly only have have of a sine wave, and that'd sound terrible, hehe.
-Justin
MJL21193 said:
What is your day job? Spindoctor?
The displacement model predicts infinite speed of propagation. It is implicit in your suggestion about the failure to propagate in a closed volume.
The compression model predicts finite speed of propagation.
Until you can reconcile your 'closed volume' prediction with the observed phenomena this sophistry is discredited without reference to external authority.
Yes, the compression is small. Yes, displacement takes place. No, it is not useful to model audio transmission in water primarily in terms of displacement.
Please do a favour to all those reading this thread with no foreknowledge of sound transmission and a desire to understand by ceasing to add to the background noise.
w
No sweat, Justin. I guess that unlike theories of sound propagation there's room for conflicting signatures.
I'm sorry about the confusion regarding the tags.
I did think you were having a go at my tag, although I was a little puzzled since it's intended more as a warning of the type of reparteé you can anticipate from me than an advocacy of turning it up to 11, but after I realised that it was just a coincidence the prospect of going through the whole thing to sort it out seemed about as tortuous as explaining a joke, and since we seemed to be in agreement about a lot of things anyway, I thougt it better to let the issue fade.
It's a pleasure to encounter someone with your good manners, good humour and (despite my former comment) open mind.
All the best...
w
I'm sorry about the confusion regarding the tags.
I did think you were having a go at my tag, although I was a little puzzled since it's intended more as a warning of the type of reparteé you can anticipate from me than an advocacy of turning it up to 11, but after I realised that it was just a coincidence the prospect of going through the whole thing to sort it out seemed about as tortuous as explaining a joke, and since we seemed to be in agreement about a lot of things anyway, I thougt it better to let the issue fade.
It's a pleasure to encounter someone with your good manners, good humour and (despite my former comment) open mind.
All the best...
w
wakibaki said:
The pleasure is all mine. You showed real character in the way you handled what you thought was me making a personal attack, and for that I thank you. It is what allowed it to be resolved before I even realized what was really going on. It's nice to see there are still civil people in this world!
And to you sir!
-Justin
ok read 2 pages..... wow
Here is my understanding of how sound works. The object emitting the sound, lets say a speaker, moves back and forth at a certain rate. this is going to cause a increase in pressure in front of the emitter when it moves forward and a decrease as it moves back. this is going force the medium away from it as it moves forward and draw it twords it as it moves rearward. The medium that is being submitted to this is going to have an increase and decrease of pressure and is going to radiate this outward from the source. Now this leading pressure wave is going to be more compressed than the base pressure of the object. It doesn't matter how much just the fact that it is. air a lot and water not so much. another factor in the pressure and compression of the medium is the initial energy of the emitter. With sound were measuring this in dB. A higher dB sound is going to have more energy than a lower dB sound at a given frequency. all sound is going to move at the same speed in a given medium all conditions being the same. as medium is radiating it in all directions and there is going to be some loss of energy due to heat (compression) there is going to be a limit to the radiation of the wave that is going to be related to the initial energy.
now if everything that i said above is correct (i'm not 100% sure if it is i haven't studied this alot yet). then the only loss of energy that the wave is going to incure is from distance due to the increasing volume of the area the radiated wave has to exist in and loss of energy due to heat (which comes from compression), also possibly the energy that is needed to compress the medium but that is going to be released when in decompresses. I cant think of anything else that is going to leech energy from the wave other than friction but i'm not sure if that plays in.
the energy IS going to move though the medium (same concept as those metal clicky ball things for desks). Now think about it for a second the wave moves through the medium by compressing and decompressing it. so the waves speed seems to be dictated by the rate at which it can compress and then decompress a given point in its radiation pattern.
Think of a room with two doors. the distance between the doors I am going to consider relative to the compressibility of the object in a given distance (by distance i don't mean volume but compressibility of a substance in a one dimensional direction). so air which can be compressed a lot there is going to be a large distance between door a and door b. now think of the wave as a person walking from door a to b. said person is always going the same speed. now if you have say a room with 15ft of distance from door a to door b and a room with 6 inches of distance from a to b next to each other and you have people walk from one door to another (all people going the exact same speed) then the one with the shorter distance is going to enter and leave that area (which is a given linear one dimensional distance of said medium) in a much shorter time.
Thus to the best of my knowledge and understanding less compressible mediums are going to allow for a more effective transfer of the energy due to reduced "waste" energy and are also going to have a increased speed at which the energy is going to be able to move through the medium relative to it's compressibility. Where in a completely incompressible object that energy would be taken as friction and all of the energy would be taken as friction and turned into heat unless there was enough energy to move the entire medium in which that medium would then become an emitter for the energy.
so i'm not sure if that was correct as i've only read up on sound for about 20 minutes about 2 weeks ago... and i'm 18 and haven't taken physics yet. so I'd LOVE to have someone correct any of this !!!
Edited for spelling. I'm going to college for areospace engineering not english so math good spelling bad
Here is my understanding of how sound works. The object emitting the sound, lets say a speaker, moves back and forth at a certain rate. this is going to cause a increase in pressure in front of the emitter when it moves forward and a decrease as it moves back. this is going force the medium away from it as it moves forward and draw it twords it as it moves rearward. The medium that is being submitted to this is going to have an increase and decrease of pressure and is going to radiate this outward from the source. Now this leading pressure wave is going to be more compressed than the base pressure of the object. It doesn't matter how much just the fact that it is. air a lot and water not so much. another factor in the pressure and compression of the medium is the initial energy of the emitter. With sound were measuring this in dB. A higher dB sound is going to have more energy than a lower dB sound at a given frequency. all sound is going to move at the same speed in a given medium all conditions being the same. as medium is radiating it in all directions and there is going to be some loss of energy due to heat (compression) there is going to be a limit to the radiation of the wave that is going to be related to the initial energy.
now if everything that i said above is correct (i'm not 100% sure if it is i haven't studied this alot yet). then the only loss of energy that the wave is going to incure is from distance due to the increasing volume of the area the radiated wave has to exist in and loss of energy due to heat (which comes from compression), also possibly the energy that is needed to compress the medium but that is going to be released when in decompresses. I cant think of anything else that is going to leech energy from the wave other than friction but i'm not sure if that plays in.
the energy IS going to move though the medium (same concept as those metal clicky ball things for desks). Now think about it for a second the wave moves through the medium by compressing and decompressing it. so the waves speed seems to be dictated by the rate at which it can compress and then decompress a given point in its radiation pattern.
Think of a room with two doors. the distance between the doors I am going to consider relative to the compressibility of the object in a given distance (by distance i don't mean volume but compressibility of a substance in a one dimensional direction). so air which can be compressed a lot there is going to be a large distance between door a and door b. now think of the wave as a person walking from door a to b. said person is always going the same speed. now if you have say a room with 15ft of distance from door a to door b and a room with 6 inches of distance from a to b next to each other and you have people walk from one door to another (all people going the exact same speed) then the one with the shorter distance is going to enter and leave that area (which is a given linear one dimensional distance of said medium) in a much shorter time.
Thus to the best of my knowledge and understanding less compressible mediums are going to allow for a more effective transfer of the energy due to reduced "waste" energy and are also going to have a increased speed at which the energy is going to be able to move through the medium relative to it's compressibility. Where in a completely incompressible object that energy would be taken as friction and all of the energy would be taken as friction and turned into heat unless there was enough energy to move the entire medium in which that medium would then become an emitter for the energy.
so i'm not sure if that was correct as i've only read up on sound for about 20 minutes about 2 weeks ago... and i'm 18 and haven't taken physics yet. so I'd LOVE to have someone correct any of this !!!
Edited for spelling. I'm going to college for areospace engineering not english so math good spelling bad
Re: materials science
I've made through the dog days of August (my busiest time of the year) and I have some free time to get brow beaten and ridiculed again.
Sy has yet to provide the evidence that he mentioned would be "trivially easy" to produce:
Yes, I'm serious.
Stress and strain are the result of applied force. Just like pressure is the result of applied force.
Look at the steel ruler as it flexes. The side of the ruler that is in tension is being stretched. Think of a rubber band when you stretch it - it gets narrower as it gets longer.
Now look at the side of the ruler that is in compression. It is being squeezed longitudinally into a shorter space. This results in its thickening. Crush a rubber block and see how it will bulge outwards.
The overall thickness and length of the ruler has not decreased, therefore no compression.
The ruler, once released, springs back to it's (nearly) original state. This is elasticity.
Do the same bending test with a similar sized strip of lead. What are the results? Do you really think that the lead is being compressed?
I've made through the dog days of August (my busiest time of the year) and I have some free time to get brow beaten and ridiculed again.
Really, do I look foolish? You "big-brained" fellows still refuse to discuss this intelligently (other than gtforme00).auplater said:
Sy has yet to provide the evidence that he mentioned would be "trivially easy" to produce:
Sy said:
despotic931 said:
Yes, I'm serious.
Stress and strain are the result of applied force. Just like pressure is the result of applied force.
Look at the steel ruler as it flexes. The side of the ruler that is in tension is being stretched. Think of a rubber band when you stretch it - it gets narrower as it gets longer.
Now look at the side of the ruler that is in compression. It is being squeezed longitudinally into a shorter space. This results in its thickening. Crush a rubber block and see how it will bulge outwards.
The overall thickness and length of the ruler has not decreased, therefore no compression.
The ruler, once released, springs back to it's (nearly) original state. This is elasticity.
Do the same bending test with a similar sized strip of lead. What are the results? Do you really think that the lead is being compressed?
the object is being compressed it is just a matter of in which direction additional force needs to be added to gain any further compression. to compress an object after a certian point you need force coming from all directions. While the rubber block does move outward that is because there is no force being exerted there to restrict it. If there where then there would be FURTHER compression.
if you have a ballon filled with air the air inside of it is compressed. now if you pop that ballon then the air suddenly has a loss of the force that is keeping it compressed at a certian point and moves to ballance it self once again.
To compress an object you igther have to constrict its volume and increass it's mass or decrease it's volume while keeping its mass constant or increasing it.
if you have a ballon filled with air the air inside of it is compressed. now if you pop that ballon then the air suddenly has a loss of the force that is keeping it compressed at a certian point and moves to ballance it self once again.
To compress an object you igther have to constrict its volume and increass it's mass or decrease it's volume while keeping its mass constant or increasing it.
Just what is gained by prolonging this discussion?
What useful predictions flow from your hypothesis?
We have done you the courtesy of taking you seriously.
Now you do us the insult of suggesting that we are closed-minded bullies because the consensus is that you have failed to make your case.
Namecalling is a game that 2 can play, 4sshole.
w
What useful predictions flow from your hypothesis?
We have done you the courtesy of taking you seriously.
Now you do us the insult of suggesting that we are closed-minded bullies because the consensus is that you have failed to make your case.
Namecalling is a game that 2 can play, 4sshole.
w
waibiki, personal attacks and name-calling are absolutely forbidden here.
Re: Re: Re: materials science
The sides of the rubber block will bulge outward because there is nothing to stop them from doing so - this is the displacement I am talking about in this discussion.
As you crush the rubber block, the biggest change is the sides bulging outward, not the minuscule compression that may be taking place.
Thanks Andrew,
When we bend the ruler, we see something happening on a big scale - the metal bends then springs back. This is elasticity at work. On a small scale, there is some compression, but it has very little to do with what's happening.
Stretching of the bonds in the metals molecular lattice structure and their ability to return to their original position is the measure of a materials elasticity. In the ruler example, the bonds are stretched longitudinally on the tension side and perpendicular on the compression side.
From the Wikipedia for Poisson’s effect:
BionicSniper said:
The sides of the rubber block will bulge outward because there is nothing to stop them from doing so - this is the displacement I am talking about in this discussion.
As you crush the rubber block, the biggest change is the sides bulging outward, not the minuscule compression that may be taking place.
AndrewT said:
Thanks Andrew,
When we bend the ruler, we see something happening on a big scale - the metal bends then springs back. This is elasticity at work. On a small scale, there is some compression, but it has very little to do with what's happening.
Stretching of the bonds in the metals molecular lattice structure and their ability to return to their original position is the measure of a materials elasticity. In the ruler example, the bonds are stretched longitudinally on the tension side and perpendicular on the compression side.
From the Wikipedia for Poisson’s effect:
rulers, rubber blocks, hydraulics, oh my!
what a silly game for adults to play at pretending they seriously believe in a story that they know isn't true to see what people might say to try to help "them".
Denying that sound travels by a compression wave is as tenable as claiming the earth is flat. It's a proven fact for at least a hundred years which makes this thread an interesting example of what bored people do with their time on the internet. I know it, you know it, everyone knows it, what the heck is this here for? Are there people out there that actually think for one second the whole world is wrong and some random uneducated guy from canada knows more about the subject than a professor of underwater acoustics that says he's wrong?
...I guess there are people that read this junk and want to believe it. Probably the same people that think we never landed on the moon and anyone who went to school is an "elitist" lying to them.
what a silly game for adults to play at pretending they seriously believe in a story that they know isn't true to see what people might say to try to help "them".
Denying that sound travels by a compression wave is as tenable as claiming the earth is flat. It's a proven fact for at least a hundred years which makes this thread an interesting example of what bored people do with their time on the internet. I know it, you know it, everyone knows it, what the heck is this here for? Are there people out there that actually think for one second the whole world is wrong and some random uneducated guy from canada knows more about the subject than a professor of underwater acoustics that says he's wrong?
...I guess there are people that read this junk and want to believe it. Probably the same people that think we never landed on the moon and anyone who went to school is an "elitist" lying to them.
poptart said:
Where did I deny that sound travels by a compression wave? Re-read my posts, this time with some understanding.
With an applied force there is always compression. Holding a empty pop can aloft on the back of your hand is an example of a applied force - overcoming the gravity that will make the can fall. What is actually happening and how much compression of the materials involved is relevant?
I have explained my motives to a couple of members here via email, but for others here it is:
This is purely an educational endeavor. All those involved will be encouraged to research and learn more in the pursuit of proving each other wrong.
If this topic irritates you to the point of name calling and personal attach or open ridicule perhaps another thread is a better place to focus your attention. I will ignore any post that does not have relevant counter arguments.
Re: Re: materials science
Yes, there will be areas of molecular compression in the bent strip of lead. Are you also going to tell me now that sound waves cause displacement in the lead? If we put the lead in a container with infinitely stiff sides that will not flex would sound fail to travel through it as well? I fail to see how all these examples involving a ruler, a rubber block, and a strip of lead, tie in to you proving your theory about how sound travels through water. Can you maybe do a recap/summery?
MJL21193 said:
Yes, there will be areas of molecular compression in the bent strip of lead. Are you also going to tell me now that sound waves cause displacement in the lead? If we put the lead in a container with infinitely stiff sides that will not flex would sound fail to travel through it as well? I fail to see how all these examples involving a ruler, a rubber block, and a strip of lead, tie in to you proving your theory about how sound travels through water. Can you maybe do a recap/summery?
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