Well congrats to that nail hammering science teacher at least. I've never heard of a class demonstration that had such a lasting effect.
This really has nothing to do with hydraulics, volume changes, steam or any other red herring. Everyone has explained it in a dozen different ways and you're either not reading any of their replies or you have to be trolling because this is too repetitious and block headed for there to be any other answer. I remember seeing many of your posts over the years (has it only been one?) without ever thinking you were a troll but this is pushing the limit. You are absolutely alone in your insistence that compression waves don't "compress" anything, no references of any kind because it's ridiculous really. I'll check back in a few days and see if you've stopped playing games.
This really has nothing to do with hydraulics, volume changes, steam or any other red herring. Everyone has explained it in a dozen different ways and you're either not reading any of their replies or you have to be trolling because this is too repetitious and block headed for there to be any other answer. I remember seeing many of your posts over the years (has it only been one?) without ever thinking you were a troll but this is pushing the limit. You are absolutely alone in your insistence that compression waves don't "compress" anything, no references of any kind because it's ridiculous really. I'll check back in a few days and see if you've stopped playing games.
John, John, John,
I chose the elementary level reference because you referenced your experience from a similar period in your education.
I've provided a reference that contradicts what you are espousing.
What references have you provided?
Just like the horse at the trough, we can lead you there but not make you drink.
Tell us John. What do you want? Really.
I chose the elementary level reference because you referenced your experience from a similar period in your education.
I've provided a reference that contradicts what you are espousing.
What references have you provided?
Just like the horse at the trough, we can lead you there but not make you drink.
Tell us John. What do you want? Really.
Re: Re: This is kind a' like waterproof wood finishes
'do not like to be compressed' ... so now we're talking about the emotional feelings of molecules? I say d4mn them all to h3ll ... they'll compress whether they like it or not!
And 'unless there is enough' ... so how much is enough? There is no answer. Any amount of force applied to a substance can create compression.
Water is a substance, and it will compress given the application of force. If that force is caused by water beetle walking on the surface, the sound coming from a whale, it doesn't matter. Water is not infinitely stiff and cannot defend against the natural forces. Water compresses just like any other substance in the universe.
Now you're starting to getting it. Way to go champ!
MJL21193 said:
'do not like to be compressed' ... so now we're talking about the emotional feelings of molecules? I say d4mn them all to h3ll ... they'll compress whether they like it or not!
And 'unless there is enough' ... so how much is enough? There is no answer. Any amount of force applied to a substance can create compression.
Water is a substance, and it will compress given the application of force. If that force is caused by water beetle walking on the surface, the sound coming from a whale, it doesn't matter. Water is not infinitely stiff and cannot defend against the natural forces. Water compresses just like any other substance in the universe.
MJL21193 said:
Now you're starting to getting it. Way to go champ!
Well, then. If I have a linear string of water molecules stretching from Earth to Proxima Certauri, then by your claim, I can send a message to the stars instantaneously, and to hell with the speed of light. LOL!
Credit to Critofur for making the same point above.
The problem with bogus theories based on false assumptions is they lead to unresolvable contradictions. But it takes brains to see the contradictions, and therein lies the rub.
This is the essential paradox of internet discussion boards, not to mention society in general. I can't think of a way to get around it, but twenty-five years of using the 'net have convinced me our civilization is doomed to collapse because there are just so many damned unreasonable people.
I am embarrassed for you, John! But it's a good feeling when people pay attention to you, isn't it? Ultimately, though, only you have the power to save yourself from... yourself.
Have a nice day.
-Henry
You fellows know how to kick when a guy's down, yes? 
A civilized discussion without resorting to blatant mockery would be nice. Too much to ask for? Also, cool it on the emails, especially the one that criticized my writing, spelling, punctuation and grammar.
Back on topic.
Since I obviously don't know what I'm talking about, why don't I pose a few questions for the more educated members to answer. Then, instead of firing insults, you can provide me with the answers and set me straight.
Here's my first question:
Water, according to this table has a density of 1 at 4*C. That is it's maximum density at standard pressure, according to this article ( see the paragraph titled: Density of water and ice)
Will sound travel through water at this temperature under standard pressure? If yes, how is it happening?
A civilized discussion without resorting to blatant mockery would be nice. Too much to ask for? Also, cool it on the emails, especially the one that criticized my writing, spelling, punctuation and grammar.
Back on topic.
Since I obviously don't know what I'm talking about, why don't I pose a few questions for the more educated members to answer. Then, instead of firing insults, you can provide me with the answers and set me straight.
Here's my first question:
Water, according to this table has a density of 1 at 4*C. That is it's maximum density at standard pressure, according to this article ( see the paragraph titled: Density of water and ice)
Will sound travel through water at this temperature under standard pressure? If yes, how is it happening?
Yes, it will, and in exactly the same way as explained before. "Maximum density," to misquote Inigo Montoya, does not mean what you think it means; I would agree that for normal periodic waves, the average density will be at a maximum at 4C if we're at 1atm pressure. That has nothing to do with local density.
Diversion - The compression of silicone - A much more interesting topic for internet nerds.
So how would sound from my HiFi system reach my ears if my head was stuck between these then?
So how would sound from my HiFi system reach my ears if my head was stuck between these then?
An externally hosted image should be here but it was not working when we last tested it.
SY said:
How can local density be denser than maximum density? Here is an definition of maximum density: "The maximum density of a substance is the highest attainable density of the substance under given conditions."
My take on it is that when you introduce sound in this instance, it will actually decrease density, rather than increase it. After all, energy is being pumped into the medium. Energy in effects a temperature change.
At the 4*C point in water at standard pressure, molecules are not moving. Do something to excite movement, and an expansion takes place. The sound wave will "loosen" the tightly packed medium. Overall density goes down to allow local density (wave propagation, the so called compression) stays the same. The "compressed" part of the wave is the original state; the "rarefaction" part is the new looser arrangement - increased space between molecules.
Am I explaining it clearly?
So, that is why I say there is no real compression, just displacement.
The flat earth society is looking for a few good men
...is the qualifier you are overlooking...the given conditions are not absolute, they can change...and when that happens the characteristics of the material, including density, can change.
You are explaining yourself clearly...your conclusions are incorrect.
Says who?
Where is there any supportive argument in the literature for what you are concluding ?
edit: clarify
...is the qualifier you are overlooking...the given conditions are not absolute, they can change...and when that happens the characteristics of the material, including density, can change.
You are explaining yourself clearly...your conclusions are incorrect.
Says who?
Where is there any supportive argument in the literature for what you are concluding ?
edit: clarify
MJL21193 said:
Temperature and pressure both change when you release the steam.
look at a can of compressed air--you know, those "electronics dusters". Or even a propane tank. both have highly compressed gases to the point where they are liquid (no temp changes, they are stored at room temp)
if you quickly release the gas, what happens? pressure inside the can drops fast and the can is rigid so volume can't change to accomodate the pressure change. net result: the can gets COLD.
pressure drops inside the can and temperature drops to catch up with the pressure drop.
then after a short while, temperature re-equalizes with the room temperature and the can's internal pressure rises again.
you could do this with water if it was a gas at room temperature too.
MJL21193 said:
Ohhhh ... they certainly are moving. They will continue to do so until the energy level drops to 0 at around −273.15 °C (0 K). It's not until absolute zero when matter finally goes to sleep.
MJL21193 said:
If there is any compression, then I'm afraid it is very real. If sound travels through water, then the water has been compressed and expanded as the wave passes through.
Under the circumstances, I think you're been treated pretty well, John. To your credit, you've shown you're willing to back up and ask questions. Maybe there's hope for you yet.
In my opinion, you're making this too complicated. It should be good enough to use the balls-and-springs analogy here. What you are saying is that for water, in its (not it's) liquid state, the springs between the balls are infinitely stiff. It follows that if you line up a series of balls and springs and push on the ball at one end, then the ball at the other end will start moving instantaneously. If this is true, then this represents transmission of information at infinite speed, something we ought to agree is impossible.
The thought experiment of the line of molecules extending from Earth to Proxima Centauri is just an extreme way to illustrate the point.
If, on the other hand, we concede that it takes some time for the displacement wave to travel from one end of the sample to the other, then it must be that in the interim the sample has been compressed -- one end moved, but the other didn't.
Since most of the space inside a volume of water is vacuum, you might want to ask yourself what the mechanism is that transmits the force from one molecule to another. Then research the properties of that force and understand why it acts more like a spring than like a perfectly rigid rod.
-Henry
In my opinion, you're making this too complicated. It should be good enough to use the balls-and-springs analogy here. What you are saying is that for water, in its (not it's) liquid state, the springs between the balls are infinitely stiff. It follows that if you line up a series of balls and springs and push on the ball at one end, then the ball at the other end will start moving instantaneously. If this is true, then this represents transmission of information at infinite speed, something we ought to agree is impossible.
The thought experiment of the line of molecules extending from Earth to Proxima Centauri is just an extreme way to illustrate the point.
If, on the other hand, we concede that it takes some time for the displacement wave to travel from one end of the sample to the other, then it must be that in the interim the sample has been compressed -- one end moved, but the other didn't.
Since most of the space inside a volume of water is vacuum, you might want to ask yourself what the mechanism is that transmits the force from one molecule to another. Then research the properties of that force and understand why it acts more like a spring than like a perfectly rigid rod.
-Henry
Re: The flat earth society is looking for a few good men
Keep an open mind:
The medium is at 4*C, standard pressure - this is the condition before sound. When sound starts to move through it, it changes density and temperature. It only stands to reason that the excitation of molecules from the energy of the sound wave will increase temperature from friction. With this temperature change, you will see a density change, as density will decrease as temperature rises.
Energy from the sound wave is being dissipated in the medium - this produces heat.
For the above, the medium could be at any constant temperature or pressure. Injecting energy from a wave source produces movement which in turn produces heat from friction. Heat will increase temperature, density will lower.
How is this conclusion incorrect?
Ed LaFontaine said:
Keep an open mind:
The medium is at 4*C, standard pressure - this is the condition before sound. When sound starts to move through it, it changes density and temperature. It only stands to reason that the excitation of molecules from the energy of the sound wave will increase temperature from friction. With this temperature change, you will see a density change, as density will decrease as temperature rises.
Energy from the sound wave is being dissipated in the medium - this produces heat.
For the above, the medium could be at any constant temperature or pressure. Injecting energy from a wave source produces movement which in turn produces heat from friction. Heat will increase temperature, density will lower.
How is this conclusion incorrect?
y8s said:
The idea was that steam will compress back to water without a temperature drop. I think that when you relese the pressure on the compressed water, given that there wasn't a temperature drop, it will revert to steam. My point is that in order for steam to condense into water, its temperature needs to drop.
That really doesn't matter. Energy into a system produces heat. Heat will effect a density decrease. Please read my reply to Ed - I'm getting tired of typing the same thing over and over.MartinQ said:
MartinQ said:
You sound very sure of yourself. You being on the "right" side of the discussion makes that acceptable.
Sorry if I missed this already posted, but this is my favorite resource on wave propagation in solids vs liquids vs gasses. Unfortunately a couple of the equations have broken links now but almost everything is there.
http://hyperphysics.phy-astr.gsu.edu/Hbase/sound/sprop.html#c1
http://hyperphysics.phy-astr.gsu.edu/Hbase/sound/sprop.html#c1
from post 95:
I think you conclude from reading the word "maximum" that it describes a condition for density not to be exceeded. It can be exceeded when the standard conditions change. The presence of sound waves is not part of "standard conditions"
You conveniently omit the compression resulting from the passage of the sound wave.
The passage of a sound wave is not one sided. The density fluctuates from the high side to the low side of "standard pressure" in cycles.
Be careful, you have almost admitted to the compression of water by using those statements.
Your fatigue stems from your dogged determination to avoid the conventions the majority of us are at peace with...it is a result of choices you make yourself...not something thrust upon you.
I think you conclude from reading the word "maximum" that it describes a condition for density not to be exceeded. It can be exceeded when the standard conditions change. The presence of sound waves is not part of "standard conditions"
You conveniently omit the compression resulting from the passage of the sound wave.
The passage of a sound wave is not one sided. The density fluctuates from the high side to the low side of "standard pressure" in cycles.
Be careful, you have almost admitted to the compression of water by using those statements.
Your fatigue stems from your dogged determination to avoid the conventions the majority of us are at peace with...it is a result of choices you make yourself...not something thrust upon you.
hpasternack said:
Maybe I would have only .01 posts per day if I were to proof read all of my contributions with the same vigor as you read yours. I do pretty good considering.
BTW, I know the difference between its and it's, but thanks for the corrective email and the lesson anyway.
hpasternack said:
The circumstances being that I don't agree with you? This is reason to be harsh?
I'm glad that you feel there is hope for me, and I am impressed that you have "compressed" your posting frequency down from 1 in a hundred days to voice your thoughts here.
hpasternack said:
Not what I said at all actually.
MartinQ said:
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.