If gases did not have attractive forces holding them together you wouldn't need a vacuum pump to pull them apart by force, just go ahead and let them expand out into space forever. No pump, no electricity, no vacuum chamber to keep the gas from gathering back together without it, why would they if they only expand?
https://ecampusontario.pressbooks.pub/c ... -behavior/
https://homework.study.com/explanation/ ... other.html
https://app.jove.com/science-education/ ... s-equation
Attractive forces between gas molecules in our atmosphere always exist, but ordinarily, left alone, the attractive and repulsive forces balance. Obviously.
Start torturing the gas by rapid expansion and compression in an engine and you are upsetting the equilibrium.
https://youtu.be/nCJcouN9Fdk
Etc. etc. etc.
Stirling Engine & Heat Pump
Re: Stirling Engine & Heat Pump
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Your YouTube video at about 4:14 states, if the molecules get far enough apart the attractive forces and repulsive forces are both effectively zero. Zero in a vacuum, gas molecules are far apart.
I don't think you understand the effect of r^-6 and r^-12 on force strength, so I didn't bring it up. Perhaps one day you will realize that it means the forces go to zero when not very far away. True for the low density gas molecules we deal with, all the way down to a perfect vacuum, where there is no attractive forces by definition.
Vacuum pumps don't "pull" gas molecules in. They push gas molecules out until the volume inside the pump is zero, or close to it. The piston then goes to bottom dead center providing a vacuum in it. What in a vacuum could possibly "pull" a molecule? Exactly, Nothing. Because there is nothing in a vacuum that can "pull" or even 'attract'.
Gases outside the vacuum push into the vacuum because they have a pressure.
Don't take my word for it, you never do. Make some experiments on your own to verify if a gas always has pressure or if it can somehow magically"pull" on the speeding around molecules.
As I've said numerous times, if you don't understand that one point, of scientifically verifiable data, the rest of thermodynamics will be out of your reach. Gasses always push.
Put an ice cube into a balloon and put it in a vacuum. Watch it continue to expand, at least until the balloon's tensile strength provides enough pressure to stop the sublimation, or it bursts. Try it with liquid water. Fill it under water so there is no air in it.
Look up how escape velocity works. Items above the escape velocity always expand outwardly, including gas molecules. At least until they hit something. Like tennis balls bouncing off a racket pushing the two players apart. No attraction needed, except in the container's solid materials.
Your first link has a compressibility chart it shows that for 10 atmospheres or less there is about a 10% error or less between the ideal gas model and the real gas molecule model or data. Attraction and repulsion only apply to high densities or very low temperatures. Our engines don't operate there. The real verses ideal gas behavior isn't worth any consideration. Either model is sufficient.
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Your YouTube video at about 4:14 states, if the molecules get far enough apart the attractive forces and repulsive forces are both effectively zero. Zero in a vacuum, gas molecules are far apart.
I don't think you understand the effect of r^-6 and r^-12 on force strength, so I didn't bring it up. Perhaps one day you will realize that it means the forces go to zero when not very far away. True for the low density gas molecules we deal with, all the way down to a perfect vacuum, where there is no attractive forces by definition.
Vacuum pumps don't "pull" gas molecules in. They push gas molecules out until the volume inside the pump is zero, or close to it. The piston then goes to bottom dead center providing a vacuum in it. What in a vacuum could possibly "pull" a molecule? Exactly, Nothing. Because there is nothing in a vacuum that can "pull" or even 'attract'.
Gases outside the vacuum push into the vacuum because they have a pressure.
Don't take my word for it, you never do. Make some experiments on your own to verify if a gas always has pressure or if it can somehow magically"pull" on the speeding around molecules.
As I've said numerous times, if you don't understand that one point, of scientifically verifiable data, the rest of thermodynamics will be out of your reach. Gasses always push.
Put an ice cube into a balloon and put it in a vacuum. Watch it continue to expand, at least until the balloon's tensile strength provides enough pressure to stop the sublimation, or it bursts. Try it with liquid water. Fill it under water so there is no air in it.
Look up how escape velocity works. Items above the escape velocity always expand outwardly, including gas molecules. At least until they hit something. Like tennis balls bouncing off a racket pushing the two players apart. No attraction needed, except in the container's solid materials.
Your first link has a compressibility chart it shows that for 10 atmospheres or less there is about a 10% error or less between the ideal gas model and the real gas molecule model or data. Attraction and repulsion only apply to high densities or very low temperatures. Our engines don't operate there. The real verses ideal gas behavior isn't worth any consideration. Either model is sufficient.
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Re: Stirling Engine & Heat Pump
10% seems like a HUGE margin of error to me.
Anyway, there is you, some "fool" on a message board saying gases "never" attract vs. dozens and dozens of expert references, websites, tutorials, videos, textbooks, PDFs stating that gases do in fact attract and that this has measurable effects, such as lowering the pressure on a vessel.
Your just fixated on validating the Ideal gas law which is only an approximation at best and actually exactly right only something like 1/10,000 of the time getting worse and worse at higher pressure and lower temperature.
Live in your high school level science class, I don't care.
Real gases DO have forces of attraction
Anyway, there is you, some "fool" on a message board saying gases "never" attract vs. dozens and dozens of expert references, websites, tutorials, videos, textbooks, PDFs stating that gases do in fact attract and that this has measurable effects, such as lowering the pressure on a vessel.
Your just fixated on validating the Ideal gas law which is only an approximation at best and actually exactly right only something like 1/10,000 of the time getting worse and worse at higher pressure and lower temperature.
Live in your high school level science class, I don't care.
Real gases DO have forces of attraction
Re: Stirling Engine & Heat Pump
Obviously if gases have a mean free path measured in distances many orders of magnitude smaller than the width of a human hair, all air molecules are colliding with another air molecule in a Stirling engine something like 5 billion times per second and only increasing with compression in a cylinder
https://spark.iop.org/further-discussion-mean-free-path
So much for not interacting at all.
https://spark.iop.org/further-discussion-mean-free-path
So much for not interacting at all.
Re: Stirling Engine & Heat Pump
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See again, 10% error or less. You only look on the cherry picked points. Furthermore, if you'd taken just one college level physics course, you'd have learned that 10% or better is not that bad for this. Ten percent error very rarely proves anything wrong. That's what we've all been pointing out about your garage based thermodynamic experiments. They are well within 10%, so prove nothing, except that you are doing things wrong. Come back when you have reliable data, and proper data. Until then you will continue in the inconclusive zone.
No gasses don't attract or pull. I've described experiments that you can do to verify that it is a known scientific fact. Again, your reasoning that molecules attract, therefore gasses do is invalidated by all the data, science, and logic, that is out there, and all the references you've given. You aren't the only fool out there, but you are wrong about thermodynamics.
None of your references that you've given make the claim that gasses do anything else but push.
Remember. I've learned from college level courses on this. You are the one that is sadly lacking any formal higher education on this.
It appears that your blind rage against understanding me, has failed you in your ability to learn this simple concept. Your cherry picking and denial of facts has more than proven your failure to comprehend. Molecules attract and repel. Gasses don't attract, but do repel. Do not confuse the effect of molecular forces on volume, temperature, and pressure, at higher densities and lower temperatures, with the property of gasses always pushing. Gasses always push, they never pull. It is a scientific fact.
Google: "do gasses always push never pull", or just: "do gasses pull".
Or check this out (probably over your head):
https://physics.stackexchange.com/quest ... -the-fluid
Simplified: "Suction is not a real thing. It is like darkness... "
P.S., Gas pressure is a result of the molecular speed from energy being over the escape velocity of the molecular forces.
See again, 10% error or less. You only look on the cherry picked points. Furthermore, if you'd taken just one college level physics course, you'd have learned that 10% or better is not that bad for this. Ten percent error very rarely proves anything wrong. That's what we've all been pointing out about your garage based thermodynamic experiments. They are well within 10%, so prove nothing, except that you are doing things wrong. Come back when you have reliable data, and proper data. Until then you will continue in the inconclusive zone.
No gasses don't attract or pull. I've described experiments that you can do to verify that it is a known scientific fact. Again, your reasoning that molecules attract, therefore gasses do is invalidated by all the data, science, and logic, that is out there, and all the references you've given. You aren't the only fool out there, but you are wrong about thermodynamics.
None of your references that you've given make the claim that gasses do anything else but push.
Remember. I've learned from college level courses on this. You are the one that is sadly lacking any formal higher education on this.
Again the point that gasses always push is as important as a proper pressure measurement. If you fail to understand this you will fail to understand anything in thermodynamics.Google AI wrote:AI Overview
No, gases generally do not "pull" in the sense of exerting a significant attractive force on each other because the particles in a gas are very far apart and have minimal intermolecular forces, meaning they barely interact with one another; instead, they primarily exert pressure by colliding with the walls of their container due to their constant random motion.
It appears that your blind rage against understanding me, has failed you in your ability to learn this simple concept. Your cherry picking and denial of facts has more than proven your failure to comprehend. Molecules attract and repel. Gasses don't attract, but do repel. Do not confuse the effect of molecular forces on volume, temperature, and pressure, at higher densities and lower temperatures, with the property of gasses always pushing. Gasses always push, they never pull. It is a scientific fact.
Google: "do gasses always push never pull", or just: "do gasses pull".
Or check this out (probably over your head):
https://physics.stackexchange.com/quest ... -the-fluid
Simplified: "Suction is not a real thing. It is like darkness... "
P.S., Gas pressure is a result of the molecular speed from energy being over the escape velocity of the molecular forces.
.Google AI wrote:AI Overview "Boiling molecular velocity" refers to the average speed at which molecules in a liquid must be moving in order to overcome the intermolecular forces and escape the liquid phase, essentially reaching the point where the liquid boils and transitions into a gas; it is directly related to the boiling point of the liquid, meaning higher boiling points correspond to a higher required molecular velocity for boiling to occur.
Re: Stirling Engine & Heat Pump
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When molecules bounce, it is the repulsive force that is important in bouncing. Neither repulsive nor attractive forces add any energy to the bounce. The molecules come out of the bounce with a total energy that is the same as what they had when they went in. No more. No less. Interact, yes. Have any effect, no. The molecular forces in a gas have little effect at low densities and high temperatures. That is what they are telling you. I'm just translating it to simpler terms for you.
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When molecules bounce, it is the repulsive force that is important in bouncing. Neither repulsive nor attractive forces add any energy to the bounce. The molecules come out of the bounce with a total energy that is the same as what they had when they went in. No more. No less. Interact, yes. Have any effect, no. The molecular forces in a gas have little effect at low densities and high temperatures. That is what they are telling you. I'm just translating it to simpler terms for you.
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Re: Stirling Engine & Heat Pump
You are, of course correct, if you confine your studies and references to "ideal" gases.
Unfortunately many references, though talking about "ideal" gases, either out of neglect or ignorance leave off the word "ideal" giving a false impression.
In reality however, there is no such animal as an "ideal gas". It's a mathematical fiction. An OK approximation for most ordinary circumstances and conditions.
Your Kinetic model of gases whizzing around like tiny bullets is obsolete.
More likely gas molecules are simply "vibrating" in place, hardly moving in a "straight line" until they "collide with the walls of the container" at all.
Probably they don't actually move much at all but appear and disappear like ghosts out of the quantum foam or some such thing.
The point about gas molecules colliding or interacting 5 billion times / sec. at 1 atmosphere is they are plenty close enough to "feel" each others attractive force, not so far apart that they "never" interact at all.
Unfortunately many references, though talking about "ideal" gases, either out of neglect or ignorance leave off the word "ideal" giving a false impression.
In reality however, there is no such animal as an "ideal gas". It's a mathematical fiction. An OK approximation for most ordinary circumstances and conditions.
Your Kinetic model of gases whizzing around like tiny bullets is obsolete.
More likely gas molecules are simply "vibrating" in place, hardly moving in a "straight line" until they "collide with the walls of the container" at all.
Probably they don't actually move much at all but appear and disappear like ghosts out of the quantum foam or some such thing.
The point about gas molecules colliding or interacting 5 billion times / sec. at 1 atmosphere is they are plenty close enough to "feel" each others attractive force, not so far apart that they "never" interact at all.
Re: Stirling Engine & Heat Pump
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The vibrating in place model is incompatible with observed flowing and expanding data from real gasses. It's wrong.
Wrong. They need to be slowed down to capture speed to liquify. Above that the attractive force does very little, especially if well above that.
They always feel the attractive and repulsive forces, it's just that they are going so fast they wiz right by. Unless colder/slower, or forced together. (Not at the temperatures and pressures of our engines.
Care to supply a reference to an accepted and published new theory. Classical thermodynamics is no more obsolete than Newtonian physics. Your theory isn't new, it was discarded because of known facts.Tom Booth wrote:Your Kinetic model of gases whizzing around like tiny bullets is obsolete.
Real gasses don't pull. They always push. In fact they push more so than ideal gasses at higher densities, because their sizes and repulsive forces come together.Tom Booth wrote:You are, of course correct, if you confine your studies and references to "ideal" gases.
Mean free path is hardly a straight line until they hit a container wall. Your depiction of classical theory is all messed up. Vibrating in place is the model for a solid. Vibrating and moving around is the model for liquid. Bouncing off each other and walls, above the boiling speed is the model for real gasses. As soon as a change of state is observed the ideal model gets discarded from classical theory. They teach that in first year thermodynamics.Tom Booth wrote:More likely gas molecules are simply "vibrating" in place, hardly moving in a "straight line" until they "collide with the walls of the container" at all.
The vibrating in place model is incompatible with observed flowing and expanding data from real gasses. It's wrong.
Tom Booth wrote:The point about gas molecules colliding or interacting 5 billion times / sec. at 1 atmosphere is they are plenty close enough to "feel" each others attractive force, not so far apart that they "never" interact at all.
Wrong. They need to be slowed down to capture speed to liquify. Above that the attractive force does very little, especially if well above that.
They always feel the attractive and repulsive forces, it's just that they are going so fast they wiz right by. Unless colder/slower, or forced together. (Not at the temperatures and pressures of our engines.
Re: Stirling Engine & Heat Pump
Sorry but your simply ignorant and your brains are calcified. All you talk about is "models" this and "models" that.
A model is not reality.
I've already provided dozens of references that say you're wrong, but like I said, think what you like. I think your fixated and delusional.
A model is not reality.
I've already provided dozens of references that say you're wrong, but like I said, think what you like. I think your fixated and delusional.
Re: Stirling Engine & Heat Pump
You haven't provided any reference that says a gas pulls. All glasses push, always. They never pull. Just Google,
"Do gasses pull"
See for yourself.
"Do gasses pull"
See for yourself.
Re: Stirling Engine & Heat Pump
Are you paid by trump?
Re: Stirling Engine & Heat Pump
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Many college graduates get thermodynamics wrong. Some even get fluid dynamics wrong. Example: They hear the words 'water is an incompressible fluid' and think erroneously that water can't be compressed. But all fluids are compressible. Some, such as gasses, more so than liquids. Incompressible fluid is use appropriately for certain modeling, such as for a hydraulic jack, or a manometer.
My point here is that models work correctly if used correctly. And that any idiot with an incomplete knowledge base can be erroneous.
To deny all models, is to be erroneous and ignorant. It stems from having an incomplete knowledge base. We must choose what we learn, we can't learn it all, I've tried. Therefore we are all ignorant by choice, by circumstance, accident, lack of memory, inability, and by ignorance. The worst think we all do is to ignorant of being ignorant. The biggest fool is the fool who thinks he, or she, isn't a fool. We are all Bozos on this bus. We fool ourselves more than anyone else fools us. You are definitely proof of that. Maybe one day you can agree with this.
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Many college graduates get thermodynamics wrong. Some even get fluid dynamics wrong. Example: They hear the words 'water is an incompressible fluid' and think erroneously that water can't be compressed. But all fluids are compressible. Some, such as gasses, more so than liquids. Incompressible fluid is use appropriately for certain modeling, such as for a hydraulic jack, or a manometer.
My point here is that models work correctly if used correctly. And that any idiot with an incomplete knowledge base can be erroneous.
To deny all models, is to be erroneous and ignorant. It stems from having an incomplete knowledge base. We must choose what we learn, we can't learn it all, I've tried. Therefore we are all ignorant by choice, by circumstance, accident, lack of memory, inability, and by ignorance. The worst think we all do is to ignorant of being ignorant. The biggest fool is the fool who thinks he, or she, isn't a fool. We are all Bozos on this bus. We fool ourselves more than anyone else fools us. You are definitely proof of that. Maybe one day you can agree with this.
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