Mordred Posted July 8, 2015 Posted July 8, 2015 (edited) I'll wait till I get to the topic. I'd like to know where I was "missing something" in the remarks I made earlier (post 04.04) or if I was on the mark? Before i put more remarks on futher information of the first article. Which, I must say is a marvelous source of understanding the subject. Could you post which remarks, I'm currently using mobile version being near the North pole catching occassional signals. Telus tower coverage up here is poor lol. Edited July 8, 2015 by Mordred
Andre Lefebvre Posted July 9, 2015 Author Posted July 9, 2015 OK Here it is: Taking the U-tube manometer as an example, It works on the same principle as a water level used in a hose. If I have a “bubble” of air (gas) in the water of the hose, the level at each end is not at the same height because the gas in the bubble is pressurised by the weight of the water and is not situated at the center of the length of the hose. Nevertheless the pressure of the air (gas) in the bubble is due to the weight of the water pressing on each side of the air bubble; and is different from the “weight” (Pressure) of the “free” air (gas) coming at each end of the hose. But I agree that inside the air “bubble” the pressure is “homogeneous”. Regarding the temperature (my comments are in red): We can make two observations: 1. Increasing the temperature broadens the distribution and shifts the peak to higher velocities. This means that there are more ‘fast’ particles at higher temperatures, but there will still be many ‘slow’ ones as well. (It also mean that each particle movement is “using” more space so it increases pressure of the total space) 2. Decreasing the mass of the gas particles (is either decreasing the number of particles (diluting the gas, so diminishing the pressure) or changing for another gas whose each particle mass is less) has the same effect as increasing the temperature i.e. heavier particles have a slower, narrower distribution of speeds than lighter particles. (But the heavy gas particles have more space to use (less pressure on them) and so move faster; or the less mass particles move faster than the previous particles for the same reason. Finally, decreasing the mass of the gas (or of the particles) is decreasing the pressure). Which explains why decreasing the mass doesn't change the temperature. I must be wrong somewhere?
Mordred Posted July 9, 2015 Posted July 9, 2015 (edited) A couple of points you missed. Pressure is a measure of force per unit volume. If you increase the space you decrease the pressure and temperature. They are talking the mass of the individual particles not number of particles. More massive particles require greater force to move than lighter particles. F=ma applies. Less massive particles at a given pressure will gain greater momentum at a given pressure than massive particles. One thing to be careful of is thermodynamic state. Certain properties in thermaldynamic systems are state functions. Ie entropy and enthalpy. ( The last is more a side note. When studying the ideal gas laws state functions can trip you up) https://en.m.wikipedia.org/wiki/State_function Also remember particles can gain or lose inertial mass. We're not dealing with rest mass. Edited July 9, 2015 by Mordred
Andre Lefebvre Posted July 9, 2015 Author Posted July 9, 2015 Thank you. I'll take note of it and think about it. I want to understand perfectly without any "blurred" spots. Pressure is a measure of force per unit volume. If you increase the space you decrease the pressure and temperature. That's an evidence. They are talking the mass of the individual particles not number of particles. I agree. More massive particles require greater force to move than lighter particles That's a fact; but what force moves them (massive particles)? I think it's their "peculiar" (proper) energy which is either "restrainded" by pressure or "liberated" by space increase. Any pressure increases temperature so all particles are "restrained in their "proper" movement. I'll check the link tomorrow. and I'll see if I understand perfectly.
Mordred Posted July 9, 2015 Posted July 9, 2015 (edited) That's a fact; but what force moves them (massive particles)? I think it's their "peculiar" (proper) energy which is either "restrainded" by pressure or "liberated" by space increase. Any pressure increases temperature so all particles are "restrained in their "proper" movement. . This last part makes no sense. Pressure is force per unit volume. In terms of particles it's the averaging of the force of particle to particle collisions per unit volume. Or in the first articles mannerisms collisions on the container walls (could just be the wording in the quoted parts, translation thingy lol) Say for example you have a hypothetical particle that never interacts with other particles including itself. This particle never has collisions. So it can never deliver any force, a multi particle collection of this particles pressure influence will always be zero. Of course this particle doesn't exist ( lol if it did it would be impossible to contain or detect it. Too sci fi but it's a hypothetical example to show the principle of pressure) If you increase the number of moles of particles you increase its density and the number of collisions. If the number of collisions is constant heavier particles will deliver more force per collision. If you increase the Temperature the particles gain kinetic energy so the number of collisions also increases. If you increase the volume the number of collisions decreases. Here lets use this This law has the following important consequences: If temperature and pressure are kept constant, then the volume of the gas is directly proportional to the number of molecules of gas. If the temperature and volume remain constant, then the pressure of the gas changes is directly proportional to the number of molecules of gas present. If the number of gas molecules and the temperature remain constant, then the pressure is inversely proportional to the volume. If the temperature changes and the number of gas molecules are kept constant, then either pressure or volume (or both) will change in direct proportion to the temperature. https://en.m.wikipedia.org/wiki/Gas_laws http://www.indiana.edu/~geog109/topics/10_Forces&Winds/GasPressWeb/PressGasLaws.html Edited July 9, 2015 by Mordred
Andre Lefebvre Posted July 9, 2015 Author Posted July 9, 2015 Let's go through that again: 1)If you increase the number of moles of particles you increase its density and the number of collisions. If the number of collisions is constant heavier particles will deliver more force per collision. How can you increase the number of moles without increasing the number of particles or putting in "heavier" particles? 2)If you increase the Temperature the particles gain kinetic energy so the number of collisions also increases. If you increase temperature by putting the container of gas on the stove, you give it energy from the stove, so the particles move faster and the collisions increase. The only other way to increase the temperature is by increasing the pressure. Then you're not adding energy; you're just diminishing the space availlable for particles movement (increasing density). So their movements are shorter thus faster; and their energy seemed increased. 3)If you increase the volume the number of collisions decreases. That's normal; you increase the space for particles to move (decrease density); so the energy, even if the same, is diluted in their lenght of the movement (space). The same as expansion dilutes the energy of the universe. a)If temperature and pressure are kept constant, then the volume of the gas is directly proportional to the number of molecules of gas. I'd say that the amplitude of the movement of the particles is stabilised so volume is thus determined. b)If the temperature and volume remain constant, then the pressure of the gas changes is directly proportional to the number of molecules of gas present. So you have to add particles to change the pressure while keeping the volume. c)If the number of gas molecules and the temperature remain constant, then the pressure is inversely proportional to the volume. inversely proportional to... the space for the movement (energy) of particles. d)If the temperature changes and the number of gas molecules are kept constant, then either pressure or volume (or both) will change in direct proportion to the temperature. If there's no adding of outside energy, temperature changes is caused by a change in pressure which needs a diminution of volume. This is what comes from my logic. I'll check the two links you gave me. Thank you.
Mordred Posted July 9, 2015 Posted July 9, 2015 Mole. The Mole A mole (abbreviated mol) of a pure substance is a mass of the material in grams that is numerically equal to the molecular mass in atomic mass units (amu). A mole of any material will contain Avogadro's number of molecules. For example, carbon has an atomic mass of exactly 12.0 atomic mass units http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/idegas.html
Andre Lefebvre Posted July 9, 2015 Author Posted July 9, 2015 .A mole of any material will contain Avogadro's number of molecules. That's why I said that to increase the number of mole of particles, you have to, either change the molecules for heavier ones, or add some of the same molecules you already have. There's something I don't catch here I guess.
Mordred Posted July 9, 2015 Posted July 9, 2015 Your point under number two is inacurrate. Pressure seems to give you trouble. It's inaccurate as you can't increase pressure without increasing the number of collisions or force of each collision. Other than that good thus far That's why I said that to increase the number of mole of particles, you have to, either change the molecules for heavier ones, or add some of the same molecules you already have. There's something I don't catch here I guess. You just need to look at how units are defined. However you are catching on
Andre Lefebvre Posted July 9, 2015 Author Posted July 9, 2015 Your point under number two is inacurrate. Pressure seems to give you trouble. It's inaccurate as you can't increase pressure without increasing the number of collisions or force of each collision. Are you saying that increasing pressure doesn't increase temperature? My number two was: If you increase temperature by putting the container of gas on the stove, you give it energy from the stove, so the particles move faster and the collisions increase. The only other way to increase the temperature is by increasing the pressure. Then you're not adding energy; you're just diminishing the space availlable for particles movement (increasing density). So their movements are shorter thus faster; and their energy seemed increased.
Mordred Posted July 9, 2015 Posted July 9, 2015 (edited) Yes it does I must have misread somewhere. My apologies however you don't need the portion seemed increased. Increase of pressure also increases temperature. Temperature is an increase in average kinetic energy. Key note average. https://en.m.wikipedia.org/?title=Temperature Edited July 9, 2015 by Mordred
Andre Lefebvre Posted July 9, 2015 Author Posted July 9, 2015 (edited) No problem. But now I'm asking myself if pressure is giving me trouble and why or where? You just need to look at how units are defined. However you are catching on But the reasons I see are not exactly the same as the units definitions. I'll try to compare with more precision. But it's going to be tomorrow. I'm falling asleep. Take care. Edited July 9, 2015 by Andre Lefebvre
Mordred Posted July 9, 2015 Posted July 9, 2015 (edited) I would recommend just using volume instead of space. Volume is automatically 3d. Just a side note just reads easier as your defining the dimensions. No problem. But now I'm asking myself if pressure is giving me trouble and why or where? But the reasons I see are not exactly the same as the units definitions. I'll try to compare with more precision. But it's going to be tomorrow. I'm falling asleep. Take care. Have a good sleep, myself I'm enjoying a few drinks lol(Units are extremely important in physics) Edited July 9, 2015 by Mordred
Andre Lefebvre Posted July 9, 2015 Author Posted July 9, 2015 I would recommend just using volume instead of space. Volume is automatically 3d. Just a side note just reads easier as your defining the dimensions. Thank you I'll do that. Have a good sleep, myself I'm enjoying a few drinks lol Thanks and like I said: Take care.
Andre Lefebvre Posted July 9, 2015 Author Posted July 9, 2015 (edited) So here is the "round up" of the informations: Gas laws results in The Combined Gas Law or General Gas Equation: This can also be written as With the addition of Avogadro's Law, the combined gas law develops into the Ideal Gas Law: where p is pressure V is volume n is the number of moles R is the universal gas constant T is temperature (K) where the proportionality constant, now named R, is the Gas constant with a value of 0.08206 (atm∙L)/(mol∙K). An equivalent formulation of this Law is: where p is the pressure V is the volume N is the number of gas molecules k is the Boltzmann constant (1.381×10−23 J·K−1 in SI units) T is the absolute temperature This law has the following important consequences (my previous comments en red, my new questions in blue): If temperature and pressure are kept constant, then the volume of the gas is directly proportional to the number of molecules of gas. (I’d say that the amplitude of the movement of the particles (kinetic energy) is stabilised so volume is thus determined). Could it be possible to use the amplitude of movement of each particles instead of "number of particles" in the formulation of the law? If the temperature and volume remain constant, then the pressure of the gas changes is directly proportional to the number of molecules of gas present (So you have to add particles to change the pressure while keeping the volume. Then you’re changing the pressure by changing the density of the gas. It’s like heating the gas on the stove to change the temperature (exterior addition). No question here since exterior addition is irrelevant. If the number of gas molecules and the temperature remain constant, then the pressure is inversely proportional to the volume (inversely proportional to... the volume of space for the movement (kinetic energy) of particles). Again we're in front of the amplitude of kinetic energy (movement) of each particles. Could that be define in the formulation of the law? (This could be the same difining the same thing as my first question). If the temperature changes and the number of gas molecules are kept constant, then either pressure or volume (or both) will change in direct proportion to the temperature (If there's no adding of outside energy, temperature changes is caused by a change in pressure which needs a diminution of volume). No question here; but "diminution of volume" is again changing the amplitude of movement (kinetic energy) of each particles. Another detail: “however you don't need the portion seemed increased. Increase of pressure also increases temperature. Temperature is an increase in average kinetic energy. Key note average.” I’d say that temperature is an increase "in the measurement" of average kinetic energy. You can’t “create” energy. Example: The expansion of the universe is diluting its energy; not eliminating part of it. Gravitation is compressing energy, not creating energy. So there’s no real “increase” of kinetic energy in pressurising the gas. It’s a kind of illusion. At least the way I see it. So it seems to me that this (or these) gas law leaves "in the dark" the factor "kinetic energy" (movement of each particles) which cannot describe the real factors involved in the event and so the real event itself. I'd like to "let pass" this detail; but I cannot unless I have very good reasons to understand it wouldn't modify further interpretations that could be related to it. The question is: Is the factor of defining the individual kinetic energy (movement) of the particle important for future interpretations? For now, I'd say it is. The next question would be how would it change the formulation of the law? Edited July 9, 2015 by Andre Lefebvre
Mordred Posted July 9, 2015 Posted July 9, 2015 (edited) Change in amplitude is a change in frequency which will change the energy of each particle not the number of particles. You have to remember were dealing with classical particles as well. The gas laws must apply universally to complex compounds as well as single particles. So trying to change it to say a quantum description doesn't make a whole lot of sense. Also gas laws are taught in school, so it's handy to keep simpler decriptives. Also keep in mind the article I posted to you is basic statistical mechanics. Full length articles and books average 300 to 1000 pages long. I could post you a copy if you like but be forewarned the sheer volume of math will make anyone's head swim. Movement is already defined by temperature via average kinetic energy. Remember the gas laws are an averaging system. It doesn't try to predict all the dynamics of individual particles. It describes the averaged influence. Think of it this way how does one change the number of NaCl particles? In this case you need to literally add or subtract the quantity yourself. Quanta of particles won't apply in this case. Also were now dealing with atomic mass. It's best for now to study the current definitions and methodology rather than trying to reinvent the wheel as they say. One has to consider what a change in a fundamental model will affect universally over a broad spectrum of applications. Ideal gas laws are also of great importance in chemistry as well as physics. That will also explain why you see chemistery terms used, ie number of moles. Edited July 9, 2015 by Mordred
Andre Lefebvre Posted July 9, 2015 Author Posted July 9, 2015 Change in amplitude is a change in frequency which will change the energy of each particle not the number of particles. Ok I get it; by increasing and decreasing pressure you compress or extend the wavelength so, increase or decrease frequency without changing the particle. In fact, for particles of matter you're changing the particle, but the law has to be general including light wavelength. Thanks I could post you a copy if you like but be forewarned the sheer volume of math will make anyone's head swim. No thank you. When I swim I like to keep my head out of the water as much I can. But I'm still sorry to leave out kinetic energy. To me it is the source of everything that exists. But then, I'll have to wait if ever we get to it.
Mordred Posted July 9, 2015 Posted July 9, 2015 (edited) Can one derive a quantum descriptive. Absolutely however they are already done. It's not obvious though as they are part of the energy tensor. Ie electromagnetic stress energy tensor. Or in the case of Cosmology stress energy momentum tensor and FLRW metric. The laws were currently dealing with is classical formulation. Everyday applications in chemistery etc. Ok I get it; by increasing and decreasing pressure you compress or extend the wavelength so, increase or decrease frequency without changing the particle. In fact, for particles of matter you're changing the particle, but the law has to be general including light wavelength. Thanks No thank you. When I swim I like to keep my head out of the water as much I can. But I'm still sorry to leave out kinetic energy. To me it is the source of everything that exists. But then, I'll have to wait if ever we get to it. Kinetic energy and potential energy are handy to fully understand. They have carefully designed applications. The original false vacuum model involves kinetic energy it's just termed a pressure relation vacuum. A higher vaccuum region (higher energy state) false vaccuum tunnels to a lower.vacuum energy state true vacuum. Just one example Some people learn cosmology differently. Not necessarily wrong. Some prefer using LQC, or QFT they prefer describing particles in terms of wave functions or particle interactions as fields. Others prefer particle descriptives. You might find your personal way of thinking is suitable to QFT. However the math takes some getting used to. Same for QM style mathematics. Edited July 9, 2015 by Mordred
Andre Lefebvre Posted July 9, 2015 Author Posted July 9, 2015 Can one derive a quantum descriptive. Absolutely however they are already done. It's not obvious though as they are part of the energy tensor. Ie electromagnetic stress energy tensor. Or in the case of Cosmology stress energy momentum tensor and FLRW metric. The laws were currently dealing with is classical formulation. Everyday applications in chemistery etc. Is there any easy accessible links I could find that quantum descriptive? I've got problems with tensors but I'll teach my mind to let them have their right "to be". In my mind mathematic needs them but universe doesn't. That the most difficult part for me to accept them. But I will if I have to.
Mordred Posted July 9, 2015 Posted July 9, 2015 (edited) Tensors are incredibly handy in surprisingly enough simplifying complex relations. Remember mathematics is a tool. The universe doesn't care how we measure it. However physics does lol. I'll dig up some QFT articles for you. I would still recommend looking at how the FLRW metric adapts the classical ideal gas laws. The same techniques will be used in other fields. Be forewarned though I personally understand QFT better than QM. Which is kind of funny. Edited July 9, 2015 by Mordred
Mordred Posted July 9, 2015 Posted July 9, 2015 (edited) I do currently have a good LQC article immediately handy. It's a good alternative to LCDM. Equally a good observation to modelling. http://arxiv.org/abs/1201.4598"Introduction to Loop Quantum Cosmology by Abhay Ashtekar Been awhile since I last read it though a couple on QFT http://www.google.ca/url?sa=t&source=web&cd=3&ved=0CCQQFjAC&url=http%3A%2F%2Fwww.damtp.cam.ac.uk%2Fuser%2Ftong%2Fqft%2Fqft.pdf&rct=j&q=introductory%20to%20Quantum%20field%20theory.&ei=tbOeVeKVN8io-QG1s5OYBQ&usg=AFQjCNHHFlwG-paMpV6erDOOQglsYtw9pw&sig2=d86N3fliPeeZmbOC5KRyXg http://arxiv.org/pdf/hep-th/0510040 Edited July 9, 2015 by Mordred
Mordred Posted July 9, 2015 Posted July 9, 2015 No prob, QFT can be broken down further. QED electromagnetic. Quantum chromodynamics, strong force Quantum flavour dynamics weak force Quantum geometrodynamics gravity. One technique I use when googling good papers add pdf at the end. You tend to hit better articles. Less pop media. Also my technique when studying new material is stop when you hit a section you don't understand. Look for the key words or metrics then Google those metrics or terms. Say for example Klien Gordon equation. Google Klien Gordon equation pdf.
Andre Lefebvre Posted July 9, 2015 Author Posted July 9, 2015 That's about my technique also. I copy what I feel important and don't let it go until I understand it getting information and explications wherever I can find them. I add those info to my copied text. So I'll be having a lot of work to do.
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