# Tom Booth

Senior Members

150

1. ## Help needed for pv=nrt calculation

Well, that's a good start. It would be nice if it were possible to get some rough idea how much lower the temperature could go. Can we just plug in some arbitrary values? For example, the maximum volume is whatever the cylinder can hold with the piston fully expanded. I'm guessing 1 pint. Start out with 1/2 pint of air in the cylinder (60 F 1 ATM) expand that to double the initial volume.
2. ## Help needed for pv=nrt calculation

The piston is being driven by an air motor (external force). No, the piston does not move because of anything that happens in the cylinder. I'm going to say that the pressure before it moves is 1 atm. This is necessarily fudging things but I don't see any other way to proceed. Reasonably, as the piston moves down the pressure drops along with the temperature. No additional air is admitted.
3. ## Help needed for pv=nrt calculation

OK, great! What I imagine happens is the piston is at top. No air is in the cylinder. As the piston moves down it creates a vacuum. When the vacuum is strong enough the valve is forced open slightly by atmospheric pressure outside the cylinder and a little air enters providing some relief, then the valve closes again while the piston continues to the bottom. (or the valve remains slightly open till the piston reaches the bottom then closes). I think, effectively, this would be more or less the same as if there was a little air in the cylinder initially, and this small amount of air was then expanded. So I'm going to say 1/2 pint of air is in the cylinder initially, then the piston moves down expanding this 1/2 pint to twice the volume. The 1/2 pint of air is at 60 degrees Fahrenheit temperature and 1 atmosphere pressure. It is then expanded to twice its initial volume.
4. ## Help needed for pv=nrt calculation

The patent for the compressor does not say that this valve or cylinder is for cooling. That's just my theory. The patent does say that air in the tank is below freezing. Heaters are used to bring the temperature back up above freezing to drive a compressed air engine. It seems reasonable to assume then that the compressor is delivering below freezing cold air to the tank. Somehow the air is being cooled. It looks to me like this valve that may be restricting air intake may be the source of the extreme cooling. I'm just trying to figure out if I might be on the right track or not with this theory. Could ordinary ambient air be cooled significantly below freezing by drawing it through a tightly closed valve into a cylinder? That's the basic question. Then, if so, how much cooling might actually be possible ? -10, -100, liquefaction ? It seems some similar process is commonly used for liquefaction of gases, refrigeration, cryogenics etc. In other words, looking at this picture: Could the top cylinder be for cooling by "pulling a vacuum", expanding rather than compressing the air. Does this seem like a reasonable hypothesis given the apparent strong spring on the inlet valve? If so, how much cooling might be possible at various different spring strengths? I thought it might be possible to get some idea using the ideal gas law formula but I don't really know how to use it.
5. ## Help needed for pv=nrt calculation

Sorry, as I tried to explain, the patent does not provide enough information to give any exact values. Other than; all I know for sure is that there is plain old ambient temperature atmospheric air being drawn into the cylinder, the rest is mostly guesswork or assigning some reasonable arbitrary values. I can say what doesn't change. Assuming 1/2 pint of air enters the chamber (arbitrary), This "amount" (number of air molecules in 1/2 pint of air - moles?) does not change, at least not for the purposes of calculation. Is it at least possible to calculate, or is it already generally known what "amount" of air (moles?) there would be in 1/2 pint of air at ambient temperature (arbitrarily set at 60 degrees F) at ordinary atmospheric pressure ? Since air is being "throttled" or drawn in and expanded simultaneously it is practically impossible to give an actual starting and finishing value as far as "amount". !/2 pint is not really in the cylinder and then expanded to twice the volume. Initially there is nothing in the cylinder. The air is actually drawn in and expanded simultaneously, but to simplify matters it could be said that X amount of air is drawn in and then expanded to twice or three times or whatever the volume, though in a running "compressor" both would be happening simultaneously. Everything else changes. Volume is increased. Pressure and temperature presumably decrease.
6. ## Help needed for pv=nrt calculation

I have been looking over a patent for an air compressor (Bob Neal Compressor). Looking at the illustrations and reading the patent it seems apparent that this "compressor" is not so much compressing air as it is cooling it. Theoretically, by cooling the air significantly it will condense or contract, thereby reducing the volume and in this way effecting "compression". At least that is the theory I'm working with at this point. There is, what seems to me, a rather strange valve arrangement for a compressor. Here is a clip of an image from the relevant illustration from the patent itself: The main valve in question (#44 in the illustration at the top of the "compression" cylinder) has no rocker arms or valve lifters to mechanically open the valve. On the contrary it is held closed by, what looks like a rather strong valve spring. This is the air intake. There is also a check valve (#43) for exhaust but this can largely be ignored along with the check valves at the bottom. When the piston (#25) is moving down, it appears that the only way the valve (#44) can open would be by the piston "pulling a vacuum". How much of a vacuum would depend on how strong the spring is (which, unfortunately, is not specified in the patent). The question became, why this apparently strong spring when another simple check valve as on the bottom would due? It appears that the function of this top cylinder chamber is probably cooling by expansion. The piston moves down but the air intake is restricted by the valve spring. The result being, presumably, a certain degree of mechanical expansion of the air that does get through the valve. It can be assumed that the piston is pulling in atmospheric pressure air at ambient temperature. The volume of the chamber into which the air is admitted through the valve is not specified in the patent but we could assign some reasonable arbitrary value. Say, if the valve were missing or "wide open" the piston would draw in 1 pint of air (at one atm ambient temperature) with no resistance. Let's say ambient temperature is 60 degrees Fahrenheit. The air intake is, however, restricted, so I think it can be assumed that something less than 1 pint of air is actually drawn in. The piston however, continues downward, expanding whatever amount of air is admitted to the full 1 pint volume. The actual percentage of the potential 1 pint actually drawn in would depend upon the spring tension. We don't know the spring tension but I think it should be possible to get some rough idea how much COOLING by expansion might be possible with such an arrangement. For example, if just 3/4 pint of 1 atm 60 F air is drawn in and expanded to the full 1pint volume. Or with a stronger spring, if 1/2 pint is drawn in and expanded to the full volume. What would be the resulting temperature if these values are plugged in to pv=nrt ? That is, for the second "strong spring" example, If 1/2 pint of 60 degree ambient atmospheric air is drawn in and expanded to twice its initial volume, what will be the temperature of the gas when the piston reaches the bottom of the cylinder? Do we have enough information? What would be the resulting temperatures for various arbitrary ratios of expansion? (spring strengths or tensions). What would be the temperature reduction ? I've tried to do some calculations using online calculators and am coming up with what seem like ridiculously low temperatures, like -300 degrees F and such, but I find the formula rather confusing and have no confidence that I'm doing it right. Given the above rough figures, starting with ambient air at 1 atm and a potential volume of 1 pint can anyone help me figure out what the resulting temperatures might be after expansion for various arbitrary expansion ratios ? I hope I have made it clear what I'm trying to figure out here. If anyone can help, feel free to use whatever values seem reasonable that will produce some round numbers, I'm just looking to find out what degree of cooling might be possible. Someone is planning to actually reproduce this compressor, but at this point I'm just trying to figure out how much cooling of the air might be possible with such an arrangement.
7. ## Vortex Tube

Introducing the All-In-One Handy-Dandy Vortex Tube: It makes Hot, it makes Cold, it runs a propeller, it even vacuums the floor, Get yours now! Video : Vortex Tube spinning propeller and vacuuming talc (7.06 MB mpg)

10. ## Vortex Tube

I was about to head out to the shop this morning (with a cup of coffee to make some modifications to the small vortex tube as discussed earlier. Probably start by cutting off the top of the "handle" and replacing it with something non-heat conducting, like wood,) when a new theory occurred to me that I thought I would share. I got a clue from the vacuum effect on the cold tube when the stop was off the end of the hot tube. It appears that there is something like a "venturi effect" going on. Air gets thrown to the perimeter of the tube and due to its high speed of rotation cannot exit through the orifice in the diaphragm but goes the other way towards the exit at the other end (Hot or long end) of the tube leaving a vacuum in the middle. The vacuum is sucking air through the orifice from the cold end of the tube (or at least trying to). This is not particularly unusual. Many IC engine carburetors utilize the venturi effect to deliver fuel to the carburetor. But when the end of the Hot tube is blocked the air trying to rush out is bounced back creating a kind of concussion wave that travels back towards the diaphragm. The "Back Pressure" or reverse wave collides with the air being drawn in through the orifice due to the venturi effect. This sets up a kind of back and forth reverberation at the orifice between the two tubes So I'm guessing that there is some sort of "standing wave" situation which accounts for the acoustical-like dimensionality requirements but this is, strictly speaking, I think, more on the order of a concussion wave, shock wave or pressure wave rather than a "sound" wave. By adjusting the valve at the end of the Hot tube it is possible to cause a kind of conflict of interests at the diaphragm orifice where the air is alternately sucked through one way due to the venturi effect and then pushed back due to the rebounding concussion wave from the stop or plug at the other "Hot" end. This sets up a reverberation which is amplified due to the tubes precise acoustical dimensions which creates a kind of pressure or concussive standing wave. I'm thinking that the usual vortex theory is somewhat incomplete, or at least, I'm speculating that the temperature difference is not a result of heat transfer between an internal and external vortex. Maybe it is, I don't know, but my new theory is that the real action is all taking place at the diaphragm orifice. Lets say that there is a standing wave due to the reverberation. The air is traveling through the diaphragm orifice, first one way then the other. If this reversal were in step with the standing wave, say the direction reverses every 1/2 cycle of the wave the pressure/temperature would reverse as well. In other words, each time the air flows one way through the orifice a small pocket of cold air would be delivered through the orifice then there would be a reversal and a small pocket of compressed hot air would be delivered through the orifice in the opposite direction. With every reversal of direction in air flow there would be a corresponding reversal in temperature on one side or the other of the diaphragm opening. In other words there would be a kind of Doppler effect or something where there would be a tendency for the air going left through the orifice to be compressed/heated and to the right expanded/cooled repeatedly in rapid succession but with relatively little actual air flow in either direction so that that the difference in temperature would tend to be cumulative. As left to itself, the air would be suctioned in through the "cold" end and ejected out the "Hot" end, there only need be a valve at the hot end to regulate the flow so that the flow through the diaphragm orifice in either direction can be adjusted more to the left (venturi effect) or more to the right (back flow). - but I still think it is the standing waves set up due to this reverberation that accounts for the heat separation at the diaphragm opening more so, or rather than, the heat separation taking place due to the rapid spinning of the air in the vortex(s) in the hot tube. Of course, this is just another "guess". I'll probably have an entirely new theory by tomorrow, but I think it should be possible to discover something one way or the other through additional experimentation.

12. ## Stirling Turbine

Well I went ahead and made another "Vortex Tube" from scratch being as careful as possible to stick with the specifications given. I used the smallest of the three configurations which involved using some tubing from a scrap air conditioner as it had the right size tubing. Here are some photos of the finished product: I hooked it up to the air line and cautiously started cranking up the pressure. There seemed to be a good steady flow of air. No leaks. I tried allowing some of the air to blow across my hand from a distance, But there seemed no difference in temperature. The air from either end seemed perfectly even. About the same as room temperature. I got the pressure all the way up to 125 PSI. As high as the compressor could go. I ended up actually putting the jets of air on my tongue to see if any difference in temperature at all could be detected. Not a thing. I did various experiments like using objects to block or partially block one end or the other. Insulating the pipes on one side or the other. I even put some stainless steel turnings in the end of the Hot Pipe as a "regenerator". This made no change. The tube made no particularly unusual sound. Just the sound of air flow. Reportedly these things create some sort of loud sound when working properly. I think this tends to rule out the idea that the vortex tube works by the air expansion alone. I think the air was certainly expanding through the tubes. One thing I thought I might have done "wrong" is when I drilled the hole for the air inlet I was a little afraid of getting too close to the "diaphragm" and may have drilled the hole a hair or two further away from the diaphragm than I might have done otherwise. So what difference would that make ? My thought is, If I did everything to exact specifications, as far as possible with materials at hand, I think I kept very very close to specifications, within 1/2 a mm or so, and it still isn't performing in the slightest little bit My best guess at this point is: There is some kind of necessity for some sound production. I'm thinking that the orifice between the Hot and Cold chambers or "diaphragm" with the hole in it with the jet of air swirling around it is what is supposed to generate sound. Kind of like blowing across the top of a pop bottle. If you have ever tried to do that it might be understood that this takes some finesse to get the air stream to cut across the bottle opening "just so" at just the right angle with the right pressure at just the right distance and so forth, It can be exceedingly difficult at times. It is easier to generate a tone with some bottles more than others, or, the effect may be something akin to rubbing a finger around the edge of a wine glass to cause it to sing. Or whistling. Some people just cant whistle for some reason. One of the names for this thing means "whistle" so perhaps that is accurate and perhaps the "diaphragm" is called a diaphragm as it is intended to be - like a loudspeaker, an actual sound producing, vibrating diaphragm and not just an orifice. If this is the case than quite possibly the reason for the failure is that the jet of air is just not hitting or not spinning around the diaphragm opening at the right angle or distance of something, so no sound is being produced. I imagine the diaphragm acting similar to a speaker in a thermalacoustic engine. One thing seems certain. There is some "trick" to this thing and it seems it is necessary to get it just right to get any effect at all. I was fairly certain when I decided to make a vortex tube that even if It was not perfect there would still be some detectable temperature difference. So far with these first two vortex tubes, I cannot detect any temperature difference whatsoever at all. Just regular plain old lukewarm - normal compressor air from either end. But so far neither one has produced any unusual sound either. Everyone who has ever had one of these things working has made mention of the loud sound produced. This seems a bit of additional confirmation that with no sound, there is no cooling effect, on the other hand, it doesn't seem there is much of any "vortex" being generated either. I'm thinking that this may require sound as well. A kind of acoustically driven vortex - if such a thing is possible.
13. ## Stirling Turbine

Here is what looks to me like some additional confirmation of the acoustic theory: I reviewed the various information available again paying closer attention to size and proportions. An old graph gives a proportion of 1:32 Yes the newer working commercial model disassembled in one of the videos was measured to have an inside diameter of 10 millimeters and a length of only 80 millimeters. A ratio of 1:8 There is a common denominator here. These are octaves. Do Re Me Fa So La Te Do 1 2 3 4 5 6 7 8 8 16 32 etc. With this information I drew a graph with various possible waveforms thus: It can be seen how a full octave, that is, a 1:8 ratio between ID and length creates what might be called "Supernodes". That is, "standing waves" have nodal points but with a 1:8 ratio between inside diameter and length a resonant chamber is formed where all possible wavelength converge at the ends forming "supernodes". My theory at this point is that these "supernodes" create points where air molecules are forced to gather along the lines of the Chhaladni figures. One of these supernodes is located directly at the convergence point of the air inlet, the vortex "spinner" device which is supposed to create a vortex and the "diaphragm" that separates the Hot from the Cold chambers. By controlling the flow of compressed air with the valve/regulator at the end of the Hot tube the flow of compressed air can be, in a sense, "tuned" to the same frequency. That is as the molecules oscillate a corresponding volume of air is made to draw the accumulated molecules at the node through the hole in the diaphragm. Since the nodal accumulation, that is, since the wave form reverses continually, Once one accumulation of molecules passes through the diaphragm another node forms. I suspect that the speed of the air passing through the orifice in the diaphragm should be "tuned" so as to be proportionately the same as the volume of one unit of air per oscillation for maximum efficiency. By unit I mean the air volume contained within one segment of the pipe or resonant chamber. By segment I mean a length of pipe with a 1:1 ratio to the ID of the pipe as illustrated above. I may not be correct as to detail but I'm fairly certain that I'm on the right track. I will make some modifications to my model based on this acoustic theory and let you know what happens. BTW I measured the ID of my existing Hot Pipe and used this to mark off the length of the pipe using the ID of the pipe as a unit of measure. It turned out to have a length of about 11 and 1/4 "units". This is perhaps the worst possible ratio in terms of acoustics. Putting this into a graph similar to the one above, no wavelengths converged anywhere at all so that there was no possibility of any nodal points forming, except at the point that corresponded with the point where I was holding the tube and tapping it with a knife handle and it rang out, but very little. A few waves converged at that particular point when marked out graphically. I double checked this by marking the pipe according to the graph or measurements, that is, using the ID of the pipe as a unit of measure. Holding the pipe at that point it would make a ringing sound when struck. Otherwise it was a total dud. If I simply cut off the equivalent of about 3 and 1/4 units of measure off the pipe that would give it a 1:8 ratio.

15. ## What is heat?

Yes, that is Tesla describing his theory. But this is IMO at least, identical to saying; (if we applied it to the "drinking bird"): "by expending initially a certain amount of work to create a sink for the heat... to flow in" (He is only using water as a metaphore for heat i.e. If we first dunk the drinking birds head into the glass of water to create a heat sink for ambient heat to flow towards) "We would thus produce... a condition enabling us to get any amount of energy without further effort" (i.e. the bird will continue drinking so as to maintain the sink while also producing some energy). I realize Tesla was being, perhaps, a bit over-optimistic and envisioned something more than a toy bird generating a micro-amp but what he is suggesting IMO is no different in principle than the toy bird which does function as Tesla described. Once set in motion by getting its head wet and initiating a "heat sink" it keeps going on its own without any further effort on our part. Tesla was describing a heat engine and this bird is a heat engine that functions in the way he described, except perhaps in regard to the amount of useable energy produced. Could this principle be scaled up to produce some usable energy for practical purposes ? I'm not going to conclude its "impossible". At least not until somebody actually tries it. If the principle is sound, there are other more efficient ways of creating a "cold hole" than wetting 1/2 sqare inch or so of felt on a toy birds beak and much more efficient heat engines I should think.
16. ## Stirling Turbine

Well, I couldn't resist. I had some extra time today so I tried my hand at knocking together a Vortex Tube. I didn't follow any specific directions. They seem so simple and I've seen so many examples online I thought I'd have no trouble making one. I even made some modifications I thought might make the thing work better at lower pressures (added an extra set of groves in a metal slug to generate the vortex). I hooked it up to the compressor and, forgot I only had it held together with duck tape for low pressure testing and the compressor was at 125 PSI or so and it blew all apart. I found the pieces and put it back together and started out at very low presure and gradually increased the pressure. Nothing much happened. The air came out both sides of the tube but otherwise there was no difference in temperature though the lower portion of the T that I was using for a handle did seem to get a little bit cold. Well, I did not follow any specific directions or make any accurate measurements as far as lengths of tubing and such, and it didn't work. I guess I should try making one to specifications to start out with. Apparently it does matter because I got no temperature difference whatsoever up to about 50 PSI when the thing came apart again. Disassembled: I might mention that as usual, after turning on the compressor the pipes leading from the compressor to the compressor tank got blistering hot.
17. ## What is heat?

Maybe, I'm not entirely sure. It seems like a gray area. Some things can look like, or in being described, sound like perpetual motion but aren't. The difference between one and the other can be rather subtle sometimes, especially if only going by a description. For example, If I say that I'm going to use a siphon to extract energy. I'm going to take the siphon and put it in some water and then put a turbine in the siphon tube and in this way get "free energy" indefinitely without having to do any additional work. Is that "perpetual motion" or isn't it ? Sounds like it and it could be, but maybe not. I didn't say that I was going to use the energy produced by the turbine to pump the water back to its source to start the process all over again making it a closed system. Also I didn't mention that by "some water" I meant a lake at a high elevation in an area of adequate rainfall to keep the lake filled. The difference is one is an open system the other isn't. I don't think Tesla was proposing a closed system. You can put Tesla's proposed engine in a sealed room and say "see, if you put it in a closed room it would be perpetual motion". But that is taking an open system and changing the conditions to make it a closed system and is not what Tesla proposed at all. But, I'm guessing you are right anyway. Probably couldn't work, but I still see it as a gray area. As far as I know, nobody has ever tried it, although in some respects I think the principle has already been demonstrated on a small scale, though even this is debatable I suppose. For example, there is no stable "heat sink" for the heat engine (in the following video) to run on. If this heat engine were to stop running for some reason the "Heat Sink" in the form of effective evaporative cooling would disappear. The cooling or "Heat Sink" is created "on the fly" through the engines own mechanical output. The engine uses its own power to maintain its own cooling system and so run on a combination of ambient heat and evaporative cooling but it is not "perpetual motion" because it is an open system. It is, in effect, a very small and inefficient ambient heat engine. Theoretically you could build a giant version of this thing and set it next to a lake and it would run and perhaps generate power "indefinitely". Looks like perpetual motion but isn't. But again, I'm afraid this is getting off topic here, even if it is "heat" related.
18. ## Stirling Turbine

Here is a website about the Vortex Tube that includes a couple videos demonstrating a small commercial unit freezing water in a test tube and also recording the temperature differential produced. Also in the second video one is disassembled to show (close up and in detail), the inner workings. Vortex Tube Videos at http://www.machine-history.com/ One thought regarding the efficiency of the Vortex Tube. Some sites I have been reading suggest that the efficiency (For Refrigeration Purposes Alone) is Low compared to a conventional refrigerator. I am wondering though, how much of that "inefficiency" is due to the bulky compressors that would normally supply air to the unit. In a conventional compressor a tremendous amount of energy is wasted. In fact a typical shop compressor has cooling fins to help dissipate the "waste heat". Some say that ALL the energy used to compress the air by a conventional compressor is lost and that the only reason you can extract any energy from compressed air is due to the latent "internal energy" not due to any energy added by the compressor. This is all lost as "waste heat". I think if there were a "compressor" that ran on heat so that all of this "waste heat" could be utilized the overall efficiency of this, or any air-cycle type heat exchange system utilizing compressed air as a refrigerant would be greatly increased.
19. ## What is heat?

As far as the heat engine is concerned, I could really care less about entropy & the second law. I just want to know if there is any chance in Hades of the thing actually working. If the second law doesn't apply because it is not a closed system then I can stop worrying about finding loopholes in the second law.
20. ## What is heat?

But how can you really gauge complexity / order ? I used to have this problem with my X-Girlfriend. I had some manuscripts I'd be working on and would have the chapters all organized so I could look everything over at a glance - spread out on a long table. Very complicated but well organized, slips of paper inserted between pages with notes, cross references, footnotes etc. Whenever I went out though my girlfriend, in the process of straightening up the house would get things neat and organized by picking up my mess on the table and putting it all into a box in the back of the closet.
21. ## Stirling Turbine

Here is something else interesting. Quite a long time ago, possibly living in Arizona or California or where exactly I cant remember but I saw what I believe was a local news broadcast of some guys in a garage who were blowing air through a T shaped tube with a shop air compressor. The thing appeared to be nothing more than some copper plumbing pipe but they were blowing air into the bottom of the T and naturally the air was coming out the other two legs of the T but the remarkable thing was that bitter cold freezing air was coming out one side and burning hot air was coming out the other. It has been a long time since then but I have finally, very recently, (thanks to the internet which didn't exist back in those days) located information regarding what I saw in that brief newscast so many years ago. One name for it is "Wirbelrohr" also "Hilsch Vortex Tube" and is sometimes also referred to by some as "Maxwell's demon". There are quite a few DIY guides or instructions, diagrams etc. to build your own. Not very much to it really but apparently it works. Here is one site with rather detailed diagrams: http://www.visi.com/~darus/hilsch/index.html Of course, you need compressed air. If you had an air compressor that could run from a temperature differential than here is another very simple way to get the temperature differential to run the air compressor with no additional moving parts! According to some reports it seems that it is possible to get the heating and cooling effect by simply blowing through the thing by mouth, though you would need pretty good lungs apparently. There are also commercial versions being sold. I'm currently working on putting together a slightly bigger test model of the "Ice Powered" Air compressor. Wooden Body to reduce heat loss by conduction Lighter weight Styrofoam Displacer Larger copper heat conducting plates.
22. ## What is heat?

I find this very interesting. In particular "Further, the energy that fuels you ultimately comes from the sun, so you don't have a closed system." What I am really interested in in regard to all this is how it might apply to a particular design for a Heat Engine of my own invention. I've been told repeatedly by various persons over the years that it cannot work because it would be a violation of the Second Law of Thermodynamics. One of my arguments to the contrary was that the engine is not a closed system and that the fuel to run the engine is ultimately heat from the sun. This seems to be the same as the argument you are putting forth here that Life does not violate the Second Law of Thermodynamics for the same reasons I came to find out recently that Tesla conceived a similar engine that he believed could operate on ambient heat he called a "Self acting engine" - able to run on indirect heat from the sun stored in the medium. He seems to be saying that it would be possible under some special circumstances which he describes quite clearly IMO, to extract heat from the atmosphere (heat ultimately coming from the sun) and convert that heat into a different form of energy so as to leave behind a "Sink" or "Cold Hole" for additional heat energy to flow into and thus be able to extract additional energy from that heat. The energy gained could then be used to expel any residual heat not converted so that the "cold hole" could be maintained indefinitely - so long as at least some of the incoming heat continued to be converted to some other form of energy. It seems to me that my engine design is conceptually identical to what Tesla describes. My question is, regardless of any particular design, conceptually, is Tesla's (or my) idea "a violation of the second law of thermodynamics" ? I posted excerpts from Tesla's article here: http://www.scienceforums.net/topic/46143-stirling-turbine/page__view__findpost__p__619315 There are also some diagrams and a GIF animation providing a conceptual "working model" of the engine. I'm sure some posting here have already viewed this, but I would be interested in getting any opinions regarding this 2nd Law question.
23. ## What is heat?

OK,... if you say so. Would you agree that at one time "animate" objects (life forms) were conceived to be excluded as obvious exceptions ? If so, at what time or place was there an official change or pronouncement that "animate" life forms would be included in the formulation ? Or no longer excluded rather ? It seems a great deal about the general theory of thermodynamics involves the imagination and includes what seem to me to be arbitrary definitions with no clearly fixed boundaries. For example: "isolated system" in particular I've been having some trouble with. Granted, the sun was shining. I had eaten something previously, I was breathing air, etc. If a so called "isolated system" is found to have negative entropy, the argument goes that you just move the boundary until you come up with the right numbers to satisfy the formula. (Or imagine that you have.) The definitions of "System", "open system", "isolated system" don't seem to have any governing rules. It is impossible to win an argument against the second law of thermodynamics not because it is true but because the game is fixed. Heads I win, Tails you lose. This kind of moving boundary argument is something I've seen repeatedly in discussions of the topic practically from its first inception. It seems to me that this is changing the definitions to satisfy what amounts to a belief, I think. If the numbers don't square right you can just redefine your "isolated system". Move the boundary line. So, lets go ahead and do that. Now we include my "lunch" or consumption of "fuel". At this point we have introduced another case of negative entropy. Metabolism. And another. Since my food consisted of various complex organic compounds we would have to include the processes involved in growing plants. Inert molecules (dirt) combining with air and sunshine to assemble themselves into the highly complex cellular formations to be found in the tomato on my sandwich for example. We may have shifted the problem further away from the immediate area but I don't see how this solves the "problem" of life in all its varied forms exhibiting "negative entropy" or creating order out of disorder. We can continue moving the boundary. Redefining what constitutes our "closed system" until we reach the ends of the universe, but by this time I think we have left reality and gone off into literal flights of the imagination. Can it be, or has it ever been "proven" that "the universe" is an "isolated system" ? If the ashes that constitute the inert remains of a human being are scattered around my wood pile and "fuel"; (air, sunshine and a BLT sandwich) is added to the mix, does the pile of wood that was dumped out of a truck then assemble itself into stacks ? But this is all getting rather philosophical and pretty far removed from the subject of heat I think. BTW, I benefited from the exercise. Breathed fresh air and was considerably invigorated by the wood stacking. So how did my entropy increase during the process ? Also, in regard to my lunch. It went from a state of relative disorder as a sandwich to a state of considerably greater complexity as part of my blood and bones, muscles, general cellular structure, mitochondria, ribosomes, lysosomes, enzymes, DNA etc. so how did the entropy or state of disorder of the sandwich increase ?
24. ## What is heat?

Well, There are a few things posted earlier I might respond to at some other time but I have a thought on this at the moment so I'll post it before going off to work. (to stack more firewood). My point in my earlier posts made last night was that Life seems to violate entropy. (i.e. 2nd Law.) True, the firewood did not stack itself. A life form stacked the firewood. Your statement above it seems to me, reflects an unconscious assumption that this "Life Form" is excluded from the "system" under consideration. This goes all the way back to the earliest formulations of the "Laws" of thermodynamics. If as suggested earlier I took a nap on the ground, taking the "Tom, Yard, Firewood" system as a whole and viewing it strictly in terms of a collection of inanimate atoms. (i.e. making no pre-judgement in regard to the definition of "animate" or "inanimate") There was an apparent "spontaneous" ordering performed by the collection of atoms that compose the Tom-Firewood-Yard "System". This "Spontaneous ordering" or apparent "negative entropy" took place on a Maco scale over a period of several hours, not nano-seconds. So why is a few seconds of "negative entropy" of a few beads floating in water so Newsworthy ? What is the basis for making a distinction between "animate" and "inanimate" and excluding the latter ? What I am saying is that in order for the "Law" to hold it is necessary to arbitrarily discount "Life forms" as being part of the "System" or to make an arbitrary distinction between "animate" and "inanimate". according to the original formulation of "The Law". This is reflected in the wording of the text or "Laws". i.e. No "inanimate" machine can... such and such and so and so. So what energy was applied to the system that caused the apparent "spontaneous" ordering ? There was a pile of matter on the ground composed mostly of "inanimate" firewood that happened to include a relatively small sleeping life form. Viewed as a simple pile of "inanimate" material, what energy invaded the "system" which suddenly caused a portion of this inert matter to "wake up" and begin putting things in order (stacking the firewood) ? I'm not asking for an answer to that question. I'm just pointing out that "Life" as a factor in the "System" or in thermodynamic calculations has apparently and I think admittedly been excluded as an element. I think this is arbitrary. But this is an entirely different issue than the "Heat" question and probably off-topic for this thread. Just something to think about. ----------------- "II., no inanimate material agency could produce more mechanical effect from a given quantity of heat, with a given available range of temperatures, than an engine satisfying the criterion stated in the enunciation of the proposition." (Source: "The Second Law of Thermodynamics" by William Francis Magie pg 127) "The demonstration of the second proposition is founded on the following axiom: "It is impossible, by means of inanimate material agency, to derive mechanical effect from any portion of matter by cooling it below the temperature of the coldest of the surrounding objects." (pg 116) -----------------------