On Fri, May 31, 2013 at 1:36 PM, David Roberson <dlrober...@aol.com> wrote:
> This is a good start Josh. I think I can explain that to you since you > seem to be a pretty sharp guy. > Thank you Mr Roberson for that kind compliment. Unfortunately it also takes an explanation that is realistic and a sharp guy to explain it. And you seem to be a guy who thinks he's a lot sharper than he is. I wish you'd look at my much simpler intuitive argument, and tell me what's wrong with it. For example, if 360 W from the outside can trigger the reaction, why would 1.6 kW from the inside not sustain it? I get that the basic claim is that the reaction power alone is not enough to maintain the reaction, so it decays toward zero, but the sum of the external and reaction powers is enough to make it grow, even to a temperature at which runaway occurs. But the problem is that it seems unlikely that a plausible temperature dependence of the reaction rate and of heat loss would produce that situation, given the constraints represented by the claimed observations. In particular, the much higher output power compared to the input power. While they claim a COP of 3 or 6 for the device, that would correspond to a much higher COP for the fuel itself, because much less than half of the input heat would reach the fuel. As I see it, you only need to postulate how the reaction rate depends on temperature, and how the heat loss depends on temperature to determine what will happen to the system. For a given input power and temperature, you can then calculate the net power (total power produced by the external plus reaction minus the heat loss). If that's positive, it will get hotter, if negative it will cool down. When it encounters a change in sign it will stabilize, A sign change (or zero net power) occurs when the heat loss is equal to external power plus the reaction power, much like the sun is stable with it's heat loss balancing its reaction rate. If the net power is positive, and it grows with temperature, then you get a runaway condition. In my brief tests I only used simple functions (of the temperature for the reaction rate, and of the temperature difference from ambient for the heat loss), and if the system is designed to be stable at 2 kW output for 360 W input, as in the December run, the removal of the input always left a system stable at a somewhat lower temperature. The reason is that the reaction rate has to grow quickly at the beginning to keep the total input power ahead of the heat loss so it is always positive until it reaches the 2 kW level in the December test. In my calculations, if it grows fast enough to ensure that it reaches 2 kW, where the sign changes by design, then removal of the external drive doesn't quench it. This is true even assuming all 360 W reach the fuel. Realistically, far less than half would, especially at the higher temperatures, and this makes removal of the external even less significant. Now, it is surely possible to contrive a reaction rate dependence and a heat loss dependence to make it quench without the external heat, but it's far from obvious that it would be realistic, and that one could engineer the necessary dependence, particularly in so many and varied configurations. So, that's why I asked what your proposed functional dependences are that would give the observed behavior. How does the reaction rate depend on temperature, and how does the heat loss depend on temperature? And are they realistic dependences? But the real question, which is what raised the issue to begin with, is *why bother* trying to engineer these dependences. You and Storms admit that Rossi has difficult engineering challenges to make such a system stable with a high COP. Why would he make it so difficult for himself? No sane person would do it this way. If the reaction rate depends on temperature, and there is danger of runaway, then the obvious way to control it is with thermostatically controlled cooling. And then you could easily make it self-sustaining, by adjusting the cooling to give any temperature necessary. Instead he adds heat with the pretense of controlling the heat, because of course, that may be all the heat he's actually got. It's like so many cold fusion claims. It's not that there is an obvious alternative explanation for the apparent excess heat. It's that there are far more direct, straightforward, transparent, and well-established ways to demonstrate it that are not used. It seems like the claims only occur when the experiment is unnecessarily indirect and complex. So, I think it's a waste of time analyzing results like this. Do the experiment with an isolated finite power source, with flow calorimetry that integrates heat in a visual way, and do it under public scrutiny without restrictions on observers, and then the world will change. As Aesop's fable "The leap at Rhodes" finshes: "No need of witnesses. Suppose this city is Rhodes. Now show us how far you can jump." > The ECAT operates as a device with a positive temperature coefficient with respect to heat. At low temperatures there is little if any extra heat being internally produced by the core. When the drive electronics heats the resistors they conduct heat to the core of the device which rises in temperature as a result. There is a functional relationship between the core temperature and the heat it produces. I have tried numerous functions and they all behave in a somewhat related fashion. The exact one in play by Rossi's device is hidden at this point so don't try to muddy the water by asking for that knowledge since you like to avoid the main issues. That's not avoidance. I'm just asking for an example of a functional relationship that would work. > The ECAT core finds itself driving a thermal resistance that depends upon the system design. The functional relationship of core heat released versus temperature can be differentiated throughout it operating range. Now, if you take the product of the thermal resistance and the above derivative you will find a temperature above which this result is greater than 1. The resistance is presumably constant, so this means the function must have a slope that increases with temperature. Is that the case? I'd need to see this equality justified, and as I see it, it's not necessary. The thermal resistance will go into the temperature dependence of the heat loss. But we can skip the details and just give the resulting dependence. It should be stronger than linear because the temperature difference which determines the conductance will depend on the radiation from the outside, which has a 4th power dependence. Anyway, thermal resistance has an area factor, so you're talking about a surface power density here or your product is not dimensionless. > This is the first temperature which I call critical and is where the positive feedback gain is greater than 1. > If the ECAT is left in this region, it can go either higher in temperature with an ever increasing rate toward destruction, or cool off and return back to room temperature. > This is the point that it is important for you to acknowledge. Do you accept that this is possible so that we can continue further into the details? If you state that it is not possible for any heat to be generated by the core, then the rest of the discussion is not worth pursuing. I will not play Simplicio to your Salviati, because it's a terribly inefficient way to present an explanation in this sort of a forum (unless you write both sides, as Galileo did) and involves guessing about your absent justifications. If you have an explanation, present it, start to finish, and actually, all I'm interested in is the temperature dependencies I mentioned. That's how it's normally done. In fact, I'm surprised you haven't already written it up and published it. Quite apart from cold fusion, using input heat to control positive thermal feedback would be a novel and interesting presentation in its own right. You could submit it to some prestigious engineering transactions. At the very least JCMNS would eat it up. And you should be prepared for when Rossi is universally accepted, because then you could get your explanation published straight away in Nature or Science or PRL, and you'd be famous. The snail's pace at which you are proceeding looks a little like you're stalling -- like you're hoping to trip me up or find a disagreement so you can plead futility without actually having to present the full story, for whatever reason. I have no problem with the possibility of a critical temperature above which runaway occurs, but I don't like vague descriptions like "it can go either way" without specifying what determines which way it goes. And without knowing how the heat loss and reaction rate depend on temperature, I am not prepared to say one exists in this case, or that it would be reached given the constraints of the observations. So write up a complete explanation for how you think external heat controls positive thermal feedback, and I'll have a look at it. All I really want is the two dependencies, but you may want to elaborate. Unfortunately, I'm traveling for the next few weeks, and so this is the my last batch of posts for some time. But I will respond when I have time again. That gives you a little time to put together a nice presentation. Most people, I think, much prefer to have the whole presentation laid out. That's why people don't publish theories one paragraph at a time, and ask for approval on each step. And, like I said, if it's a solid explanation, it will be well worth your while, because it will make an impressive publication whether or not cold fusion has merit.
