exchemist

Fat finger trouble? I presume you meant to reply to the OP rather than to me.

My understanding is yes this is what happens. However the rate of decay is not such as to cause an appreciable bulk charge to accumulate, as a rule - there may be weird exceptions with some exceptionally highly radioactive species, I suppose. There are flows of ions and electrons at very low levels in the atmosphere and in the ground all the time, which we don't notice.

Yes it does. Ambient heat supplies energy to break the hydrogen bonds in the ice crystal, increasing the chemical potential energy of the working medium. This potential energy then flows out when the temperature is reduced and the ice diverts some of that energy into work, as the ice forms and lifts the weight. And then the cycle repeats itself. I've deleted the rest as it just adds confusion.

Yes. But in the end, what's new here is just a magnet. This has been "jam tomorrow" ever since I was a kid. I remember the ZETA torus (for some reason not called a tokamak, though it looked to me like one), with its promise of limitless power, just around the corner. And now I'm over 65 - and people are still designing magnets for toruses, with the promise of limitless power just around the corner...... Like everyone, I hope we are getting closer, but history makes me sceptical.

No. You continue to add confusion. I start to fear this may be deliberate on your part, to keep the Tesla dream alive. Suppose the ice engine converts 5% of the heat input from the ambient surroundings into lifting the weight. The other 95% is exported by the ice engine into the compartment of your freezer. Your freezer then re-exports this heat back into the ambient surroundings. To do that, it does work, input in the form of electrical power. So the amount of heat coming out of the freezer radiator is the 95% of the heat that the ice engine took from the surroundings, PLUS the extra heat due to the energy input from the electricity consumption of the freezer. The theoretical minimum this extra will be is the missing 5% that the ice engine converted to work. In practice, it will more - quite a lot more, since neither the ice engine nor the freezer heat pump will achieve Carnot efficiency. It does not matter how you dress it up, or make it complicated to obscure what is going on. That is the bottom line. You will end up consuming more energy from electricity than the work the ice engine does.

I don't think there will be a sharp ice/water interface, hurtling round the planet. There will just be a progressive wave of melting and thawing. I'm not sure I follow why the water has to move at all. Won't it just gently expand and contract in situ? Just as any other wave does not involve net physical motion in the direction of travel of the wave.

Was this item the only one made of this "slate", or were other objects made of it as well? And was it really slate, or could it have been siltstone? Real slate flakes easily into layers and is not ideal for carving, whereas siltstone is much more suitable. I quote an extract from the Wikipedia article on the Narmer Palette, which was thought to be made of slate but is actually siltstone. The Narmer Palette is a 63-centimetre-tall (2.07 ft), shield-shaped, ceremonial palette, carved from a single piece of flat, soft dark gray-green siltstone. The stone has often been wrongly identified, in the past, as being slate or schist. Slate is layered and prone to flaking, and schist is a metamorphic rock containing large, randomly distributed mineral grains. Both are unlike the finely grained, hard, flake-resistant siltstone, whose source is from a well-attested quarry that has been used since pre-dynastic times at Wadi Hammamat.[13] This material was used extensively during the pre-dynastic period for creating such palettes and also was used as a source for Old Kingdom statuary. A statue of the 2nd dynasty pharaoh Khasekhemwy, found in the same complex as the Narmer Palette at Hierakonpolis, also was made of this material.[1 From: https://en.wikipedia.org/wiki/Narmer_Palette

Yes it's on this thread a couple of pages back. I was referring to the mechanism that causes frost shattering of rock. Water gets into cracks, freezes at night, jacking open the crack, thaws again, refreezes and jacks it open a bit more, etc. I was being a bit figurative, as it is not a constructed engine as such, but it does operate in a cycle, exploits a heat source and heat sink and does mechanical work, using water as the working fluid, by exploiting the ice/water phase change. So if you put it like that, it has all the elements of an engine. That's because videos are a crap way of communicating experiments. To analyse what you did, we need to see a precise description of the exact set up, with a diagram. Whatever you did, you did NOT run it without a heat sink. That I guarantee.

Yes, that would be the principle employed by the natural ice engines you get at the tops of mountains or in deserts, as @sethoflagospointed out a while back. You can certainly exploit the temperature difference between day and night to run an engine. Just don't imagine you can run a heat engine with only a heat source and no heat sink. That is wacko - like poor Tesla.

However the electricity you use to run the freezer will exceed the power output of the ice engine.

Nor has anyone. And there is no reason to think that is what is depicted in these carvings.

Bingo! You've got it - except that in fact you have to add back MORE heat than was taken away, in order to complete the cycle. So yup, its thermodynamics are just like any other heat engine. Exactly. The intermolecular force in the case of water comes mainly from hydrogen bonding. It happens that, because of the relative positions and angles the molecules need to take up, to maximise the energy released by forming these bonds, they have to move apart somewhat, compared to their average spacing in liquid water. Hence we get expansion on freezing. (One or two other materials also expand on freezing, but it is very unusual.)

Not so much weaponised by the wealthy as by the marketing departments of consumer goods companies, I'd have thought. Whole industries have been built on creating and fanning the flames of dissatisfaction. It is a commonly observed fact that poor rural families with very little by way of possessions often seem far happier and more contented than blokes in jags. I myself remember when I got rid of my old Morris Minor, in favour of an MGB roadster, that I was suddently assailed by worries about it getting scratched or stolen, whereas before I couldn't have cared less about the rusty old Minor. Same when I bought my first house.

....and we are where, now, exactly????

Agreed. They are obviously aubergines.

When you say your proposed machine converts atmospheric heat in useful power (electricity I suppose), where is the waste heat rejected? Into water cooler than the air, or something?

Because if you are not not a rabbit, then you are a rabbit. It's just logic.

This seems to have dissolved into rambling incoherence. I don't think there's much point in me continuing this discussion.

Some of these "Mysteries-of-the-Ancients", von Daniken loonies insist they are Crookes tubes!

No I think you re complicating this unnecessarily. The way I envisage this, for simplicity, is that the ratchet acts to stop the load pressing on the ice the moment it starts to melt, i.e. it engages immediately to support the load. So NO work is done on it by the load during what you might call the "return stroke" of the engine. So ignore the ratchet: its function in this scenario is to make things simple. Regarding the atmosphere, yes, a tiny bit of work is done by the atmosphere when the ice melts, sure. But we can forget that too, since it is (i) very small and (ii) an equal and opposite amount of work is done against it during the expansion "power stroke". The ice has not only to push up the load, but also push back the atmosphere too, right? So it makes no net difference to anything. So again, forget it, to make things simple. Also ignore taking machines in and out of freezers and all that jazz. You have a warm reservoir at T1 and a cold one at T2 and you put the engine in contact with each alternately: it does not matter how. Forget the engineering. It does not matter a toss and it is preventing you seeing the essence of the scenario clearly. The point is that, stripped to its essentials, you have a standard heat engine, to which the Carnot cycle principle can be applied, as it can to any other heat engine. As to what does the work during the expansion "power stroke", it is chemical energy. As ice crystallises, chemical bonds are formed as the molecules move to a lower energy state. This releases energy, which emerges in the form of both heat and in any work that has to be done to push the molecules apart, as they start to take up the more open but bonded, rigid structure they have in solid ice. During the return stroke, heat has to be added to give the molecules the thermal kinetic energy to break those bonds again.

I certainly can't - and I doubt anyone else can since it seems, from the link I gave you earlier in the thread, to depend on what borate product you are using. The DOT product in the link is said to give a more or less ideal pH on its own. At least, that is how I interpret this passage: "When used in pools at typical dilution, the new formulation has an ideal pH of ≈7.6. Above pH 8, the chlorine becomes much less effective as a sanitizer, but below pH 7.4 the equilibrium trends toward hypochlorous acid and chlorine is lost more rapidly." So, as I say, I think the best bet is to check with the supplier's recommendations for whatever borate product you are using - or have in mind to use.

Tell us what you think about it first and then maybe we can guide you a bit.

What I mean by normal is that the principle of the Carnot cycle still applies. You have heat flowing from higher temperature T1 to a lower temperature T2, and some of it gets converted to mechanical work. The Carnot cycle says nothing about the means you choose to use to make the conversion. It just lays down the maximum efficiency achievable in theory, over any heat engine cycle. There is no "corruption" of anything that I can see, nor any reason to suppose that thermodynamics ceases to apply, just because we are dealing with a substance that expands on cooling. I can see, though, that it could be interesting, in an academic sort of way, to work out exactly how the efficiency limitations manifest themselves, in this unusual form of heat engine.

Indeed. But we can forget that effect here. The J-T coefficient for N2 is 0.2K/bar and 10mmHg is ~ 0.13bar, so we're looking at cooling of 0.025K or so due to the Joule Thomson effect. The intermolecular attractions of N2 and O2 are not very strong, so air does not deviate that much from an ideal gas.

I don't think even the Russians would see military potential in this ice engine of yours! But I was thinking about it this afternoon. It could be interesting to distill it down to its simplest. You have a vertical cylinder with water in it, a piston and a ratchet so that when it freezes it lifts a weight and when it melts, the weight can't fall back down. You alternately connect the cylinder to a warm reservoir at say 20C and a cold reservoir at say -20C. The warm reservoir provides heat to melt the ice and the cold reservoir freezes it again. What happens? You start with water, connect to the cold reservoir and freeze the water. Heat flows into it, corresponding to Latent Heat of Fusion minus the work done in lifting the weight. Then you connect to the warm reservoir. Heat flows from it to the cylinder to melt the ice, this time the full Latent Heat of fusion, as the water is no longer under pressure, thanks to the ratchet. So you have a heat flow from warm to cold, with some of the heat being converted to mechanical work. It's a normal heat engine, really, isn't it?