A Resource card in Steve Jackson's (utterly superb) semi-Collectable Card Game Illuminati: New World Order aka INWO.

The owner of the Resource can link it to any Group or their Illuminati itself. This gives the linked Group one extra action token per turn. It is especially good to link this to your Illuminati (especially if you are The Network and can have an Eliza or two too) or to a card that can stockpile actions like Germany.

The card has the attributes Unique, Artifact, Gadget.

fnord.

A machine, device or system which continues in motion for ever. Also known as a perpetuum mobile, the latin translation of perpetual motion machine.

Scientists and engineers are taught from an early age that it is impossible to make a practical perpetual motion machine because of the three key laws of thermodynamics.

We’ll start with the second law of thermodynamics. (non-techies should skip this boring, pedantic paragraph and go straight to the next) This says that for any given process in a closed system, the change in entropy of the complete system will always be equal to, or greater than zero. Thornton gives a number of ways to express it mathematically in his write-up.

Basically that means anything and everything which moves or otherwise changes, will somehow convert useful energy (motion, electricity, etc) into less useful forms of energy (heat, for example), except in one special case, which I’ll talk about later.

Now we have to look at the first law of thermodynamics. This says that in any closed system there is no way to create energy out of nothingness. To put that another way, the total energy within the system will remain the same, no matter what you do to it.

Combine these two, and it’s easy to see that in any closed system, the total energy within that system will remain the same, but if anything changes, then some of the energy will be converted into useless forms of energy, such as heat.

The rather depressing conclusion is that all things eventually run down, converting more and more of their useful energy into less useful forms. Thus , no machine can go on for ever, unless it has some kind of external energy source, which constantly tops up the energy 'lost' in various energy conversion processes.

But what about that special case where energy is converted with zero loss? That is where the third law comes into play. The third law basically says that friction is a fact of life, and that whenever you get into the practical world of making and building stuff, then it is physically impossible to build something which can convert energy without some small fraction of that energy being changed into heat.

OK, so the engineers dismiss perpetual motion by invoking the god of thermodynamics and declaring that perpetual motion is impossible at all times, in all places and in all environments. End of story. No arguments allowed.


Hey! You’re such a smartass! Tell me why the laws of thermodynamics are so inviolable.

Here’s the easy answer: If someone made a perpetual motion machine, it would be so useful and so valuable that it could not be hidden or forgotten. Throughout history no records indicate that such machines have ever been built, despite great intellectual efforts by many millions of people.

Nope, sorry, that’s not good enough

Hmmm, thought you might say that. OK, let me put it another way. The only way we humans can analyse how the universe works is by looking at our experience, thinking about those experiences and drawing conclusions. From this we can formulate some rules about how the world works and use those rules to make predictions about what should happen in the future.

The second law—along with its two relations—is one of those rules which is based on the sum total of human experience. People have pummelled it with all the other theories of how stuff works, tested it with physical experiments and thought experiments designed to find the tiniest crack in the wall of certainty surrounding it. Yet. despite all this, they have never found a way to break it: never even found the tiniest aberration which might make it give some weird and unexplained result.

That is as much as anyone can say about any of our so-called fundamental laws of physics. We have never seen or thought of anything which might imply that they are in any sense fallible. The reason that the second law is so revered by engineers and scientists is that it is absolutely fundamental to all branches of engineering. You might imagine that if there were anything wrong with it, then all the different types of test, experiment and theory would have revealed some kind of crack, but no. Nothing has ever dented our certainty in the second law of thermodynamics.

Hmm, doesn’t sound like much to base a whole way of life on?

Well, you might be right, but that’s the way the scientific business works, most of the time. If you don’t like it, start reading more on the philosophy of science.

So, err, does that mean I might be able to actually build a perpetual motion machine?

No, not here on earth. However, there might be places in the universe where things are so different that the experience we have accumulated here on earth in the last couple of millennia simply do not apply. And in those places, I suppose, it might well be possible.

Example of a machine (and why it won’t work)

Designs for perpetual motion machines fall into two broad categories: the ones invented by people thinking they have stumbled on the secret of eternal wealth, and those thought up by scientists and engineers to help explain the issues involved.The latter group are usually the more interesting. Almost always, the scientists produce ideas which are much harder to de-bunk. Here is a nice one from one of my heroes.

Feynman’s gas unit

http://manor.york.ac.uk/htdocs/perpetual/perpetual.html
               ______________________________
              |                              |
              |  _______________________     |
    ---       |  \     /               /     |
   /   \      |   \   /               /      |
  |     |__________\_/               /       |
  |     |           /_______________/        |
  |     |————------——————/\        |        
   \   /      |   /  \               \       |
     -|       |  /____\_______________\      |
      |       |                              |
 _____|____   |                              |
|         |   |      Low pressure gas        |
| Ratchet |   |______________________________|
|_________|               

The above diagram shows a machine proposed by Prof. Richard Feynman in his book, The character of Physical Law. It is a shaft with a series of vanes in a low-pressure atmosphere. The shaft is attached to a ratchet mechanism which allows rotation in one direction, but not in the other. Although pressure is normally evenly spread, the statistical nature of molecular motion means that every now and again, the pressure on one side of the vane will be higher than on the other, causing a slight positive torque on the shaft, leading to a small positive rotation. Because of statistics, there will be just as many occasions when the pressure is reversed, generating a negative torque on the shaft. But there will be no motion on those occasions, because the ratchet prevents it.

Although the motion will be very slow, and with a low torque, this appears to be a perpetual motion machine, driven by the kinetic energy of the molecules in the gas.

Can you spot the fallacy?

I first thought that the energy comes from the temperature of the gas, which will fall very slightly every time the vanes move. If a gas atom hits the vane, it will rebound with some energy. When the vane remains stationary, then the atom rebounds elastically. However, when the vane recoils as the gas atom hits, then the atom's rebound speed will be slightly slower, leading to a cooling of the gas. Eventually there will be no energy left in the gas, or not enough to turn the vanes, in any case.

Read Professor Pi's explanation (below) of why Feynman is right and I am wrong. This is incredibly subtle and shows how many traps there can be for the unwary when de-bunking such machines.

Please read wrinkly's excellent writeup in this node first.

Surely Mr. Feynman wasn't joking with his example for a perpetual motion machine. Of course the Nobel Prize winner never had any hopes that this hypothetical device would actually work: it was merely an exercise for his students to spot the flaws. However, the underlying thermodynamics and physics to this problem are subtle.

The First law of thermodynamics: conservation of energy by itself does not exclude the possibility a perpetual motion machine. The system under consideration must be a closed system (no energy exchange with the environment) or the net energy flux must equal zero (influx = outflux). Note that this would be true for ideal systems, as well as real systems.

However, the situation is different for the Second law of thermodynamics, which states that during an adiabatic process entropy cannot decrease. An alternative formulation of the law is that it is impossible to convert the heat of a system into work without the occurrence of other simultaneous changes in the system or its environment. As a result, the second law of thermodynamics is inherently for real systems, because it makes a prediction of the entropy of the system. Real systems strive towards a situation where the availability of energy is minimized (a greater disorder.)

As a result, we must consider the Feynman perpetual motion machine --- like any other perpetuum mobile--- as a real system. If we neglect the second law of thermodynamics it is not difficult to design a perpetual motion machine: an object spinning in zero gravity and a perfect vacuum would spin indefinitely. However, a perfect vacuum cannot be created. In fact, the second law of thermodynamics predicts that a perfect vacuum does not exist. It is easy to become trapped in a circular logic: theory disproves the possibility of making a perpetual motion machine, whereas the hypothetical machine disproves the theory.

In the Feynman machine, a shaft is propelled by transfer of kinetic energy (i.e. thermal energy) of gas molecules to turbine blades that are attached to the shaft. The hypothesized principle of operation is based on kinetic molecular theory, or the random motion of gas molecules inside the chamber. The concept is analogous to Brownian motion, except that this device is supposed to "channel" random motion into a specific direction by means of a ratchet and a gear with teeth.

Kinetic molecular theory certainly does not forbid anisotropy of pressure inside the system: the pressure that is exerted on the system is simply caused by the collisions of randomly moving gas molecules. There is a very small statistical probability that one side of the turbine blades at one point in time receives more collisions, or more energetic collisions than the other side. However, the kinetic energy per gas molecule is limited (on the order of 10- 18  J per molecule at room temperature), and the number of collisions per second is large (on the order of 1020 molecules cm2 s-1). These two factors make the occurrence of spontaneous directed thermal motion highly unlikely (look around: every day objects don't randomly move by themselves).

However, the statistical improbability described above does not fully explain why the Feynman machine would never work. For this, one needs to look at the other components of the system: the shaft and ratchet. Because the principle of the Feynman machine is based on molecular motion, one cannot neglect this phenomenon in other parts of the system.

The shaft and ratchet are in thermal equilibrium with the rest of the system. As a result, these atoms of these parts also have a certain kinetic energy, although their motion is restricted by their physical state (i.e. a solid). Instead of freely moving molecules, the shaft and ratchet consist of atoms that exhibit thermal vibration. As a result, the ratchet and teeth of the gear are not in perfect contact with each other. Visualize this as beating a drum with grains of sand on it. Of course these thermal vibrations are on a very small, molecular scale, and in reality the gear and ratchet are always in contact due to surface roughness.

The ratchet can only have very small downforce and friction on the gear, otherwise the required torque on the shaft would be too high to move the ratchet over a notch. As explained above, the low kinetic energy of the gas is limiting the theoretical torque that can be generated. Because of the required small downforce of the ratchet, thermal vibration of the ratchet and gear cannot be neglected. This thermal vibration will reduce the effectiveness of the ratchet: the ratchet no longer grips on the sawteeth of the gear.

Thus, the thermal vibration of the ratchet/teeth cannot be neglected. Increase the downforce of the ratchet and the shaft won't turn. Decrease the downforce, and the shaft will be able to rotate freely in both directions.

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