Perpetual-Motion Machines of the Second Kind: Commonplace?
(trop ancien pour répondre)
Pentcho Valev
2017-11-30 12:22:25 UTC
An artificial muscle obviously able to produce an unlimited amount of work:

"Artificial muscle basic-motion"

Is the device a perpetual-motion machine of the second kind? In this particular case there is no information how the work-producing force is activated. If, in increasing and then decreasing the work-producing force, the experimentalist loses less work than he gains from weight-lifting, then, yes, the device is a perpetual-motion machine of the second kind. In other words, if the net work extracted from a cycle is positive, the second law of thermodynamics is violated.

Here we do have the needed information - work-producing cycles will occur if the pH of the system is regularly changed:

"pH-Responsive Hydrogel Composite Artificial Muscle. Here we see a pH-responsive polyacrylic acid hydrogel contained within an unbound carbon fibre braid. The artificial muscle (McKibben style) actuates when placed in a solution with high pH, generating contraction free strains of ~30%."

All pH-sensitive polymers are potential perpetual-motion machines of the second kind:

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"When the pH is lowered (that is, on raising the chemical potential, μ, of the protons present) at the isothermal condition of 37°C, these matrices can exert forces, f, sufficient to lift weights that are a thousand times their dry weight." http://www.google.com/patents/US5520672

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A. KATCHALSKY, POLYELECTROLYTES AND THEIR BIOLOGICAL INTERACTIONS, p. 15, Figure 4: "Polyacid gel in sodium hydroxide solution: expanded. Polyacid gel in acid solution: contracted; weight is lifted." https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1367611/pdf/biophysj00645-0017.pdf

Consider Figure 4 in Katchalsky's article. The following four-step isothermal cycle, if carried out quasi-statically (reversibly), clearly violates the second law of thermodynamics:

1. The polymer is initially stretched. The experimentalist adds hydrogen ions (H+) to the system. The force of contraction increases.
2. The polymers contracts and lifts a weight.
3. The experimentalist removes the same amount of H+ from the system. The force of contraction decreases.
4. The experimentalist stretches the polymer and restores the initial state of the system.

The net work extracted from the cycle is positive unless the following is the case:

The experimentalist, as he decreases and then increases the pH of the system (steps 1 and 3), does (loses; wastes) more work than the work he gains from weight-lifting.

However electrochemists know that, if both adding hydrogen ions to the system and then removing them are performed quasi-statically, the net work involved is virtually zero (the experimentalist gains work if the hydrogen ions are transported from a high to a low concentration and then loses the same amount of work in the backward transport). That is, the net work involved in steps 1 and 3 is zero, and the net work extracted from steps 2 and 4 is positive, in violation of the second law of thermodynamics.

Pentcho Valev
Pentcho Valev
2017-12-01 09:57:00 UTC
Here is vigorous motion of water in an electric field, obviously able to produce work - e.g. by rotating a waterwheel:

"The Formation of the Floating Water Bridge including electric breakdowns"

"The water movement is bidirectional, i.e., it simultaneously flows in both directions." https://www.wetsus.nl/home/wetsus-news/more-than-just-a-party-trick-the-floating-water-bridge-holds-insight-into-nature-and-human-innovation/1

The work (rotating a waterwheel) will be done at the expense of what energy? The first hypothesis that comes to mind is:

At the expense of electric energy. The system is, essentially, an electric motor.

However close inspection would suggest that the hypothesis is untenable. Scientists use triply distilled water to reduce the conductivity and the electric current passing through the system to minimum. If, for some reason, the current is increased, the motion stops - the system cannot be an electric motor.

If the system is not an electric motor, then it is a perpetual-motion machine of the second kind! Here arguments describing perpetual-motion machines as impossible, idiotic, etc. are irrelevant - the following conditional is valid:

IF THE SYSTEM IS NOT AN ELECTRIC MOTOR, then it is a perpetual-motion machine of the second kind.

In other words, if the work is not done at the expense of electric energy, it is done at the expense of AMBIENT HEAT. No third source of energy is conceivable.

In the electric field between the plates of a capacitor, the same turbulent motion can be seen:

"Liquid Dielectric Capacitor"

Here work can be done by using the rising of the water - e.g. floating weights can be lifted. Again, the crucial question is:

The work (lifting floating weights) will be done at the expense of what energy?

Obviously "electric energy" is not the correct answer - the capacitor is not an electric motor. Then the only possible answer remains "ambient heat". The system is a perpetual-motion machine of the second kind!

Pentcho Valev
Pentcho Valev
2017-12-01 18:02:23 UTC
Potentially, catalyzed chemical reactions are also perpetual-motion machines of the second kind. The second law of thermodynamics has an absurd implication:

If we have a reversible chemical reaction and a catalyst increases the rate of the forward reaction by a factor of, say, 745492, it obligatorily increases the rate of the reverse reaction by exactly the same factor, 745492, despite the fact that the two reactions - forward and reverse - may be entirely different (e.g. the diffusion factor is crucial for one but not important for the other).

The absurd implication is usually referred to as "Catalysts do not shift chemical equilibrium":

"A catalyst reduces the time taken to reach equilibrium, but does not change the position of the equilibrium. This is because the catalyst increases the rates of the forward and reverse reactions BY THE SAME AMOUNT." http://www.bbc.co.uk/bitesize/higher/chemistry/reactions/equilibrium/revision/2/

"In the presence of a catalyst, both the forward and reverse reaction rates will speed up EQUALLY... [...] If the addition of catalysts could possibly alter the equilibrium state of the reaction, this would violate the second rule of thermodynamics..." https://www.boundless.com/chemistry/textbooks/boundless-chemistry-textbook/chemical-equilibrium-14/factors-that-affect-chemical-equilibrium-106/the-effect-of-a-catalyst-447-3459/

The absurd implication is not obeyed by chemical reactions of course. Here is a publication in Nature describing a catalyst accelerating the forward and SUPPRESSING the reverse reaction:

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Yu Hang Li et al. Unidirectional suppression of hydrogen oxidation on oxidized platinum clusters. https://www.nature.com/articles/ncomms3500

Another example of disobedience: Perpetual (limited only by the deterioration of the system) motion of dimer A_2 and monomer A between two catalytic surfaces, S1 and S2:

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See the explanations here: https://en.wikipedia.org/wiki/Duncan%27s_Paradox

That catalysts can violate the second law of thermodynamics by shifting chemical equilibrium is presented by Wikipedia as a fact:

"Epicatalysis is a newly identified class of gas-surface heterogeneous catalysis in which specific gas-surface reactions shift gas phase species concentrations away from those normally associated with gas-phase equilibrium. [...] A traditional catalyst adheres to three general principles, namely: 1) it speeds up a chemical reaction; 2) it participates in, but is not consumed by, the reaction; and 3) it does not change the chemical equilibrium of the reaction. Epicatalysts overcome the third principle..." https://en.wikipedia.org/wiki/Epicatalysis

Scientists should have exposed the absurdity of this implication of the second law of thermodynamics long ago. Consider the dissociation-association reaction

A <-> B + C

which is in equilibrium. We add a catalyst, e.g. a macroscopic catalytic surface, and it starts splitting A - the rate constant of the forward (dissociation) reaction increases by a factor of 745492. If the second law of thermodynamics is obeyed, the catalyst must increase the rate constant of the reverse (association) reaction by exactly the same factor, 745492. But this is obviously absurd! The reverse reaction is entirely different from the forward one - B and C must first get together, via diffusion, and only then can the catalyst join them to form A. Catalysts don't accelerate diffusion! If, in the extreme case, the reverse reaction is diffusion-controlled, the catalyst cannot accelerate it at all - the rate constant already has a maximal and unsurpassable value.

The second law of thermodynamics is OBVIOUSLY false.

Pentcho Valev
Pentcho Valev
2017-12-03 17:26:41 UTC
Jos Uffink, professor at the University of Minnesota, claims that the second law of thermodynamics is obscure and has nothing to do with the arrow of time:

Jos Uffink, Bluff your way in the Second Law of Thermodynamics: "I therefore argue for the view that THE SECOND LAW HAS NOTHING TO DO WITH THE ARROW OF TIME. [...] Before one can claim that acquaintance with the Second Law is as indispensable to a cultural education as Macbeth or Hamlet, it should obviously be clear what this law states. This question is surprisingly difficult. The Second Law made its appearance in physics around 1850, but a half century later it was already surrounded by so much confusion that the British Association for the Advancement of Science decided to appoint a special committee with the task of providing clarity about the meaning of this law. However, its final report (Bryan 1891) did not settle the issue. Half a century later, the physicist/philosopher Bridgman still complained that there are almost as many formulations of the second law as there have been discussions of it. And EVEN TODAY, THE SECOND LAW REMAINS SO OBSCURE that it continues to attract new efforts at clarification." http://philsci-archive.pitt.edu/313/1/engtot.pdf

Uffink could be wrong of course but the problem is that in the post-truth world truth and wrongness are obsolete notions. When asked "Is professor Uffink wrong?", all other professors immediately reply: "Who cares".

Pentcho Valev
Pentcho Valev
2017-12-04 16:30:14 UTC
"Entropy was discovered when it was noticed to be a quantity that behaves as a function of state, as a consequence of the second law of thermodynamics." https://en.wikipedia.org/wiki/Entropy

It was Clausius who "noticed" that the entropy is a state function, but was he correct? Here is the story:

If you define the entropy S as a quantity that obeys the equation dS=dQrev/T, you will find that, so defined, the entropy is a state function FOR AN IDEAL GAS. Clausius was very impressed by this statefunctionness and decided to prove that the entropy (so defined) is a state function for ANY system. So "Entropy is a state function" became a fundamental theorem in thermodynamics. Clausius deduced it from the assumption that any cycle can be disintegrated into small Carnot cycles, and nowadays this deduction remains the only justification of "Entropy is a state function":

"Carnot Cycles: S is a State Function. Any reversible cycle can be thought of as a collection of Carnot cycles - this approximation becomes exact as cycles become infinitesimal. Entropy change around an individual cycle is zero. Sum of entropy changes over all cycles is zero."

"Entropy Changes in Arbitrary Cycles. What if we have a process which occurs in a cycle other than the Carnot cycle, e.g., the cycle depicted in Fig. 3. If entropy is a state function, cyclic integral of dS = 0, no matter what the nature of the cycle. In order to see that this is true, break up the cycle into sub-cycles, each of which is a Carnot cycle, as shown in Fig. 3. If we apply Eq. (7) to each piece, and add the results, we get zero for the sum." http://ronispc.chem.mcgill.ca/ronis/chem213/hnd8.pdf

The assumption on which "Entropy is a state function" is based - that any cycle can be subdivided into small Carnot cycles - is obviously false. An isothermal cycle CANNOT be subdivided into small Carnot cycles. A cycle involving the action of conservative forces CANNOT be subdivided into small Carnot cycles.

Conclusion: The belief that the entropy is a state function is totally unjustified. Any time scientists use the term "entropy", they don't know what they are talking about.

"My greatest concern was what to call it. I thought of calling it 'information', but the word was overly used, so I decided to call it 'uncertainty'. When I discussed it with John von Neumann, he had a better idea. Von Neumann told me, 'You should call it entropy, for two reasons: In the first place your uncertainty function has been used in statistical mechanics under that name, so it already has a name. In the second place, and more important, nobody knows what entropy really is, so in a debate you will always have the advantage."

Pentcho Valev
Pentcho Valev
2017-12-05 07:29:39 UTC
The version of the second law of thermodynamics stated as "Entropy always increases" (a version which, according to A. Eddington, holds "the supreme position among the laws of Nature") is in fact a theorem deduced by Clausius in 1865:

Jos Uffink, Bluff your Way in the Second Law of Thermodynamics, p. 37: "Hence we obtain: THE ENTROPY PRINCIPLE (Clausius' version) For every nicht umkehrbar [irreversible] process in an adiabatically isolated system which begins and ends in an equilibrium state, the entropy of the final state is greater than or equal to that of the initial state. For every umkehrbar [reversible] process in an adiabatical system, the entropy of the final state is equal to that of the initial state." http://philsci-archive.pitt.edu/archive/00000313/

Clausius' deduction was based on three postulates:

Postulate 1 (implicit): The entropy is a state function.

Postulate 2: Clausius' inequality (formula 10 on p. 33 in Uffink's paper) is correct.

Postulate 3: Any irreversible process can be closed by a reversible process to become a cycle.

All the three postulates remain totally unjustified even nowadays. Postulate 1 can easily be disproved by considering cycles (heat engines) converting heat into work in ISOTHERMAL conditions. Postulate 3 is almost obviously false:

Uffink, p.39: "A more important objection, it seems to me, is that Clausius bases his conclusion that the entropy increases in a nicht umkehrbar [irreversible] process on the assumption that such a process can be closed by an umkehrbar [reversible] process to become a cycle. This is essential for the definition of the entropy difference between the initial and final states. But the assumption is far from obvious for a system more complex than an ideal gas, or for states far from equilibrium, or for processes other than the simple exchange of heat and work. Thus, the generalisation to all transformations occurring in Nature is somewhat rash."

Note that, even if Clausius's theorem were correct (it is not), it only holds for "an adiabatically isolated system which begins and ends in an equilibrium state". This means that (even if Clausius's theorem were correct) all applications of "Entropy always increases" to processes which do not begin and end in equilibrium would be still unjustified!

Pentcho Valev
Pentcho Valev
2017-12-10 20:51:36 UTC
Another perpetual-motion machine of the second kind announced, euphemistically, by the University of Arkansas (the scientific community couldn't be more silent):

"A Potential Source of Clean, Limitless Energy"

Pentcho Valev
Pentcho Valev
2017-12-11 08:10:17 UTC
Water in an electric field automatically forms a perpetual-motion machine of the second kind:

"A deviation from the second law of thermodynamics has been demonstrated experimentally for the first time. [...] To test the idea, the researchers put about 100 latex beads - each 6.3 µm across - into a WATER-FILLED CELL, which was placed on the stage of a microscope. The researchers focused a laser onto one of the beads, which induced a dipole moment in the bead and drew it towards the most intense region of the ELECTRIC FIELD in the laser beam." http://physicsworld.com/cws/article/news/2002/jul/16/small-systems-defy-second-law

Nature: "Second law broken. Researchers have shown for the first time that, on the level of thousands of atoms and molecules, fleeting energy increases violate the second law of thermodynamics. [...] They found that over periods of time less than two seconds, variations in the random thermal motion of water molecules occasionally gave individual beads a kick. This increased the beads' kinetic energy by a small but significant amount, in apparent violation of the second law." http://www.nature.com/news/2002/020722/full/news020722-2.html

Scientific American: "Second Law of Thermodynamics Violated. [...] ...the water molecules interacted with the bead in such a way that energy was transferred from the liquid to the bead. These additional kicks used the random thermal motion of the water to do the work of moving the bead, in effect yielding something for nothing. For periods of movement lasting less than two seconds, the bead was almost as likely to gain energy from the water as it was to add energy to the reservoir, the investigators say." https://www.scientificamerican.com/article/second-law-of-thermodynam/

In an electric field, a non-conservative force (pressure) emerges in water. This pressure pushes in all directions and produces cyclical flows able to convert ambient heat into work, in violation of the second law of thermodynamics:

Wolfgang K. H. Panofsky, Melba Phillips, Classical Electricity and Magnetism, pp.115-116: "Thus the decrease in force that is experienced between two charges when they are immersed in a dielectric liquid can be understood only by considering the effect of the PRESSURE OF THE LIQUID ON THE CHARGES themselves." http://www.amazon.com/Classical-Electricity-Magnetism-Second-Physics/dp/0486439240?tag=viglink21401-20

"However, in experiments in which a capacitor is submerged in a dielectric liquid the force per unit area exerted by one plate on another is observed to decrease... [...] This apparent paradox can be explained by taking into account the DIFFERENCE IN LIQUID PRESSURE in the field filled space between the plates and the field free region outside the capacitor." http://farside.ph.utexas.edu/teaching/jk1/lectures/node46.html

Tai Chow, Introduction to Electromagnetic Theory: A Modern Perspective, p. 267: "The strictly electric forces between charges on the conductors are not influenced by the presence of the dielectric medium. The medium is polarized, however, and the interaction of the electric field with the polarized medium results in an INCREASED FLUID PRESSURE ON THE CONDUCTORS that reduces the net forces acting on them." http://www.amazon.com/Introduction-To-Electromagnetic-Theory-Perspective/dp/0763738271

Liquid Dielectric Capacitor [Note the turbulent motion between the plates] http://youtu.be/T6KAH1JpdPg

"The Formation of the Floating Water Bridge including electric breakdowns"x http://youtu.be/17UD1goTFhQ

Pentcho Valev