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Second Law of Thermodynamics: Paradoxical or False?



 
 
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  #1  
Old September 17th 17, 09:15 AM posted to sci.astro
Pentcho Valev
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Default Second Law of Thermodynamics: Paradoxical or False?

"Davide Castelvecchi recently has an article published in Nature regarding on the same topic. The article highlighted that the laws of thermodynamics are many times "paradoxical," especially the second law of thermodynamics."
http://www.scienceworldreport.com/ar...namic-laws.htm

The second law of thermodynamics has long been under attack but only for small, microscopic, quantum etc. systems:

Nature 2002: "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." http://www.nature.com/news/2002/0207...s020722-2.html

The truth is that MACROSCOPIC systems violating the second law of thermodynamics are COMMONPLACE. The problem is that misleading education has diverted the attention from relevant examples:

"A necessary component of a heat engine, then, is that two temperatures are involved. At one stage the system is heated, at another it is cooled."
http://physics.bu.edu/~duffy/py105/Heatengines.html

Richard Feynman: "The whole subject of thermodynamics depends essentially upon the following kind of consideration: because a rubber band is "stronger" at higher temperatures than it is at lower temperatures, it ought to be possible to lift weights, and to move them around, and thus to do work with heat." http://www.feynmanlectures.caltech.edu/I_44.html

Educators present the two temperatures as necessary but that is not true - e.g. the rubber-band heat engine described by Feynman has isothermal (one temperature only) analogs which almost obviously violate the second law of thermodynamics:

http://www.gsjournal.net/old/valev/val3.gif

POLYELECTROLYTES AND THEIR BIOLOGICAL INTERACTIONS, A. KATCHALSKY, pp. 13-15: "Let the polymolecule be a negatively charged polyacid in a stretched state and have a length L. Now let us add to the molecule a mineral acid to provide hydrogen ions to combine with the ionized carboxylate groups and transform them into undissociated carboxylic groups according to the reaction RCOO- + H+ = RCOOH. By means of this reaction, the electrostatic repulsion which kept the macromolecule in a highly stretched state vanishes and instead the Brownian motion and intramolecular attraction cause a coiling up of the polymeric chains. Upon coiling, the polymolecule contracts and lifts the attached weight through a distance ΔL. On lifting the weight, mechanical work f*ΔL was performed... [...] FIGURE 4: Polyacid gel in sodium hydroxide solution: expanded. Polyacid gel in acid solution: contracted; weight is lifted."
http://www.ncbi.nlm.nih.gov/pmc/arti...0645-0017..pdf

"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

Pentcho Valev
  #2  
Old September 17th 17, 07:19 PM posted to sci.astro
Pentcho Valev
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Default Second Law of Thermodynamics: Paradoxical or False?

Thermodynamicists readily teach this, non-isothermal, heat engine:

http://readingpenrose.files.wordpres...and-engine.gif

But they never teach its isothermal analog which almost obviously violates the second law of thermodynamics (one should only evaluate the work involved in a quasi-static cycle):

http://www.gsjournal.net/old/valev/val3.gif

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/ar...00645-0017.pdf

Pentcho Valev
  #3  
Old September 18th 17, 07:51 AM posted to sci.astro
Pentcho Valev
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Posts: 8,078
Default Second Law of Thermodynamics: Paradoxical or False?

When a parallel-plate capacitor is submerged into a liquid dielectric (water), a non-conservative force (pressure) emerges between the plates - if the capacitor is only partially submerged, the liquid between the plates rises:

https://www.researchgate.net/profile...he-Maxwell.ppm

The system obviously violates the second law of thermodynamics - it can cyclically lift floating weights, and the only conceivable source of energy is the ambient heat:

http://www.youtube.com/watch?v=T6KAH1JpdPg
"Liquid Dielectric Capacitor"

The following system is essentially the same - water is placed in an electric field. Here the violation of the second law of thermodynamics is even more obvious - there is vigorous motion of the water able to produce work (e.g. by rotating a waterwheel):

https://www.youtube.com/watch?v=17UD1goTFhQ
"The Formation of the Floating Water Bridge including electric breakdowns"

The work will be done at the expense of heat absorbed from the surroundings - assuming that the energy converted into work has a different origin is unreasonable.

Pentcho Valev
  #4  
Old September 19th 17, 12:45 AM posted to sci.astro
Pentcho Valev
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Posts: 8,078
Default Second Law of Thermodynamics: Paradoxical or False?

"A small, closed, high temperature cavity contained two metal catalysts (rhenium and tungsten), which were known to dissociate molecular hydrogen (H2) to different degrees (Figure 1). (Rhenium dissociates hydrogen molecules into atoms better than tungsten does; conversely, tungsten recombines hydrogen atoms back into hydrogen molecules better than rhenium.) Because the dissociation reaction (H2 - 2H) is endothermic (absorbs heat), and the recombination reaction (2H - H2) is exothermic (liberates heat), when hydrogen was introduced into the cavity, the rhenium surfaces cooled (up to more than 125 K) relative to the tungsten (Figure 2). Because the hydrogen-metal reactions were ongoing in the sealed cavity, the rhenium stayed cooler than the tungsten indefinitely. This permanent temperature difference - this steady-state nonequilibrium - is expressly forbidden by the second law, not just because the system won't settle down to a single-temperature equilibrium, but because this steady-state temperature difference can, in principle, be used to drive a heat engine (or produce electricity) solely by converting heat back into work, which is a violation of one of the most fundamental statements of the second law (Kelvin-Planck formulation)." http://microver.se/sse-pdf/edgescience_24.pdf

The following picture was published in Nature in 2013 - here the catalyst accelerates the recombination reaction (2H - H2) and SUPPRESSES the dissociation reaction (H2 - 2H):

https://images.nature.com/m685/natur...mms3500-f1.jpg

Here is the publication:

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

If catalysts can speed up the forward and the reverse reaction DIFFERENTLY, as in the above examples, then the second law of thermodynamics is false:

"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/...lyst-447-3459/

Pentcho Valev
  #5  
Old September 20th 17, 11:41 PM posted to sci.astro
Pentcho Valev
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Posts: 8,078
Default Second Law of Thermodynamics: Paradoxical or False?

Is the scientific community ready for a revolution in thermodynamics? There was a sensation in 2012 - researchers had described a graphene-based device converting ambient heat into electricity, in violation of the second law of thermodynamics. Yet only the technological aspects were discussed - the violation of the second law was not mentioned in the original paper and the comments (not even in Nature's comment):

https://www.technologyreview.com/s/4...ctric-current/
"Graphene Battery Turns Ambient Heat Into Electric Current. Physicists have built a graphene battery that harvests energy from the thermal movement of ions in solution."

http://arxiv.org/abs/1203.0161
Self-Charged Graphene Battery Harvests Electricity from Thermal Energy of the Environment, Zihan Xu et al: "Moreover, the thermal velocity of ions can be maintained by the external environment, which means it is unlimited. However, little study has been reported on converting the ionic thermal energy into electricity. Here we present a graphene device with asymmetric electrodes configuration to capture such ionic thermal energy and convert it into electricity. [...] To exclude the possibility of chemical reaction, we performed control experiments... [...] In conclusion, we could not find any evidences that support the opinion that the induced voltage came from chemical reaction. The mechanism for electricity generation by graphene in solution is a pure physical process..."

http://blogs.nature.com/news/2012/03...y-device..html
Natu "Although materials scientist Yury Gogotsi of Drexel University in Philadelphia, Pennsylvania, doubts the latest claim, he points out that the mystery should at least be relatively easy to clear up. "The device described by Xu's group is very simple and numerous labs can easily repeat this experiment to check the validity of the results," he says. [...] Comments are closed."

Comments were really closed in 2012, and the promise that "numerous labs can easily repeat this experiment to check the validity of the results" was immediately forgotten.

In 2013 Zihan Xu and co published a similar paper, in a prestigious journal, and this time the violation of the second law WAS mentioned. That was fatal. Scientists love violations in microscopic or nanosystems but a macroscopic violation of the second law of thermodynamics acts like the face of Medusa the Gorgon - on seeing it, scientists get petrified and never recover. So the second paper did not become a sensation - there were no comments at all:

http://scitation.aip.org/content/aip...1063/1.4825269
Electricity generated from ambient heat across a silicon surface, Guoan Tai, Zihan Xu, and Jinsong Liu, Appl. Phys. Lett. 103, 163902 (2013): "We report generation of electricity from the limitless thermal motion of ions across a two-dimensional (2D) silicon (Si) surface at room temperature. [...] ....limitless ambient heat, which is universally present in the form of kinetic energy from molecular, particle, and ion sources, has not yet been reported to generate electricity. [...] This study provides insights into the development of self-charging technologies to harvest energy from ambient heat, and the power output is comparable to several environmental energy harvesting techniques such as ZnO nanogenerator, liquid and gas flow-induced electricity generation across carbon nanotube thin films and graphene, although this remains a challenge to the second law of thermodynamics..."

Pentcho Valev
  #6  
Old September 21st 17, 02:48 PM posted to sci.astro
Pentcho Valev
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Default Second Law of Thermodynamics: Paradoxical or False?

"The Kelvin-Planck statement (or the heat engine statement) of the second law of thermodynamics states that it is impossible to devise a cyclically operating device, the sole effect of which is to absorb energy in the form of heat from a single thermal reservoir and to deliver an equivalent amount of work. This implies that it is impossible to build a heat engine that has 100% thermal efficiency." https://en.wikipedia.org/wiki/Kelvin...anck_statement

The problem is that the Kelvin-Planck statement is practically unfalsifiable. How can one prove that the forbidden device is possible after all? By building one and demonstrating it to a jury? But there can be various technological and other reasons (that have nothing to do with the second law of thermodynamics) why the device would not work. And even if all those reasons are overcome, the jury would refuse to consider the project because the constructor is insane by definition.

Here I am going to convert the above unfalsifiable statement of the second law of thermodynamics into an easily refutable version.

For a closed system (exchanges energy but not matter with the surroundings) the first law of thermodynamics defines the internal energy change, dU, to be:

dU = dQ - dW = dQ - FdX /1/

where dQ is the heat absorbed, dW is the work done by the system on the surroundings, F0 is the work-producing force and dX is the respective displacement.

Let us consider a system with two work-producing forces, F1 and F2 - here is an oversimplified illustration:

http://www.learnthermo.com/images/ch...xt-springs.png

We assume that the system does work quasi-statically and isothermally. The work done by this system on the surroundings is:

dW = dW1 + dW2 = F1dX1 + F2dX2 /2/

Is W a function of the displacements X1 and X2? If yes, the second law of thermodynamics (Kelvin-Planck version) is obeyed - at the end of any cycle W returns to its initial value and no net work is done on the surroundings.

The following theorem is relevant:

Theorem: W is a function of X1 and X2 if and only if the mixed partial derivatives are equal:

http://www.youtube.com/watch?v=Y-lEuHpTS9k
"Mixed Partial Derivatives"

Since F1 and F2 are in fact the first partial derivatives, the theorem can be expressed in the following way:

Theorem: W is a function of X1 and X2, that is, the second law is obeyed, if and only if:

(∂F1/∂X2)_X1 = (∂F2/∂X1)_X2 /3/

For our system with two work-producing forces, the Kelvin-Planck version of the second law now states:

EQUIVALENT TO KELVIN-PLANCK VERSION: The partial derivatives (∂F1/∂X2)_X1 and (∂F2/∂X1)_X2 are equal.

That is, if experiments show that the two sides of /3/ are equal, the second law is confirmed. If, however, experiments unambiguously show that the two sides of /3/ are not equal - e.g. (∂F2/∂X1)_X2 is positive and (∂F2/∂X1)_X2 negative - the second law of thermodynamics is false and will have to be abandoned.

Let us consider two types of macroscopic contractile polymers which on acidification (decreasing the pH of the system) contract and can lift a weight:

http://www.google.com/patents/US5520672
"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.ncbi.nlm.nih.gov/pmc/arti...00645-0017.pdf
POLYELECTROLYTES AND THEIR BIOLOGICAL INTERACTIONS, A. KATCHALSKY, p. 15: "FIGURE 4: Polyacid gel in sodium hydroxide solution: expanded. Polyacid gel in acid solution: contracted; weight is lifted."

Polymers designed by Urry (U) absorb protons as their length, Lu, increases, whereas polymers designed by Katchalsky (K) release protons as their length, Lk, increases. See discussion on p. 11020 in Urry's paper:

http://pubs.acs.org/doi/abs/10.1021/jp972167t
J. Phys. Chem. B, 1997, 101 (51), pp 11007 - 11028, Dan W. Urry, "Physical Chemistry of Biological Free Energy Transduction As Demonstrated by Elastic Protein-Based Polymers". p. 11020: "Stretching causes an uptake of protons" for Urry's polymers, and "stretching causes the release of protons", for Katchalsky's polymers.

Let us assume that two macroscopic polymers, one of each type (U and K) are suspended in the same system. At constant temperature, IF THE SECOND LAW IS TRUE, we must have

∂Fu/∂Lk = ∂Fk/∂Lu

where Fu0 and Fk0 are work-producing forces of contraction. The values of the partial derivatives ∂Fu/∂Lk and ∂Fk/∂Lu can be assessed from experimental results reported on p. 11020 in Urry's paper. As K is being stretched (Lk increases), it releases protons, the pH decreases and, accordingly, Fu must increase. Therefore, ∂Fu/∂Lk is positive. In contrast, as U is being stretched (Lu increases), it absorbs protons, the pH increases and Fk must decrease. Therefore, ∂Fk/∂Lu is negative. One partial derivative is positive, the other negative: the second law of thermodynamics is false.

Pentcho Valev
 




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