A Note on Solid-State Maxwell Demon

Physica A: Statistical Mechanics and its Applications

2011

Self Cite

Recently [Physics Letters A, 374, (2010) 1801] the concept of vacuum capacitor spontaneously charged harnessing the heat from a single thermal reservoir at room temperature has been introduced, along with a mathematical description of its functioning and a discussion on the main paradoxical feature that seems to violate the Second Law of Thermodynamics. In the present paper we investigate the theoretical and practical possibility of exploiting a such thermo-charged capacitor as voltage/current generator: we show that if very weak provisos on the physical characteristics of the capacitor are fulfilled, then a non-zero current should flow across the device, allowing the generation of potentially usable voltage, current and electric power out of a single thermal source at room temperature. Preliminary results show that the power output is tiny but non-zero.Comment: 23 Pages, 10 Figures. Physica A 390/6 (2011) 482 + Addendum (2013

Section: Introductionmentioning

confidence: 93%

On the exploitability of thermo-charged capacitors

Physica A: Statistical Mechanics and its Applications

2011

Self Cite

“…Given that and according to the analysis done in [2,5,6,7,11], even without the external static magnetic field, an equilibrium space charge eventually settles inside the bulb due to the thermionic emission. Under such an equilibrium, the electrode with lower work function ends up with an excess of positive charge with respect to the electrode with higher work function (which has an excess of negative charge).…”

Section: Scenario IImentioning

confidence: 99%

“…I have explicitly shown [11] that no electric field, and thus no voltage drop, builds up between the surfaces at the free ends of two materials with different work functions when the materials are physically joined at one end. In [11] I presented three arguments: the first two were more heuristic, the third one was more theoretical. Let me sketch here the last one, namely an explicit application of the path-independence law and/or Kirchhoff's loop rule.…”

Section: Scenario IImentioning

confidence: 99%

“…in advance that will prevent this final equilibrium. This means that, according to [2,5,6,7,11], even without the external magnetic field a voltage drop settles between the two terminals of the bulb and a current flows when the terminals are shunted by a load. When the permanent magnet is moved close to the bulb, the magnetic field can only modify the geometry of the space charge distribution.…”

Section: Scenario IImentioning

confidence: 99%

See 1 more Smart Citation

The Demon in a Vacuum Tube

2013

Entropy

In the present paper, several issues concerning the second law of thermodynamics, Maxwell's demon and Landauer's principle are dealt with. I argue that if the demon and the system on which it operates without dissipation of external energy are made of atoms and molecules (gas, liquid or solid) in thermal equilibrium (whose behaviour is described by a canonical distribution), then the unavoidable reason why the demon cannot successfully operate resides in the ubiquity of thermal fluctuations and friction. Landauer's principle appears to be unnecessary. I also suggest that if the behaviour of the demon and the system on which it acts is not always describable by a canonical distribution, as would happen for instance with the ballistic motion of electrons at early stages of thermionic emission, then a successful working demon cannot be ruled out a priori. A critical review of two recent experiments on thermionic emission Maxwell's demons is also given.

“…Although the existence of an intense electric field in J-II has been recently put into question on the basis of some heuristic and theoretical arguments (which do not appeal circularly to the validity of the second law [89]), micro-metric partial hammer and anvil prototypes have been fabricated and are currently undergoing laboratory tests. The authors report that preliminary results appear to be positive [90].…”

Section: Solid State Challengesmentioning

confidence: 99%

The peculiar status of the second law of thermodynamics and the quest for its violation

Studies in History and Philosophy of Science Part B: Studies in

2012

Even though the second law of thermodynamics holds the supreme position among the laws of nature, as stated by many distinguished scientists, notably Eddington and Einstein, its position appears to be also quite peculiar. Given the atomic nature of matter, whose behaviour is well described by statistical physics, the second law could not hold unconditionally, but only statistically. It is not an absolute law. As a result of this, in the present paper we try to argue that we have not yet any truly cogent argument (known fundamental physical laws) to exclude its possible macroscopic violation. Even Landauer's information-theoretic principle seems to fall short of the initial expectations of being the fundamental 'physical' reason of all Maxwell's demons failure. Here we propose a modified Szilard engine which operates without any steps in the process resembling the creation or destruction of information. We argue that the information-based exorcisms must be wrong, or at the very least superfluous, and that the real physical reason why such engines cannot work lies in the ubiquity of thermal fluctuations (and friction).We see in the above peculiar features the main motivation and rationale for pursuing exploratory research to challenge the second law, which is still ongoing and probably richer than ever. A quite thorough (and critical) description of some of these challenges is also given.