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1. Approximations of arbitrarily large but finite systems are often mistaken for infinite idealizations in statistical and thermal physics. The problem is illustrated by thermodynamically reversible processes.
2. Whether phase transitions comprise a failure of reduction is confounded by a confusion of two senses of "level": the molecular versus the thermodynamic level and the few component versus the many component level. |
"Infinite Idealizations," Prepared for Vienna Circle Institute Yearbook (Springer: Dordrecht-Heidelberg-London-New York. Download Draft. |
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Entropy creation in excess of that tracked by Landauer's principle is needed to overcome fluctuations in molecular scale computation. This paper is a short account of the "no go" result reported in "Waiting for Landauer." It also blocks a potential escape. |
"The End of the Thermodynamics of Computation: A No Go Result." Download. |
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This paper proposes that idealizations are distinguished from approximations in that only idealizations involve novel reference. This difference is important when idealizations are created by taking infinite limits such as in statistical mechanics. For these infinite limits may have very strange properties, much odder than the discontinuities of phase transitions now widely acknowledged in the literature. |
"Approximation and Idealization: Why the Difference Matters" Download. |
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At the age of sixteen, Einstein imagined chasing after a beam of
light. He later recalled that the thought experiment had played a
memorable role in his development of special relativity. Famous as it
is, it has proven difficult to understand just how the thought
experiment delivers its results. It fails to generate problems for an
ether-based electrodynamics. I propose that Einstein’s canonical
statement of the thought experiment from his 1946
“Autobiographical Notes,” makes most sense not as an
argument against ether-based electrodynamics, but as an argument
against “emission” theories of light. |
"Chasing the Light: Einstein's Most Famous Thought
Experiment," prepared for Thought Experiments in Philosophy, Science
and the Arts, eds., James Robert Brown, Mélanie Frappier and
Letitia Meynell, Routledge. Download. |
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The failure of Einstein’s co-authored “EPR”
attempt to show the incompleteness of quantum theory is demonstrated
directly for spatial degrees of freedom using only elementary notions.
The analysis uses only spatially distributed waves that collapse on
measurement. The same system is modeled more realistically using three
spatially separated, singly ionized hydrogen molecules. |
"Little boxes: A simple implementation of the
Greenberger, Horne, and Zeilinger result for spatial degrees of
freedom" American Journal of Physics, 79(2)(2011), pp. 182-188. Download |
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Galileo's refutation of the speed-distance law of fall in his Two
New Sciences is routinely dismissed as a moment of confused
argumentation. We urge that Galileo's argument correctly identified why
the speed-distance law is untenable, failing only in its very last
step. Using an ingenious combination of scaling and self-similarity
arguments, Galileo found correctly that bodies, falling from rest
according to this law, fall all distances in equal times. What he
failed to recognize in the last step is that this time is infinite, the
result of an exponential dependence of distance on time. Instead,
Galileo conflated it with the other motion that satisfies this 'equal
time' property, instantaneous motion. |
"Galileo's Refutation of the Speed-Distance Law of Fall
Rehabilitated," (with Bryan Roberts) Download. |
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Landauer's Principle asserts that there is an unavoidable cost in
thermodynamic entropy creation when data is erased. It is usually
derived from incorrect assumptions, most notably, that erasure must
compress the phase space of a memory device or that thermodynamic
entropy arises from the probabilistic uncertainty of random data.
Recent work seeks to prove Landauer’s Principle without using
these assumptions. I show that the processes assumed in the proof, and
in the thermodynamics of computation more generally, can be combined to
produce devices that both violate the second law and erase data without
entropy cost, indicating an inconsistency in the theoretical system.
Worse, the standard repertoire of processes selectively neglects
thermal fluctuations. Concrete proposals for how we might measure
dissipationlessly and expand single molecule gases reversibly are shown
to be fatally disrupted by fluctuations. |
"Waiting for Landauer," Studies in History and Philosophy of Modern Physics, 42(2011), pp. 184-198.Download.
See also Goodies pages:
When a Good Theory meets a Bad Idealization: The Failure of the Thermodynamics of Computation.
No Go Result for the Thermodynamics of Computation |
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A probabilistic logic of induction is unable to separate cleanly
neutral support from disfavoring evidence (or ignorance from
disbelief). Thus, the use of probabilistic representations may
introduce spurious results stemming from its expressive inadequacy.
That such spurious results arise in the Bayesian “doomsday
argument” is shown by a reanalysis that employs fragments of
inductive logic able to represent evidential neutrality. Further, the
improper introduction of inductive probabilities is illustrated with
the “self-sampling assumption.” |
"Cosmic Confusions: Not Supporting versus Supporting
Not-"Philosophy of Science. 77 (2010), pp. 501-23. Download. |
