Essays in Science

SPACE-TIME-MATTER

This essay examines our fundamental conceptions of time, spacetime, the asymmetry of time, and the motion of a quantum mechanical particle. The concept of time has multiple meanings and these are often confused in the literature and must be distinguished if any light is to be thrown on this age-old issue. The asymmetry of time also has different meanings that depend on context—although the fundamental time asymmetry is associated with the expansion of the universe. These and related issues are discussed in both classical and quantum mechanical contexts.

(Reference 4 has been corrected in this version)

SPACE—TIME—MATTER-F (pdf)

Essays in Science
Physics

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GROUPS: NATURE’S “INVISIBLE HAND”: AN ESSAY ON THE STANDARD MODEL

It is the purpose of this essay to take the reader from some elementary ideas about groups to the essence of the Standard Model of particle physics along a relatively straight and intuitive path. The idea is to give an Olympian view of this evolution, one that is often missing when absorbing the detailed subject matter of the Standard Model as presented in an historical approach to the subject.

Groups Natures Hidden Symmetry

Errata:

p. 59: Line after 2nd equation from the bottom of the page should read, “This corresponds to a right-handed spinor and, for spin 1/2 is designated (1/2, 0).”

The end of the last line should read, ” . . . is designated by (0, 1/2).”

Essays in Science
Physics

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The Challenge to the Enlightenment

USA Today Magazine (November 2012)

“. . . The conflict here and abroad really is between two fundamentally different and mutually exclusive world views; one based on science, reason, and observation; the other on an interpretation of Scripture that dates back to past periods of religious intolerance.”

CHALLENGE TO ENLIGHTENMENT.pdf

Biology
Essays in Science
General Interest
USA Today Magazine

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The Problem of the “Prebiotic and Never Born Proteins”

International Journal of Astrobiology / FirstView Article / October 2012, pp 1- 5
DOI: 10.1017/S1473550412000468, Published online.

International Journal of Astrobiology 12 (1): 94–98 (2013)

It has been argued that the limited set of proteins used by life as we know could not have arisen by the process of Darwinian selection from all possible proteins. This probabilistic argument has a number of implicit assumptions that may not be warranted. A variety of considerations are presented to show that the number of amino acid sequences that need to have been sampled during the evolution of proteins is far smaller than assumed by the argument.

NeverBornProteins-IJAB

 

How to cite this article:
Gerald E. Marsh The problem of the ‘prebiotic and never born proteins’. International Journal of Astrobiology, Available on
CJO doi:10.1017/S1473550412000468

Biology
Essays in Science
General Interest

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Quantum Mechanics and Motion: A Modern Perspective

Physics Essays Vol. 23, pp. 242-247 (2010)

This essay is an attempted to address, from a modern perspective, the motion of a particle. Quantum mechanically, motion consists of a series of localizations due to repeated interactions that, taken close to the limit of the continuum, yields a world-line. If a force acts on the particle, its probability distribution is accordingly modified. This must also be true for macroscopic objects, although now the description is far more complicated by the structure of matter and associated surface physics.

Quantum Mechanics and Motion-A Modern Perspective

Essays in Science
Physics

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The Demystification of Emergent Behavior

Emergent behavior that appears at a given level of organization may be characterized as arising from an organizationally lower level in such a way that it transcends a mere increase in the behavioral degree of complexity. It is therefore to be distinguished from chaotic behavior, which is deterministic but unpredictable because of an exponential dependence on initial conditions. In emergent phenomena, higher-levels of organization are not determined by lower-levels of organization; or, more colloquially, emergent behavior is often said to be “greater than the sum of the parts”. This essay is intended to demystify at least some aspects of the mystery of emergence.

PDF

Biology
Essays in Science
General Interest
Physics

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