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www.penn.museum/expedition 52 (2): 43-52 (2008). For tens of thousands of years, humans have expressed themselves artistically on their surroundings? painting, etching, carving, and molding designs, decorations, and imagery on surfaces ranging from portable, often hand-held objects (such as animal bone and stone) to more stationary features of the landscape, such as scattered rocks, caves, and cliffs. The most famous early examples of this so-called rock art are the fabulous Paleolithic cave paintings from southwestern France and northern Spain, which date to about 15,000 years ago (see Expedition 47(3):20-24). Less well known, but far more common, are the petroglyphs (drawings or etchings carved on stone) that have been identified around the world. Besides a general human fascination with visual representation in different media, these rock art images can tell us not only about the people who made them?a broadly anthropological question?but also about environmental conditions of the past.

The discovery that objects from the Neolithic or Early Bronze Age carry patterns associated with high-current Z-pinches provides a possible insight into the origin and meaning of these ancient symbols produced by humans. Part I deals with the comparison of graphical and radiation data from high-current -pinches to petroglyphs, geoglyphs, and megaliths. Part I focused primarily, but not exclusively, on petroglyphs of some 84 different morphologies: pictures found in laboratory experiments and carved on rock. These corresponded to mankind's visual observations of ancient aurora as might be produced if the solar wind had increased (T. Gold) at times between one and two orders of magnitude, millennia ago. Part II focuses on the source of light and its temporal change from a current-increasing Z-pinch or dense-plasma-focus aurora. Orientation and field-of-view data are given as surveyed and contributed from 139 countries, from sites and fields containing several millions of these objects. This information allows a reconstruction of the auroral form presumably associated with extreme geomagnetic storms and shows, based on existent geophysical evidence, plasma flow inward at Earth's south polar axis.

The discovery that objects from the Neolithic or Early Bronze Age carry patterns associated with high-current Z-pinches provides a possible insight into the origin and meaning of these ancient symbols produced by man. This paper directly compares the graphical and radiation data from high-current Z-pinches to these patterns. The paper focuses primarily, but not exclusively, on petroglyphs. It is found that a great many archaic petroglyphs can be classified according to plasma stability and instability data. As the same morphological types are found worldwide, the comparisons suggest the occurrence of an intense aurora, as might be produced if the solar wind had increased between one and two orders of magnitude, millennia ago.

IEEE International Conference on Plasma Science, Jeju, Korea, 2003, pp. 143 and 120.

With the advent of fully three-dimensional, fully electromagnetic, particle-in-cell simulations, investigations of Birkeland currents and magnetic-field-aligned electric fields have become possible in plasmas not accessible to in situ measurement, i.e., in plasmas having the dimensions of galaxies or systems of galaxies. The necessity for a three-dimensional electromagnetic approach derives from the fact that the evolution of magnetized plasmas involves complex geometries, intense self-fields, nonlinearities, and explicit time-dependence. A comparison of the synchrotron radiation properties of simulated currents to those of extragalactic sources provides observational evidence for galactic-dimensional Birkeland currents.

Laser and Particle Beams (ISSN 0263-0346), vol. 6, Aug. 1988, p. 471-491. Cosmic plasma physics and the concept of the universe is in a state of rapid revision. This change started with in situ measurements of plasmas in earth's ionosphere, cometary atmospheres, and planetary magnetospheres; the transition of knowledge from laboratory experiments to astrophysical phenomena; discoveries of helical and filamentary plasma structures in the Galaxy and double radio sources; and the particle simulation of plasmas not accessible to in situ measurement. Because of these, Birkeland (field-aligned) currents, double layers, and magnetic-field-aligned electric fields are now known to be far more important to the evolution of space plasma, including the acceleration of charged particles to high energies, than previously thought. This paper reviews the observational evidence for a plasma universe threaded by Birkeland currents and particle beams.

Cosmic plasma physics and our concept of the universe is in a state of rapid revision. This change started with in-situ measurements of plasmas in Earth's ionosphere, cometary atmospheres, and planetary magnetospheres; the translation of knowledge from laboratory experiments to astrophysical phenomena; discoveries of helical and filamentary plasma structures in the Galaxy and double radio sources; and the particle simulation of plasmas not accessible to in-situ measurement. Because of these, Birkeland (field-aligned) currents, double layers, and magnetic-field-aligned electric fields are now known to be far more important to the evolution of space plasma, including the acceleration of charged particles to high energies, than previously thought. This paper and its sequel investigate the observational evidence for a plasma universe threaded by Birkeland currents or filaments. This model of the universe was inspired by the advent of threedimensional fully electromagnetic particle simulations and their application to the study of laboratory z pinches. This study resulted in totally unexpected phenomena in the data post-processed from the simulation particle, field, and history dumps. In particular, when the simulation parameters were scaled to galactic dimensions, the interaction between pinched filaments led to synchrotron radiation whose emission properties were found to share the following characteristics with double radio galaxies and quasars: power magnitude, isophotal morphology, spectra, brightness along source, polarization, and jets. The evolution of these pinched synchrotron emitting plasmas to elliptical, peculiar, and spiral galaxies by continuing the simulation run is addressed in a sequel paper.

The model of the plasma universe, inspired by totally unexpected phenomena observed with the advent and application of fully three-dimensional electromagnetic particle-in-cell simulations to filamentary plasmas, consists of studying the interaction between field-aligned current-conducting, galactic-dimensioned plasma sheets or filaments (Birkeland currents). In a preceding paper, the evolution of the interaction spanned some 108-109 years, where simulational analogs of synchrotron-emitting double radio galaxies and quasars were discovered. This paper reports the evolution through the next 109-5 ?? 109 years. In particular, reconfiguration and compression of tenuous cosmic plasma due to the self-consistent magnetic fields from currents conducted through the filaments leads to the formation of elliptical, peculiar, and barred and normal spiral galaxies. The importance of the electromagnetic pinch in producing condense states and initiating gravitational collapse of dusty galactic plasma to stellisimals, then stars, is discussed. Simulation data are directly compared to galaxy morphology types, synchrotron flux, Hi distributions, and fine detail structure in rotational velocity curves. These comparisons suggest that knowledge obtained from laboratory, simulation, and magnetospheric plasmas offers not only to enhance our understanding of the universe, but also to provide feedback information to laboratory plasma experiments from the unprecedented source of plasma data provided by the plasma universe.