23,058 research outputs found
The Earth as a living planet: human-type diseases in the earthquake preparation process
The new field of complex systems supports the view that a number of systems
arising from disciplines as diverse as physics, biology, engineering, and
economics may have certain quantitative features that are intriguingly similar.
The earth is a living planet where many complex systems run perfectly without
stopping at all. The earthquake generation is a fundamental sign that the earth
is a living planet. Recently, analyses have shown that human-brain-type disease
appears during the earthquake generation process. Herein, we show that
human-heart-type disease appears during the earthquake preparation of the
earthquake process. The investigation is mainly attempted by means of critical
phenomena, which have been proposed as the likely paradigm to explain the
origins of both heart electric fluctuations and fracture induced
electromagnetic fluctuations. We show that a time window of the damage
evolution within the heterogeneous Earth's crust and the healthy heart's
electrical action present the characteristic features of the critical point of
a thermal second order phase transition. A dramatic breakdown of critical
characteristics appears in the tail of the fracture process of heterogeneous
system and the injury heart's electrical action. Analyses by means of Hurst
exponent and wavelet decomposition further support the hypothesis that a
dynamical analogy exists between the geological and biological systems under
study
Pulsar timing array observations of gravitational wave source timing parallax
Pulsar timing arrays act to detect gravitational waves by observing the
small, correlated effect the waves have on pulse arrival times at Earth. This
effect has conventionally been evaluated assuming the gravitational wave
phasefronts are planar across the array, an assumption that is valid only for
sources at distances , where is physical extent of
the array and the radiation wavelength. In the case of pulsar timing
arrays (PTAs) the array size is of order the pulsar-Earth distance (kpc) and
is of order pc. Correspondingly, for point gravitational wave sources
closer than ~Mpc the PTA response is sensitive to the source parallax
across the pulsar-Earth baseline. Here we evaluate the PTA response to
gravitational wave point sources including the important wavefront curvature
effects. Taking the wavefront curvature into account the relative amplitude and
phase of the timing residuals associated with a collection of pulsars allows us
to measure the distance to, and sky position of, the source.Comment: 11 pages, 2 figures, submitted to MNRA
Coherent Radio Pulses From GEANT Generated Electromagnetic Showers In Ice
Radio Cherenkov radiation is arguably the most efficient mechanism for
detecting showers from ultra-high energy particles of 1 PeV and above. Showers
occuring in Antarctic ice should be detectable at distances up to 1 km. We
report on electromagnetic shower development in ice using a GEANT Monte Carlo
simulation. We have studied energy deposition by shower particles and
determined shower parameters for several different media, finding agreement
with published results where available. We also report on radio pulse emission
from the charged particles in the shower, focusing on coherent emission at the
Cherenkov angle. Previous work has focused on frequencies in the 100 MHz to 1
GHz range. Surprisingly, we find that the coherence regime extends up to tens
of Ghz. This may have substantial impact on future radio-based neutrino
detection experiments as well as any test beam experiment which seeks to
measure coherent Cherenkov radiation from an electromagnetic shower. Our study
is particularly important for the RICE experiment at the South Pole.Comment: 44 pages, 29 figures. Minor changes made, reference added, accepted
for publication in Phys. Rev.
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