Cosmic g-Rays From Intergalactic Structure Formation, Nature 
Excerpt: The Universe is filled with a diffuse
background of g -ray
radiation1, the origin of which remains one of the unsolved
puzzles of cosmology. Less than one-quarter of the
g -ray flux can be
attributed to unresolved discrete sources, such as active galactic
nuclei; the remainder appears to constitute a truly diffuse
background. Here we show that the shock waves induced by gravity
in the gas of the intergalactic medium, during the formation of
large-scale structures like filaments and sheets of galaxies,
produce a population of highly relativistic electrons. These
electrons scatter a small fraction of the cosmic microwave
background photons in the local Universe up to g-ray
energies, thereby providing the g
-ray background. The predicted diffuse flux agrees
with the observed background across more than four orders of
magnitude in photon energy, and the model predicts that the
g -ray background, though
generated locally, is isotropic to better than five per cent on
angular scales larger than a degree. Moreover, the agreement
between the predicted and observed background fluxes implies a
mean cosmological density of baryons that is consistent with Big
Bang nucleosynthesis.
Reduction of Tropical Cloudiness by Soot, Science
Abstract: Measurements and models show that enhanced
aerosol concentrations can augment cloud albedo not only by
increasing total droplet cross-sectional area, but also by
reducing precipitation and thereby increasing cloud water content
and cloud coverage. Aerosol pollution is expected to exert a net
cooling influence on the global climate through these conventional
mechanisms. Here, we demonstrate an opposite mechanism through
which aerosols can reduce cloud cover and thus significantly
offset aerosol-induced radiative cooling at the top of the
atmosphere on a regional scale. In model simulations, the daytime
clearing of trade cumulus is hastened and intensified by solar
heating in dark haze (as found over much of the northern Indian
Ocean during the northeast monsoon).
Lie Detection And Language Comprehension, Nature
Excerpt: People are usually no better than chance
at detecting lies from a liar's demeanour1, 2, even when clues to
deceit are evident from facial expression and tone of voice3. We
suspected that people who are unable to understand words
(aphasics) may be better at spotting liars, so we tested their
performance as lie detectors. We found that aphasics were
significantly better at detecting lies about emotion than people
with no language impairment, suggesting that loss of language
skills may be associated with a superior ability to detect the
truth.
Interacting Molecular Loops in the Mammalian Circadian Clock, Science
Abstract: We show that, in the mouse, the core
mechanism for the master circadian clock consists of interacting
positive and negative transcription and translation feedback
loops. Analysis of Clock/Clock mutant mice, homozygous
Period2Brdm1 mutants, and Cryptochrome-deficient mice reveals
substantially altered Bmal1 rhythms, consistent with a dominant
role of PERIOD2 in the positive regulation of the Bmal1 loop. In
vitro analysis of CRYPTOCHROME inhibition of CLOCK: BMAL1-mediated
transcription shows that the inhibition is through direct
protein:protein interactions, independent of the PERIOD and
TIMELESS proteins. PERIOD2 is a positive regulator of the Bmal1
loop, and CRYPTOCHROMES are the negative regulators of the Period
and Cryptochrome cycles.
- Interacting
Molecular Loops in the Mammalian Circadian
Clock, Lauren P.
Shearman, Sathyanarayanan Sriram, David R. Weaver,
Elizabeth S. Maywood, In s Chaves, Binhai Zheng,
Kazuhiko Kume, Cheng Chi Lee, Gijsbertus T. J. van der
Horst, Michael H. Hastings, Steven M. Reppert,
Science, Volume 288, Number 5468 Issue of 12 May 2000,
pp. 1013 - 1019
Senator Proposes Tax Credit for Telecommuters, NYTimes
Excerpts: (...) Sen. Rick Santorum's bill, the
Telework Tax Incentive Act, will provide a $500 tax credit for
every worker who telecommutes at least 75 days per year. (...)
Supporters argue that telecommuting reduces traffic congestion,
air pollution, gas consumption and dependency on foreign oil. They
say the arrangement also benefits working parents, retirees and
people who may find it difficult to commute to or work in a
traditional office. (...)
However, companies have shied away from allowing employees to
work from home because of traditional business values and the
extra cost of building home offices.
The Web Is A Bow Tie, Nature
Excerpt: A study of the web's structure, five times
larger than any attempted previously, reveals that it isn't the
fully interconnected network that we've been led to believe. The
study suggests that the chance of being able to surf between two
randomly chosen pages is less than one in four.
Researchers from three Californian groups - at IBM's Almaden
Research Center in San Jose, the Altavista search engine in San
Mateo and Compaq Systems Research Center in Palo Alto - have
analysed 200 million web pages and 1.5 billion hyperlinks. Their
results, which will be presented next week at the World Wide Web 9
Conference in Amsterdam, indicate that the web is made up of four
distinct components.
-
DM is the name we give to models of fundamental processes
in physics that are entirely discrete and finite. We will
illustrate the power of DM models by defining a particular model,
assigning a small number of properties to the elements of the
model, and then deriving a large number of physically correct
properties from the model. In particular, we will start with a
simple binary 3+1D lattice, where the time dimension has extent 2
and some further complexity. In a sense, this model has 10
dimensions, a 3+1D space time lattice with 6 extra dimensions of
time. We then define just one conserved element, B. Bs can occupy
sites in the lattice. Each site either is occupied by a B or is
empty. Of course, there must be a rule that determines what
happens to the Bs. In this model there are 3 fundamental units, B,
Length and Time. That's it, BL&T; that's all we put into the
model. Here's what we get out: We will show in simple terms
exactly how the model represents space, time, energy, momentum,
force, charge, temperature, QCD color, why (within the model)
particles are colorless, why there are particles and
antiparticles, why there are conservation laws, how things move,
why there is CPT parity, how angular isotropy arises despite
angular anisotropy at the most microscopic level and finally why
so many fundamental numbers exist in the standard model.
It even offers a yet unheard of explanation of Bell's
inequality. To understand and absorb all these explanations, the
listeners must tolerate an inordinate amount of hand waving and in
addition must be able to temporarily suspend many of their most
cherished beliefs. If you can force yourself to swallow a byte of
the BL&T theory of physics, you might not like it, but it will
be good for you.
Scale Relativity, Fractal Space-Time and Morphogenesis, Sciences of the Interface
The theory of scale relativity extends Einstein's
principle of relativity to scale transformations of resolutions.
It is based on the giving up of the axiom of differentiability of
the space-time continuum. Three consequences arise from this
withdrawal.
(i) The geometry of space-time must be fractal, i.e.,
explicitly resolution-dependent: this allows one to describe a
non-differentiable physics in terms of differential equations
acting in the scale space. The requirement that these equations
satisfy the principle of scale relativity leads to introduce scale
laws having a Galilean form (constant fractal dimension), then a
Lorentzian one (in which the Planck length-time scale becomes a
minimal scale, invariant under dilations), and finally to attempt
constructing a generalized scale relativity which includes
non-linear scale transformations and scale-motion coupling.
(ii) The geodesics of a non-differentiable space-time are
fractal and in infinite number: this leads one to use a fluid-like
description and implies adding new terms in the differential
equations of mean motion.
(iii) Time reversibility is broken at the infinitesimal level:
this can be described in terms of a two-validness of the velocity
vector, then by jumping to a complex representation. These three
effects can be combined to construct a covariant time derivative
operator, which transforms the fundamental equations of classical
dynamics into a generalized Schrödinger equation. This
provides us with a theory of morphogenesis and self-organization,
since the solutions of this equations yield probability densities,
which are interpreted as a tendency for the system to make
structures. Several new theoretical predictions can be made by
applying this approach to the equations of motion of
test-particles in various gravitational potentials of
astrophysical relevance. These predictions are successfully
checked by a comparison with observational data on a wide range of
scales, ranging from planetary systems to large scale cosmological
structures.
Editor's Note
We apologize for the reduced format of this issue. It was
compiled while traveling with difficult access to the Internet and
additional technical problems.
| Editor-in-Chief: Carlos Gershenson
| Founding Editor: Gottfried Mayer
