Hemeroteca del mes julio, 2012

Chávez: La oposición me ha lanzado brujería para que yo no haga campaña

Por • 18 jul, 2012 • Category: Nacionales

Hugo Chávez en Guárico aseguró que el candidato de la unidad, Henrique Capriles representa el pasado “más terrible” de Venezuela pero aclaró: “nuestro pasado (los 14 años de su gestión) no es malo, es heroico”.

Scientific History And The Lessons For Today’s Emerging Ideas

Por • 18 jul, 2012 • Category: Educacion

One way to approach this question is to examine our own attitude to science at the end of the 19th century and the beginning of the 20th. The popular account goes a little like this. This era was characterised by a sense that the universe could be more or less completely described by Newton’s laws of mechanics, the laws of thermodynamics and Maxwell’s electromagnetic theory. All was well, save for one or two minor cracks that everyone expected could be easily papered over. Of course, these eventually led to two of the greatest revolutions in scientific thought: Max Planck’s quantum theory in 1900 and Einstein’s theories of special and general relativity a few years later. However, this popular account understates much of the complexity of scientific debate at the time. In particular, it fails to capture the extent to which many mainstream scientific ideas turned out to be spectacularly wrong. These ideas were widely discussed, much cherished and, in many cases, widely supported. Now these cul de sacs of science are largely forgotten. Today, Helge Kragh at Aarhaus University in Denmark puts the record straight by re-examining the end-of-the-century, or fin-de-siecle, physics and the ideas that dominated it. There is much to learn from the stories he tells. One largely forgotten episode was the general dissatisfaction at this time with the notion of ‘matter’. Various lines of thought seemed to suggest that the idea of an atomistic universe built from fundamental units of matter was flawed.

Diosdado, el valor de la lealtad

Por • 17 jul, 2012 • Category: Nacionales

En medio de las dificultades que lo anterior envuelve, la lealtad adquiere un valor insospechado. Por eso uno percibe frecuentes muestras de la confianza que el presidente deposita en Diosdado Cabello y la entrega del monaguense en momentos cruciales.

Quantum measurements are physical processes. Comment on “Consciousness and the double-slit interference pattern: Six experiments,” By Dean Radin et al. [Physics Essays 25, 2 (2012)]

Por • 16 jul, 2012 • Category: Ambiente

The validity of the assertion that some recent double-slit interference experiments, conducted by Radin et al., would have tested the possible role of the experimenter’s mind in the collapse of the quantum wave function, is questioned. It is emphasized that quantum mechanics doesn’t need any psychophysical ingredient to explain the measurement processes, and therefore parapsychologists shouldn’t resort to the latter to support the possibility of psychokinesis, but search for more convincing explanations

A roll of the dice

Por • 16 jul, 2012 • Category: Opinion

Quantum theory is close to optimal in terms of its predictive power, say researchers from the Perimeter Institute in Waterloo, the University of Calgary’s Institute for Quantum Information Science, and the Eidgenössische Technische Hochschule (ETH) in Zürich.

Chávez: ¿Intolerancia mesiánica o provocación pedagógica ante una extrema derecha apátrida?

Por • 15 jul, 2012 • Category: Nacionales

Ninguno de nosotros, los bolivarianos más conscientes, somos o seremos capaces de avalar cualquier fanatismo, cualquier discurso único, sea cual sea su justificación o naturaleza: ni filosófica, ni ideológica o política, ni religiosa, racial, étnico-nacional o de cualquier procedencia, civil o militar. El advenimiento de Hugo Chávez al ruedo político nacional e internacional, representó una innovación de una revolución pacífica, pero no desarmada.

Statistical Basis for Predicting Technological Progress

Por • 15 jul, 2012 • Category: Economía

Forecasting technological progress is of great interest to engineers, policy makers, and private investors. Several models have been proposed for predicting technological improvement, but how well do these models perform? An early hypothesis made by Theodore Wright in 1936 is that cost decreases as a power law of cumulative production. An alternative hypothesis is Moore’s law, which can be generalized to say that technologies improve exponentially with time. Other alternatives were proposed by Goddard, Sinclair et al., and Nordhaus. These hypotheses have not previously been rigorously tested. Using a new database on the cost and production of 62 different technologies, which is the most expansive of its kind, we test the ability of six different postulated laws to predict future costs. Our approach involves hindcasting and developing a statistical model to rank the performance of the postulated laws. Wright’s law produces the best forecasts, but Moore’s law is not far behind. We discover a previously unobserved regularity that production tends to increase exponentially. A combination of an exponential decrease in cost and an exponential increase in production would make Moore’s law and Wright’s law indistinguishable, as originally pointed out by Sahal. We show for the first time that these regularities are observed in data to such a degree that the performance of these two laws is nearly tied. Our results show that technological progress is forecastable, with the square root of the logarithmic error growing linearly with the forecasting horizon at a typical rate of 2.5% per year. These results have implications for theories of technological change, and assessments of candidate technologies and policies for climate change mitigation.

Unveiling the Higgs mechanism to students

Por • 14 jul, 2012 • Category: Educacion

In this paper we give the outline of a lecture given to undergraduate students aiming at understanding why physicists are so much interested in the Higgs boson. The lecture has been conceived for students not yet familiar with advanced physics and is suitable for several disciplines, other than physics. The Higgs mechanism is introduced by semi-classical arguments mimicking the basic field theory concepts, assuming the validity of a symmetry principle in the expression of the energy of particles in a classical field. The lecture is divided in two parts: the first, suitable even to high–school students, shows how the mass of a particle results as a dynamical effect due to the interaction between a massless particle and a field (as in the Higgs mechanism). The audience of the second part, much more technical, consists mainly of teachers and university students of disciplines other than physics.

Plato’s theory of knowledge of Forms by Division and Collection in the Sophistes is a philosophic analogue of periodic anthyphairesis (and modern continued fractions)

Por • 14 jul, 2012 • Category: Filosofía

The aim of this paper is to show that Plato’s theory of knowledge of Forms (intelligible Beings, Ideas) in the Sophistes, obtained by Division and Collection, is a close philosophic analogue of the geometric theory of periodic anthyphairesis, an ancient theory of incommensurability (developed by the Pythagoreans, Theodorus and Theaetetus) having its modern counterpart in the theory of continued fractions. Division corresponds to infinite anthyphairetic division, Collection to the Logos Criterion, resulting in periodicity and a self-similar One, precisely the One of a Platonic Form.

Origins of Mass

Por • 14 jul, 2012 • Category: Leyes

Newtonian mechanics posited mass as a primary quality of matter, incapable of further elucidation. We now see Newtonian mass as an emergent property. Most of the mass of standard matter, by far, arises dynamically, from back-reaction of the color gluon fields of quantum chromodynamics (QCD). The equations for massless particles support extra symmetries – specifically scale, chiral, and gauge symmetries. The consistency of the standard model relies on a high degree of underlying gauge and chiral symmetry, so the observed non-zero masses of many elementary particles ($W$ and $Z$ bosons, quarks, and leptons) requires spontaneous symmetry breaking. Superconductivity is a prototype for spontaneous symmetry breaking and for mass-generation, since photons acquire mass inside superconductors. A conceptually similar but more intricate form of all-pervasive (i.e. cosmic) superconductivity, in the context of the electroweak standard model, gives us a successful, economical account of $W$ and $Z$ boson masses. It also allows a phenomenologically successful, though profligate, accommodation of quark and lepton masses. The new cosmic superconductivity, when implemented in a straightforward, minimal way, suggests the existence of a remarkable new particle, the so-called Higgs particle.