Artículos con la etiqueta ‘frontera’

Breve nota sobre las hipótesis acerca del origen del lenguaje humano

Por • 1 jul, 2012 • Category: sociologia

Comenzamos por advertir que nuestra discusión pivotará en torno a la hipótesis del protolenguaje en el sentido de Bickerton{2}, se organizará sobre ella, por así decir, le concederemos la virtud de haber reorganizado el campo de las hipótesis sobre el asunto del origen del lenguaje. Al proceder de esta manera nos situaremos en la proximidad de formulaciones que se inscriben muy claramente en la lingüística y la teoría del lenguaje de Chomsky. Aunque ese territorio es habitado también por adversarios de éste, de ellos cabría decir que sólo pueden contradecirle porque, precisamente, Chomsky desarrolló la teoría del lenguaje y la lingüística{3} sobre las que crecieron muchas de las corrientes en lingüística que ahora registramos, aunque no todas desde luego{4}, ni muchísimo menos. No se trata, parafraseando en cierto modo lo antes afirmado a propósito de la hipótesis del protolenguaje, de que sea imposible hacer lingüística fuera del ámbito inaugurado por Chomsky: lo que vino a ocurrir con la irrupción de éste es que todas las lingüísticas se pudieron clasificar o situar desde las coordenadas que esa misma irrupción proporcionó. Sin perjuicio del valor del trabajo de muchos lingüistas, éste sólo se entiende históricamente como una respuesta, técnica –pongamos Joan Bresnan– o de un calado más ideológico –digamos Pinker– al autor de Syntactic Structures. Y obraremos de esta manera no especialmente movidos por la verdad positiva que podamos adjudicar a las teorías de Chomsky o de Bickerton, sino por el modo en que éstas, en su mismo planteamiento, revelan los problemas más o menos latentes en la ciencia lingüística.

Space-time crystals of trapped ions

Por • 27 jun, 2012 • Category: Opinion

Great progresses have been made in exploring exciting physics of low dimensional materials in last few decades. Important examples include the discovering and synthesizing of fullerenes (zero dimensional, 0D), carbon nanotubes (1D) and graphene (2D). A fundamental question is whether we can create materials with dimensions higher than that of conventional 3D crystals, for example, a 4D crystal that has periodic structures in both space and time. Here we propose a space-time crystal of trapped ions and a method to realize it experimentally by confining ions in a ring-shaped trapping potential with a static magnetic field. The ions spontaneously form a spatial ring crystal due to Coulomb repulsion. This ion crystal can rotate persistently at the lowest quantum energy state in magnetic fields with fractional fluxes. The persistent rotation of trapped ions produces the temporal order, leading to the formation of a space-time crystal. We show that these space-time crystals are robust for direct experimental observation. The proposed space-time crystals of trapped ions provide a new dimension for exploring many-body physics and emerging properties of matter.

Don’t undervalue Sino-Russian friendship

Por • 8 jun, 2012 • Category: Política

Though enhancing bilateral military ties was only briefly mentioned in the joint statement, it appeared in the headlines of many Chinese media. China and Russia share 4,300 kilometers of borders, almost all located in the Far East area. Military trust significantly helps the two sides save on defense budgets, benefiting people of both countries. The long period of tranquility along the border has made people forget the value of this peace. During the Cold War, China’s military budget was heavily burdened preparing for war in the northern and western regions. The burden has been completely removed now due to deep military trust between China and Russia. This trust has been further cemented by the Shanghai Cooperation Organization. The adjustment has lifted a large part of the strategic pressure on both countries. The comprehensive strategic partnership makes it possible for both Beijing and Moscow to shift their strategic focus. In the Cold War era, the Russian threat was the biggest factor behind China’s military-focused national economy, significantly delaying improvements in people’s daily life and national power. The Soviet Union, forced to face strategic pressure both in the east and west, suffered high financial losses too, making it more challenging to compete with the US. The shift from adversary to comprehensive strategic partnership creates valuable security space for these two powers.

Chávez no descarta que las FARC estén en territorio venezolano

Por • 22 may, 2012 • Category: Nacionales

El presidente de la República, aseguró este lunes que a raíz de un enfrentamiento con las Fuerzas Armadas de Colombia en Matajuna, localidad del departamento de La Guajira, un grupo de irregulares de las Fuerzas Armadas Revolucionarias de Colombia (FARC) pudiera haber migrado a territorio venezolano

Irán cuestiona pacto de Obama con Karzai

Por • 14 may, 2012 • Category: Internacionales

El sábado, en una enérgica declaración, el Ministerio de Exteriores iraní advirtió contra el despliegue de tropas estadounidenses en Afganistán. La declaración dice: Los “roles poco claros definidos para las fuerzas estadounidenses y sus bases militares” según el pacto constituyen “grandes fuentes de preocupación para Irán y otros países regionales”. El pacto no puede resolver los problemas de seguridad de Afganistán y desestabilizará aún más el país y empeorará la seguridad. La República Islámica de Irán cree que el establecimiento de paz y seguridad en Afganistán es posible mediante la retirada total de las fuerzas extranjeras, el cierre de bases militares y el diálogo entre los afganos en el marco del Alto Consejo de la Paz.

Spreading scientific philosophies with instruments: the case of Atwood’s machine

Por • 17 abr, 2012 • Category: sociologia

We study how the paradigm of Newton’s science, based on the organization of scientific knowledge as a series of mathematical laws, was definitively accepted in science courses – in the last decades of the XVIII century, in England as well as in the Continent – by means of the «universal» dynamical machine invented by George Atwood in late 1770s just for this purpose. The spreading of such machine, occurred well before the appearance of Atwood’s treatise where he described the novel machine and the experiments to be performed with it, is a quite interesting historical case, which we consider in some detail. In particular, we focus on the «improvement» introduced by the Italian Giuseppe Saverio Poli and the subsequent «simplifications» of the machine, underlying the ongoing change of perspective after the definitive success of Newtonianism. The case studied here allows to recognize the relevant role played by a properly devised instrument in the acceptance of a new paradigm by non-erudite scholars, in addition to the traditional ways involving erudite scientists, and thus the complementary role of machine philosophy with respect to mathematical, philosophical or even physical reasoning.

Quantum biology on the edge of quantum chaos

Por • 4 abr, 2012 • Category: Ambiente

We give a new explanation for why some biological systems can stay quantum coherent for long times at room temperatures, one of the fundamental puzzles of quantum biology. We show that systems with the right level of complexity between chaos and regularity can increase their coherence time by orders of magnitude. Systems near Critical Quantum Chaos or Metal-Insulator Transition (MIT) can have long coherence times and coherent transport at the same time. The new theory tested in a realistic light harvesting system model can reproduce the scaling of critical fluctuations reported in recent experiments. Scaling of return probability in the FMO light harvesting complex shows the signs of universal return probability decay observed at critical MIT. The results may open up new possibilities to design low loss energy and information transport systems in this Poised Realm hovering reversibly between quantum coherence and classicality.

Multidisciplinary Cognitive Content of Nanoscience and Nanotechnology

Por • 4 abr, 2012 • Category: Crítica

This article examines the cognitive evolution and disciplinary diversity of nanotechnology as expressed through the terminology used in titles of nano journal articles. The analysis is based on the NanoBank bibliographic database of 287,106 nano articles published between 1981 and 2004. We perform multifaceted analyses of title words, focusing on 100 most frequent terms. Hierarchical clustering of title terms reveals three distinct time periods of cognitive development of nano research: formative (1981-1990), early (1991-1998), and current (after 1998). Early period is characterized by the introduction of thin film deposition techniques, while the current period is characterized by the increased focus on carbon nanotube and nanoparticle research. We introduce a method to identify disciplinary components of nanotechnology. It shows that the nano research is being carried out in a number of diverse parent disciplines. Cognitive content of research published in nano-only journals is closest to nano research published in condensed matter and applied physics journals.

Towards a realistic interpretation of quantum physics providing a physical model of the natural world

Por • 4 abr, 2012 • Category: Opinion

It is stressed the advantage of a realistic interpretation of quantum mechanics providing a physical model of the quantum world. After some critical comments on the most popular interpretations, the difficulties for a model are pointed out and possible solutions proposed. In particular the existence of discrete states, the quantum jumps, the alleged lack of objective properties, measurement theory, the probabilistic character of quantum physics, the wave-particle duality and the Bell inequalities are commented. It is conjectured that an intuitive picture of the quantum world could be obtained compatible with the quantum predictions for actual experiments, although maybe incompatible with alleged predictions for ideal, unrealizable, experiments.

Thoughts about a conceptual framework for relativistic gravity

Por • 27 mar, 2012 • Category: Crítica

I consider the isolation of general relativity research from the rest of theoretical physics during the 1930s-1950s, and the subsequent reinvigoration of the field. I suggest that the main reason for the isolation was that relativists of the time did not develop heuristic concepts about the physics of the theory with which they could communicate with other physicists, and that the revival happened when they began to develop such concepts. A powerful heuristic today is the concept of a black hole, which is a robust and stable component of many astronomical systems. During the 1930s relativists could only offer the «Schwarzschild singularity». I argue that the change occurred at least partly because key theoretical physicists schooled in quantum theory entered relativity research and began to approach problematic issues by asking questions about observable effects and the outcomes of thought experiments. The result was the development of a physical intuition about such things as black holes, which could then be communicated to non-specialists. Only then was it possible to integrate general relativity fully into the rest of physics.