Relación de perturbación perturbación en mecánica cuántica (Disturbance-disturbance relation in quantum mechanics)

"Physics is a science that has had an extraordinary development through the centuries and decades. The knowledge about nature has increased thanks to the investigation and experimentation in particle, statistical, optical, and quantum physics. All this kwnowledge needs to convey to new generations of physicists in an acceptable form, thus, the importance of teaching physics should be a main topic into our academic routine. In particular, quantum mechanics is somewhat rough for theaching. Many bad habits in teaching have affected the general understanding of this area and has effects such as a general misunderstanding of many main topics like the uncertainty principle and the measurement in quantum mechanics. A very important example of these misunderstandings is the Stern-Gerlach experiment (SGE). In many textbooks the SGE is studied in a semiclassical manner. This gives a wrong idea about what is the meaning of the SGE and the way that we understand it. In a recent work we studied the SGE by means of a complete quantum analysis. In particular, we found that the SGE is a creator of entangled states with an easy treatment (simply employing the general solution of the Schrodinger equation), a result that is not unknown to the quantum physics community, but which is not mentioned on usually textbooks.

Freedom Giving Birth to Order: Philosophical Reflections on Peirce's Evolutionary Cosmology and its Contemporary Resurrections

This paper seeks to show that Charles Sanders Peirce's interest in an evolutionary account of the laws of nature is motivated both by his desire to extend the scope of the application of the Principle of Sufficient Reason (PSR) and by his attempt to explain the success of our deployment of the PSR, which presupposes the existence of determinate causal structures. One can situate Peirce's concern with the explanation of the laws of nature in relation to the influences of Naturphilosophie on Peirce. I then show that some strands of contemporary physics can be understood as resurrections of Peirce's evolutionary cosmology. I show that we can understand Lee Smolin's theory of "cosmological natural selection" as a version of Peirce's evolutionary cosmology that is characterized by greater refinement and determinacy. However I argue that, contrary to Smolin's claim, an evolutionary account of the laws of nature need not require the abandonment of the relativity of simultaneity as established by the special theory of relativity. I also argue that Lee Smolin and Roberto Unger's characterization of the "original state" in their account of evolutionary cosmology raises philosophical problems of individuation that are best approached from the perspective of Chinese process metaphysics. Finally I turn to the wider consequences of evolutionary cosmology in relation to how we traditionally "rank" fields of knowledge that deal with atemporal structures as "more rigorous" than fields that deal with historical phenomena

Steps towards "Quantum Gravity" and the practice of science: will the merger of mathematics and physics work?

The author recalls general tendencies of the "mathematization" of the sciences and derives challenges and tentative obstructions for a successful merger of mathematics and physics on fancied steps towards "Quantum Gravity". This is an edited version of the author's opening words to an international workshop "Quantum Gravity: An Assessment", Denmark, May 17-18, 2008. It followed immediately after the Quantum Gravity Summer School 2008, see http://QuantumGravity.ruc.dk/Comment: To appear as part of a Springer Lecture Notes in Physics publication: "Quantum Gravity - New Paths towards Unification" (B. Booss-Bavnbek, G. Esposito, M. Lesch, Eds.

Beyond Desartes and Newton: Recovering life and humanity

Attempts to ‘naturalize’ phenomenology challenge both traditional phenomenology and traditional approaches to cognitive science. They challenge Edmund Husserl’s rejection of naturalism and his attempt to establish phenomenology as a foundational transcendental discipline, and they challenge efforts to explain cognition through mainstream science. While appearing to be a retreat from the bold claims made for phenomenology, it is really its triumph. Naturalized phenomenology is spearheading a successful challenge to the heritage of Cartesian dualism. This converges with the reaction against Cartesian thought within science itself. Descartes divided the universe between res cogitans, thinking substances, and res extensa, the mechanical world. The latter won with Newton and we have, in most of objective science since, literally lost our mind, hence our humanity. Despite Darwin, biologists remain children of Newton, and dream of a grand theory that is epistemologically complete and would allow lawful entailment of the evolution of the biosphere. This dream is no longer tenable. We now have to recognize that science and scientists are within and part of the world we are striving to comprehend, as proponents of endophysics have argued, and that physics, biology and mathematics have to be reconceived accordingly. Interpreting quantum mechanics from this perspective is shown to both illuminate conscious experience and reveal new paths for its further development. In biology we must now justify the use of the word “function”. As we shall see, we cannot prestate the ever new biological functions that arise and constitute the very phase space of evolution. Hence, we cannot mathematize the detailed becoming of the biosphere, nor write differential equations for functional variables we do not know ahead of time, nor integrate those equations, so no laws “entail” evolution. The dream of a grand theory fails. In place of entailing laws, a post-entailing law explanatory framework is proposed in which Actuals arise in evolution that constitute new boundary conditions that are enabling constraints that create new, typically unprestatable, Adjacent Possible opportunities for further evolution, in which new Actuals arise, in a persistent becoming. Evolution flows into a typically unprestatable succession of Adjacent Possibles. Given the concept of function, the concept of functional closure of an organism making a living in its world, becomes central. Implications for patterns in evolution include historical reconstruction, and statistical laws such as the distribution of extinction events, or species per genus, and the use of formal cause, not efficient cause, laws

Chain of Superconducting Loops as a Possible Quantum Register

The idea of the quantum computation is based on paradoxical principles of quantum physics, superposition and entanglement of quantum states. This idea looks well-founded on the microscopic level in spite of the absence of an universally recognized interpretation of these paradoxical principles since they were corroborated over and over again by reliable experiments on the microscopic level. But the technology can not be able in the near future to work on the microscopic level. Therefore macroscopic quantum phenomenon - superconductivity is very attractive for the realization of the idea of quantum computer. It is shown in the present paper that a chain of superconducting loops can be only possible quantum register. The proposals by some authors to provide the EPR correlation with help of a classical interaction witness the misunderstanding of the entanglement essence. The problem of the possibility of superposition of macroscopically distinct states is considered.Comment: 10 pages, 0 figure. Presented at International Symposium "Quantum Informatics 2004" Moscow, October 5-8, 200

Laudatores Temporis Acti, or Why Cosmology is Alive and Well - A Reply to Disney

A recent criticism of cosmological methodology and achievements by Disney (2000) is assessed. Some historical and epistemological fallacies in the said article have been highlighted. It is shown that---both empirically and epistemologically---modern cosmology lies on sounder foundations than it is portrayed. A brief historical account demonstrates that this form of unsatisfaction with cosmology has had a long tradition, and rather meagre results in the course of the XX century.Comment: 11 pages, no figures; a criticism of astro-ph/0009020; Gen. Rel. Grav., accepted for publicatio