Vol. 57 No. 2 Jul-Dec (2011): Revista Mexicana de Física E
Published:
2011-01-01
Artículos
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Luminiscencia up-convertida de iones TR3 +
Abstract:In the scenario of the imminent development of photonics technology, up-converted luminescence applications displayed by the trivalent rare earth ions (RT$^{3 + }$ ions) are especially relevant. From the production of compact solid-state lasers in the visible, high brightness displays, optical relays to materials for optical cooling. The present work aims to provide practical information on the process of frequency conversion from infrared to visible light and some possibilities of application in photonics technology.⬇️ Scroll down to see the full summary -
Comentario sobre el artículo ``Separación de variables en la ecuación cinemática $v^2 = v_0^2 + 2\vec{a}\mathbf{\cdot}\delta\vec{r}$ y su importancia'' de los autores S. Díaz-Solórzano y L.A. Gonzalez-Díaz [Rev. Mex. Fís. 56, 141-143 (2010)]
Abstract:We comment on a wrong application of the separation of variable idea as applied to derive an important equation of the cinematic of particles. We also point out conceptual errors on how the pointed equation should be applied.⬇️ Scroll down to see the full summary -
Buenaventura Suarez, S.J. (1679-1750) Part 1: Telescope maker, Jovian satellites observer
Abstract:During the first half of the 18$^{th}$ century, Father Buenaventura Suarez performed a series of astronomical observations in the Jesuit Reductions of Paraguay. His observations were published in prestigious European journals such as the Philosophical Transactions of the Royal Society and the Acta of the Royal Scientific Society of Uppsala. Working in the antipodes of the Jesuit astronomical centers of Europe and Asia, Suarez was not cut off from their mainstream activities. Educated at Cordoba, present day Argentina, under the Jesuit scholarly tradition, he was familiar with the observations and astronomical knowledge of his time. In spite of being an untutored astronomer he was capable of constructing his own telescopes, perhaps the first telescopes ever built in the Americas. Our present work analyzes the happy local circumstances that allowed him to produce his own astronomical instruments in Paraguay. By examining factual evidence from fictitious tales we show that, contrary to the common belief, Suarez was not provided with English telescopes for his observations. In addition we examine the circumstances and context of his observations on Jupiter's satellites, and the accuracy of his measurements. We show how his observations reached the Royal Society of London. Our findings prove that the politics of the Royal Society facilitated him this communication and it was not through a rather complicated network that Suarez sent London his data as was previously published. By examining factual accomplishments from alleged deeds we try to breakdown the mythology associated to this extraordinary personage.⬇️ Scroll down to see the full summary -
Los Elements de la Philosophie de Newton de Voltaire y su interpretación de la naturaleza de la luz
Abstract:The problem of the nature of light as presented in the book Elements de la Philosophie de Newton by Voltaire is presented and its controversy with Cartesian physics. Newton corpuscular proposal for the nature of light, defended by Voltaire, had to face the well accepted physics of Descartes and its followers who proposed that light behaves as a fluid made up of small vortex. It is in this context where the debate of light nature is presented in Voltaire book and here discussed. It is worth noting that this debate would historically and scientifically shadowed by the discussion on the ondulatory and corpuscular theories of light of Huygens and Newton. While the last discussion was rather objective since it was based in solid evidence, the first one had a high degree of speculation where physical, metaphysical and theological arguments would be equally considered. As it is shown, even though Newton proposed an ``incorrect'' theory of light, he had for his defence the extraordinary encyclopaedism and wit of Voltaire.⬇️ Scroll down to see the full summary -
Buenaventura Suarez, S.J. (1679-1750) Part 2: His book, lunario
Abstract:In the previous paper (part 1 Rev. Mex. Fis. E 57 (2011) 121--133) we have analyzed some aspects of the astronomical production of Buenaventura Suarez, a Jesuit missionary that worked in the Reductions of Paraguay in the early 18$^{th}$ century. To date, his only existing manuscript is the book ``Lunario de un Siglo''; a sort of almanac containing a hundred years calendar of: moon's phases, solar and lunar eclipses predictions and ecclesiastical dates. In this paper (part 2) we shall analyze the contents of Father Suarez's opus, its structure, scope and the accuracy of its predictions. Thereafter we shall concentrate on the reasons why Suarez translated from Portuguese into Spanish the book ``True Theory of Tides: according to the incomparable gentleman Isaac Newton'' by Jacob de Castro Sarmento, a London-based Portuguese physician and Fellow of the Royal Society. We suggest that Suarez probably shared with Sarmento the common conviction that the Moon's phases had an influence upon human beings. This might explain why Suarez included a Moon's phase calendar into his book.⬇️ Scroll down to see the full summary -
Comparative study between toroidal coordinates and the magnetic dipole field
Abstract:There is a similar behaviour between the toroidal coordinates and the dipole magnetic field produced by a circular loop. In this work we evaluate up to what extent the former can be used as a representation of the latter. While the tori in the toroidal coordinates have circular cross sections, those of the circular loop magnetic field are nearly elliptical ovoids, but they are very similar for large aspect ratios.The centres of the latter displace from the axis faster than the former. By making a comparison between tori of similar aspect ratios, we find quantitative criteria to evaluate the accuracy of the approximation.⬇️ Scroll down to see the full summary -
An early drawing of solar granulation?
Abstract:The discovery of solar granulation was announced by Nasmyth in 1861. However, an early solar engraving that could contain the first graphic description of solar granulation is showed in this short contribution. This solar drawing was made by the Mexican astronomers José Ignacio Bartolache and José Antonio Alzate to describe the Venus transit of 1769.⬇️ Scroll down to see the full summary -
The generating function of a canonical transformation
Abstract:An elementary proof of the existence of the generating function of a canonical transformation is given. A shorter proof, making use of the formalism of differential forms is also given.⬇️ Scroll down to see the full summary -
Magnetares y su posible relaci´on con las estrellas de quarks
Abstract:⬇️ Scroll down to see the full summaryIn the Universe there are stable stars with strong magnetic fields, larger than 1013 Gauss at the surface, which are called Magnetars. These objects could explain the astrophysical observations from peculiar emissions of some kind of pulsars like the Anomalous X-ray pulsars or Soft Gamma Repeaters. In this article, two principal hypothesis to explain the magnetic field intensity in Magnetars are presented. Further, the possibility that such objects could be quark stars is discussed (QSs). Also, an analytical solution for the mass-radius relationship of QSs under strong magnetic field is presented from the energy variational principle in General Relativity.
