An analysis of Helium resonant states in terms of entropy, information, complexity and entanglement measures

ABSTRACT: Shannon entropies and Fisher information calculated from one-particle density distributions and von Neumann and linear entropies (the latter two as a measure of entanglement) computed from the reduced oneparticle density matrix are analyzed for the 1,3Se,1,3 Po and 1,3De Rydberg series of He doubly excited states below the second ionization threshold. We find that both Fisher information and entanglement measures are able to discriminate resonances pertaining to different (K, T)A series

Information and entanglement measures applied to the analysis of complexity in doubly excited states of helium

ABSTRACT: Shannon entropy and Fisher information calculated from one-particle density distributions and von Neumann and linear entropies (the latter two as measures of entanglement) computed from the reduced one-particle density matrix are analyzed for the 1,3 Se, 1,3 Po, and 1,3 De Rydberg series of He doubly excited states below the second ionization threshold. In contrast with the Shannon entropy, we find that both the Fisher information and entanglement measures are able to discriminate low-energy resonances pertaining to different 2(K,T )An2 series according to the Herrick-Sinano˘glu-Lin classification. Contrary to bound states, which show a clear and unique asymptotic value for both Fisher information and entanglementmeasures in their Rydberg series 1sn for n→∞ (which implies a loss of spatial entanglement), the variety of behaviors and asymptotic values of entanglement above the noninteracting limit value in the Rydberg series of doubly excited states 2(K,T )A n2 indicates a signature of the intrinsic complexity and remnant entanglement in these high-lying resonances even with infinite excitation n2→∞, for which all known attempts of resonance classifications fail in helium

Diseño de un sistema de control de bajo costo para un observatorio astronómico

This work shows the engineering process carried out for the design of a low cost control system for an astronomical observatory. The work describes the implementation to adapt the equipment of the observatory to a Master Control System (MCS) and be able to use it remotely. The instruments and software required for the integration of the equipment as part of a robotic observatory are also described.En este artículo se expone el proceso de ingeniería llevado a cabo para el diseño de un sistema de control de bajo costo para un observatorio astronómico. En el artículo se describe la implementación para adaptar el equipo del observatorio a un Sistema de Control Maestro (SCM) y poder utilizarlo a distancia. También se describen los instrumentos y programas informáticos necesarios para la integración del equipo como parte de un observatorio robótico

Función de Wigner y Decoherencia Cuántica para Sistemas Átomo-Campo en Cavidades QED

ABSTRACT: The processes of quantum decoherence in QED cavities have been extensively studied in the last decade, both experimentally by Haroche, Raimond et. al., as theoretically by Nemes, Davidovich et. to the. We present here the dynamics of the Wigner function for a system consisting of a two-level atom and a cavity in a dissipative environment, using a numerical integration scheme that allows us to consider initial Squeezed and Schrodinger's Cat States. The interaction between the atom and the single-mode field is considered by a dispersive model, that is, the interaction in the Hamiltonian of Jaynes-Cummings appears as a small disturbance. The interest is focused both on the quantum characteristics of the dispersive approach (preparation of mesoscopic states) and on the aspects that characterize dynamics and dissipation. In particular, the gradual loss of quantum coherence is observed through the use of the Wigner function, where the disappearance of the interference regions of the initial quantum states is evidenced.RESUMEN: Los procesos de decoherencia cuántica en cavidades QED han sido extensamente estudiados en la última década, tanto experimentalmente por Haroche, Raimond et. al., como teóricamente por Nemes, Davidovich et. al. Se presenta aquí la dinámica de la función de Wigner para un sistema conformado por un átomo de dos niveles y una cavidad en un ambiente disipativo, usando un esquema de integracion numérica que permite considerar estados iniciales tipo Squeezed y Schrodinger’s Cat States. La interacción entre el átomo y el campo monomodo se considera mediante un modelo dispersivo, es decir, la interacción en el Hamiltoniano de Jaynes-Cummings aparece como una pequeña perturbación. El interés se enfoca tanto en las características cuánticas de la aproximación dispersiva (preparación de estados mesoscópicos) como en los aspectos que caracterizan la dinámica y la disipación. En particular, se observa la pérdida gradual de las coherencias cuánticas mediante el uso de la función de Wigner, en donde se evidencia la desaparición de las regiones de interferencia de los estados cuánticos iniciales

Location, orbit and energy of a meteoroid impacting the moon during the Lunar Eclipse of January 21, 2019

During lunar eclipse of January 21, 2019 a meteoroid impacted the Moon producing a visible light flash. The impact was witnessed by casual observers offering an opportunity to study the phenomenon from multiple geographical locations. We use images and videos collected by observers in 7 countries to estimate the location, impact parameters (speed and incoming direction) and energy of the meteoroid. Using parallax, we achieve determining the impact location at lat. $-29.43^{+0.30}_{-0.21}$, lon. $-67.89^{+0.07}_{-0.09}$ and geocentric distance as 356553 km. After devising and applying a photo-metric procedure for measuring flash standard magnitudes in multiple RGB images having different exposure times, we found that the flash, had an average G-magnitude $\langle G\rangle = 6.7\pm0.3$. We use gravitational ray tracing (GRT) to estimate the orbital properties and likely radiant of the impactor. We find that the meteoroid impacted the moon with a speed of $14^{+7}_{-6}$ km/s (70% C.L.) and at a shallow angle, $\theta < 38.2$ degrees. Assuming a normal error for our estimated flash brightness, educated priors for the luminous efficiency and object density, and using the GRT-computed probability distributions of impact speed and incoming directions, we calculate posterior probability distributions for the kinetic energy (median $K_{\rm med}$ = 0.8 kton), body mass ($M_{\rm med}$ = 27 kg) and diameter ($d_{\rm med}$ = 29 cm), and crater size ($D_{\rm med}$ = 9 m). If our assumptions are correct, the crater left by the impact could be detectable by prospecting lunar probes. These results arose from a timely collaboration between professional and amateur astronomers which highlight the potential importance of citizen science in astronomy.Comment: 19 pages, 11 figures, 4 tables. Data and scripts available in https://github.com/seap-udea/MoonFlashes. Accepted for publication in MNRA

The habitable zone of inhabited planets

ABSTRACT: In this paper we discuss and illustrate the hypothesis that life substantially alters the state of a planetary environment and therefore, modifies the limits of the HZ as estimated for an uninhabited planet. This hypothesis lead to the introduction of the Habitable Zone for Inhabited planets (hereafter InHZ), defined here as the region where the complex interaction between life and its abiotic environment is able to produce plausible equilibrium states with the necessary physical conditions for the existence and persistence of life itself. We support our hypothesis of an InHZ with three theoretical arguments, multiple evidences coming from observations of the Earth system, several conceptual experiments and illustrative numerical simulations. Conceptually the diference between the InHZ and the Abiotic HZ (AHZ) depends on unique and robust properties of life as an emergent physical phenomenon and not necesarily on the particular life forms bearing in the planet. Our aim here is to provide conceptual basis for the development of InHZ models incorporating consistently life-environment interactions. Although previous authors have explored the effects of life on habitability there is a gap in research developing the reasons why life should be systematically included at determining the HZ limits. We do not provide here definitive limits to the InHZ but we show through simple numerical models (as a parable of an inhabited planet) how the limits of the AHZ could be modified by including plausible interactions between biota and its environment. These examples aim also at posing the question that if limits of the HZ could be modified by the presence of life in those simple dynamical systems how will those limits change if life is included in established models of the AHZ

Posibles disposiciones solsticiales y lunares del Complejo de Petroglifos Precolombinos de Támesis, Colombia

Se analizan las posibles relaciones astronómicas y espaciales del complejo prehispánico de petroglifos de Támesis, Colombia. Con base en cartografía satelital y datos tomados en terreno, se muestran evidencias de la posible alineación de 93 piedras con petroglifos precolombinos, que, debido a su posición geográfica, parecen orientarse hacia el solsticio de junio, así como hacia la detención lunar mayor con respecto a unas formaciones montañosas conocidas como los Farallones de La Pintada. Las observaciones sugieren la posible existencia de un calendario de horizonte con un fuerte énfasis lunar. Este trabajo busca contribuir al estudio de la Astronomía en la Cultura de los grupos precolombinos del occidente de Colombia.Possible astronomical and spatial relationships of the prehispanic complex of petroglyphs in Támesis, Colombia are analyzed. Based on satellite cartography and data taken in the field, evidences of the possible alignment of 93 stones with pre-Columbian petroglyphs are shown, which due to their geographical position, seem to be oriented towards the June solstice, as well as towards the Moon in its northernmost position and some mountainous formations known as the Farallones de la Pintada. Our observations suggest the possible existence of a horizon calendar with strong lunar emphasis. This work seeks to contribute to the study of Astronomy in Culture of pre-Columbian groups in western Colombia.Sociedad Interamericana de Astronomía en la CulturaFacultad de Ciencias Astronómicas y Geofísica

Circumbinary habitability niches

ABSTRACT: Binaries could provide the best niches for life in the Galaxy. Although counterintuitive, this assertion follows directly from stellar tidal interaction theory and the evolution of lower mass stars. There is strong evidence that chromospheric activity of rapidly rotating young stars may be high enough to cause mass loss from atmospheres of potentially habitable planets. The removal of atmospheric water is most critical. Tidal breaking in binaries could help reduce magnetic dynamo action and thereby chromospheric activity in favour of life. We call this the Binary Habitability Mechanism (BHM) that we suggest allows for water retention at levels comparable to or better than the Earth. We discuss novel advantages that life may exploit, in these cases, and suggest that life may even thrive on some circumbinary planets. We find that while many binaries do not benefit from BHM, high-quality niches do exist for various combinations of stars between 0.55 and 1.0 solar masses. For a given pair of stellar masses, BHM operates only for certain combinations of period and eccentricity. Binaries having a solar-type primary seem to be quite well-suited niches having wide and distant habitable zones with plentiful water and sufficient light for photosynthetic life. We speculate that, as a direct result of BHM, conditions may be suitable for life on several planets and possibly even moons of giant planets orbiting some binaries. Lower mass combinations, while more restrictive in parameter space, provide niches lasting many billions of years and are rich suppliers of photosynthetic photons