We describe the Tonnetz web environment and some of the possible applications we have developed w... more We describe the Tonnetz web environment and some of the possible applications we have developed within a pedagogical workshop on mathematics and music that has been conceived for high-school students. This web environment makes use of two geometrical representations that constitute intuitive ways of accessing some theoretical concepts underlying the equal tempered system and their possible mathematical formalizations. The environment is aimed at enhancing “mathemusical” learning processes by enabling the user to interactively manipulate these representations. Finally, we show how Tonnetz is currently being adapted in order to lead computer-based experiences in music perception and cognition that will be mainly carried at universities. These experiences will explore the way in which geometrical models could be implicitly encoded during the listening process. Their outcome may reinforce educational strategies for learning mathematics through music.
<p>... more <p>Until about 600 million years ago, our planet experienced temporary snowball conditions, with continental and sea ices covering a large fraction of its surface. This points to a potential bistability of Earth’s climate, that can have at least two different (statistical) equilibrium states for the same external forcing (i.e., solar radiation). Here we explore the probability of finding bistable climates in rocky exoplanets, and consider the properties of planetary climates obtained by varying the semi-major orbital axis (thus, received stellar radiation), eccentricity and obliquity, and atmospheric pressure. To this goal, we use the Earth-like planet surface temperature model (ESTM), an extension of 1D Energy Balance Models developed to provide a numerically efficient climate estimator for parameter sensitivity studies and long climatic simulations. After verifying that the ESTM is able to reproduce Earth climate bistability, we identify the range of parameter space where climate bistability is detected. An intriguing result of the present work is that the planetary conditions that support climate bistability are remarkably similar to those required for the sustainance of complex, multicellular life on the planetary surface. The exploration of potential climate bistability proceeds with the case of a Earth-like planet partially covered by vegetation that generates a positive vegetation-albedo feedback, in the spirit of the Charney conceptual model. In this case, it is shown that the presence of this vegetation feedback can induce relevant changes in climate dynamics and alter the range of habitable conditions for the planet.</p>
Sound is a preferred context to build foundations on wave phenomena, one of the most important di... more Sound is a preferred context to build foundations on wave phenomena, one of the most important disciplinary referents in physics. It is also one of the best-set frameworks to achieve transversality, overcoming scholastic level and activating emotional aspects which are naturally connected with every day life, as well as with music and perception. Looking at sound and music by a transversal perspective-a borderline approach between science and art, is the adopted statement for a teaching proposal using meta-cognition as a strategy in scientific education. This work analyzes curricular proposals on musical acoustics, planned by prospective secondary-school teachers in the framework of a Formative Intervention Module answering the expectation of making more effective teaching scientific subjects by improving creative capabilities, as well as leading to build logical and scientific categorizations able to consciously discipline artistic activity in music students. With this aim, a particular emphasis is given to those concepts-like sound parameters and structural elements of a musical piece, which are best fitted to be addressed on a transversal perspective, involving simultaneously physics, psychophysics and music.
MAGIC is a 17m diameter Imaging Air Cherenkov Telescope installed on the Canary Island La Palma. ... more MAGIC is a 17m diameter Imaging Air Cherenkov Telescope installed on the Canary Island La Palma. The telescope is designed for gamma-ray astronomy in the 30 GeV to 30 TeV energy range. Particle physics models predict candidate particles for Dark Matter, that might annihilate into gamma rays. Their predicted energy is in the accessible range of the MAGIC telescope. The expected gamma fluxes depend strongly on the density profiles in the innermost regions of the Dark Matter halos. The prospects and strategies for indirect Dark Matter searches with the MAGIC Telescope are described. The observability and flux expectations from possible targets are discussed.
The Galactic Center (GC) is a very interesting region for gamma ray astronomy. Various possibilit... more The Galactic Center (GC) is a very interesting region for gamma ray astronomy. Various possibilities for the production of very high energy (VHE) gamma rays near the GC are discussed in the literature, like accretion flow onto the central black hole, supernova shocks in Sgr A East, proton acceleration near the event horizon of the black hole, or WIMP dark matter annihilation. At the Canary Island La Palma, the GC culminates at about 58 deg zenith angle (ZA). Between May and August it can be observed with the MAGIC telescope at up to 60 deg ZA. The large zenith angle leads to a good sensitivity for energies in the TeV range. The observation and analysis strategies are outlined and the status of the ongoing analysis is presented.
We describe the first stage of a two-stage semialgorithmic approach to music performance renderin... more We describe the first stage of a two-stage semialgorithmic approach to music performance rendering. In the first stage, we estimate the perceptual salience of immanent accents (phrasing, metrical, melodic, harmonic) in the musical score. In the second, we manipulate timing, dynamics and other performance parameters in the vicinity of immanent accents (e. g., getting slower and/or louder near an accent). Phrasing and metrical accents emerge from the hierarchical structure of phrasing and meter; their salience depends on the hierarchical levels that they demarcate, and their salience. Melodic accents follow melodic leaps; they are strongest at contour peaks and (to a lesser extent) valleys; and their salience depends on the leap interval and the distance of the target tone from the local mean pitch. Harmonic accents depend on local dissonance (roughness, non-harmonicity, non-diatonicity) and chord/key changes. The algorithm is under development and is being tested by comparing its predictions with music analyses, recorded performances and listener evaluations.
High Energy Gamma-Ray Experiments - Proceedings of the Third Workshop on Science with the New Generation of, 2006
We discuss the main properties of substructures in the halos of galaxies. After having introduced... more We discuss the main properties of substructures in the halos of galaxies. After having introduced a subhalo mass function, we consider a scenario in which the most promising candidates for halo dark matter are weakly interacting massive particles (WIMPs), and give an estimation of the cumulative enhancement in the gamma-ray signal from subhalos of a given mass in the halo of M31. A self-consistent analysis of the dynamical evolution of subhalos is approached, with a particular interest in the description of the effects of mass loss and orbital decay and their implications on the halo merging history.
Luminosities and fluxes of the expected population of galactic gamma-ray pulsars become foreseeab... more Luminosities and fluxes of the expected population of galactic gamma-ray pulsars become foreseeable if physical distributions at birth and evolutive history are assigned. In this work we estimate the contribution of pulsar fluxes to the gamma-ray background, which has been measured by the EGRET experiment on board of the CGRO. For pulsar luminosities we select some of the most important gamma-ray emission models, taking into account both polar cap and outer gap scenarios. We find that this contribution strongly depends upon controversial neutron star birth properties. A comparison between our simulation results and EGRET data is presented for each model, finding an average contribution of about 10%. In addition, we perform the calculation of the number of new gamma-ray pulsars detectable by GLAST and AGILE, showing a remarkable difference between the two classes of models. Finally, we suggest some improvements in the numerical code, including more sophisticated galactic m odels and different populations of pulsars like binaries, milliseconds, anomalous pulsars and magnetars.
With its diameter of 17m, the MAGIC telescope is the largest Cherenkov detector for gamma ray ast... more With its diameter of 17m, the MAGIC telescope is the largest Cherenkov detector for gamma ray astrophysics. It is sensitive to photons above an energy of 30 GeV. MAGIC started operations in October 2003 and is currently taking data. This report summarizes its main characteristics, its first results and its potential for physics.
The introduction of modern physics topics in secondary schools is one of the highest challenges i... more The introduction of modern physics topics in secondary schools is one of the highest challenges in physics education. In this regard, a specific exercise has been carried out in the context of a dedicated Summer School involving both teachers with a Master in Education and secondary school students previously acquainted with these teachers. In the case of enlightening and overcoming conceptual and learning problems-with a deep insight to concepts and terms in contrast with common sense and everyday experience-a dedicated analysis of two different curricular proposals is outlined, showing possible weaknesses and strengths in both teaching frameworks and approaches.
Sound is a preferred context to build foundations on wave phenomena, one of the most important di... more Sound is a preferred context to build foundations on wave phenomena, one of the most important disciplinary referents in physics. It is also one of the best-set frameworks to achieve transversality, overcoming scholastic level and activating emotional aspects which are naturally connected with every day life, as well as with music and perception. Looking at sound and music by a transversal perspective-a borderline approach between science and art, is the adopted statement for a teaching proposal using meta-cognition as a strategy in scientific education. This work analyzes curricular proposals on musical acoustics, planned by prospective secondary-school teachers in the framework of a Formative Intervention Module answering the expectation of making more effective teaching scientific subjects by improving creative capabilities, as well as leading to build logical and scientific categorizations able to consciously discipline artistic activity in music students. With this aim, a particular emphasis is given to those concepts-like sound parameters and structural elements of a musical piece, which are best fitted to be addressed on a transversal perspective, involving simultaneously physics, psychophysics and music.
Accents are local musical events that attract the attention of the listener, and can be either im... more Accents are local musical events that attract the attention of the listener, and can be either immanent (evident from the score) or performed (added by the performer). Immanent accents involve temporal grouping (phrasing), meter, melody, and harmony; performed accents involve changes in timing, dynamics, articulation, and timbre. In the past, grouping, metrical and melodic accents were investigated in the context of expressive music performance. We present a novel computational model of immanent accent salience in tonal music that automatically predicts the positions and saliences of metrical, melodic and harmonic accents. The model extends previous research by improving on preliminary formulations of metrical and melodic accents and introducing a new model for harmonic accents that combines harmonic dissonance and harmonic surprise. In an analysis-by-synthesis approach, model predictions were compared with data from two experiments, respectively involving 239 sonorities and 638 sonorities, and 16 musicians and 5 experts in music theory. Average pair-wise correlations between raters were lower for metrical (0.27) and melodic accents (0.37) than for harmonic accents (0.49). In both experiments, when combining all the raters into a single measure expressing their consensus, correlations between ratings and model predictions ranged from 0.43 to 0.62. When different accent categories of accents were combined together, correlations were higher than for separate categories (r = 0.66). This suggests that raters might use strategies different from individual metrical, melodic or harmonic accent models to mark the musical events.
Assuming the lightest neutralino in the minimal supersymmetric extension to the Standard Model (M... more Assuming the lightest neutralino in the minimal supersymmetric extension to the Standard Model (MSSM) as the main dark matter (DM) component, we estimate the cumulative enhancement of the neutralino-induced gamma-ray signal in the Galactic halo due to the presence of subhalos. A realistic semi-analytical model for the spatial mass function of subhalos is implemented, incorporating effects that may influence the distribution and the evolution of substructures, such as the mass loss due to the tidal stripping and the orbital decay due to the dynamical friction.
We describe the Tonnetz web environment and some of the possible applications we have developed w... more We describe the Tonnetz web environment and some of the possible applications we have developed within a pedagogical workshop on mathematics and music that has been conceived for high-school students. This web environment makes use of two geometrical representations that constitute intuitive ways of accessing some theoretical concepts underlying the equal tempered system and their possible mathematical formalizations. The environment is aimed at enhancing “mathemusical” learning processes by enabling the user to interactively manipulate these representations. Finally, we show how Tonnetz is currently being adapted in order to lead computer-based experiences in music perception and cognition that will be mainly carried at universities. These experiences will explore the way in which geometrical models could be implicitly encoded during the listening process. Their outcome may reinforce educational strategies for learning mathematics through music.
<p>... more <p>Until about 600 million years ago, our planet experienced temporary snowball conditions, with continental and sea ices covering a large fraction of its surface. This points to a potential bistability of Earth’s climate, that can have at least two different (statistical) equilibrium states for the same external forcing (i.e., solar radiation). Here we explore the probability of finding bistable climates in rocky exoplanets, and consider the properties of planetary climates obtained by varying the semi-major orbital axis (thus, received stellar radiation), eccentricity and obliquity, and atmospheric pressure. To this goal, we use the Earth-like planet surface temperature model (ESTM), an extension of 1D Energy Balance Models developed to provide a numerically efficient climate estimator for parameter sensitivity studies and long climatic simulations. After verifying that the ESTM is able to reproduce Earth climate bistability, we identify the range of parameter space where climate bistability is detected. An intriguing result of the present work is that the planetary conditions that support climate bistability are remarkably similar to those required for the sustainance of complex, multicellular life on the planetary surface. The exploration of potential climate bistability proceeds with the case of a Earth-like planet partially covered by vegetation that generates a positive vegetation-albedo feedback, in the spirit of the Charney conceptual model. In this case, it is shown that the presence of this vegetation feedback can induce relevant changes in climate dynamics and alter the range of habitable conditions for the planet.</p>
Sound is a preferred context to build foundations on wave phenomena, one of the most important di... more Sound is a preferred context to build foundations on wave phenomena, one of the most important disciplinary referents in physics. It is also one of the best-set frameworks to achieve transversality, overcoming scholastic level and activating emotional aspects which are naturally connected with every day life, as well as with music and perception. Looking at sound and music by a transversal perspective-a borderline approach between science and art, is the adopted statement for a teaching proposal using meta-cognition as a strategy in scientific education. This work analyzes curricular proposals on musical acoustics, planned by prospective secondary-school teachers in the framework of a Formative Intervention Module answering the expectation of making more effective teaching scientific subjects by improving creative capabilities, as well as leading to build logical and scientific categorizations able to consciously discipline artistic activity in music students. With this aim, a particular emphasis is given to those concepts-like sound parameters and structural elements of a musical piece, which are best fitted to be addressed on a transversal perspective, involving simultaneously physics, psychophysics and music.
MAGIC is a 17m diameter Imaging Air Cherenkov Telescope installed on the Canary Island La Palma. ... more MAGIC is a 17m diameter Imaging Air Cherenkov Telescope installed on the Canary Island La Palma. The telescope is designed for gamma-ray astronomy in the 30 GeV to 30 TeV energy range. Particle physics models predict candidate particles for Dark Matter, that might annihilate into gamma rays. Their predicted energy is in the accessible range of the MAGIC telescope. The expected gamma fluxes depend strongly on the density profiles in the innermost regions of the Dark Matter halos. The prospects and strategies for indirect Dark Matter searches with the MAGIC Telescope are described. The observability and flux expectations from possible targets are discussed.
The Galactic Center (GC) is a very interesting region for gamma ray astronomy. Various possibilit... more The Galactic Center (GC) is a very interesting region for gamma ray astronomy. Various possibilities for the production of very high energy (VHE) gamma rays near the GC are discussed in the literature, like accretion flow onto the central black hole, supernova shocks in Sgr A East, proton acceleration near the event horizon of the black hole, or WIMP dark matter annihilation. At the Canary Island La Palma, the GC culminates at about 58 deg zenith angle (ZA). Between May and August it can be observed with the MAGIC telescope at up to 60 deg ZA. The large zenith angle leads to a good sensitivity for energies in the TeV range. The observation and analysis strategies are outlined and the status of the ongoing analysis is presented.
We describe the first stage of a two-stage semialgorithmic approach to music performance renderin... more We describe the first stage of a two-stage semialgorithmic approach to music performance rendering. In the first stage, we estimate the perceptual salience of immanent accents (phrasing, metrical, melodic, harmonic) in the musical score. In the second, we manipulate timing, dynamics and other performance parameters in the vicinity of immanent accents (e. g., getting slower and/or louder near an accent). Phrasing and metrical accents emerge from the hierarchical structure of phrasing and meter; their salience depends on the hierarchical levels that they demarcate, and their salience. Melodic accents follow melodic leaps; they are strongest at contour peaks and (to a lesser extent) valleys; and their salience depends on the leap interval and the distance of the target tone from the local mean pitch. Harmonic accents depend on local dissonance (roughness, non-harmonicity, non-diatonicity) and chord/key changes. The algorithm is under development and is being tested by comparing its predictions with music analyses, recorded performances and listener evaluations.
High Energy Gamma-Ray Experiments - Proceedings of the Third Workshop on Science with the New Generation of, 2006
We discuss the main properties of substructures in the halos of galaxies. After having introduced... more We discuss the main properties of substructures in the halos of galaxies. After having introduced a subhalo mass function, we consider a scenario in which the most promising candidates for halo dark matter are weakly interacting massive particles (WIMPs), and give an estimation of the cumulative enhancement in the gamma-ray signal from subhalos of a given mass in the halo of M31. A self-consistent analysis of the dynamical evolution of subhalos is approached, with a particular interest in the description of the effects of mass loss and orbital decay and their implications on the halo merging history.
Luminosities and fluxes of the expected population of galactic gamma-ray pulsars become foreseeab... more Luminosities and fluxes of the expected population of galactic gamma-ray pulsars become foreseeable if physical distributions at birth and evolutive history are assigned. In this work we estimate the contribution of pulsar fluxes to the gamma-ray background, which has been measured by the EGRET experiment on board of the CGRO. For pulsar luminosities we select some of the most important gamma-ray emission models, taking into account both polar cap and outer gap scenarios. We find that this contribution strongly depends upon controversial neutron star birth properties. A comparison between our simulation results and EGRET data is presented for each model, finding an average contribution of about 10%. In addition, we perform the calculation of the number of new gamma-ray pulsars detectable by GLAST and AGILE, showing a remarkable difference between the two classes of models. Finally, we suggest some improvements in the numerical code, including more sophisticated galactic m odels and different populations of pulsars like binaries, milliseconds, anomalous pulsars and magnetars.
With its diameter of 17m, the MAGIC telescope is the largest Cherenkov detector for gamma ray ast... more With its diameter of 17m, the MAGIC telescope is the largest Cherenkov detector for gamma ray astrophysics. It is sensitive to photons above an energy of 30 GeV. MAGIC started operations in October 2003 and is currently taking data. This report summarizes its main characteristics, its first results and its potential for physics.
The introduction of modern physics topics in secondary schools is one of the highest challenges i... more The introduction of modern physics topics in secondary schools is one of the highest challenges in physics education. In this regard, a specific exercise has been carried out in the context of a dedicated Summer School involving both teachers with a Master in Education and secondary school students previously acquainted with these teachers. In the case of enlightening and overcoming conceptual and learning problems-with a deep insight to concepts and terms in contrast with common sense and everyday experience-a dedicated analysis of two different curricular proposals is outlined, showing possible weaknesses and strengths in both teaching frameworks and approaches.
Sound is a preferred context to build foundations on wave phenomena, one of the most important di... more Sound is a preferred context to build foundations on wave phenomena, one of the most important disciplinary referents in physics. It is also one of the best-set frameworks to achieve transversality, overcoming scholastic level and activating emotional aspects which are naturally connected with every day life, as well as with music and perception. Looking at sound and music by a transversal perspective-a borderline approach between science and art, is the adopted statement for a teaching proposal using meta-cognition as a strategy in scientific education. This work analyzes curricular proposals on musical acoustics, planned by prospective secondary-school teachers in the framework of a Formative Intervention Module answering the expectation of making more effective teaching scientific subjects by improving creative capabilities, as well as leading to build logical and scientific categorizations able to consciously discipline artistic activity in music students. With this aim, a particular emphasis is given to those concepts-like sound parameters and structural elements of a musical piece, which are best fitted to be addressed on a transversal perspective, involving simultaneously physics, psychophysics and music.
Accents are local musical events that attract the attention of the listener, and can be either im... more Accents are local musical events that attract the attention of the listener, and can be either immanent (evident from the score) or performed (added by the performer). Immanent accents involve temporal grouping (phrasing), meter, melody, and harmony; performed accents involve changes in timing, dynamics, articulation, and timbre. In the past, grouping, metrical and melodic accents were investigated in the context of expressive music performance. We present a novel computational model of immanent accent salience in tonal music that automatically predicts the positions and saliences of metrical, melodic and harmonic accents. The model extends previous research by improving on preliminary formulations of metrical and melodic accents and introducing a new model for harmonic accents that combines harmonic dissonance and harmonic surprise. In an analysis-by-synthesis approach, model predictions were compared with data from two experiments, respectively involving 239 sonorities and 638 sonorities, and 16 musicians and 5 experts in music theory. Average pair-wise correlations between raters were lower for metrical (0.27) and melodic accents (0.37) than for harmonic accents (0.49). In both experiments, when combining all the raters into a single measure expressing their consensus, correlations between ratings and model predictions ranged from 0.43 to 0.62. When different accent categories of accents were combined together, correlations were higher than for separate categories (r = 0.66). This suggests that raters might use strategies different from individual metrical, melodic or harmonic accent models to mark the musical events.
Assuming the lightest neutralino in the minimal supersymmetric extension to the Standard Model (M... more Assuming the lightest neutralino in the minimal supersymmetric extension to the Standard Model (MSSM) as the main dark matter (DM) component, we estimate the cumulative enhancement of the neutralino-induced gamma-ray signal in the Galactic halo due to the presence of subhalos. A realistic semi-analytical model for the spatial mass function of subhalos is implemented, incorporating effects that may influence the distribution and the evolution of substructures, such as the mass loss due to the tidal stripping and the orbital decay due to the dynamical friction.
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Papers by Erica Bisesi