Fernando J. Ballesteros

University of Valencia | UV · Astronomical Observatory

The subjective number-space mapping and, especially, its evolution in young children has been the subject of intense controversy among different competing models. Many studies point out that: (i) young children's innate estimates follow a logarithmic mapping (Weber-Fechner law) and (ii) driven by education, children evolve into a linear mapping. In...

The origin of eukaryotes represents one of the most significant events in evolution, since it allowed the posterior emergence of multicellular organisms 1,2 . Evolutionary biologists have tried to unveil the mechanism leading to eukaryotes, most likely the symbiosis between two previously unrelated organisms ³ . Yet, it remains unclear how the gene...

Poe and Science

We predicted a stellar occultation of the bright star Gaia DR1 4332852996360346368 (UCAC4 385-75921) (mV= 14.0 mag) by the centaur 2002 GZ32 for 2017 May 20th. Our latest shadow path prediction was favourable to a large region in Europe. Observations were arranged in a broad region inside the nominal shadow path. Series of images were obtained with...

We predicted a stellar occultation of the bright star Gaia DR1 4332852996360346368 (UCAC4 385-75921) (m$_{\rm V}$= 14.0 mag) by the centaur 2002 GZ$_{32}$ for 2017 May 20$^{\rm th}$. Our latest shadow path prediction was favourable to a large region in Europe. Observations were arranged in a broad region inside the nominal shadow path. Series of im...

La pandemia de COVID-19, provocada por el coronavirus SARS-CoV-2, constituye la� crisis sanitaria global más seria a la que se ha enfrentado la humanidad desde la epidemia mundial de gripe de 1918. Al tratarse de un virus completamente nuevo para las personas, no disponemos de respuesta inmunitaria ni de vacuna para pa- liar sus efectos. Sin embarg...

Tell Bartolo Luque and Fernando Ballesteros how far the Sun is from the Earth, and they will tell you the size of the Universe.

16 pages, 14 figures, submitted to Astronomy & Astrophysics

Understanding the evolutionary history of the Magellanic Clouds requires an in-depth exploration and characterization of the stellar content in their outer regions, which ultimately are key to tracing the epochs and nature of past interactions. We present new deep images of a shell-like over-density of stars in the outskirts of the Small Magellanic...

This chapter delves into the life of the famous scientist Marie Curie, winner of two Nobel prizes who worked together with her husband in the understanding of radioactivity.

This chapter presents a review of the history and development of lunar nomenclature, the first maps, and the work to obtain a uniform and consensual international lunar nomenclature.

This chapter deals with Gerty Cori and her husband, Carl, both biologists, and their work with the metabolism of glucose which made them winners of the Nobel Prize.

This chapter talks about the life of the Sharon Christa McAuliffe, a teacher who, when participating in the Teacher in Space program, died in the explosion of the space shuttle Challenger.

This chapter focuses on the work and life of the marriage formed by Annie Maunder and her husband, both astronomers.

This chapter describes the figure of Lise Meitner, famous Austrian physicist and co-discoverer of the nuclear fusion of uranium, who had to flee her country during the Second World War because she was of Jewish religion.

This chapter talks about the astronomer Annie Cannon, author of the stellar classification that is used nowadays.

This chapter is about the Scottish scientific writer Mary Somerville: her life and her relationships with the main scientists of the time.

This chapter tells the few things that are known about the life of Anne Sheepshanks, a patron of nineteenth-century science.

The fascinating life of Russian mathematician Sofia Kovalévskaya is narrated in this chapter, along with her problems in being accepted as an equal in the academic world.

This chapter provides background material to put the Moon in context and to understand how craters came to be formed, as part of the formation of the solar system. It presents a brief history of the solar system and the first observations of the Moon, and how they affected its portrayal in art and literature. The measurement of its distance and the...

The main subject of this chapter is the life of Maria Mitchell, the first American woman to discover a comet, and the first director of the Vassar Observatory.

This chapter tells of the vicissitudes of Williamina Fleming, who went from single mother and domestic assistant, to direct the first female staff of astronomers at the Harvard Observatory.

The chapter tells the life of the astronomer Antonia Maury and the difficulties she had to overcome in order for her scientific opinion to be recognized.

This chapter describes the figure of Mary Proctor, American popularizer of astronomy, and her work to make science understandable.

This chapter narrates the life of Hypatia of Alexandria, famous scientist of the ancient world and how the conflicts of religion ended her life.

For each of the “Women of the Moon”, a biography and the reason for receiving the honor are described. The women included are Hypatia of Alexandria, Catherine of Alexandria, Nicole-Reine de la Briere Lepaute, Caroline Lucretia Herschel, Mary Fairfax Greig Somerville, Anne Sheepshanks, Catherine Wolfe Bruce, Maria Mitchell, Agnes Mary Clerke, Sofia...

This chapter focuses on the work and life of the marriage formed by Priscilla Fairfield Bok and her husband, Bart Bok, both astronomers.

This chapter tells how little is known about the life of the patron Catherine Wolfe Bruce.

This chapter focuses on the life of the American astronaut Judith Resnik, who died in the explosion of the space shuttle Challenger.

This chapter describes Laurel Clark, an American astronaut who died during the disintegration of the space shuttle Columbia when it entered the atmosphere.

Of the 1586 lunar craters that have been named to honor scientists and philosophers, only 28 honor a woman. This book recounts briefly the story of lunar nomenclature, delves into a few misunderstood questions about the Moon, and then looks at the lives of the few women that were honored. Who were these women? This book recounts their lives, strugg...

This chapter explains what is known about the life and work of the astronomer Louise Freeland Jenkins.

The Moon is no longer the “in” thing. We see it as often as the Sun and give it little thought—we’ve become indifferent. However, the Moon does reflect more than just sunlight. The nomenclature of lunar craters holds up a mirror to an important aspect of human history. Of the 1586 lunar craters that have been named honoring philosophers and scienti...

This chapter describes the painful life of Henrietta Leavitt, who discovered the tool that allows the distances to other galaxies to be measured.

Brief summary of some characteristics of the Women of the Moon

This chapter deals with the life of the mathematician Emmy Noether, her escape from her country due to the rise of Nazism, as well as her scientific contributions.

This chapter deals with the life of the Indian astronaut Kalpana Chawla, who died during the disintegration of the space shuttle Columbia when it entered the atmosphere.

This chapter talks about Nicole Lepaute, an eighteenth-century French computer that accurately calculated the passage of Halley’s Comet.

This chapter is about the astronomer Caroline Herschel, sister of the famous William Herschel with whom she developed her scientific career.

This chapter is about the Irish scientific writer Agnes Clerke and her work for the popularization of science and astronomy.

This chapter is about the person who put order to the chaos that was in the lunar nomenclature at the beginning of the twentieth century, Mary Adela Blagg.

This chapter narrates the life of Catherine of Alexandria, saint of whose existence there is no record but who had a notable influence on Christianity.

This chapter deals with the life of Valentina Tereshkova, and how she managed to become the first woman in history to go out into space.

One of the basic tenets of exobiology is the need for a liquid substratum in which life can arise, evolve, and develop. The most common version of this idea involves the necessity of water to act as such a substratum, both because that is the case on Earth and because it seems to be the most viable liquid for chemical reactions that lead to life. O...

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

The origin and shape of metabolic scaling has been controversial since Kleiber found that basal metabolic rate of animals seemed to vary as a power law of their body mass with exponent 3/4, instead of 2/3, as a surface-to-volume argument predicts. The universality of exponent 3/4 -claimed in terms of the fractal properties of the nutrient network-...

KIC 8462852 stood out among more than 100,000 stars in the Kepler catalogue because of the strange features of its light curve: a wide and asymmetric dimming taking up to 15 per cent of the total light, together with a period of multiple, narrow dimmings happening approximately 700 days later. Several models have been proposed to account for this a...

The original ALHAMBRA catalogue contained over 400 000 galaxies selected using a synthetic F814W image, to the magnitude limit AB(F814W) ≈ 24.5. Given the photometric redshift depth of the ALHAMBRA multiband data (〈z〉 = 0.86) and the approximately I-band selection, there is a noticeable bias against red objects at moderate redshift. We avoid this b...

This chapter defines a graph entropy and process of renormalization for visibility graphs that characterize these routes and analyze the relationship between the flow of renormalization and the extremes of the entropy function. Nonlinear time series analysis develops from techniques such as nonlinear correlation functions, embedding algorithms, mul...

Unlabelled: As the number of detected extrasolar planets increases, exoplanet databases become a valuable resource, confirming some details about planetary formation but also challenging our theories with new, unexpected properties. Key words: Exoplanets-Gravity-Planetary habitability and biosignatures. Astrobiology 16, 325-327.

When we talk about the origins of science fiction and literature, the names Herbert G. Wells or Jules Verne immediately come to mind, indeed these prolific late nineteenth-century authors inspired later generations. However, few take account of Edgar Allan Poe, an author from the beginning of that century who inspired the aforementioned authors. In...

In the title of this paper, we have changed the slogan of the International Year of Astronomy, " The Universe yours to discover " to " The Universe for all to discover " in order to emphasize the need to think about broader audiences when we plan astronomical activities at school or during outreach events. The strategy we propose follows what is kn...

In addition to his well known literary facet, Poe was fond of science since he was young and he often read popular science literature. As a result, he used many scientific elements in his stories and journalistic hoaxes that helped increase his popularity. But Poe was not confined to using science in literature. He also put his writing at the servi...

The Javalambre-Physics of the Accelerated Universe Astrophysical Survey (J-PAS) is a narrow band, very wide field Cosmological Survey to be carried out from the Javalambre Observatory in Spain with a purpose-built, dedicated 2.5m telescope and a 4.7 sq.deg. camera with 1.2Gpix. Starting in late 2015, J-PAS will observe 8500sq.deg. of Northern Sky a...

The Javalambre-Physics of the Accelerated Universe Astrophysical Survey (J-PAS) is a narrow band, very wide field Cosmological Survey to be carried out from the Javalambre Observatory in Spain with a purpose-built, dedicated 2.5m telescope and a 4.7deg² camera with 1.2Gpix. Starting in 2015, J-PAS will observe 8500deg² of Northern Sky and measure 0...

La Luna es uno de los primeros objetos astronómicos que observamos en nuestras vidas, y nuestra experiencia de ella es puramente visual. Este proyecto busca que las personas con problemas de visión puedan también disfrutar de la Luna, pero a través del tacto.

The Moon is, together with the Sun, the very first astronomical object that we experience in our life. As this is an exclusively visual experience, people with visual impairments need to follow a different path to experience it too. Here we will show the process of designing and testing a tactile 3D Moon sphere whose goal is to reproduce on a tacti...

A novel class of graphs, here named quasiperiodic, are constructed via application of the Horizontal Visibility algorithm to the time series generated along the quasiperiodic route to chaos. We show how the hierarchy of mode-locked regions represented by the Farey tree is inherited by their associated graphs. We are able to establish, via Renormali...

Time series are proficiently converted into graphs via the horizontal visibility (HV) algorithm, which prompts interest in its capability for capturing the nature of different classes of series in a network context. We have recently shown [B. Luque et al., PLoS ONE 6, 9 (2011)] that dynamical systems can be studied from a novel perspective via the...

Planck's law describes the radiation of black bodies. The study of its properties is of special interest, as black bodies are a good description for the behavior of many phenomena. In this work a new mathematical study of Planck's law is performed and new properties of this old acquaintance are obtained. As a result, the exact form for the locus in...

The Aula d'Astronomia is a teaching laboratory of the Faculty of Physics, University of Valencia, managed by the Departamentd'Astronomia i Astrofísica. In it, practices of some astronomical specialities are taught. Therefore, we have a classroomwith computers together with four specific telescopes installed on the terrace (a solar one, a reflector...

The recently formulated theory of horizontal visibility graphs transforms time series into graphs and allows the possibility of studying dynamical systems through the characterization of their associated networks. This method leads to a natural graph-theoretical description of nonlinear systems with qualities in the spirit of symbolic dynamics. We...

If SETI produces results, and we manage to detect signals from other civilizations in the galaxy, we will have a problem. No doubt, the commotion due to this news would be enormous and its repercussions wide-ranging. But the problem we refer to here is different. Could we understand the signal? Even if this signal were designed by our galactic neig...

The belief in the existence of extraterrestrial civilizations starts from the so-called principle of mediocrity. This principle postulates that Earth is a normal planet that rotates around a normal star, which in turn is located in a normal galaxy. That is to say, there is nothing so special in our world as to make it unique. This is a logical conc...

SETI scientists are convinced that, of all possible types of radiation, any signal coming to us from another galactic civilization will have the form of electromagnetic waves; therefore, the search centers exclusively on these types of radiation. Why electromagnetic waves?

The previous chapter has shown us that life on Earth arose surprisingly fast and easy, as soon as the conditions were right for liquid water to be sustained on the surface. We saw that there is evidence of the presence of this valuable substance in at least two other bodies in the Solar System, and these are encouraging indications that life in the...

Perhaps you remember Steven Spielberg’s movie released in 1977, Close Encounters of the Third Kind. The memorable end of this movie shows how humans might communicate with extraterrestrials through the interchange of music, with the famous melody “D E C C G” that we all hummed.

As we have seen, radio waves can be excellent candidates for interplanetary communication, due to the fact that our galaxy is transparent to them. The problem lies in properly identifying the origin – artificial or natural – of an arriving signal. When we tune a radio receiver and we turn the antenna toward the cosmos, we gather hundreds of differe...

Europa, the smallest of the four moons of Jupiter discovered by Galileo­ Galilei, has attracted much speculation on whether it might be inhabited ever since it was observed by the Voyager probes. This is mostly due to the fact that water, or better said, water-ice, is the most evident feature of that world, with ice covering this interesting satell...

In the previous chapter, we have seen that it was quite easy for life to appear in our world. But how did it arise? What processes occurred for life to appear so quickly? Are these processes common to other worlds?

Are others actually out there? If so, why don’t we know anything about them yet? Although this may seem a trivial question, it is not an easy one to answer at all.

When we study communication systems in other animal species, we are led to the conclusion that extraterrestrial intelligent beings are likely to have systems of communication similar to the human one in at least some aspects. That is to say, communication is accomplished by means of the combination of certain information elements playing a role ana...

In SETI, the strategies used for searching for celestial signals are divided into two main groups. The first group focuses on the study of specific targets with a known location, which are, for one or more reasons, good candidates to have civilizations. This type of search usually concentrates on nearby stars, from which a hypothetical signal would...

The visibility algorithm has been recently introduced as a mapping between time series and complex networks. This procedure allows us to apply methods of complex network theory for characterizing time series. In this work we present the horizontal visibility algorithm, a geometrically simpler and analytically solvable version of our former algorith...

Baryon Acoustic Oscillations (BAOs) provide a "standard ruler" of known physical length, making it one of the most promising probes of the nature of dark energy (DE). The detection of BAOs as an excess of power in the galaxy distribution at a certain scale requires measuring galaxy positions and redshifts. "Transversal" (or "angular") BAOs measure...

A study of the galaxy distribution in the field of the elliptical galaxy NGC 1600 has been undertaken. Although this galaxy is often classified as a member of a loose group, all the neighboring galaxies are much fainter and could be taken as satellites of NGC 1600. The number density profile of galaxies in the field of this galaxy shows a decline w...

In this work we present a simple and fast computational method, the visibility algorithm, that converts a time series into a graph. The constructed graph inherits several properties of the series in its structure. Thereby, periodic series convert into regular graphs, and random series do so into random graphs. Moreover, fractal series convert into...

In this paper we study in detail the behavior of random-walk networks (RWN's). These networks are a generalization of the well-known random Boolean networks (RBN's), a classical approach to the study of the genome. RWN's are also discrete networks, but their response is defined by small variations in the state of each gene, thus being a more realis...

Several order parameters have been considered to predict and characterize the transition between ordered and disordered phases in random Boolean networks, such as the Hamming distance between replicas or the stable core, which have been successfully used. In this work, we propose a natural and clear new order parameter: the temporal variance. We co...

Random Boolean networks are among the best-known systems used to model genetic networks. They show an on–off dynamics and it is easy to obtain analytical results with them. Unfortunately very few genes are strictly on–off switched. On the other hand, continuous methods are in principle more suitable to capture the real behavior of the genome, but h...

Random Boolean networks have been proposed as discrete models of genetic networks. Depending on the values of their control parameters, these networks fall by themselves in order or disorder phases. These networks are autonomous systems: no external inputs are considered. Nevertheless, in the real world the genetic networks are influenced by extern...

When using γ-ray coded-mask cameras, one does not get a direct image as in classical optical cameras but the correlation of the mask response with the source. Therefore the data must be mathematically treated in order to reconstruct the original sky sources. Generally this reconstruction is based on linear methods, such as correlating the detector...

Standard random Boolean networks display an order-disorder phase transition. We add to the standard random Boolean networks a disconnection rule that couples the control and order parameters. In this way, the system is driven to the critical line transition. Under the influence of perturbations the system points out self-organized critical behavior...

Two years after launch (04.21.97), LEGRI is operating on Minisat-01 in a LEO orbit. The LEGRI detector plane is formed by two type of gamma-ray solid state detectors: HgI2 and CdZnTe. Detectors are embedded in a box containing the FEE and DFE electronics. This box provides an effective detector passive shielding. Detector plane is multiplexed by a...

The simpler imaging reconstruction methods used for γ-ray coded mask telescopes are based on correlation methods, very fast and simple-to-use but with limitations in the reconstructed image. To improve these results, other reconstruction methods have been developed, such as the maximum entropy methods or the Iterative Removal Of Sources (IROS). How...

In this paper we present the phase A studies which were carried out for the optimization of the design and evaluation of the scientific performances of the Imager, which is one of the two main instruments under development for the INTEGRAL mission, selected by ESA as the next scientific mission of medium size (M2).These studies were done by Monte C...

The Low Energy Gamma Ray Imager (LEGRI) is one of two astronomical instruments on the MINISAT-01 mission and is devoted to exploring the hard X-ray and low gamma-ray emission of the celestial bodies. MINISAT-01 launch is due for December 1996 by a Pegasus launcher in the Canary Islands area. A coded mask coupled to a 100 pixel detector plane formed...

The Low Energy Gamma Ray Imager (LEGRI) on board the first MINISAT mission, is a telescope with imaging capabilities working in the 20-100 KeV spectral region. The main goal of LEGRI is to perform a galactic survey in order to observe compact objects like black hole candidates, neutron stars, pulsars and high mass X-ray binaries. By considering LEG...

The two JEM-X (Joint European X-Ray Monitor) instruments on-board INTEGRAL (International Gamma-Ray Astrophysics Laboratory) will each carry a coded mask in the form of a Hexagonal Uniformly Redundant Array (HURA). The masks will contain around 24247 hexagonal cells, approximately 50% opaque (tungsten) and 50% open, within a circular area of diamet...

Imaging reconstruction methods for coded mask telescopes devoted to studying celestial X and γ ray sources, normally are based on correlation methods, using Fast Fourier Transforms to increase the computational speed In complex telescopes using large arrays these methods are more suitable because they allow the images to be reconstructed quickly. I...

A detailed simulation program of the INTEGRAL Imager has been written and implemented using the GEANT-3 Monte Carlo code. The expected detection efficiency and continuum sensitivity have been evaluated. The results obtained for the CsI configuration of the Imager are compared with those obtained with the new configuration which foresees a top plane...

The Low Energy Gamma Ray Imager (LEGRI) will be one of the three instruments carried by the first MINISAT mission. LEGRI aims to demonstrate the technological feasibility of a new generation of low energy gamma-ray telescopes with imaging, medium resolution spectroscopy and high continuum sensitivity in the 20-200 keV spectral region, based on HgI2...