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The Breakthrough Listen Search for Extraterrestrial IntelligenceJul 11 2019The discovery of the ubiquity of habitable extrasolar planets, combined with revolutionary advances in instrumentation and observational capabilities, have ushered in a renaissance in the millenia-old quest to answer our most profound question about the ... More
Analyses of Scissors Cutting Paper at Superluminal SpeedsJul 10 2019A popular physics legend holds that scissors can cut paper with a speed faster than light. Here this counter-intuitive myth is investigated theoretically using four simple examples of scissors. For simplicity, all cases will involve a static lower scissors ... More
Searching for Extraterrestrial Intelligence by Locating Potential ET Communication Networks in SpaceJul 10 2019There have been periodic efforts in recent decades to search for extraterrestrial intelligence (SETI), especially by trying to find an extraterrestrial (ET) radio signal or other technosignature in space. Yet, no such technosignatures have been found. ... More
Life under Daylight Saving Time regulations: why should we think twice before abolishing DST?Jul 09 2019We analyze large scale (N~10000) time use surveys in United States, Spain, Italy, France and Great Britain to ascertain seasonal variations in the sleep/wake cycle and the labor cycle after daylight saving time -- summer time arrangements -- regulations ... More
All-optical switch and logic gates based on all-dielectric hybrid silicon-Ge2Sb2Te5 metamaterialsJul 09 2019We numerically propose an all-dielectric hybrid metamaterial (MM) to realize all-optical switch and logic gates in shortwave infrared (SWIR) band. Such MM consists of one silicon rod and one Ge2Sb2Te5 (GST) rod pair. Utilizing the transition from amorphous ... More
The sounds of science: a symphony for many instruments and voicesJul 05 2019This paper is a celebration of the frontiers of science. Goodenough, the maestro who transformed energy usage and technology through the invention of the lithium ion battery, opens the programme, reflecting on the ultimate limits of battery technology. ... More
The Scientists' Experience in Participated Science CommunicationJul 05 2019Since 2006 a small group of researchers from the Italian National Institute for Nuclear Physics started to realized one of the first European Researchers' Night in Europe: a one night-event, supported by the European Commission, that falls every last ... More
Pedagogical Materials and Suggestions to Cure Misconceptions Connecting Special and General RelativityJul 04 2019Many professional physicists do not fully understand the implications of the Einstein equivalence principle of general relativity. Consequently, many are unaware of the fact that special relativity is fully capable of handling accelerated reference frames. ... More
The increasing importance of Ashi Waza, in high level competition. (Their Biomechanics, and small changes in the form)Jul 02 2019In this paper we are interested, both: at the description of Biomechanics of the Ashi Waza techniques, with precision of few of them, members of the Japanese, so called, Ko Waza group; and at the biomechanical analysis of the small changes in the applicative ... More
Gamow's Cyclist: A New Look at Relativistic Measurements for a Binocular ObserverJun 26 2019The visualisation of objects moving at relativistic speeds has been a popular topic of study since Special Relativity's inception. While the standard exposition of the theory describes certain shape-changing effects, such as the Lorentz-contraction, it ... More
Pushing Tensor Networks to the LimitJun 24 2019This $Physics$ viewpoint considers recent work by Tilloy and Cirac [Phys. Rev. X 9, 021040 (2019), arXiv:1808.00976]; those authors overcame several past limitations in the generalization of tensor networks to the continuum and proposed a new class of ... More
Modeling Consonance and its Relationships with Temperament, Harmony, and Electronic AmplificationJun 15 2019After briefly revising the concepts of consonance/dissonance, a respective mathematic-computational model is described, based on Helmholtz's consonance theory and also considering the partials intensity. It is then applied to characterize five scale temperaments, ... More
Widening Perspectives: The Intellectual and Social Benefits of Astrobiology, Big History, and the Exploration of SpaceJun 15 2019Astrobiology is the field of science devoted to searching for life elsewhere in the Universe. It is inherently interdisciplinary, integrating results from multiple fields of science, and in this respect has strong synergies with 'big history'. I argue ... More
Catching Gravitational Waves With A Galaxy-sized Net Of PulsarsJun 14 2019Until recently, the only way to observe the Universe was from light received by telescopes. But we are now able to measure gravitational waves, which are ripples in the fabric of the Universe predicted by Albert Einstein. If two very dense objects (like ... More
A quick how-to user-guide to debunking pseudoscientific claimsJun 13 2019Have you ever wondered why we have never heard of psychics and palm readers winning millions of dollars in state or local lotteries or becoming Wall Street wolfs? Neither have I. Yet we are constantly bombarded by tabloid news on how vaccines cause autism ... More
Bosons, Fermions, Spin, Gravity, and the Spin-Statistics ConnectionJun 13 2019Satyendra Nath Bose's attempt to describe the quantum statistical aspects of light consistently in terms of particles, and Einstein's generalisation, lead to the concept of Bosons as a class of quanta obeying `Bose-Einstein statistics'. Their identity ... More
On the physical (im)possibility of lightsabersJun 06 2019In this paper, we use a science fiction theme (i.e. the iconic lightsaber from the Star Wars universe) as a pedagogical tool to introduce aspects of nonlinear electrodynamics due to the quantum vacuum to an audience with an undergraduate physics background. ... More
Acoustics of Margravial Opera House BayreuthMay 31 2019The Margravial Opera House Bayreuth, built between 1745 and 1750, is a well preserved Baroque court theatre designed by Giuseppe Galli Bibiena [1]. It provides an opportunity to experience not only the visual but also the acoustic design of opera theatres ... More
The naval battle of Actium and the myth of the ship-holder: the effect of bathymetryMay 27 2019A myth of antiquity is explained with modern science in the context of an ancient naval battle. A legend was invoked by the admiral Pliny the Elder to explain the defeat of Antony and Cleopatra against Octavian at the naval battle of Actium. A fish, called ... More
How much of the Solar System should we leave as Wilderness?May 24 2019"How much of the Solar System should we reserve as wilderness, off-limits to human development?" We argue that, as a matter of policy, development should be limited to one eighth, with the remainder set aside. We argue that adopting a "1/8 principle" ... More
Analysis of the Indian ASAT test on 27 March 2019May 22 2019On March 27, 2019, India tested its first anti-satellite (ASAT) missile against its own "live" satellite, Microsat-R, launched on 24 January, 2019, as part of "Mission Shakti". The test parameters were chosen with extreme caution to minimize the hazard ... More
Does the evolution of complex life depend on the stellar spectral energy distribution?May 17 2019This paper presents the proportional evolutionary time hypothesis, which posits that the mean time required for the evolution of complex life is a function of stellar mass. The "biological available window" is defined as the region of a stellar spectrum ... More
Measuring Mountains on the MoonMay 15 2019Following a technique of Galileo we compute the height on a mountain on the Moon. It is based on a simple observation that precisely on a half Moon day, the Earth, the Moon, and the Sun form the vertices of a right triangle with the Moon at the 90 degree ... More
Driving upside-down in a circular trackMay 09 2019In this article, we point out an interesting solution for the dynamics of a racecar in a banked circular track with banking angle well over 90o. We call this track configuration an Inverted Track, at which a racecar can drive partially upside-down. We ... More
Persistence of Technosignatures: A Comment on Lingam and LoebMay 08 2019In a recent paper in this journal, Lingam and Loeb (2018) develop an excellent heuristic for searches for biosignatures vs. technosignatures. We consider two ways in which their approach could be extended and sharpened, with focus on durability of technosignatures. ... More
Science Communication a New Frontier of Researcher's JobMay 08 2019In the world of communication, nobody can be out of the fray! Since many years science communication and more in general the ability of a researcher to communicate his/her work to founding agency, policy makers, entrepreneurs and public at large, starts ... More
SETI in Russia, USSR and the post-Soviet space: a century of researchMay 07 2019Studies on extraterrestrial civilisations in Russia date back to the end of the 19th century. The modern period of SETI studies began in the USSR in the early 1960s. The first edition of the I.S. Shklovsky's book {\it Universe, Life, Intelligence} published ... More
Construction of a Model of the Solar System with Temperature Control for Visually Impaired StudentsApr 24 2019In this work, we present a study carried out to develop a didactic kit based on the use of touch and thermal receivers for the teaching of Astronomy. The proposal arose in the face of the difficulties encountered in the search for experiments capable ... More
Physics of rowing oarsApr 11 2019In each rowing sport, the oars have their very own characteristics most of the time selected through a long time experience. Here we address experimentally and theoretically the problem of rowing efficiency as function of row lengths and blades sizes. ... More
Oumuamua and Scout ET ProbesApr 09 2019Numerous advantages may accrue to ET from the use of probes for the conveyance of information relative to the alternative of beaming information electromagnetically from its home star system. However, probes would benefit from a trans-galactic communications ... More
Ensuring Uninterrupted Power Supply to Lunar Installations Through an Organic Rankine CycleApr 08 2019Apr 12 2019We propose using the temperature gradients between the Moon's surface and the soil at a certain depth to power an Organic Rankine Cycle that could supply a permanent installation, particularly at night, when solar power is not available. Our theoretical ... More
Ensuring Uninterrupted Power Supply to Lunar Installations Through an Organic Rankine CycleApr 08 2019We propose using the temperature gradients between the Moon's surface and the soil at a certain depth to power an Organic Rankine Cycle that could supply a permanent installation, particularly at night, when solar power is not available. Our theoretical ... More
Does it Swing? Microtiming Deviations and Swing Feeling in JazzApr 06 2019Jazz music that swings has the fascinating power to elicit a pleasant sensation of flow in listeners and the desire to synchronize body movements with the music. Whether microtiming deviations (MTDs), i.e. small timing deviations below the bar or phrase ... More
"Black holes ain't so black": An introduction to the great discoveries of Stephen HawkingApr 02 2019Between 1974 and 1975, Stephen Hawking revolutionized the world of physics by proposing that black holes have temperature, entropy, and evaporate gradually. The objective of this article is to offer a brief and updated introduction to these three remarkable ... More
Human Mars Mission Architecture -- Plan to Settle the Red Planet with 1000 PeopleApr 02 2019Exploration is one of the attentive endeavor to mankind and a strategy for evolution. We have been incessantly reconnoitering our planet and universe from Mesopotamian era to modern era. The progression of rocketry and planetary science in past century ... More
Introduction to Regge Calculus for GravitationApr 01 2019With the theory of general relativity, Einstein abolished the interpretation of gravitation as a force and associated it to the curvature of spacetime. Tensorial calculus and differential geometry are the mathematical resources necessary to study the ... More
Advanced Aspects of the Galactic HabitabilityApr 01 2019Apr 14 2019Context. Astrobiological evolution of the Milky Way (or the shape of its "astrobiological landscape") has emerged as one of the key research topics in recent years. In order to build precise, quantitative models of the Galactic habitability, we need to ... More
Advanced Aspects of the Galactic HabitabilityApr 01 2019Context. Astrobiological evolution of the Milky Way (or the shape of its "astrobiological landscape") has emerged as one of the key research topics in recent years. In order to build precise, quantitative models of the Galactic habitability, we need to ... More
Possibility of a coordinated signaling scheme in the Galaxy and SETI experimentsApr 01 2019We discuss a Galaxy-wide coordinated signaling scheme with which a SETI observer needs to examine a tiny fraction of the sky. The target sky direction is determined as a function of time, based on high-precision measurements of a progenitor of a conspicuous ... More
Forecasting Future Murders of Mr. Boddy by Numerical Weather PredictionMar 29 2019Despite a previous description of his state as a stable fixed point, just past midnight this morning Mr. Boddy was murdered again. In fact, over 70 years Mr. Boddy has been reported murdered $10^6$ times, while there exist no documented attempts at intervention. ... More
Worlds in MigrationMar 29 2019In this paper we discuss an alternative track for migration that can explain the existence of Hot Jupiters observed in close orbits around their stars based on a novel interpretation of established work. We also discuss the population of sub-Earth rogue ... More
The Long Night: Modeling the Climate of WesterosMar 28 2019Many previous authors have attempted to find explanations for Westeros's climate, characterized by a generally moderate, Earth-like climate punctuated by extremely long and cold winters, separated by thousands of years. One explanation that has been proposed ... More
Solving the Fermi paradox without assumptionsMar 27 2019This paper suggests that a universal solution to the Fermi paradox exists and can be derived directly from the definition of life and/or intelligence, therefore eliminating the need for any questionable assumptions and even for the anthropic principle. ... More
A non-invasive investigation of Egyptian faience using a long wavelength optical coherence tomography (OCT) at 2umMar 25 2019Egyptian faience is a non-clay ceramic semi-transparent material, formed of a quartz core and alkali lime glaze with some cases exhibiting an interaction layer between them. Several possible glazing methods have been identified. Previous investigations ... More
Looking for LurkersMar 22 2019A recently discovered group of nearby co-orbital objects is an attractive location for extraterrestrial intelligence (ETI) to locate a probe to observe Earth while not being easily seen. These near-Earth objects provide an ideal way to watch our world ... More
A Brief history of mangnetismMar 17 2019In this article an overview of the historical development of the key ideas in the field of magnetism is presented. The presentation is semi-technical in nature.Starting by noting down important contribution of Greeks, William Gilbert, Coulomb, Poisson, ... More
Markov-chain-inspired search for MH370Mar 14 2019Markov-chain models are constructed for the probabilistic description of the drift of marine debris from Malaysian Airlines flight MH370. En route from Kuala Lumpur to Beijing, the MH370 mysteriously disappeared in the southeastern Indian Ocean on 8 March ... More
A Shiny New Method for SETI: Specular Reflections from Interplanetary ArtifactsMar 14 2019Glints of light from specular reflection of the Sun are a technosignature of artificial satellites. If extraterrestrial intelligences have left artifacts in the Solar System, these may include flat mirror-like surfaces that also can glint. I describe ... More
Searching for Technosignatures: Implications of Detection and Non-DetectionMar 14 2019The search for technosignatures from the Galaxy or the nearby universe raises two main questions: What are the possible characteristics of technosignatures? and How can future searches be optimized to enhance the probability of detection? Addressing these ... More
Vacuum balloon - a 350-year-old dreamMar 12 2019The centuries-old idea of a lighter-than-air vacuum balloon has not materialized yet as such structure needs to be both light enough to float in the air and strong enough to withstand atmospheric pressure. We propose a design of a rigid spherical sandwich ... More
"Perché il mare è blu?": una rivisitazione in chiave pedagogica ("Why is the sea blue": a pedagogical review)Mar 09 2019Popularized explanations of the color of the sea often prove to be incomplete or oversimplified, and hence inadequate to become acquainted with the phenomenon in its whole. In this paper, after a historical review of the investigations on the subject ... More
Banjo Ring from Stretching String: A Zero Break Angle DemoMar 07 2019A novel bridge and tailpiece design allows direct comparison of the sound of zero break angle with same banjo (and all its parts) configured to have an angle of 13 degrees. This lends additional support to the 2014 proposal that a key element in banjo ... More
Machine learning meets quantum physicsMar 04 2019The marriage of machine learning and quantum physics may give birth to a new research frontier that could transform both.
Indigenous use of stellar scintillation to predict weather and seasonal changeMar 04 2019Indigenous peoples across the world observe the motions and positions of stars to develop seasonal calendars. Additionally, changing properties of stars, such as their brightness and colour, are also used for predicting weather. Combining archival studies ... More
Predator-Prey Behaviour in Self-Replicating Interstellar ProbesMar 02 2019The concept of a rapid spread of self-replicating interstellar probes (SRPs) throughout the Milky Way adds considerable strength to Fermi's Paradox. A single civilisation creating a single SRP is sufficient for a fleet of SRPs to grow and explore the ... More
Mars Missions Failure Report Assortment : Review and ConspectusMar 01 2019Mars has been successfully explored by various space firms. Globally, 44 mission attempts were made and lamentably 27 encountered ineffective. There have been instances where a small misstep in the progressive accomplishment of spaceflight sequence may ... More
Influence of Hockey Tape on Speed, Rotation and Energy of ShotsFeb 20 2019Parameters of a shot of an ice hockey player are mostly determined by the capabilities of the player itself and the stick that is used. However, every hockey player uses also hockey tape for an adjustment of the stick blade to get better skills in shooting, ... More
Comment on 'The aestivation hypothesis for resolving Fermi's paradox'Feb 18 2019In their article [arXiv:1705.03394], 'That is not dead which can eternal lie: the aestivation hypothesis for resolving Fermi's paradox', Sandberg et al. try to explain the Fermi paradox (we see no aliens) by claiming that Landauer's principle implies ... More
The Fermi Paradox and the Aurora Effect: Exo-civilization Settlement, Expansion and Steady StatesFeb 12 2019We model the settlement of the galaxy by space-faring civilizations in order to address issues related to the Fermi Paradox. We explore the problem in a way that avoids assumptions about the intent and motivation of any exo-civilization seeking to settle ... More
Comment to Impact of Daylight Saving Time on circadian timing system: An expert statementFeb 11 2019Mar 06 20191000 words comment on a paper published in the European Journal of Internal Medicine by a panel of experts. My point is authors address the magnitude of the change (one hour) but fail to consider in any way its seasonal features. DST is not a random change ... More
Introduction: Detectability of Future EarthFeb 11 2019Earth's future detectability depends upon the trajectory of our civilization over the coming centuries. Human civilization is also the only known example of an energy-intensive civilization, so our history and future trajectories provide the basis for ... More
Calendrical Interpretation of Spirals in Irish Megalithic ArtFeb 11 2019The tumuli of Newgrange and Knowth in Ireland are among the most monumental heritages of the Neolithic era. The megalithic constructions date back to around 3'200 BC, centuries before the completion of Stonehenge and the Egyptian pyramids. Passageways ... More
Is The Starry Night Turbulent?Feb 09 2019Vincent van Gogh's painting, The Starry Night, is an iconic piece of art and cultural history. The painting portrays a night sky full of stars, with eddies (spirals) both large and small. \cite{Kolmogorov1941}'s description of subsonic, incompressible ... More
Is The Starry Night Turbulent?Feb 09 2019Feb 15 2019Vincent van Gogh's painting, The Starry Night, is an iconic piece of art and cultural history. The painting portrays a night sky full of stars, with eddies (spirals) both large and small. \cite{Kolmogorov1941}'s description of subsonic, incompressible ... More
Magnetic Shielding for Interplanetary TravelFeb 03 2019A proposed design for radiation shielding in interplanetary travel is presented with primary shielding created by a superconducting split toroid magnetic field and unconfined magnetic fields created by two deployable superconducting loops. The split toroid's ... More
The Roman Colonia Marciana Ulpia Traiana Thamugadi (Timgad) and Trajan's BirthdayFeb 01 2019It is told that the Roman Colonia Marciana Ulpia Traiana Thamugadi, that is Timgad in Algeria, had been oriented to the sunrise on the day of Trajan's birthday, that is 18 September 100 AD. Here we use software CalSKY to investigate the sunrise azimuth ... More
Top SciComm: Communicating ATLAS Top Physics Results to the PublicJan 31 2019An essential component of the long-term success of scientific research is communicating the methodology and significance of new results to the wider public. Utilising various social media platforms is a vital tool for this endeavour. Over the years, there ... More
Numerical constraints on the size of generation ships from total energy expenditure on board, annual food production and space farming techniquesJan 28 2019In the first papers of our series on interstellar generation ships we have demonstrated that the numerical code HERITAGE is able to calculate the success rate of multi-generational space missions. Thanks to the social and breeding constraints we examined, ... More
Simplifying the vacuum bazookaJan 17 2019Mar 19 2019This paper provides a simplified explanation of the vacuum bazooka through diagrams and builds a theoretical model only using concepts found in introductory mechanics. Our theory suggests that the velocity of the projectile is proportional to the hyperbolic ... More
Simplifying the vacuum bazookaJan 17 2019This paper provides a simplified explanation of the vacuum bazooka through diagrams and builds a theoretical model only using concepts found in introductory mechanics. Our theory suggests that the velocity of the projectile is proportional to the hyperbolic ... More
Women in Physics: Scissors Effect from the Brazilian Olympiad of Physics to Professional LifeJan 16 2019Despite the legislation in force in most countries and the discourse on gender equality, the observed reality, still today, shows a clear picture of inequality and restrictions for women, particularly when the issue is the choice of a career and the subsequent ... More
Going back to the roots: how to create stroboscopic photos from digital videosJan 15 2019We show here how to create from digital films using the well-known software Tracker stroboscopic photos in order to analyze different types of movements. The advantage of this procedure is that it is possible to analyze the printed photo or on a computer ... More
A dynamical model of remote-control model carsJan 15 2019Simple experiments for which differential equations cannot be solved analytically can be addressed using an effective model that satisfactorily reproduces the experimental data. In this work, the one-dimensional kinematics of a remote-control model (toy) ... More
A search for technosignatures from TRAPPIST-1, LHS 1140, and 10 planetary systems in the Kepler field with the Green Bank Telescope at 1.15-1.73 GHzJan 13 2019As part of our ongoing search for technosignatures, we collected over three terabytes of data in May 2017 with the L-band receiver (1.15-1.73 GHz) of the 100 m diameter Green Bank Telescope. These observations focused primarily on planetary systems in ... More
A Critical Review on the Assumptions of SETIJan 11 2019The Search for Extraterrestrial Intelligence (SETI) makes certain assumptions which guide all current search programs. To illustrate some, this includes (1) that interstellar flight is not possible (2) that the motivations of interstellar cultures are ... More
Interstellar Probes: The Benefits to Astronomy & AstrophysicsJan 11 2019Long range observations in the field of astronomy have opened up our understanding of the Solar System, the Galaxy and the wider Universe. In this paper we discuss the idea of direct in-situ reconnaissance of nearby stellar systems, using robotic probes. ... More
Why planetary and exoplanetary protection differ: The case of long duration Genesis missions to habitable but sterile M-dwarf oxygen planetsJan 08 2019Time is arguably the key limiting factor for interstellar exploration. At high speeds, flyby missions to nearby stars by laser propelled wafersats taking 50-100 years would be feasible. Directed energy launch systems could accelerate on the other side ... More
Black holes and quantum entanglementJan 02 2019The black hole information paradox is a contradiction between fundamental principles which has puzzled physicists for over forty years. The crux of the problem lies in an assumption about the structure of entanglement across the event horizon, namely, ... More
Julia Augusta Taurinorum, an archaeoastronomical reloadDec 30 2018Discussion of the astronomical orientation of Turin as Julia Augusta Taurinorum, based on the results previously given in 2012 and available at arXiv:1206.6062, and here refined according to the natural horizon.
Julia Augusta Taurinorum, an archaeoastronomical reloadDec 30 2018May 27 2019Discussion of the astronomical orientation of Turin as Julia Augusta Taurinorum, based on the results previously given in 2012 and available at arXiv:1206.6062, and here refined according to the natural horizon, the refraction of atmosphere, and the use ... More
On times and shadows: the observational analemmaDec 27 2018The observation that the shadows of objects change during the course of the day and also for a fixed time during a year led curious minds to realize that the Sun could be used as a timekeeper. However, the daily motion of the Sun has some subtleties, ... More
Scanning for time: Science and art on a photocopierDec 22 2018Combine the scanning properties of a common office photocopier with an object in motion to create stunning imagery. Produce a scan or hard copy that records the artifact of two motions, the moving object and the moving photocopier scan bar. Images illustrate ... More
Programming Curvature using Origami TessellationsDec 21 2018Origami describes rules for creating folded structures from patterns on a flat sheet, but does not prescribe how patterns can be designed to fit target shapes. Here, starting from the simplest periodic origami pattern that yields one degree-of-freedom ... More
Super-resolution imaging within reachDec 14 2018Dec 18 2018Although several optical techniques have been recently developed in order to overcome the resolution limit in microscopy, the imaging of sub-wavelength features is still a real challenge. In practise, super-resolution techniques remain difficult to build ... More
Descartes-Newton-Young rainbowNov 29 2018We discuss three rainbow theories created by Descartes, Newton and Young. The note is written primary for school students.
Le onde gravitazionali nella fisica modernaNov 24 2018A brief introduction to gravitational waves, addressing those questions that nowadays more and more frequently arise within a large audience (not only of insiders): what is a gravity wave, how can it be detected and, above all, what impact on modern physical ... More
Six Strange Facts About`OumuamuaNov 21 2018Nov 22 2018`Oumuamua is nothing like we expected or seen before in the Solar System.
The black hole fifty years after: Genesis of the nameNov 15 2018Black holes are extreme spacetime deformations where even light is imprisoned. There is an extensive astrophysical evidence for the real and abundant existence of these prisons of matter and light in the Universe. Mathematically, black holes are described ... More
Artificial Intelligence for Interstellar TravelNov 15 2018Nov 19 2018The large distances involved in interstellar travel require a high degree of spacecraft autonomy, realized by artificial intelligence. The breadth of tasks artificial intelligence could perform on such spacecraft involves maintenance, data collection, ... More
Clearing certain misconception in the common explanations of the aerodynamic liftOct 26 2018Air travel has become one of the most common means of transportation. The most common question which is generally asked is: How does an airplane gain lift? And the most common answer is via the Bernoulli principle. It turns out that it is wrongly applied ... More
The unsustainable legacy of the Nuclear AgeOct 23 2018It is seldom acknowledged the tremendous burden that the Nuclear Age leaves on future generations, and the environment, for an extremely long time. Nuclear processes, and products, are activated at energies millions of times higher than the energies of ... More
Algol as Horus in the Cairo Calendar: the possible means and the motives of the observationsOct 05 2018An ancient Egyptian Calendar of Lucky and Unlucky Days, the Cairo Calendar (CC), assigns luck with the period of 2.850 days. Previous astronomical, astrophysical and statistical analyses of CC support the idea that this was the period of the eclipsing ... More
Exploring the Kuiper Belt with Sun-diving Solar SailsSep 30 2018We discuss a possibility to survey many Kuiper Belt Objects (KBO) with a single launch using a few smallscale spacecraft, each equipped with solar sails, which could be unfurled from a single interplanetary bus at the perihelion of that craft's solar ... More
Recommendations from the Ad Hoc Committee on SETI NomenclatureSep 18 2018The Ad Hoc Committee on SETI Nomenclature was convened at the suggestion of Frank Drake after the Decoding Alien Intelligence Workshop at the SETI Institute in March 2018. The purpose of the committee was to recommend standardized definitions for terms, ... More
Snellius meets Schwarzschild - Refraction of brachistochrones and time-like geodesicsSep 02 2018The brachistochrone problem can be solved either by variational calculus or by a skillful application of the Snellius' law of refraction. This suggests the question whether also other variational problems can be solved by an analogue of the refraction ... More
Limitations of Chemical Propulsion for Interstellar Escape from Habitable Zones around Low-Mass StarsAug 24 2018Aug 29 2018The habitable zones of low-mass stars are characterized by escape speeds that can be a few times higher than the Earth's orbit around the Sun. Owing to the exponential dependence of the required fuel mass on the terminal speed for chemical rockets, interstellar ... More
A Novel Entry, Descent and Landing Architecture for Mars LandersAug 23 2018Sep 10 2018Landing robotic spacecrafts and humans on the surface of Mars has become one of the inevitable technological necessity for humans. To accomplish this intention, we need to land enormous number of cargoes, crewed modules, return vehicles and scientific ... More
Effects of exoplanetary gravity on human locomotor abilityAug 22 2018At some point in the future, if mankind hopes to settle planets outside the Solar System, it will be crucial to determine the range of planetary conditions under which human beings could survive and function. In this article, we apply physical considerations ... More
The Hawking temperature, the uncertainty principle and quantum black holesAug 14 2018In 1974, Stephen Hawking theoretically discovered that black holes emit thermal radiation and have a characteristic temperature, known as the Hawking temperature. The aim of this paper is to present a simple heuristic derivation of the Hawking temperature, ... More
Tetraquarks and pentaquarksAug 13 2018Greig Cowan and Tim Gershon describe new types of matter called tetraquarks and pentaquarks, and discuss the outlook for understanding these particles.