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arXiv2022

Beyond the Blue Sky of Multimodal Interaction: A Centennial Vision of Interplanetary Virtual Spaces in Turn-based Metaverse

Human habitation across multiple planets requires communication and social connection between planets. When the infrastructure of a deep space network becomes mature, immersive cyberspace, known as the Metaverse, can exchange diversified user data and host multitudinous virtual worlds. Nevertheless, such immersive cyberspace unavoidably encounters latency in minutes, and thus operates in a turn-taking manner. This Blue Sky paper illustrates a vision of an interplanetary Metaverse that connects Earthian and Martian users in a turn-based Metaverse. Accordingly, we briefly discuss several grand challenges to catalyze research initiatives for the `Digital Big Bang' on Mars.

cs.HC↗
arXiv2022

Evidencing the interaction between science fiction enthusiasm and career aspirations in the UK astronomy community

The anecdotal connection between an interest in science fiction and career aspirations in astrophysics is well established. However strong statistical evidence for such a connection, and a quantitative assessment of its prevalence, has been missing. Here I report the results of two surveys examining the connection between science fiction enthusiasm and astronomical careers - first a case study of the University of Warwick Astronomy and Astrophysics group, carried out in February 2021, and second a larger survey of attendees at the UK National Astronomy Meeting in July 2022. In both surveys, a significant majority of respondents expressed an interest in science fiction. In the larger survey, 93% of UK astronomers (223 of 239 respondents) expressed an interest in science fiction, while 69% (164) stated that it had influenced their life or career choices. This study provides strong statistical evidence for the role of science fiction in influencing the adoption of astronomical careers.

astro-ph.IM↗
arXiv2022

A causal limit to communication within an expanding cosmological civilization

If a civilization embarks on high-speed intergalactic expansion, growing to a cosmological scale over time, communication between remote galaxies in the civilization will incur an extreme time delay, due to the distance involved. Indeed, if the net expansion speed v is more than .26c, most of the final volume of such a civilization will not be able to signal the home galaxy at all, due to the presence of a causal horizon. We illustrate the regions of such a civilization according to the degree of "conversation" that is possible with the home galaxy, and describe how the geometry depends on expansion speed. We conclude by reflecting on the value of space settlement beyond the horizon, where colonies can never be observed by the initiating home galaxy.

physics.pop-ph↗
arXiv2022

Unidentified aerial phenomena I. Observations of events

NASA commissioned a research team to study Unidentified Aerial Phenomena (UAP), observations of events that cannot scientifically be identified as known natural phenomena. The Main Astronomical Observatory of NAS of Ukraine conducts an independent study of UAP also. For UAP observations, we used two meteor stations. Observations were performed with colour video cameras in the daytime sky. We have developed a special observation technique, for detecting and evaluating UAP characteristics. According to our data, there are two types of UAP, which we conventionally call: (1) Cosmics, and (2) Phantoms. We note that Cosmics are luminous objects, brighter than the background of the sky. Phantoms are dark objects, with contrast from several to about 50 per cent. We observe a significant number of objects whose nature is not clear. Flights of single, group and squadrons of the ships were detected, moving at speeds from 3 to 15 degrees per second. Some bright objects exhibit regular brightness variability in the range of 10 - 20 Hz. We use colourimetry methods to determine of distance to objects and evaluate their colour characteristics. Objects RGB colours of the Adobe colour system had converted to the Johnson BVR astronomical colour system using the colour corrections. Phantom shows the colour characteristics inherent in an object with zero albedos. It is a completely black body that does not emit and absorbs all the radiation falling on it. We see an object because it shields radiation due to Rayleigh scattering. An object contrast makes it possible to estimate the distance using colourimetric methods. Phantoms are observed in the troposphere at distances up to 10 - 12 km. We estimate their size from 3 to 12 meters and speeds up to 15 km/s.

astro-ph.IM↗
arXiv2022

Planetary Structure & Dynamic in Science Fiction. Scientific Analysis & Review of Interstellar [UCM Bachelor Thesis, 2015]

Christopher Nolan's latest blockbuster, Interstellar, has supposed a revolution not only from a cinematographically viewpoint, but also in the relation between current spectators and science. The aim of this report is to analyze some features presented in Interstellar. Basic Newtonian Physics shows how a planet orbiting a supermassive black hole like Gargantua must travel at 0.25 the speed of light in order to be in a stable orbit. Thus, this orbit is too far from the black hole to explain the time dilatation observed in Miller's Planet and an the orbit that could explain such a time dilatation is much more smaller that Roche's limit. Furthermore, I explain how enormous waves as Miller's Planet ones could appear by studying the tidal potential created by Gargantua, obtaining a wave of 200 kilometers high, but better results are obtained by considering a series of tsunamis in Miller's Planet. Finally, I present an explanation to Mann's Planet ice-covered landscape in which Snowball Earth Theory plays a fundamental role. No difficult General Relativity formulas will be used in order to make easier the comprehension of the research. Supervisors: M. L. Osete & J. Gorgas

physics.pop-ph↗
arXiv2022

Overview of the Galileo Project

The Galileo Project is the first systematic scientific research program in search for potential astro8 archaeological artifacts or remnants of extraterrestrial technological civilizations (ETCs) or potentially active equipment near Earth. Taking a path not taken, it conceivably may pick some low-hanging fruit, and without asserting probabilities -- make discoveries of ETC-related objects, which would have far-reaching implications for science and our worldview.

physics.pop-ph↗
arXiv2022

Malicious aliens and why Caballero's estimates about them should be rejected

In a paper by Alberto Caballero, a methodology is stated for estimating the probability of an exoplanet alien civilization having malicious intentions toward the human civilization after being messaged by it and estimating the number of malicious exoplanet civilizations in the Milky Way. Caballero states his paper attempts to provide these estimates. Caballero's methodology uses questionable hypotheses and excludes important parameters, indicating his methodology and estimates should be rejected.

physics.soc-ph↗
arXiv2022

How to delay death and look further into the future if you fall into a black hole

In this note, we present a pedagogical illustration of peculiar properties of motion in the vicinity and inside black holes. We discuss how a momentary impulse can modify the lifetime of an object radially falling into a Schwarzschild black hole down to singularity. The well known upper limit for a proper time spent within a horizon, in fact, requires an infinitely powerful kick. We calculate the proper time interval (perceived as personal lifetime of a falling observer) till the contact with the singularity, as well as the time interval in the Lemaître frame (which reflects how far into the future of the outer world a falling observer can look), for different values of the kick received by the falling body. We discuss the ideal strategy to increase both time intervals by the engine with a finite power. This example is suitable for university seminars for undergraduate students specializing in General Relativity and related astrophysical subjects.

physics.pop-ph↗
arXiv2022

Requisites on viscoelasticity for exceptional points in passive elastodynamic metamaterials

The recent progress of non-Hermitian physics and the notion of exceptional point (EP) degeneracies in elastodynamics has led to the development of novel metamaterials for the control of elastic wave propagation, hypersensitive sensors, and actuators. The emergence of EPs in a Parity-Time symmetric system relies on judiciously engineered balanced gain and loss mechanisms. Creating gain requires complex circuits and amplification mechanisms, making engineering applications challenging. Here, we report strategies to achieve EPs in passive non-Hermitian elastodynamic systems with differential loss derived from viscoelastic materials. We compare different viscoelastic material models and show that the EP emerges only when the frequency-dependent loss-tangent of the viscoelastic material remains nearly constant in the frequency range of operation. Such type of loss tangent occurs in materials that undergo stress-relaxation over a broad spectrum of relaxation times, for example, materials that follow the Kelvin-Voigt fractional derivative (KVFD) model. Using dynamic mechanical analysis, we show that a few common viscoelastic elastomers such as Polydimethylsiloxane (PDMS) and polyurethane rubber follow the KVFD behavior such that the loss tangent becomes almost constant after a particular frequency. The material models we present and the demonstration of the potential of a widely available material system in creating EPs pave the way for developing non-Hermitian metamaterials with hypersensitivity to perturbations or enhanced emissivity.

physics.app-ph↗
arXiv2022

Preserving the Sun from the Cold by a Perfectly Reflecting Dyson Sphere

Some entities, such as humans, survive longest if their environment is neither too hot nor too cold, and the sun is no exception. It is rather obvious that if the sun were enclosed inside a thermally conducting sphere surrounded by a heat bath kept much hotter than the present central temperature of the sun, its nuclear burning would occur faster, so that the sun would last for a shorter time. It is less obvious that if the sun were surrounded by a perfectly reflecting sphere to prevent its radiation from escaping to cold empty space, it could actually last longer. Here I shall show that this is the case for such a sphere at least somewhat larger than the present solar radius. This naively paradoxical result is a consequence of the negative specific heat of many gravitating systems, so as the energy emitted by the sun is reflected back to increase the thermal energy, the sun expands and its central temperature goes down rather than up and reduces the nuclear burning rate, so that the sun can last much longer than five billion years, for a lifetime growing roughly exponentially with the cube root of the radius of the perfectly reflecting sphere.

physics.gen-ph↗
arXiv2022

Constraints on extragalactic transmitters via Breakthrough Listen

The Breakthrough Listen Initiative has embarked on a comprehensive SETI survey of nearby stars in the Milky Way that is vastly superior to previous efforts as measured by a wide range of different metrics. SETI surveys traditionally ignore the fact that they are sensitive to many background objects, in addition to the foreground target star. In order to better appreciate and exploit the presence of extragalactic objects in the field of view, the Aladin sky atlas and NED were employed to make a rudimentary census of extragalactic objects that were serendipitously observed with the 100-m Greenbank telescope observing at 1.1-1.9 GHz. For 469 target fields (assuming a FWHM radial field-of-view of 4.2 arcminutes), NED identified a grand total of 143024 extragalactic objects, including various astrophysical exotica e.g. AGN of various types, radio galaxies, interacting galaxies, and one confirmed gravitational lens system. Several nearby galaxies, galaxy groups and galaxy clusters are identified, permitting the parameter space probed by SETI surveys to be significantly extended. Constraints are placed on the luminosity function of potential extraterrestrial transmitters assuming it follows a simple power law and limits on the prevalence of very powerful extraterrestrial transmitters associated with these vast stellar systems are also determined. It is demonstrated that the recent Breakthrough Listen Initiative, and indeed many previous SETI radio surveys, place stronger limits on the prevalence of extraterrestrial intelligence in the distant Universe than is often fully appreciated.

astro-ph.HE↗
arXiv2022

Opportunities for Technosignature Science in the Planetary Science and Astrobiology Decadal Survey

Solar system exploration provides numerous possibilities for advancing technosignature science. The search for life in the solar system includes missions designed to search for evidence of biosignatures on other planetary bodies, but many missions could also attempt to search for and constrain the presence of technology within the solar system. Technosignatures and biosignatures represent complementary approaches toward searching for evidence of life in our solar neighborhood, and beyond. This report summarizes the potential technosignature opportunities within ongoing solar system exploration and the recommendations of the "Origins, Worlds, and Life" Planetary Science and Astrobiology Decadal Survey. We discuss opportunities for constraining the prevalence of technosignatures within the solar system using current or future missions at negligible additional cost, and we present a preliminary assessment of gaps that may exist in the search for technosignatures within the solar system.

astro-ph.IM↗
arXiv2022

Hello Quantum World! A rigorous but accessible first-year university course in quantum information science

Addressing workforce shortages within the Quantum Information Science and Engineering (QISE) community requires attracting and retaining students from diverse backgrounds early on in their undergraduate education. Here, we describe a course we developed called Hello Quantum World! that introduces a broad range of fundamental quantum information and computation concepts in a rigorous way but without requiring any knowledge of mathematics beyond high-school algebra nor any prior knowledge of quantum mechanics. Some of the topics covered include superposition, entanglement, quantum gates, teleportation, quantum algorithms, and quantum error correction. The course is designed for first-year undergraduate students, both those pursuing a degree in QISE and those who are seeking to be `quantum-aware'.

physics.ed-ph↗
arXiv2022

Using Physics Simulations to Find Targeting Strategies in Competitive Bowling

This article demonstrates a new approach to finding ideal bowling targeting strategies through computer simulation. To model bowling ball behaviour, a system of five coupled differential equations is derived using Euler equations for rigid body rotations. We used a computer program to demonstrate the phases of ball motion and output a plot that displays the optimum initial conditions that can lead to a strike. When the bowler is modeled to be imperfect, it is shown that some targeting strategies can lead to higher strike rates due to the miss room created by the inhomogeneity of the oil pattern.

physics.pop-ph↗
arXiv2022

Exploration of M31 via Black-Hole Slingshots and the "Intergalactic Imperative"

I show that a gravitational slingshot using a stellar-mass black hole (BH) orbiting SgrA* could launch robotic spacecraft toward M31 at $0.1\,c$, a speed that is ultimately limited by the tensile strength of steel and the BH mass, here conservatively estimated as $m_{\rm bh}=5\,M_\odot$. The BH encounter must be accurate to $\lesssim 1\,$km, despite the fact that the BH is dark. Navigation guided by gravitational microlensing can easily achieve this. Deceleration into M31 would rely on a similar engagement (but in reverse) with an orbiting BH near the M31 center. Similarly for a return trip, if necessary. Colonization of M31 planets on 50 Myr timescales is therefore feasible provided that reconstruction of humans, trans-humans, or androids from digital data becomes feasible in the next few Myr. The implications for Fermi's Paradox (FP) are discussed. FP is restated in a more challenging form. The possibility of intergalactic colonization on timescales much shorter than the age of Earth significantly tightens FP. It can thereby impact our approach to astrobiology on few-decade timescales. I suggest using a network of tight white-dwarf-binary "hubs" as the backbone of a $0.002\,c$ intra-Galactic transport system, which would enable complete exploration of the Milky Way (hence full measurement of all non-zero terms in the Drake equation) on 10 Myr timescales. Such a survey would reveal the reality and/or severity of an "intergalactic imperative".

physics.pop-ph↗
arXiv2024

Names from Greek Myth in Fundamental Physics

Greek mythology supplies fundamental physics with the names of numerous (100+) experiments, machines, codes, and phenomena. I present the central narrative of Greek mythos via these names. Hyperlinks are provided for their physics counterparts, and the names are collected in myth- and physics-themed indices.

physics.pop-ph↗