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Search indexed arXiv papers on artificial intelligence, large language models, computer vision and robotics. Read source abstracts and follow links to arXiv.

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At least 721 records · Page 40Linked to original sources
arXiv2023

Autonomous Restructuring of Asteroids into Rotating Space Stations

Asteroid restructuring uses robotics, self replication, and mechanical automatons to autonomously restructure an asteroid into a large rotating space station. The restructuring process makes structures from asteroid oxide materials; uses productive self-replication to make replicators, helpers, and products; and creates a multiple floor station to support a large population. In an example simulation, it takes 12 years to autonomously restructure a large asteroid into the space station. This is accomplished with a single rocket launch. The single payload contains a base station, 4 robots (spiders), and a modest set of supplies. Our simulation creates 3000 spiders and over 23,500 other pieces of equipment. Only the base station and spiders (replicators) have advanced microprocessors and algorithms. These represent 21st century technologies created and trans-ported from Earth. The equipment and tools are built using in-situ materials and represent 18th or 19th century technologies. The equipment and tools (helpers) have simple mechanical programs to perform repetitive tasks. The resulting example station would be a rotating framework almost 5 kilometers in diameter. Once completed, it could support a population of over 700,000 people. Many researchers identify the high launch costs, the harsh space environment, and the lack of gravity as the key obstacles hindering the development of space stations. The single probe addresses the high launch cost. The autonomous construction eliminates the harsh space environment for construction crews. The completed rotating station provides radiation protection and centripetal gravity for the first work crews and colonists.

physics.pop-ph↗
arXiv2023

The swinging counterweight trebuchet. On scaling and optimization

The swinging counterweight trebuchet was at its full blossom in the Late Middle Ages an artillery piece of great importance that could destroy the defenses of castles under siege by bombardment with stones from considerable distances. The exact dimensions of these engines are unfortunately unknown, but would have been valuable for an assessment of the true significance of the weapon. Presumed dimensions derived from interpreted historical accounts must be tested and examined critically. This has been done by full-scale experimental reconstructions or by~\textit{ad hoc} theoretical estimates. A more systematic approach is made possible by the present theory, which is based on a mathematical quality function for the trebuchet. This function can be maximized and the maximizing design parameters are by definition the optimal parameters. A simple analytical expression for these optimal parameters is given.

physics.class-ph↗
arXiv2023

Opinion | Think Physics, Think Man: Barrier's to Women's Participation in Physics Education

An analysis of barriers to women's participation in physics education is presented. It is expected that in undergraduate physics the most common situation for a women is that she is cisgender and one of a numerical minority in the classroom. The effects of other intersectional identities are not considered. The analysis is based on evidence from the author's lived experience as a transgender woman who transitioned as an undergraduate and on evidence from the literature on the effects of gender differences in academic disciplines. It is expected that the teaching philosophy and practice in physics classrooms favours men over women and these gender dynamics are partially responsible for the under-representation of women in physics. These expectations require further research to be substantiated.

physics.ed-ph↗
arXiv2023

Interstellar Objects From Broken Dyson Spheres

Without extensive maintenance, Dyson spheres inevitably disintegrate by asteroid impacts over billions of years. The resulting fragments would appear as anomalous interstellar objects, potentially sharing the unusual shape and motion of 1I/Oumuamua or the unusual material strength of the first two interstellar meteors, IM1 and IM2. If the Dyson sphere tiles are light sails, the number of fragments could exceed that of interstellar asteroids because of their reduced escape speed from the star and the increase in stellar luminosity during the red giant phase.

physics.pop-ph↗
arXiv2023

Physics Breakthrough Disproves Fundamental Assumptions of the Chicago School

Classical law and economics is foundational to the American legal system. Centered at the University of Chicago, its assumptions, most especially that humans act both rationally and selfishly, informs the thinking of legislatures, judges, and government lawyers, and has shaped nearly every aspect of the way commercial transactions are conducted. But what if the Chicago School, as I refer to this line of thinking, is wrong? Alternative approaches such as behavioral law and economics or law and political economy contend that human decisionmaking is based on emotions or should not be regulated as a social geometry of bargains. This Article proposes a different and wholly novel reason that the Chicago School is wrong: a fundamental assumption central to many of its game theory models has been disproven. This Article shows that a 2012 breakthrough from world famous physicist Freeman Dyson shocked the world of game theory. This Article shows that Chicago School game theorists are wrong on their own terms because these 2 x 2 games such as the Prisoner's Dilemma, Chicken, and Snowdrift, ostensibly based on mutual defection and corrective justice, in fact yield to an insight of pure cooperation. These new game theory solutions can be scaled to design whole institutions and systems that honor the pure cooperation insight, holding out the possibility of cracking large scale social dilemmas like the tragedy of the commons. It demonstrates that, in such systems, pure cooperation is the best answer in the right environment and in the long run. It ends by calling for a new legal field to redesign the structures based on the outdated assumptions of the Chicago School game theorists.

econ.TH↗
arXiv2023

Beating the average: how to generate profit by exploiting the inefficiencies of soccer betting

In economy, markets are denoted as efficient when it is impossible to systematically generate profits which outperform the average. In the past years, the concept has been tested in other domains such as the growing sports betting market. Surprisingly, despite its large size and its level of maturity, sports betting shows traits of inefficiency. The anomalies indicate the existence of strategies which shift betting from a game of chance towards a game of skill. This article shows an example for an inefficiency detected in the German soccer betting TOTO 13er Wette, which is operated by state-run lottery agencies. Gamblers have to guess the outcome (win, draw, loss) of 13 soccer matches listed on a lottery tip. Applying stochastic methods, a recipe is presented to determine hit rates for single match outcomes. More important, the recipe provides the number of lottery tips required to achieve a specific number of strikes (number of correct match forecasts per lottery tip) for any given level of safety. An approximation is derived to cope with large numbers in hypergeometric distributions, valid under certain constraints. Overall, the strategy does lead to returns exceeding the aggregated lottery fees, resulting in moderate, but consistent profits. It is briefly discussed if lessions learned from soccer betting can be transferred back to financial markets, because gamblers and retail investors face similar challenges and opportunities.

physics.soc-ph↗
arXiv2023

When Tails Tell Tales

The enigmatic open clusters serve as a constant reminder of the mysteries of the universe, helping to confront astronomical theories. Unknown to many, these clusters often possess tails with inappropriate labels, serving as the tell-tale signs of their historical journey. But unlike typical tails, these extensions can either precede or follow the body, yet they consistently unfold a cosmic mystery to be solved. I present a succinct survey of this subject matter, detailing the intrepid efforts of astronomers who have dared to challenge our knowledge about these creatures, and offer a novel proposal for their nomenclature, while not disregarding the philosophical ramifications.

astro-ph.SR↗
arXiv2023

Galaxy Evolution in $\ddotμ$ based Cosmologies

We present the first study of galaxy evolution in $\ddotμ$ based cosmologies. We find that recent JWST observations of massive galaxies at extremely high redshifts are consistent with such a cosmology. However, the low redshift Universe is entirely divergent from the $\ddotμ$ cosmic star formation rate density. We thus propose that our Universe was at one point dominated by a Primordial Bovine Herd (PBH) which later decayed producing dark energy. Note that we do not detail the mechanisms by which this decay process takes place. Despite its vanishingly small probability for existence, a $\ddotμ$ based cosmological model marries the disparate findings in the high and low redshift Universe.

astro-ph.GA↗
arXiv2023

As a matter of colon: I am NOT digging cheeky titles (no, but actually yes :>)

What's in a name, a poet once asked. To which we present this work, where we investigate the importance of a paper title in ensuring its best outcome. We queried astronomy papers using NASA ADS and ranked 6000 of them in terms of cheekiness level. We investigate the correlation between citation counts and (i) the presence of a colon, and (ii) cheekiness ranking. We conclude that colon matters in the anatomy of a paper title. So does trying to be cheeky, but we find that too much cheekiness can lead to cringefests. Striking the right balance is therefore crucial. May we recommend aiming for a level 4 cheekiness on a scale of 1-5.

astro-ph.IM↗
arXiv2023

UFOs: Just Hot Air or Something Meteor?

For much of February 2023, the world was in panic as repeated balloon-like unidentified flying objects (UFOs) were reported over numerous countries by governments that often responded with military action. As a result, most of these craft either escaped or were destroyed, making any further observation of them nearly impossible. These were not the first time balloon-like objects have loomed over Earth, nor are they likely to be the last. This has prompted us to push for a better understanding of UFOs. First we demonstrate that the distribution of balloon incidents and other UFO reports are consistent with being drawn from the same geographic distribution, and further that both of these distributions are consistent with the areas of the Earth that feature the jet stream. Second we show that there are more UFO sightings during meteor showers, as we would expect if meteor showers, already a known source of extraterrestrial material, are being used to provide some manner of distraction to help alien craft enter the Earth's atmosphere without drawing undue attention. These links between alleged balloon incidents, UFO reports, and meteor showers establish a transport pipeline for alien craft from interplanetary and possibly interstellar space to the Earth's surface.

physics.pop-ph↗
arXiv2023

I Murdered Conan O'Brien and Nobody Will Ever Know -- an exercise in inference sabotage

I employ an optimization-based inference methodology together with an Ising model, in an intentionally ineffectual manner, to get away with murdering an obstreperous scientific collaborator. The antics of this collaborator, hereafter "Conan O'Brien," were impeding the publication of an important manuscript. With my tenure date looming, I found myself desperate. Luckily, I study inference, a computational means to find a solution to a physical problem, based on available measurements (say, a dead body) and a dynamical model assumed to give rise to those measurements (a murderer). If the measurements are insufficient and/or the model is incomplete, one obtains multiple "degenerate" solutions to the problem. Degenerate solutions are all equally valid given the information available, and thus render meaningless the notion of one "correct" solution. Typically in scientific research, degeneracy is undesirable. Here I describe the opposite situation: a quest to create degenerate solutions in which to cloak myself. Or even better: to render measurements incompatible with a solution in which I am the murderer. Moreover, I show how one may sabotage an inference procedure to commit an untraceable crime. I sit here now, typing victoriously, a free woman. Because you won't believe me anyway. And even if you do, you'll never prove a thing.

astro-ph.HE↗
arXiv2023

Protoplanet Express, a video game based on numerical simulations

Astronomical images can be fascinating to the general public, but the interaction is typically limited to contemplation. Numerical simulations of astronomical systems do permit a closer interaction, but are generally unknown outside the research community. We are developing "Protoplanet Express", a video game based on hydrodynamical simulations of protoplanetary discs. In the game, the player visits several discs, finds its relevant features and learns about them. Here we present the current version of the game, discuss its reception, and consider its further development.

physics.ed-ph↗
arXiv2023

Can AI Put Gamma-Ray Astrophysicists Out of a Job?

In what will likely be a litany of generative-model-themed arXiv submissions celebrating April the 1st, we evaluate the capacity of state-of-the-art transformer models to create a paper detailing the detection of a Pulsar Wind Nebula with a non-existent Imaging Atmospheric Cherenkov Telescope (IACT) Array. We do this to evaluate the ability of such models to interpret astronomical observations and sources based on language information alone, and to assess potential means by which fraudulently generated scientific papers could be identified during peer review (given that reliable generative model watermarking has yet to be deployed for these tools). We conclude that our jobs as astronomers are safe for the time being. From this point on, prompts given to ChatGPT and Stable Diffusion are shown in orange, text generated by ChatGPT is shown in black, whereas analysis by the (human) authors is in blue.

physics.pop-ph↗
arXiv2024

MO0NFALL: The Great Filter and Exo-Moon Occurrence

We observe neither life beyond Earth, nor moons around exoplanets, despite the prevalence of Earth-like planets across the galaxy. We suggest Moonfall as a possible mechanism to explain both simultaneously.

astro-ph.EP↗
arXiv2023

The most fundamental question of all times

In the last few decades, reading the literature, we realized that we Astronomers have a strong preference to undertake very ambitious projects, and search for answers to the most fundamental questions in the history of the entire Universe. After running multiple times into such cardinal quest, the curiosity became no more sustainable and we had to find out. To our greater surprise, in the last few decades we had been restlessly participating to this superhuman endevour. Therefore we hereby explore the roots and grounds of this fundamental search, through the past decades, centuries and millennia.

astro-ph.CO↗
arXiv2023

A network-based strategy of price correlations for optimal cryptocurrency portfolios

A cryptocurrency is a digital asset maintained by a decentralised system using cryptography. Investors in this emerging digital market are exploring the profitability potential of portfolios in place of single coins. Portfolios are particularly useful given that price forecasting in such a volatile market is challenging. The crypto market is a self-organised complex system where the complex inter-dependencies between the cryptocurrencies may be exploited to understand the market dynamics and build efficient portfolios. In this letter, we use network methods to identify highly decorrelated cryptocurrencies to create diversified portfolios using the Markowitz Portfolio Theory agnostic to future market behaviour. The performance of our network-based portfolios is optimal with 46 coins and superior to benchmarks up to an investment horizon of 14 days, reaching up to 1,066% average expected return within 1 day, with reasonable associated risks. We also show that popular cryptocurrencies are typically not included in the optimal portfolios. Past price correlations reduce risk and may improve the performance of crypto portfolios in comparison to methodologies based exclusively on price auto-correlations. Short-term crypto investments may be competitive to traditional high-risk investments such as the stock market or commodity market but call for caution given the high variability of prices.

physics.soc-ph↗
arXiv2023

Tauberian identities and the connection to Wile E. Coyote physics

The application of the motion of a vertically suspended mass-spring system released under tension is studied focusing upon the delay timescale for the bottom mass as a function of the spring constants and masses. This ``hang-time", reminiscent of the Coyote and Road Runner cartoons, is quantified using the far-field asymptotic expansion of the bottom mass' Laplace transform. These asymptotics are connected to the short time mass dynamics through Tauberian identities and explicit residue calculations. It is shown, perhaps paradoxically, that this delay timescale is maximized in the large mass limit of the top ``boulder". Experiments are presented and compared with the theoretical predictions. This system is an exciting example for the teaching of mass-spring dynamics in classes on Ordinary Differential Equations, and does not require any normal mode calculations for these predictions.

math.DS↗