Hasil untuk "physics.pop-ph"

Joanne Tan

We all love the ecstasy that comes with submitting papers to journals or arXiv. Some have described it as yeeting their back-breaking products of labor into the void, wishing they could never deal with them ever again. The very act of yeeting papers onto arXiv contributes to the expansion of the arXiverse; however, we have yet to quantify our contribution to the cause. In this work, I investigate the expansion of the arXiverse using the arXiv astro-ph submission data from 1992 to date. I coin the term "the arXiverse constant", $a_0$, to quantify the rate of expansion of the arXiverse. I find that astro-ph as a whole has a positive $a_0$, but this does not always hold true for the six subcategories of astro-ph. I then investigate the temporal changes in $a_0$ for the astro-ph subcategories and astro-ph as a whole, from which I infer the fate of the arXiverse.

Himadri Barman

We demonstrate how the quantum teleportation protocol of a single qubit can be understood by designing a simple game that can be played by three participants: Alice, Bob, and *Quantum God*.

David J. E. Marsh

Axions are an increasingly popular topic in theoretical physics, and are sparking a global experimental effort. In the following I review the motivations for the existence of axions, the theories underlying them, and the methods to search for them. The target audience is an interested amateur, physics undergraduate, or scientist in another field, and so I use no complicated mathematics or advanced theoretical topics, and instead use lots of analogies.

Salomon S. Mizrahi

Avoiding the use of mathematical formalism, this essay exposes the quantum mechanics the phenomenon of non-locality in terms of a metaphor involving human twins focused on their hands' dexterity attribute.

Huw Price, Ken Wharton

In this piece, written for a general audience, we propose a mechanism for quantum entanglement. The key ingredient is collider bias. In the language of causal models, a collider is a variable causally influenced by two or more other variables. Conditioning on a collider typically produces non-causal correlations between its contributing causes. This phenomenon can produce associations analogous to Bell correlations, in suitable post-selected ensembles. Such collider artefacts may become real connections, resembling causality, if a collider is 'constrained' (e.g., by a future boundary condition). We consider the time-reversed analogues of these points in the context of retrocausal models of QM. Retrocausality yields a collider at the source of an EPR-Bell particle pair, and in this case constraint of the collider is possible by normal methods of experimental preparation. It follows that connections resembling causality may emerge across such colliders, from one branch of the experiment to the other. Our hypothesis is that this constrained retrocausal collider bias is the origin of entanglement. This piece is based on a suggestion first made in arXiv:2101.05370v4 [quant-ph], and is an ancestor of an essay now published online in Aeon magazine [Price & Wharton 2023a]. In an updated version of the argument in arXiv:2309.10969 [quant-ph] we (i) demonstrate its application in a real Bell experiment; and (ii) show that we can do without an explicit postulate of retrocausality

Chris D. White, Anthony Phillips, Beltran Sajonia-Coburgo-Gotha

Higher Education Institutions in the UK and elsewhere are under increasing pressure to measure the impact of their research, which can include how the research has increased scientific engagement amongst the general public. For various reasons, the need for evidence can arise months, or even years, after a particular research discovery has been made. Furthermore, the right kind of evidence is needed to indicate genuine behavioural change amongst a given target audience, which can be difficult to obtain after time has passed. In this article, we present a number of strategies for retrospective evidencing of research engagement, and illustrate their use on example discoveries from up to five years ago.

Tony Robbin

Before they met, David Bohm and Roger Penrose each puzzled over the paradox of the arrow of time. After they met, the case for projective physical space became clearer.

Luc Blanchet

Contemporary astronomy is undergoing a revolution, perhaps even more important than that which took place with the advent of radioastronomy in the 1960s, and then the opening of the sky to observations in the other electromagnetic wavelengths. The gravitational wave detectors of the LIGO/Virgo collaboration have observed since 2015 the signals emitted during the collision and merger of binary systems of massive black holes at a large astronomical distance. This major discovery opens the way to the new astronomy of gravitational waves, drastically different from the traditional astronomy based on electromagnetic waves. More recently, in 2017, the detection of gravitational waves emitted by the inspiral and merger of a binary system of neutron stars has been followed by electromagnetic signals observed by the $γ$ and X satellites, and by optical telescopes. A harvest of discoveries has been possible thanks to the multi-messenger astronomy, which combines the information from the gravitational wave with that from electromagnetic waves. Another important aspect of the new gravitational astronomy concerns fundamental physics, with the tests of general relativity and alternative theories of gravitation, as well as the standard model of cosmology.

Adrian Kent

These programme notes were written for a production of "Hapgood" at the Hampstead Theatre, London in December 2015. I thank Sir Tom Stoppard for helpful suggestions.

Adrian Kent

This review, intended for a popular audience, was originally published in the online magazine Aeon on 28 January 2014. It is reproduced on the arxiv with permission. The online version (without references) can be found at https://aeon.co/essays/what-really-happens-in-schrodinger-s-box.

Chris D. White

Three of the four fundamental forces in nature are described by so-called gauge theories, which include the effects of both relativity and quantum mechanics. Gravity, on the other hand, is described by General Relativity, and the lack of a well-behaved quantum theory - believed to be relevant at the centre of black holes, and at the Big Bang itself - remains a notorious unsolved problem. Recently a new correspondence, the double copy, has been discovered between scattering amplitudes (quantities related to the probability for particles to interact) in gravity, and their gauge theory counterparts. This has subsequently been extended to other quantities, providing gauge theory analogues of e.g. black holes. We here review current research on the double copy, and describe some possible applications.

Luis A. Anchordoqui

Lecture script of a one-semester course that aims to develop an understanding and appreciation of fundemental concepts in modern physics for students who are comfortable with calculus. This document contains the last part of the course where we introduce the concept of the quantum unit to describe the dynamic properties of subatomic particles and the interactions of matter and radiation.

Jeremy Bernstein

This is an open letter on the nature of the quantum theory.

Adrian Kent

Remarks on Michael Frayn's play "Copenhagen".

R. W. Kuhne

The aim of this note is to give a short and popular review of the ideas which led to my model of magnetic monopoles (hep-ph/9708394) and my prediction of the second kind of electromagnetic radiation. I will also point out the many and far-reaching consequences if these magnetic photon rays would be confirmed.

David J. Ritchie

The Improbability Scale (IS) is proposed as a way of communicating to the general public the improbability (and by implication, the probability) of events predicted as the result of scientific research. Through the use of the Improbability Scale, the public will be able to evaluate more easily the relative risks of predicted events and draw proper conclusions when asked to support governmental and public policy decisions arising from that research.

Luis Alvarez-Gaume, Miguel A. Vazquez-Mozo

This is a semipopular introduction to the Special and General Theory of Relativity, with special emphasis on the geometrical aspects of both theories and their physical implications.

Anthony Sudbery

Alice and Bob use Aravind's version of a Bell-Kochen-Specker paradox to fend off awkward questions about what exactly they were doing in Amsterdam last week.

Gordon Baym, Frederick K. Lamb

This short encyclopedia article, reviewing current information on neutron stars, is intended for a broad scientific audience.

Alexander Zaitsev

Throughout the entire history of terrestrial civilization, only four projects involving transmitting of interstellar radio messages (IRMs) have yet been fully developed and realized. Nevertheless, we should understand a simple thing -- if all civilizations in the Universe are only recipients, and not message-sending civilizations, than no SETI searches make any sense. We present the theory and methodology of composing and transmitting of future IRMs.