1,721,229 research outputs found
Alternatives to Schwarzschild in the weak field limit of General Relativity
No full textThe metric outside an isolated object made up of ordinary matter is bound to be the classical Schwarzschild vacuum solution of General Relativity. Nevertheless, some solutions are known (e.g. Morris-Thorne wormholes) that do not match Schwarzschild asymptotically. On a phenomenological point of view, gravitational lensing in metrics falling as 1/rq has recently attracted great interest. In this work, we explore the conditions on the source matter for constructing static spherically symmetric metrics exhibiting an arbitrary power-law as Newtonian limit. For such space-times we also derive the expressions of gravitational redshift and force on probe masses, which, together with light deflection, can be used in astrophysical searches of non-Schwarzschild objects made up of exotic matter. Interestingly, we prove that even a minimally coupled scalar field with a power-law potential can support non-Schwarzschild metrics with arbitrary asymptotic behaviour
Students’ understanding of gravity using the rubber sheet analogy: an Italian experience
No full textGeneral relativity (GR) represents the most recent theory of gravity, on which all modern astrophysics is based, including some of the most astonishing results of physics research. Nevertheless, its study is limited to university courses, while being ignored at high-school level. To introduce GR in high school, one of the approaches that can be used is the so-called rubber sheet analogy (RSA), i.e. comparing space-time to a rubber sheet that deforms under a weight. In this paper, we analyse the efficacy of an activity for high-school students held at the Department of Mathematics and Physics of Roma Tre University that adopts the RSA to address several topics related to gravity. We present the results of the questionnaires we administered to over 150 Italian high-school students to investigate their understanding of the topics treated
Experience gravity in the classroom using the rubber sheet: An educational proposal from the collaboration between university and school
No full textTeaching modern physics in high school is of increasingly importance as it can offer students a more realistic and updated vision of the world, and can provide an opportunity to understand the most recent scientific discoveries. In this context, general relativity (GR) occupies a prominent place, since it is related to astonishing scientific results, such as the first image of a black hole or the discovery of gravitational waves. In this paper we describe an educational proposal aimed at teaching GR in high schools in a fun and playful way using the so-called rubber sheet analogy. We present a set of instructions to build a simple and low-cost space-time simulator, and a series of related educational cards that guide the teacher in the implementation of the activities step by step. This work is the result of a long and productive debate among Italian high school teachers who have collaborated for many years with the Department of Mathematics and Physics of Roma Tre University in Rome. As our proposal relies on the collaboration with the final users, we believe that it will meet their needs and expectations, and it will help to treat GR in high school more and more over time
Trattare la gravità a scuola attraverso lo spaziotempo
No full textLa Relativit`a Generale `e la teoria pi`u moderna della gravit`a, che spiega innumerevoli fenomeni. Nonostante ci`o, essa non `e abiltualmente trattata nella
scuola secondaria superiore. In questo articolo proponiamo una modalit`a di formazione docenti che ha l’obiettivo di renderli autonomi e confidenti nell’introdurre
la Relativit`a Generale in classe attraverso il concetto di spazio-tempo e l’uso di un
telo elastico. Tale modalit`a `e stata prima testata nell’ambito delle attivit`a PLS
dedicate agli studenti portate avanti dal Dipartimento, e poi inserita nelle iniziative PLS di sviluppo professionale dei docenti. Attraverso una lunga e proficua
discussione con i docenti in servizio, abbiamo quindi sviluppato e ottimizzato la
modalit`a di formazione docenti, definendo le linee guida e i materiali necessari per
trattare diversi fenomeni legati alla gravit`a. Per raggiungere anche docenti non
appartenenti alle nostre scuole partner PLS, abbiamo infine raccolto tutti i materiali in un manuale gratuito, che pu`o essere usato come formazione autonoma.General Relativity is the most modern theory of gravity and allows
to explain several phenomena. However, it is not usually treated in high school.
In this paper we propose a teacher training activity that aims at making them
autonomous and confident in introducing General Relativity in their classrooms
making use of the concept of space-time and a rubber sheet. This activity we developed was first tested among the PLS activities dedicated to students carried on
by the Department, and then added to the PLS initiatives addressed to teachers.
After a long and productive debate with high school teachers, we optimized our
teacher training activity, defining guidelines, materials, videos and images necessary to treat different phenomena related to gravity. In order to reach teachers
not belonging to our PLS partners, we finally collected all the materials developed
in an open access manual, that can be used as a standalone training
Lipids in platelet function: platelet and vascular prostaglandins in thromboembolic disease.
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