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In this paper, we propose the replication of scientific experiments, with the participation of the general public, as one of the possible strategies to confront science deniers. Using the social media of the Federal University of Lavras (UFLA), the project entitled : The Magic of Physics and the Universe, invited the public to reproduce the experiment carried out by the Greek Eratosthenes over 2,100 years ago, which he proved that the Earth is spherical. We present a report of this experience to suggest that it is possible for citizens to experience scientific knowledge and observe the phenomena in a simple way, in order to develop a critical interpretation of false information that circulates in society. This proposal distinctively geeks to deconstruct the denial of the Earth's curvature through direct and collective participation of citizens in Eratosthenes' experiment, which permit more reflection on how the scientific method used to study this subject works., Comment: This article is written in Portuguese

In this article, we present several apparent paradoxes of special relativity and their respective solutions. These paradoxes have appeared since the advent of relativity in 1905, and in fact they are never paradoxes. From a didactic point of view, paradoxes are an excellent learning tool. They lead the student to confront, and abandon, several central concepts of Galilean theory, such as simultaneity and rigidity of extended bodies. In particular, we review a new and simple solution to the twin paradox, recently found by one of the present authors [1]. It does not need to consider reference accelerators or light signals, which are the solutions presented in the literature., Comment: in Portuguese language, paper accepted for publication in Revista Brasileira do Ensino de F\'isica

The importance of implementing unitarity constraints in meson spectroscopy is very briefly outlined for Portuguese students of engineering sciences and therefore non-experts in the field. After explaining the profound differences between meson spectroscopy and atomic spectroscopy, attention is paid to the shortcomings of standard Breit-Wigner parametrisations in the case of broad and/or overlapping resonances. Finally, the manifestly unitary Resonance-Spectrum-Expansion model, which lies at the heart of a recent invited review paper by the present authors, is graphically presented, together with a simple yet typical application to the long-controversial $K_0^\star(700)$ resonance., Comment: in Portuguese. Invited paper for the first new edition (no. 504) of the students journal "T\'{e}cnica" published on 3 November 2021 by the "Associa\c{c}\~{a}o dos Estudantes do Instituto Superior T\'{e}cnico" of IST in Lisbon, Portugal. Article is in Portuguese language, with an English abstract; 4 pages, 5 figures. Link to published version: https://www.paperturn-view.com/?pid=MTk197448&p=25&v=1.1

The use of facial masks played a pivotal role in combating COVID-19 during the pandemic period, particularly in the absence of vaccines for the disease. This study elucidates how this type of equipment can effectively contain viruses and bacteria of nanometric dimensions, smaller than the pores of the masks themselves. To achieve this, three types of masks were chosen: cloth, surgical, and PFF2 masks. In order to compare the structure of each, a scanning electron microscopy analysis was conducted, revealing the intricate filtration layers within each mask type., Comment: in Portuguese language

Mastering semiconductor technology is essential to insert any country into the trends of the future, such as smart cities, internet of things, space exploration, etc. In this paper we present the growing annual revenue of the semiconductor industry in the last 20 years and comment on the importance of mastering semiconductor production technology and its implications for the development of a nation., Comment: in Portuguese

In this paper we describe the evolution of the Universe in terms of the Friedmann equation, which takes into account of the composition and geometry of the Universe. The dependence of the solution on the geometry and composition for different combinations of the basic constituents are discussed. The distinct behaviors for the temporal evolution of the Universe are determined and the scenario predicted by the Standard Cosmology is presented., Comment: 23 pages, 8 figures. Text in Portuguese. Published in Revista Brasileira de Ensino de Fisica

This research is about to analyze the effects of the implementation of a virtual learning space in the homogeneous second-order differential equations applied to the modeling of the phenomenon of simple pendulum physics in the framework of the alliance with the international project World Pendulum Alliance WPA. The collection of information was carried out with a five question, using pre-test and post-test. The effectiveness of the strategy was measured with the Hake gain and the evolution of learning with the vectors of Bao. It was found that the strategy is more effective, but close to that achieved by traditional models, so that students largely achieve the proposed learning objectives. The evolution of learning suggests that students after the implementation of the strategy are marked under the model of acceptable explanation in the literature, although some participants still lean towards the incorrect model or the distracter. Therefore, it is necessary to include in the strategy a greater number of activities related to the description of the physical phenomenon to be studied and the improvement of the algebraic procedures seen in previous courses., Comment: 24 pages, in Portuguese, 7 figures

The Higgs boson was predicted in 1964 by British physicist Peter Higgs. The Higgs is the key to explain the origin of the mass of other elementary particles of Nature. However, only with the coming into operation of the LHC, in 2008, there were technological conditions to search for the Higgs boson. Recently, a major international effort conducted at CERN, by means of ATLAS and CMS experiments, has enabled the observation of a new bosonic particle in the region of 125 GeVs. In this paper, by means of known mechanisms of symmetry breaking that occur in the BCS theory of superconductivity and in the theory of nuclear pairing, we discuss the Higgs mechanism in the Standard Model. Finally, we present the current state of research looking for the Higgs boson and the alternative theories and extensions of the Standard Model for the elementary particle physics. Keywords: Higgs boson, BCS theory, nuclear pairing, Higgs mechanism, Standard Model., Comment: Article in Portuguese. The paper will appear in Volume 35 of the Revista Brasileira de Ensino de F\'isica

This white book stems from the contributions presented at the Portuguese SKA Days, held on the 6th and 7th February 2018 with the presence of the SKA Deputy Director General Alistair McPherson and the SKA Science Director Robert Braun. This initiative was held to promote the Square Kilometer Array (SKA) - the world's largest radio telescope - among the Portuguese scientific and business communities with support from the Portuguese Science and Technology Foundation (FCT) with the contribution of Portuguese policy makers and researchers. The meeting was very successful in providing a detailed overview of the SKA status, vision and goals and describes most of the Portuguese contributions to science, technology and the related industry aspirations, Comment: 210 pages, UA Editora, Preface in Portuguese, contains arXiv:1607.02415, arXiv:1809.08663

In this paper we show how to obtain the Inverse-square law of the distance to the light intensity emitted from a small source in a simple, fast and with good precision way. With the aid of two smartphones, free apps and a ruler, one is able to measure the distances between the devices listed (one as a source and the other as a measuring light intensity) and the respective light intensities measured by the probeware in the device. The ease of reproduction of the proposed experiment and the penetration of the use of tablets and smartphones among students and teachers, could make the proposed activity a good alternative to the introduction of physical phenomena which exhibit the same functional dependence, such as the Law of Newton's Universal Gravitation and Coulomb's Law., Comment: in Portuguese, 3 pages, 4 figues

A century after observing the deflection of light emitted by distant stars during the solar eclipse of 1919, it is interesting to know the concepts emerged from the experiment and the theoretical and observational consequences for modern cosmology and astrophysics. In addition to confirming Einstein's gravitational theory, its greatest legacy was the construction of a new research area to cosmos science dubbed gravitational lensing. The formation and magnification of multiple images (mirages) by the gravitational field of a compact or extended lens are among the most striking phenomena of nature. This article presents a pedagogical view of the first genuine gravitational lens effect, the double quasar QSO 0957 + 561. We also describe the formation of rings, giant arcs, arclets and multiple Supernova images. It is also surprising that the Hubble constant and the amount of dark matter in the Universe can be measured by the same technique. Finally, the lensing of gravitational waves, a possible but still not yet detected effect, is also briefly discussed., Comment: 22 pages, 20 figures, in Portuguese

In 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 of presenting the best concepts involved in the teaching of Astronomy for visually impaired people. The equipment consists of the use of a model with hemispheres with Peltier pellets for simulation of temperature scale of planets of the Solar System. The research was based on the use of accessible and low-cost materials. All the materials used and the assembly of the equipment are described in this work, since the design until the application of the final product for students. This experiment was part of a set of pedagogical equipment presented at a scientific exhibition for the visually impaired during the 15 a National Science and Technology Week in the city of Juazeiro do Norte in the State of Cear\'a., Comment: 7 pages, in Portuguese, 8 figures

Despite 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 promotions. In many professions, although women represent the majority in the entrance to undergraduate courses, their participation is dramatically reduced as the career progresses to the highest levels. While the participation of men increases, that of women decreases as the academic levels move towards the top ranks. This kind of evolution of two groups in opposed directions is usually referred as the "scissors effect". This effect with respect to sexes also occurs in the area of physics, both in Brazil and in the rest of the world. But at what age does this effect begin? What is its intensity in the different stages of women's lives? In this article we aim to shed some light on these questions by analyzing data of the Brazilian Olympiad of Physics and of fellowships for physicists in Brazil. We observe the systematic occurrence of scissors effect throughout the full studied data, ranging from the first years of participation in the Olympiads (13 years old) to the highest stages of the scientific career., Comment: 7 pages, in portuguese, 2 figues

The recent observation of gravitational waves confirms one of the most interesting predictions in general relativity: the black holes. Because the gravitational waves detected by LIGO fit very well within general relativity as a phenomenon produced by two colliding black holes. Then the reality of black holes seems almost undoubted today. However, a stronger proof on the reality of black holes would be indicated by the observation of the event horizon, which is what defines it. In this article, it is indicated that only the event horizon defines a black hole. There is no mention to the singularity in its definition. Thus, it will be shown that black holes without a singularity are possible. Such black holes are called regular black holes., Comment: 7 pages. Introductory article in Portuguese. Published in Revista Brasileira de Ensino de Fisica

A simple way of measuring g in the basic lab with a an Arduino micro-controller is discussed. Experimental results are obtained and compared with values provided by the National Observatory, Rio de Janeiro. Our relative error is 0.1 %., Comment: In Portuguese. Soon an English version will be available

Physical quantities and physical dimensions are among the first concepts encountered by students in their undergraduate career. In this pedagogical review, I will start from these concepts and, using the powerful tool of dimensional analysis, I will embark in a journey through various branches of physics, from basic mechanics to quantum gravity. I will also discuss a little bit about the fundamental constants of Nature, the so-called "cube of Physics", and the natural system of units., Comment: 20 pages, 6 figures; v2: minor changes, reference added. Pedagogical article in Portuguese addressed to undergraduate students

The article is an historical overview of some of the major contributions from different areas of Science with which, for centuries, it has been built up a scientific, sound and consistent vision of the atom. Some experiments that led us to a number of evidence about the composite nature of the atom are highlighted., Comment: 14 pages, in Portuguese

This project aims to attract school students and teachers from the state education system from Ca\c{c}apava do Sul - RS to Sciences and specially to Astronomy. We made astronomical observations using a Galileoscope choosing the Moon as a primary target. We also observed others objects that present high brightness in the night sky. The selection of targets, and their identification during the observations were carried out by a free software of planetary simulation, Stellarium. The results were in qualitative form and they show the great interest demonstrated by those participating in the project. Furthermore, this project helped to improve the understanding of the physical proprieties of the night sky objects (e.g. color). Finally, the project has showed that using a simple equipment and of relatively low cost it is possible to bring more people, specially the young students, to the Science World and to Astronomy., Comment: 4 pages, text in Portuguese

Some ideas aimed to understand that time is one-dimensional are briefly reviewed. Some attempts to construct theories in varieties with more spatial and temporal components are presented. It is discussed, from the epistemological point of view, which path can be taken to try to "prove" the one-dimensionality of time (or the three-dimensionality of space) from these generalized theories., Comment: In portuguese, 10 p

Enrico Fermi was one of the greater physicists of the XX century. In 1934, he gave several lectures in Brazil. Invited by Theodoro Ramos to work in S\~ao Paulo, he preferred to stay in Rome and went to the USA in 1938. However, Fermi recommended Gleb Wataghin to come in his place. Wataghin made history in Brazil, becoming one of the first Professors of the future S\~ao Paulo University. Besides his relevance to the History of Science, Fermi eventually leaved an indelible mark on the creation and institutionalization of national scientific research due to the indication of Wataghin. Despite this fact, very little is known about Fermi's trip to Brazil. This work tries to reconstruct the fullest possible steps of the famous Italian physicist in our lands., Comment: 13 p, in Portuguese. Accepted for publication in Estudos Avan\c{c}ados da USP

In this work we present a simple way to get Macro photography (enlarged photographs) using a tablet or phone. We initially discuss the technique, which is essentially the accommodation of a drop of water on the camera lens. Next, we explore some applications to science teaching in primary and secondary levels. As discussed in the text, the simplicity and power of the technique may make it a good teaching tool for use in various disciplines such as Science, Biology and Physics., Comment: 10 pages, in Portuguese, 10 figures

The discovery of many particles, especially in the 50's, when the firsts accelerators appeared, caused the searching for a model that would describe in a simple form the whole of known particles. The Quark Model, based in the mathematical structures of group theory, provided in the beginning of the 60's a simplified description of hadronic matter already known, proposing that three particles, called quarks, would originate all the observed hadrons. This model was able to preview the existence of particles that were later detected, confirming its consistency. Extensions of the Quark Model were made in the beginning of the 70's, focusing in describing observed particles that were excited states of the fundamental particles and others that presented new quantum numbers (flavors). Recently, exotic states as tetraquarks and pentaquarks types, also called multiquarks systems, previewed by the model, were observed, what renewed the interest in the way as quarks are confined inside the hadrons. In this article we present a review of the Quark Model and a discussion on the new exotic states., Comment: In Portuguese

Scientific education and divulgation not only amplify people's vocabulary and repertory of scientific concepts but, at the same time, promote the diffusion of certain conceptual and cognitive metaphors. Here we make some hypothesis about this process, proposing a classification in terms of visible, invisible, basic and derived metaphors. We focus our attention in contemporary and classical physics metaphors applied to psychological and socio-economical phenomena, and we study two exemplar cases through an exhaustive exam of the online content of large Brazilian journalistic portals. Finally, we present implications and suggestions from the cognitive metaphor theory for the scientific education and divulgation process., Comment: In portuguese, 20 pages, 2 figures, new version submitted to RBEF

The sciences of complexity present some recurrent themes: the emergence of qualitatively new behaviors in dissipative systems out of equilibrium, the aparent tendency of complex system to lie at the border of phase transitions and bifurcation points, a historical dynamics which present punctuated equilibrium, a tentative of complementing Darwinian evolution with certain ideas of progress (understood as increase of computational power) etc. Such themes, indeed, belong to a long scientific and philosophical tradiction and, curiously, appear already in the work of Frederick Engels at the 70's of the XIX century. So, the apparent novelity of the sciences of complexity seems to be not situated in its fundamental ideas, but in the use of mathematical and computational models for illustrate, test and develop such ideas. Since politicians as the candidate Al Gore recently declared that the sciences of complexity have influenced strongly their worldview, perhaps it could be interesting to know better the ideas and the ideology related to the notion of complex adaptive systems., Comment: 29 pages, no figures, in Portuguese