Simetrias e leis de conservação: uma proposta para o ensino médio

Abstract

We present in this work an alternative proposal for the teaching of Conservation Laws in physics from the concept of symmetries. Such concept has applications in different areas, crossing the limits of the classical and quantum mechanics, going from relativity to the physics of condensed matter. If, on the one hand, the symmetries are so fundamental, on the other hand, they are useful for a more fundamental understanding of a conservation law already seen by students in the first year of high school, the Conservation of Energy. Using the ideas of Ausubel of Meaningful Learning and of Moreira, the Critical Meaningful Learning, we elaborated a PSTU (Potentially Significant Teaching Unit) that discusses symmetries in several different contexts, and allows students to understand that symmetries are not only observed in geometric/spatial setups, extrapolating these particular cases. It is concluded that the existence or breaking of symmetries can justify physical observables, in addition to giving students the understanding that the so-called Conservation of Mechanical Energy is justified by a particular type of symmetry, that of temporal evolution of a physical system.