  General 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 introduceGR in high
school one of the approaches that can be used is the so-called rubber sheet
analogy, i.e. comparing the space-time to a rubber sheet which deforms under a
weight. In this paper we analyze the efficacy of an activity for high school
students held at the Department of Mathematics and Physics of Roma Tre
University that adopts the rubber sheet analogy to address several topics
related to gravity. We present the results of the questionnaires we
administered to investigate the understanding of the topics treated to over 150
Italian high school students who participated in this activity.
