Risultati della ricerca
Anno XLI - n.4 - ottobre/dicembre 2008 Leggi, dimensioni e segno di uguaglianza
The article discusses, with many examples, the difference between the universal meaning of physical laws (e.g. proportionalities between physical quantities) and their customary computable representations. These require introducing auxiliary quantities and coefficients whose physical definitions and numerical values depend on the unit system chosen. […]
Anno XLI - n.4 - ottobre/dicembre 2008 Un gioco di P. A. M. Dirac
An ingenious and amusing activity originally devised by Dirac illustrates a topological symmetry property of the three-dimensional rotation of solids. Some mathematical aspects of this property and its relevance to the quantum physics description of fermions are explained. […]
Anno XLI - n.4 - ottobre/dicembre 2008 Risposta cromatica di celle fotovoltaiche
The article describes an experiment in which the response of polycrystalline silicon solar cells to different wavelengths is explored using unconventional apparatus: the cells were taken from discarded toys and a photographic enlarger was used as monochromator. […]
Anno XLI - n.3 - luglio/settembre 2008 Ettore Majorana, un innovatore coraggioso
In 1937 Ettore Majorana introduced quantum mechanics and relativity at the University of Naples. His remarkable lectures show his forerunning attitude, the deepness of his mind, his independence from any received teaching. After seventy years his lectures are still modern and some methodological aspects can also be applied to the teaching of physics in the school. […]
Anno XLI - n.3 - luglio/settembre 2008 Dalla radioterapia a raggi X all’adroterapia
The history of external radiation beam therapy and its important developments are briefly outlined. The physical bases of the use of ion beams, which offer several advantages over photons in the treatment of well localized cancer, are explained. […]
Anno XLI - n.3 - luglio/settembre 2008 Il profilo della Torre Eiffel
Starting with a short story by Dino Buzzati, the article explains how some features of the Eiffel Tower relate to simple physics: e.g. due to its distinctive shape, its weight balances the torque produced by the pressure of the wind. […]
Anno XLI - n.3 - luglio/settembre 2008 Sperimentare… tra le righe
The common ruler can be used in the school physics lab for simple but effective and surprising experiments. The article illustrates a series of experimental activities using rulers of different lengths and characteristics and other common material. […]