Smartphone-based experimental exercises were incorporated as part of the homework problems in an introductory mechanics course at a university. A quasi-experimental field study with two cohorts design was performed to measure the impact of such exercises on motivation, interest and conceptual understanding. The empirical results on learning…

It is not common to introduce current astronomy in school lessons. This article presents a set of experiments about gravitational lenses. It is normal to simulate them by means of computers, but it is very simple to simulate similar effects using a drinking glass full of liquid or using only the glass base. These are, of course, cheap and easy…

Discusses: how thought experiments (TES) are presented and used in physics textbooks; how and why teachers include TES in their explanations; and what understandings students draw from TES. Indicates that TES are only one of a broad class of "acts of imagination" which are essential in physics education. (JN)