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…

Cognition is a general term describing the mental capacities of an animal, and often includes the ability to categorize, remember, and communicate about objects in the environment. Numerous regions of the telencephalon (cerebral cortex and limbic system) are responsible for these cognitive functions. Although many researchers have used traditional…

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)