what is a thought experiment? is it appropriate for 8th Graders? can I apply it to Math? can I apply it to Science? can I use it as a teaching tool?
Thought experiments are devices of the imagination used to investigate the nature of things. Thought experimenting often takes place when the method of variation is employed in entertaining imaginative suppositions. They are used for diverse reasons in a variety of areas, including economics, history, mathematics, philosophy, and physics. Most often thought experiments are communicated in narrative form, sometimes through media like a diagram. Thought experiments should be distinguished from thinking about experiments, from merely imagining any experiments to be conducted outside the imagination, and from psychological experiments with thoughts. They should also be distinguished from counterfactual reasoning in general, as they seem to require an experimental element.
Albert Einstein famously used thought experiments—experiments carried out in the mind only—to work out complex ideas. Here, watch animations of Einstein chasing a light beam (which helped lead him to his theory of special relativity) and riding an elevator in free-fall (which convinced him that gravity and acceleration are one and the same). Finally, see a visualization of one of the basic concepts of general relativity—that bodies like stars and planets warp the “fabric” of space-time.