Thought Experiments in Teaching Free-Fall Weightlessness: A Critical Review and an Exploration of Mercury’s Behavior in “Falling Elevator”

Abstract

Different "thought experiments" dominate teaching approaches to weightlessness, reducing students' opportunities for active physics learning, which should include observations, descriptions, explanations and predictions of real phenomena. Besides the controversy related to conceptual definitions of weight and weightlessness, we report another controversy regarding the position of the person that weighs herself or himself in a freely-falling elevator, a "thought experiment" commonly used for introducing the concept of weightlessness. Two XIX-century "thought experiments", one from America and one from Russia, show that they have a long tradition in physics teaching. We explored experimentally a "thought experiment" that deals with the behavior of a mercury drop in a freely-falling elevator. Our experimental results show that the mercury drop neither took the expected spherical shape nor performed oscillatory motions predicted by theory. Teachers should encourage students to enrich active learning of weightlessness by thinking how to test experimentally the answers to some conceptual questions, a subclass of "thought experiments".

High school physics teachers’ perceptions and attitudes towards thought experiments in Indonesia

“…Although there is still very little information about the cognitive mechanism that supports learning from TEs, several literatures have provided ways in which students can advance their knowledge through TEs activities. Several physics researchers have revealed the pedagogical implications of TEs and stated that TEs are useful in promoting conceptual understanding (Fleer 2019, Alstein et al 2021, fostering the understanding of the history and philosophy of science (Velentzas and Halkia 2013, Balukovic et al 2017, Stuart 2021 and increasing motivation, confidence, and attitudes towards physical theories (Asikainen andHirvonen 2014, Myhrehagen andBungum 2016). TEs can effectively help students to interpret their social and moral realities more adequately by giving them opportunities to explore the scope of standardized concepts (Fleer 2019, Balg 2022.…”

“…Despite the consensus on the importance of TEs in physics learning, there is still little understanding of the process that physics teachers go through in designing learning, especially their perceptions and attitudes toward TEs. Previous studies reveal more about the processes, difficulties, and benefits experienced by students in learning by involving TEs (Asikainen and Hirvonen 2014, Myhrehagen and Bungum 2016, Balukovic et al 2017, Fleer 2019, Alstein et al 2021, Balg 2022). In fact, there are still very few studies that further investigate the implementation and implications of TEs in the teaching of physics at schools, particularly those related to the physics teachers' understanding, beliefs, or practice of TEs in teaching physics.…”