Three experiments on the Einstein’s lift

Abstract

We propose a didactic model of Einstein's lift used to show the physics in a freefalling frame of reference. We discuss three experiments in Einstein's lift: the spring-mass system, the two repelling magnets system and the pendulum oscillations in free fall. Measurements are carried out through analysing videos acquired using a digital camera by means of open-access video analysis software which allows to describe the motion in both the inertial and moving frames of reference. We also show some videos edited with the software Adobe After Effects which enable us to see what happens in a freefalling frame of reference, and a video acquired by a GoPro camera falling integral with the lift. The topic, the accessibility of the experiments and the level of analysis are appropriate for an undergraduate classical mechanics course.

An online teaching learning sequence with home experiments and simulations on relativity of motion and the equivalence principle in classical mechanics

“…The experiments of ref [18] as the one reported in in Fig 6, right were reproduced by students thanks to Algodoo simulations. The experiment, adapted from ref [18]. A sequence of photos of the freefalling model of Einstein's lift with a pendulum, where the angular velocity of the pendulum is approximately zero when it starts falling.…”

“…Although many of these proposals are excellent, only a few are suitable for unskilled students and do not require a wellequipped physics lab. These experiments were mainly aimed at presentation of Einsteinʼs lift [17,18,19] and on the physics of free fall, as the ones shown in ref. [20].…”

“…The physics exhibition physics exhibition of falling pendulum [18] shows students how a rigid pendulum behaves in absence of gravity. The experiments of ref [18] as the one reported in in Fig 6, right were reproduced by students thanks to Algodoo simulations. The experiment, adapted from ref [18].…”

“…Figure 8 (Left) Students worked with the Algodoo simulation that exactly represents the situation of the pendulum in the elevator. (Right) The experiment, adapted from ref[18]. A sequence of photos of the freefalling model of Einstein's lift with a pendulum, where the angular velocity of the pendulum is approximately zero when it starts falling.…”

Investigating the Principle of Relativity and the Principle of Equivalence in Classical Mechanics: Design and Evaluation of a Teaching–Learning Sequence Based on Experiments and Simulations

“…Thus, the spring-mass system and the oscillating pendulum in free fall were proposed to the students through some videos realized by one of the teachers of the course and then analyzed by the students with Tracker as reported in [76].…”