“…In many papers [30][31][32][33][34][35][36][37][38][39], for instance, in [30], authors modelled Huygens' coupled pendulums as two pendulums connected to a movable platform, connected to a wall through a spring and damper. We believe, however, that this model is far from the real Huygens' coupled pendulums and, to some extent, it is not a correct model, because, in the real Huygens' coupled pendulums, there is no spring (force) in the system.…”