On unconventional fall of rainbow spring

TL;DR

This paper experimentally investigates the unconventional fall behavior of rainbow springs, revealing that under certain conditions, their lower end remains stationary until the entire spring collapses, with potential applications in space positioning.

Contribution

It demonstrates a novel fall motion of rainbow springs under gravity, combining high-speed imaging and elastic wave analysis to explain this phenomenon.

Findings

Lower end remains stationary until collapse

Elastic wave propagation predicts fall duration

Potential applications in space positioning

Abstract

In this study we experimentally show that a stretched rainbow spring under gravity or extra weight may exhibit unconventional fall motion. Specially, when the rainbow spring is released from a high place, its lower end remains stationary until the spring wires stack together and then all the parts of the rainbow spring falls down together. We utilize a high-speed camera to record the fall process of one plastic and one metal rainbow spring under different loading conditions to systematically investigate this unconventional physical phenomenon. We use the time of the elastic wave propagating the length of the spring to predict the duration of the lower end of the rainbow spring remaining still. The findings from this study elucidate this physical phenomenon which has potential for the areas requiring temporary absolute space positioning.