Hooked on Science: Levitating Slinky

A wave of recent online videos showing the bottom of a dropped Slinky hovering in midair has scientists taking a closer look at the toy. Grab a Slinky from the toybox and try this experiment at home.

Materials

* Slinky

Instructions

STEP 1: Hold the Slinky up by one end.

STEP 2: Drop the Slinky and observe closely.

Explanation

If you look closely, you will observe that the bottom coils stay suspended in the air. As you hold the Slinky in the air, gravity pulls down. That downward pull is balanced by the upward pull of tension created by the coils above the coils at the bottom. When you let the slinky go, the bottom stays suspended as the top collapses. As the Slinky collapses, the coils slam into each other, creating a wave downward that eventually reaches the bottom coils, telling them to fall to the ground.

Jason Lindsey is a science outreach educator with Hooked on Science. Check out his website www.hookedonscience.org for webcasts and experiments that might get you hooked on science. Send him your science questions at jlindseyhookedonscience.com. More science experiments can be found at www.semissourian.com.