The Freaky Physics of Falling Slinkies, in Super Slow Motion


You have to see it to believe it: Slinkies look crazy not just tumbling down stairs but in free fall. In a new video, YouTube's favorite Slow Mo Guys capture the puzzling dynamics of the iconic toy at 1,600 frames per second on a Phantom Flex camera. The video, which we discovered via the curators of awesomeness at Laughing Squid, is not the first to look at the phenomenon and the Slow Mo guys (Gavin Free and Daniel Gruchy) are willing to admit their take is not exactly super informative. 

Luckily Rhett Allain, an associate professor of physics at Southeastern Louisiana University, has an in-depth look at the science at work over at Wired. He cites the YouTube series Vertiasium, which went viral with a similar falling-Slinky demo last fall. In the video below, physicist Rod Cross explains that the tension of the spring counters the pull of gravity ("equal and opposite forces"), holding the bottom end of the Slinky in place until it "gets the information that the tension has changed." By the time the bottom end of the Slinky gets the memo, the top end has fallen to meet it. What's true for Slinkies is also true in sports, including tennis rackets, according to Cross. Your hand doesn't feel the impact of a tennis racquet hitting a ball until the ball "is well on its way." 

Allain takes the analysis further, modeling the Slinky in free fall by breaking it up into separate segments (top, center of mass, bottom) and graphing their positions over time. He even has a little gif demonstrating the motion. If the math is over your head, feel free to watch this Slinky strut its stuff a treadmill instead:

For more videos from the Slow Mo Guys, visit their YouTube channel. 

Jump to comments

Kasia Cieplak-Mayr von Baldegg is the executive producer for video at The AtlanticMore

Cieplak-Mayr von Baldegg joined The Atlantic in 2011 to launch its video channel and, in 2013, create its in-house video production department. She leads the development and production of original documentaries, interviews, and other video content for The Atlantic. Previously, she worked as a producer at Al Gore’s Current TV and as a content strategist and documentary producer in San Francisco. She studied filmmaking and digital media at Harvard University.
Get Today's Top Stories in Your Inbox (preview)

Why Are Americans So Bad at Saving Money?

The US is particularly miserable at putting aside money for the future. Should we blame our paychecks or our psychology?

Elsewhere on the web

Join the Discussion

After you comment, click Post. If you’re not already logged in you will be asked to log in or register. blog comments powered by Disqus


The Death of Film

You'll never hear the whirring sound of a projector again.


How to Hunt With Poison Darts

A Borneo hunter explains one of his tribe's oldest customs: the art of the blowpipe


A Delightful, Pixar-Inspired Cartoon

An action figure and his reluctant sidekick trek across a kitchen in search of treasure.


I Am an Undocumented Immigrant

"I look like a typical young American."


Why Did I Study Physics?

Using hand-drawn cartoons to explain an academic passion



More in Video

Just In