The Slinky Factor
Posted on December 7, 2012 | posted by:
If John Thackara’s talk about space-time issues in In the Bubble got you weary, try this experiment, which makes visible the physical delay in the movement of information.
- Start with a slinky
- Dangle it above the ground so that the slinky is fully extended
- Wait for it to become still
- Get ready to carefully observe
- Drop the slinky
What you’ll see seems to defy the laws of physics: the bottom of the slinky will hover in midair for a fraction of a second before it begins to fall with the top.
The Radiolab short What a Slinky Knows explores this phenomenon. Hosts Jad Abumrad and Robert Krulwich speak with Steve Strogatz, Professor of Applied Mathematics at Cornell University, and Neil deGrasse Tyson, Director of the Hayden Planetarium, to figure out why the bottom of the slinky doesn’t move.
“So, why doesn’t it?” you ask. Because it takes time for the signal that initiates movement to travel from the top to the bottom of the slinky. This information delay is true in all objects and parts of our physical world, although the delay often passes so quickly that we may not perceive it at all.
Check out this video from the Radiolab website for more on the science behind the delay:
The profound part of the slinky experiment is that is shows us the limitations of our physical world and the laws speed. Watching the slinky, suddenly the ”light-speed crisis” Thackara discusses, in regard to the Internet and microprocessor design, becomes real for us. Thackara highlights the problem of “latency,” the delay caused by the time it takes for a remote request to be serviced through the Internet or for a message to travel between two processing locations. Network designers combat these limitations the only way possible: by moving the user closer to the data or moving the data closer to the user.
“We will forever be victims to the time delay between information around us and our capacity to receive it,” Neil deGrasse Tyson says. So as we design to meet people’s desires for increased speed and efficiency, we must take seriously the limits of our physical world. Locality—the distance between people and information—may prove to be the most challenging and influential factor of contemporary design for us to consider.
Listen to Radiolab’s short What a Slinky Knows and find other cool media surrounding the slinky factor here: http://www.radiolab.org/blogs/radiolab-blog/2012/sep/10/what-slinky-knows/