Playdough For Fun and Profit

morgan_greywolf writes with this snippet from Wired:"You're never too young (or too old) to start learning the joys of electronics. You don't need to know how to solder, or even how to plug circuit components into a breadboard. As long as you're past the 'I'm going to stick this up my nose' phase, this homemade playdough circuit project is a great way to introduce kiddos and adults alike to basic circuits and electricity."

Kirkchoff's law fail

[Zinho]

It makes me sad to read the following snippet from the article:

Chain multiple LEDs through the conductive dough, and you’ll notice the ones at the end are far dimmer than the first few. That’s because less current is making its way down the series; the current only has one path, and that’s through each LED.

Now a bunch of kids are going to go through life thinking that current gets used up as it goes through the circuit. The same current will be flowing through every component of the circuit; it's only got one path, after all.

Don't get me wrong, I love this article and I'm probably going to try this with my kids, too. It's just that I'm going to teach them Kirchoff's laws [wikipedia.org] while I'm at it.