Experiment: How About an Apple?
What can you use to control the touch-sensitive Click Wheel? Here’s an abbreviated list of what we tested:

* Finger: Yes
* Orange: Yes
* Apple: Yes
* Plastic pen cap: No
* Silly Putty: No
* Paper clip: No
* Tip of Cold Heat soldering tool: No
* Prongs from iPod charger: No

The yesses are easily explainable — fruit and flesh can conduct electricity. The no’s, however, are a bit more mysterious. The pen cap and the Silly Putty are not conductors, end of story. But what about the tip of the soldering tool, the paper clip and the charger prongs? Those are conductors! To solve this riddle, we contacted an expert in the electronics field, who recommended the following action: Wrap your finger in aluminum foil and try to work the Scroll Wheel. Our expert was thinking “surface area.” This finger-wrapped-in-foil input worked perfectly.

Can it be that the surface area of the paper clip is not enough to trigger the conductive grid? To investigate this hypothesis, we tried to work the Scroll Wheel using the blunt end of a dinner knife (approx. 0.75 in x 0.5 in). It worked. We concluded that surface area matters.

But there’s another factor, too, because holding the dinner knife between two plastic pens and moving it around the Scroll Wheel doesn’t work. Same with the apple and the orange. You need to be touching the knife or the orange in order for the Scroll Wheel to detect it. The determining factor, then, is you — the human body is a very big conductor, providing a very big neutral area for a charge to jump to. The charge difference between your body and the Click Wheel’s electrodes provides the voltage — or electrical “pressure” — that activates the Click Wheel system.

The Thing About the Battery
iPod’s battery is completely built-in — you can’t just pop in a couple of new AA batteries when it stops charging. This built-in battery has been a headache both for iPod owners and for Apple.

Originally, the iPod battery was not only non-user-replaceable, but it was also very expensive to replace via Apple. When your battery died (sometimes within a year of buying the iPod), you had to send your iPod to Apple for a replacement, and the new battery cost $100. A lot of bad press and a class-action lawsuit later, Apple’s iPod battery-replacement program costs $59. The class-action suit was settled, and iPod owners listed in the suit were compensated with $50 vouchers and partial refunds for their $100 battery replacement.

Apple defends the use of a non-user-replaceable battery by explaining that the built-in battery allows for the ultra-slim form factor for which the iPod is known.

There are ways for you to replace the battery without sending your iPod to Apple.