City folks who are shopping at grocery stores are accustomed to neatly piled bananas and apples, procured like museum objects, bright and shiny. The food and produce at these stores travel hundreds or even thousands of miles to get there, stripped of their origins and stories, hiding their carbon footprints.

Do you know where your apples came from? 

Carbon Frootprint aims to help people understand the carbon footprint of their food based on how far it traveled to get to the grocery store. Along with a shopping basket, customers could pick up their Carbon Frootprint detector upon arriving at the grocery store. By waving the wand over the produce, they can correctly identify fruit that are local and make healthy choices for themselves and the planet. It turns green for items from closer distances and red for items far away. Additionally, the wand attracts and repulses like a magnet in response to the distances.

For Introduction to Interaction Design, Joshua and Lisa explored many metaphors for the interaction before arriving at this one: the metal detector.