Tall Styrofoam box with no holes in the base, plus its lid (or a panel from another box) Three 100mm lengths of 50mm-wide PVC piping ; Knife (sharp, pointed) Bamboo skewer (about 300mm) Measuring tape ...

You know Styrofoam: The flimsy white stuff that holds soda pop at picnics and Chinese takeout, that's supposed to last for thousands of years in landfills because it doesn't biodegrade. It's so ...