A plastic water bottle may take hundreds–or even thousands–of years to degrade in a landfill. A new conceptual design for a water bottle is at the opposite extreme: Immediately after you drink it, it starts to fall apart. And if you don’t want to throw the bottle away, you can eat it. The bottle is made from agar, a powder made from algae. When it’s mixed with water, it turns into a jelly-like material that can be molded into shapes–like a bottle.