This week we nerd out on watermelons (available May to October). All living beings on Earth constantly search for water—tree roots grow into cracked or leaky underground pipes to access the water they carry, camels can go a full week without drinking thanks to the unique water-storage capacity of their oval-shaped red blood cells, and humans have used technology to produce several gallons of water per day out of thin air. In fact, humans have been designing tools to access, store, and harness water for millennia.