One of the biggest challenges of the 21st century will be figuring out how to feed our rising global population. Now, some scientists are making the radical claim that growing more food won't be enough.
Dairy farmers routinely feed their cows finger-sized magnets that settle in their digestive tracts to help keep them healthy. This is not bizarre homeopathy, but a legitimate treatment for a stomach-churning ailment called "hardware disease".
As climate change begins posing new challenges to conventional outdoor food production methods, hydroponic farming has made quick gains in popularity. This enormous indoor lettuce farm for example, produces 10,000 heads a day.