But the best ways to imagine may be the ones that position this work as a collaboration—done with people rather than to or for them—giving people and communities the freedom to learn by doing and to adapt the general into the particular.

Some of the most radical experiments have given children the chance to reimagine their own futures.

I’ve considered homeschooling my daughters around a different grand challenge each year. If I do, I’d love to get other homeschooling or unschooling families involved. I have more ambitious ideas, like pitching the concept to my local community college and offering to design a grand challenges program for them. Or maybe I’ll convince the World Bank