Radiolab

We turn to doctors to save our lives -- to heal us, repair us, and keep us healthy. But when it comes to the critical question of what to do when death is at hand, there seems to be a gap between what we want doctors to do for us, and what doctors want done for themselves.

Is reality an ethereal, mathematical poem... or is it made up of solid, physical stuff? In this short, we kick rocks, slap tables, and argue about the nature of the universe with Jim Holt.

Moments of total, world-shaking bliss are not easy to come by. Maybe that's what makes them feel so life-altering when they strike. And so worth chasing. This hour: stories of striving, grasping, tripping, and falling for happiness, perfection, and ideals.

In this short, costumed scientists create a carefully choreographed childhood for a flock of whooping cranes to save them from extinction. It's the ultimate feel-good story, but it also raises some troubling questions about what it takes to get a species back to being wild.

Once a kid is born, their genetic fate is pretty much sealed. Or is it? This hour, we put nature and nurture on a collision course and discover how outside forces can find a way inside us, shaping not just our hearts and minds, but the basic biological blueprint that we pass on to future generations.