WIRED ScienceStem cell biologists are basically modern day witches. While they’re not exactly taking a creepy fetal Lord Voldemort and turning him into noseless Ralph Fiennes, these scientists can use tinctures and concoctions to grow incredible things from just a few human skin cells. One of those things is a brain ball, a collection of stem cells that biologists have coaxed into a bobbing tangle of living neurons.
