The universe is getting messy. Like a glass shattering to pieces or a single wave crashing onto the shore, the universe’s messiness can only move in one direction – toward more chaos and disorder. But scientists think that, at least for a single electron or the simplest quantum computer, they may be able to turn back time, and restore order to chaos. This doesn’t mean we’ll be visiting with dinosaurs or Napoleon any time soon, but for physicists, the idea that time can run backward at all is