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 still a pretty big deal.
Normally, the universe’s trend toward disorder is a fundamental law: the second law of thermodynamics. It says more formally that any system can only move from more to less ordered, and that the chaos or disorder of a system – its entropy – can never decrease. But an international team of scientists led by researchers at the ...
