https://nyti.ms/2VjVWjA
Researchers have sent a very tiny simulated atom back in time a fraction of a second, using a small public quantum computer.
In other words, while you can't know both its velocity and the location at the same time, they've managed to compute how a wave function "got here" and reverse both to where it started. While complexity increases geometrically, a much larger future computer could conceivably scale this up. Yes, it was only a few qubits, on a tiny slice of IBM's smallest quantum computer. But consider how far binary computers have come in the past fifty years...
[Please forgive the whimsical topic line. This is much more important than that.]