Consider this:  replace "acid gradient" in the experiment description with "air pressure": Imagine constructing a larger version of this maze from cardboard.  A vacuum cleaner is placed at the exit of the maze.  Sucking the air out of the maze creates a pressure gradient such that there is higher air pressure nearer the entrance and lower air pressure nearer the exit.  This pressure gradient causes the ping pong ball to roll through the maze to exit.<p>This is a brilliant application of a novel idea BUT the physical process at work only seems miraculous because we do not deal with acid gradients every day.  Consider:  would the same claims that it "performs a computation" be as credible in the vacuum cleaner and air pressure version?<p>If any computation is being done, it is a search space being covered in parallel by billions of independent agents (the molecules of the medium).  The movement of the water droplet (or ping pong ball!) merely serves to display the answer.