A visitor claiming to be from outside our universe has come to our world illegally to push forward her academic project (a simulation that happens to be our universe) before it get's shut down.
Interviewed by some of our suspicious physicists, she is forced to explain how quantum physics and the theory of relativity can be united: and her answer goes along the lines of:
Humanity's progress in string theory is absolutely outstanding, because it postulates 24 dimensions, because your universe only consists of four.
My collegues and I have compressed the informations of our normal 24-dimensional universe into your 4-dimensional universe to save computational power. Unfortunately, you can not bring the two universes together, because the quantum interactions of your universe are imprecise, missing the interaction with the other 20 dimensions.
Basically, what you experience on quantum level is a floating point calculation error in the underlying computational process. The errors occur when we render your world. It's a mathematical error that cannot be overcome from within the simulation.
Is this idea one that the would allow the average reader to suspend his or her disbelief?