xkcd #3178: Hyperacute Interdynamics
Title text:
Our models fall apart where the three theories overlap; we're unable to predict what happens when a nanometer-sized squirrel eats a grapefruit with the mass of the sun.
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3178/
There really is an xkcd for everything.