Any time a sci-fi show runs into a problem there is usually some manipulation of the known world which solves the problem. Typically, the solution is a completely wrong extrapolation of something we learned in high school science with jargon flying left and right to misdirect and make it sound creditable (I’m looking at you, Eureka). When this occurs geeks and nerds across the Internet get on forums and discuss the unrealistic minutiae while being content with the Moon actually being blown off its orbit instead of being blown apart.
I digress, a writer of Futurama decided to make a mathematical proof of the plot point so as to not remove its viewers from a suspension of belief. You can read more about it here. You can also get a clear view and explanation of the therom here.