Initial data in general relativity must satisfy certain
underdetermined differential equations called the constraint equations.
A natural problem is to find a parameterization of all possible initial
data. A standard method for this is called the conformal method. In the
relatively simple ``constant mean curvature" (CMC) case, this method
provides a good parameterization of initial data. However, the
far-from-CMC case has resisted analysis. In part this is because
researchers were trying to prove theorems that are false. In this talk,
I'll introduce the problem and known results, and talk about our
numerical results that show that the standard conjectures about
solvability were all wrong. Numerical investigations can play an
important part in informing conjectures about purely analytical
questions.