

After getting into the show I went deep into the actual mathematics of the three-body problem. The whole premise is that no stable solution exists, true for generic initial conditions. But periodic exceptions do exist and they're extraordinary.
The figure-eight was proven by Chenciner and Montgomery in 2000. Three equal masses chasing each other around one curve, zero angular momentum, period T≈6.32. It genuinely shouldn't exist. This comes from integrating Newton's equations at near machine precision over one complete period.
Made a small shop putting these on shirts at Etsy for anyone who wants to carry a bit of the actual mathematics around.