Happy pi day. The most pi-representative moment of the year occurred this morning at 3:14 AM, March 14th.

Fun fact! The number pi doesn’t actually exist in reality. It’s just a convenient human abstraction for calculating the circumference of a roughly circular object based on its radius, or vice versa. Because the lowest known level of physical reality is actually “pixelated” (based on discrete Planck increments), there is no such thing as a true curve except inside a computer program or virtual reality. Einstein realized this near the end of his life, and was bummed.

Some things are darn close to a perfect circle, though. The probability distribution of an electron in a hydrogen atom is almost spherical, barring random quantum fluctuations. The folk theoretical representation of celestial bodies like the sun and moon are idealized spheres or discs. Gravity Probe B, designed to test the theory of relativity, contains a gyroscope that comes within 40 atomic diameters of a perfect sphere.

The most spherical known object is probably the neutron star. The size of a small city, these collapsed stars possess such intense gravity and density that individual atoms are shredded and their nuclei are pressed together in a neutronium soup. “Mountains” on neutron stars measure a few millimeters at the most.

One day there might exist even more perfectly circular or spherical objects. For example, a seed AI might be asked to construct as perfect of a circle as possible, or choose to create such a circle as a subgoal of something else. Without the overriding background knowledge that “general human happiness is more important than constructing a perfect circle”, the seed might choose to disassemble the Earth and arrange it into a ring of particles that most closely embodies the sacred pi ratio. What a way for the human race to go, eh?