The original atom of space, and all pyrons for that matter, are roughly 1.6 times ten to the minus-35th power meters (the Planck length) across, based on what the Loop Quantum Gravitationists say.
The original one had the following three properties:
1) It was (and still is) homogeneous. Simplicity demands it. Mandelbrot (Chaos Theory) and Wolfram (cellular automata) will explain what happens next.
2) It radiated, in the first atomic time step (from Loop Quantum Gravity: 10 to the minus 23 seconds) from its 4 faces, thus creating 4 more adjacent pyrons (faces meeting) at t = t-one step. The process continues with them as well at t=timestep number two, t=timestep number three, ... , t=timestep number infinity
3) It had an initial, specific anthropic energy. If the energy value (a single number) weren't exactly what it was, we wouldn't be here to consider it.