The substrate boils

A slice of metastable dc1/dag substrate over deep time. Bubbles of the other phase nucleate as energetic wavefronts that expand and dissipate into the bulk. Each one's growing wall releases the latent heat that, viewed from inside, looks like a Big Bang. The marked bubble is one such pop. We are deep inside one of these — until we aren't, and the marker jumps to the next universe over.

cosmic time, accelerated — each bubble is roughly one observable universe