In this episode of pplpod, we explore one of the most unsettling and fascinating ideas in cosmology: what if the expansion of the universe eventually reverses? What if every galaxy, every star, every atom in existence is destined to collapse back together into a single infinitely dense fireball known as the Big Crunch?

Using historical astronomy, theoretical physics, and modern cosmology research, this episode traces humanity’s evolving understanding of the universe’s fate. We begin with Isaac Newton and Richard Bentley’s early paradoxes about gravity and a static cosmos, move through Albert Einstein’s “greatest mistake” involving the cosmological constant, and unpack Edwin Hubble’s discovery that the universe is expanding through the phenomenon of redshift.

From there, the episode dives deep into the terrifying mechanics of a collaps ...