What if our universe is one of an infinite lineage of universes? Each coming into existence from the remnants of the last? It seems like an impossible theory. Yet, these universes may have existed. We might even see their swan songs in the destructive forces of black holes.
If those signals are there, then we must ask an astounding and terrifying question: Could we discover messages from ancient aliens living in the final days of a previous universe?
In a previous post, I introduced Conformal Cyclic Cosmology, a theory devised by the great Sir Roger Penrose to describe what happens at the end of our universe. In CCC, the universe is one of a chain, extending aeons into the past and future. The Big Bang doesn’t just represent the start of our universe but the death of an older one too.
Whilst one universe might feel like enough for most of us, we might be part of a structure much greater than a single cosmos, and despite being such an extraordinary theory, it is testable.
In the final era of our universe’s existence, it’s possible that all matter will decay. Of course, we know this to be the case for macroscopic objects. Stars will eventually run out of fuel and become white dwarfs, neutron stars or black holes. However, in CCC, all massive particles will eventually decay too.
This is plausible, though not yet accounted for in our current understanding of physics. No mechanisms are known for the decay of protons and electrons. However, our understanding of particle physics is far from complete. So, perhaps, after a significantly long time, the constituents of the atoms in our bodies, and in everything that we can see and touch, will dissolve into light.
A universe full of massless particles is an important detail for CCC. While a few massive particles are permitted in the final moments of the universe, the dominating contribution must be particles of light — photons.
The incredible feature of photons (and other bosons) is that, unlike particles of matter, they would not see a boundary at the edge of our universe. They would cross between aeons seamlessly, leaving our universe behind and entering a new one. However, everything else must be left behind at the border between old and new. Only light — a faint ghost of…