[ExI] Public draft of my book 'Tales of the Turing Church

[Stuart LaForge]

John Clark wrote:

> For the
> sake of honesty I must admit that much of what I said above about the
> very early universe is conjecture because the oldest thing anybody has
> ever detected is the Cosmic Black Body Radiation, and that doesn't come
> from the Big Bang itself but from a time 380,000 years after it when the
> universe had cooled to less than 3000K and neutral hydrogen atoms could
> form and everything was no longer opaque to electromagnetic waves.

Well I am satisfied with the admission that inflation is largely
speculation. There are alternate speculations about what happens before
the surface of last scattering. One I have been investigating lately is
Sir Roger Penrose's Conformal Cyclic Cosmology.
https://en.wikipedia.org/wiki/Conformal_cyclic_cosmology

In a nutshell, he uses uses conformal geometry to derive a solution to
Einstein's equations that allow serially expanding universes or what
Penrose calls aeons.

Penrose predicts that when the last proton in the universe decays the
universe will enter into a new "radiation era" where the universe only has
massless photons in it. Since massless particles like photons move at c
and therefore do not experience time or distance, this resets the FLRW
metric scale parameter to its minimum.

This is possible because of the conformal geometry of light rays and
subtle distinctions between different measures of space-time curvature in
General Relativity. In other words, the big bang reboots itself once all
that's left in the universe is electromagnetic radiation.

Stuart LaForge