"Where is heaven, Father?"

Some seven or eight years ago I attended a Catholic event with Clare at the church in Andover. I think it was a lecture on some theological issue or other, or maybe a talk on the Missions. In any event it was a dark night and the church was packed.

At some stage in the evening the priest, an elderly, kindly man with a poor public speaking style, took questions from the audience: a kind of 'ask me anything'.

A quavering voice - evidently an elderly Irish woman - piped up from behind us: "Father, where is heaven?"

My jaw dropped: in this day and age?

The priest was, however, up to the job. He explained that previous orthodoxy had held that heaven was beyond the sky. However, NASA had sent a great many rockets and heaven was nowhere to be seen up there. However, modern physics was very strange with quantum effects between the atoms which no-one understood. Possibly it was here that heaven was located.

There was no follow-up question.

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It made me think though. If heaven is nowhere to be found in this spacetime universe, could it really be found in Hilbert space? Perhaps in the primordial substance before spacetime geometry had ever congealed?

Let's ask Carlo Trugenberger: "Emergent 4D Quantum Geometry from Critical Space-Time Graphs".

"After a brief introduction to the problem of quantum gravity and the main solution approaches on the market I will focus on my new proposal of a quantum gravity model in which the fundamental degrees of freedom are information bits for both discrete space-time points and links connecting them.

"The Hamiltonian is a very simple network model consisting of a ferromagnetic Ising model for space-time vertices and an antiferromagnetic Ising model for the links. As a result of the frustration between these two terms, the ground state self-organizes as a new type of low-clustering graph.

"I will provide ample evidence that this simple network model has two critical points, an ultraviolet fixed point corresponding to fluctuating information bits and an infrared fixed point corresponding to an emergent geometric phase with space-time dimension 4.

"The model predicts that, at small scales, the space-time dimension decreases until space-time itself completely dissolves into a disordered soup of information bits.  The large-scale dimension 4 of the universe is related to the upper critical dimension 4 of the Ising model and to illustrate the dimension decoupling mechanism I will solve a toy version of the model in the mean field approximation.

"At finite temperatures the universe graph emerges without big bang and without singularities from a ferromagnetic phase transition in which space-time itself forms out of a hot soup of information bits."

So heaven might be 'a hot soup of information bits' (but perhaps that's the other place). Perhaps we could link this idea with Eternal Inflation to get a contemporaneous theological ontology.

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How do we know that our current universe has three spatial dimensions? Because Clare needed a minimum of three strings to deploy her self-made bird feeder (two pie dishes from Poundland).

Three strings = three spatial dimensions

The designer shows her grasp of string theory

As I carefully explained to her, the argument works best in polar coordinates.