Where is Heaven? Sure, if Heaven exists, Hell too. Then, where is Hell? These are very tricky questions. If our familiar 3 dimensions (width, height, and depth) are the only known "volumetric" dimensions, then Heaven should exist in our space. OK, it doesn't, or at least there is no evidence that exists.
Now, let us ask again these questions within the multi-dimension world of A Lifetime Waiting for Eternity. What if we take one of the 11 dimensions of the M-Theory (see "A bigger reality" post) and we use it to locate Heaven. Let's develop this idea for the purpose of the setting for the novel. We need to add a 4th "volumetric" dimension to our 3-dimension space. Which one should we pick up? The simple way is to take, let's say, the 6th dimension and define it as a volumetric dimension. This would be too easy. Remember, I didn't want to create a magical world for the novel. What about time? Time is another dimension, isn't it?
Time as a volumetric dimension
This is the moment to speculate. How can we add volume to the time dimension? It doens't have volume, we know that, but what if it actually has volume. How to explain it? Again, I took inspiration in physics. In 1908, Hermann Minkowski suggested that space and time fuse into a single four-dimensional manifold, called spacetime continuum. If we fuse them, then why not extrapolate the idea and give time a similar volumetric property than our 3D space? There is one way to visualise it, which require that we twist the interpretation of the famous balloon analogy.
According to the theories of cosmology, the universe is expanding since its creation from the Big Bang. A good way to visualise this expansion is to compare space with the surface of an expanding balloon. Arthur Eddington in 1933 used this analogy in which a balloon with many dots marked on its surface is blown up. As it inflates, the distances between the dots increase in the same way as the distances between the galaxies.
As suggested by Fred Hoyle in 1960, the volume inside the balloon can be understood as the time. This analogy inspired me to create a world where time is volumetric. Together with the 3-dimensions, time creates a "world" where the characters of the novel travel across the spacetime continuum as we do in the normal 3-dimensional space.
This world allows Ely to walk back in time but let's not be confused with actually go to the past. A multi-dimension world where maybe Heaven, and why not, Hell as well can actually exist.