C. S. Lewis was a master of finding just the right kind of simple metaphor, or analogy to illustrate a profound truth of life, or core Christian theme.
It’s an intriguing discovery that embedded in his The Magician’s Nephew is a double metaphor for black hole ‘wormhole tunnel’ travel. Basically it involves a mediating, timeless ‘no-place’ called ‘The Wood Between the Worlds’ which operates as a spacetime gateway. By jumping down and through a pool there, the kids in the story end up in another world in another universe.
One of the characters draws an analogy between the Wood and a ‘tunnel’ that runs under the roof for the entire length of the connected homes that make up the building he lives in. As he says about the tunnel: ‘It isn't a room in any of the houses. In a way, it isn't really part of any of the houses. But once you're in the tunnel you can go along it and come out into any of the houses in the row. Mightn't this wood be the same?—a place that isn't in any of the worlds, but once you've found that place you can get into them all?’ Black hole wormholes facilitate a similar end. Once you enter one, it (theoretically) could pop you back out at the other end into literally anywhere - including a parallel universe.
The related relevant notion here is that for Lewis the ‘Wood Between the Worlds’ is an obvious allegory of the wooden Christian Cross as the central Still Point, or ‘Singularity’ of history.
Correspondingly, the black hole ‘singularity’ in astronomy is a timeless, central point of infinite density, sort of like Christ - as its spiritually symbolic parallel - being an eternal core of the World Soul. Hence the whole Point (excuse the pun) of the Narnia series children ‘crossing’ over from Earth into Narnia - through the equivalent of a black hole wormhole tunnel - is that by getting to know Aslan there, they in turn might come to better know him as Christ in their own world.
And that folk, is how the great C. S. Lewis uses imagination to weave together Christ, black holes and wormholes.