A grandson is a great excuse for going to places where you'd not go alone; such as a planetarium. So we went with Huw (aged 9.8) to Intech, just outside Winchester. The place was heaving with kids on halfterm, struggling to get at the various hands-on experiences but being shoved aside by their fathers. The Planetarium shows were heavily booked, but we managed to get into the one about Black Holes.
If you thought Theology was difficult, you should try Black Holes. There were brave simulations of what it might be like to approach one - canoeists trapped in the approach to Victoria Falls and so on - and there was a great deal of "we are now certain that", which made me very dubious about the 'findings' of science. It was interesting, though, to see attempts at describing how space is warped, and a black hole pierces though it, and there time and space are dramatically altered. But why, when they will accept all this, are modern human beings so resistant to ideas like heaven and eternity?
Walsingham has done a great deal about engaging children; perhaps the cathedrals should do more. It is a huge moneyspinner, after all. Though perhaps theology, Queen of the Sciences, is no longer at the stage where anyone dares say "we are now certain" of anything.