That makes sense to me, but - neither H1 nor H2 is Earth, they are Hamiltonian spaces. And the statement that puzzles me is: “the Earth can be treated as a topo

That makes sense to me, but - neither H1 nor H2 is Earth, they are Hamiltonian spaces. And the statement that puzzles me is: “the Earth can be treated as a topological insulator”. So… I remain puzzled ((