Greg Egan in general is a solid recommendation for diamond-hard sci-fi; I actually think Quarantine is one of the weakest in this respect, though it's a fantast

Greg Egan in general is a solid recommendation for diamond-hard sci-fi; I actually think Quarantine is one of the weakest in this respect, though it's a fantastic book. Who else would think to write a series of books (https://en.wikipedia.org/wiki/Greg_Egan#Orthogonal_trilogy https://en.wikipedia.org/wiki/Greg_Egan#Orthogonal_trilogy) about what would happen if you flipped a sign in the Lorentzian metric?