Megastructures Birch Planet 1

Part of the "Megastructures: The Visual Encyclopedia" book project, on sale now at

The Birch Planet is a shellworld that surrounds a black hole. Due to the immense gravity of the black hole, each shell would have different time flows, slower time closer to the black hole, faster time towards the outer shell. The physics on this Megastructure ended up not working out, so it doesn't have an entry in the Encyclopedia, but this image still graces the back cover of the book.