The landscape was full of machines and scrap metal connected to the facility in one way or another. Always present on the horizon were the colossal cooling towers, with their green obstruction lights. If you put your ear to the ground, you could hear the heartbeat of the Loop ? he purring of the Gravitron, the central piece of engineering magic that was the focus of the Loop experiments. The facility was the largest of its kind in the world, and it was said that its forces could bend space-time itself.