Bobrick and Martire suggest instead that a massive gravitational force could be used to bend space time. The trick is finding a way to compress a planet-sized mass to a manageable spacecraft-module size in order to use its gravity. Because of the implied difficulties, a warp drive created from the https://getsocialsource.com/story14488104/5-hechos-f%C3%A1cil-sobre-espejis-descritos