In his PhD thesis, presented in 2013, the Belgian philosopher Clément Vidal argues that ETC development can best be discussed using a two-dimensional metric that combines the Kardashev and Barrow scales. In particular, he argues that SETI researchers should consider what it might mean if civilizations were at the KII–B level—civilizations that could harness the energy of a star and manipulate spacetime. If a civilization has the capacity to manipulate spacetime then its technology will be able to work with black holes —regions of spacetime from which nothing can escape.
