Globus Cassus is a utopian project for the transformation of Planet Earth into a much bigger, hollow, artificial world with an ecosphere on its inner surface. Sunlight would enter through two large windows, gravity would be provided by centrifugal force. Humans would live on two vast regions that face each other and that are connected through the empty center.
Being the Earth/World's antipode in many aspects, Globus Cassus acts as a philosophical model for the opposite-based description of the Earth/World and as a tool to understand the World's real functioning processes.
Globus Cassus was proposed by architect and artist Christian Waldvogel and presented at the Venice Architecture Biennale in 2004. It consists of a meticulous description of the transformation process, a narrative of its construction as well as of suggestions on the organizational workings on Globus Cassus. It is also the subject of a book.