Wertheim's book is part-thesis and partly a loose, academic-lite history of the concept of space from Dante to current overheated Californian eschatologies of cyberspace. The medieval cosmology was of hierarchical spheres with God's Empyrean beyond everything. To document the advance of rationalism, she chomps through the early perspectival art of Giotto, the musings of Nicholas of Tusa, Newton (to whom space was still "God's sensorium") and Descartes; then into Einstein's relativistic space, with wormholes and gravity as expressions of its curvature, and even faster through murky eleven-dimensional hyperspace. She relaxes more in "multi-dimensional" cyberspace which, to her, restores a dualistic medieval religiosity of "a despatialised egalitarian utopia of cyber-Gnostic dreams ". She cites Lacanian mind space, epidemiological viral space, Jaron Lanier's internet as "a syncretic version of Christian ritual ", cyberpunk author William Gibson's word-plays; the online cybercity of AlphaWorld, etc. While this stuff excites her native California, other cultures have a more utilitarian take on the technology, but I can think of worse ways of spending a few hours.