- "Icke takes on Einstein's theory of gravitation and succeeds beyond one's expectations" - Martin Veltman, Nobel Prize winner in Physics, 1999. Our Universe is not described by the motion of objects through space, but by the dynamics of space itself. The 21st century began with an unsettling accumulation of riddles, mostly due to the increasing precision of cosmology. It turns out that our Universe is mainly made of 'dark stuff ', the nature of which is entirely unknown. Moreover, in the beginning of our Universe an episode carrying the unfortunate name 'Big Bang' the descriptions of 'motion through space' and 'motion of space' must be combined into a single theory. Such a theory will not only do away with gravity, but will also have to replace the current views of particle interactions with something new. But with what? Often, in physics, the right question can only be formulated once the answer is known. What will the key question of 21st-century physics and cosmology turn out to be? Dutch edition: 978 90 8964 624 8 -Vincent Icke is professor of theoretical astrophysics at Universiteit Leiden, professor of cosmology at the University of Amsterdam, visual artist, and writer.