with a clear mind, anyone who has been awed by the darkness of a clear night, can solve this paradox—and thus reveal deep truths about the nature of space. Delving into other basic issues offers valuable insight about additional aspects of reality: Where are the aliens? What would happen if we fell into a black hole? Was there really a Big Bang? Can matter have negative mass? Are there extra dimensions and perhaps parallel universes? Are we as humans affected by the most remote objects we see through large telescopes, such as quasars?

In this book we demonstrate how even in this age of fantastic new technologies—with reams of telescopic data flooding astronomers’ computers—some of the most poignant dilemmas can be tackled through sheer reasoning. Often, one does not need fancy machines or complicated mathematics to get to the crux of a subject. An old English saying warns of the danger of not being able to see the wood for the trees. As we will show, our insights help us reveal the “solid wood” of modern cosmology. With all our grand explorations, nothing is more extraordinary than the power of the human mind.