Hyperspace by Michio Kaku, published by Anchor Books/Doubleday in 1994, is subtitled "A scientific odyssey through parallel universes, time warps, and the 10th dimension." Indeed it does cover it all but I feel that it glosses over quite a bit because each of these topics could be made into a book. These ideas are attractive to science fiction buffs and it seems that Kaku has intended to tap into this audience.

The book starts with visualization of dimensions. Much reference is made to Flatland by Abbot. There is a segment on various ways to represent 4 spatial dimesions in 3. We then start into a description of the standard model of the universe consisting of Einstein's space-time curvature, Maxwell's laws of electromagnetism and quantum mechanics.

The presentation is in historical order and includes a summary of current promising theoretical work to extend the standard model to a grand unified theory and eventually the theory of everything: supersymmetry; String theory; Supergravity. Here, Kaku emphasizes theorectical because there is no way to experimentally test many of the points at which these different theories diverge. Kaku strongly advocates the construction of the superconducting supercollider for experimental confirmation of these newly generated ideas.

Finally we come to the speculative stuff: parallel universes, the interior of blackholes, wormholes, time travel. This part left me unsatisfied because the treatment of these felt superficial. The book also picks up themes from Sagan's Cosmos: extra-terrestrial intelligence, the end of the universe.

The style of writing in the book varies. There are some good explanations about the mathematics at the start. However, towards the end, the text becomes breezy and even hokey on occasion:

When Captain Kirk takes us soaring through hyperspace at "warp factor 5," the "Dilithium crystals" that power the Enterprise must perform miraculous feats of warping space and time. This means that the dilitium crystals have the magical power of bending the space-time continuum into pretzels; that is, they are tremendous storehouses of matter and energy.

If the Enterprise travels from the earth to the nearest star, it does not physically move to Alpha Centauri - rather, Alpha Centauri comes to the Enterprise. Imagine sitting on a rug and lassoing a table several feet away. If we are strong enough and the floor is slick enough, we can pull the lasso until the carpet begins to fold underneath us. If we pull hard enough, the table comes to us, and the "distance" between the table and us disappears into a mass of crumpled carpeting. Then we simply hop across this "carpet warp". (p.227)

Reading this book felt like eating chinese food, you find yourself hungry for more an hour later. I think that the reader's enjoyment of this book is inversely proportional to their familiarity with the subject matter. It is a grand tour of physics-philosophy boundry and an excellent introduction to field of cosmology. However, there is not enough time at each stop and also, being 10 years old, new developments have taken place such as Spontaneous Localization theory.