I just picked up his book Hyperspace today. Really interesting so far! The book deals with many complex subjects like the fourth spatial dimension (not time). Apparently Kaku thinks that the four universal forces can be unified through higher dimensions. He has a way of explaining hard concepts really well. Of course this is all theory but theory drives exploration and discovery. He mentions some intriguing things that light may be a wave in the fourth dimension allowing it to travel through the vacuum of D space. I don't think everything he says as law but it is fun to think about and they could be possible. I'm thinking about getting more of his work. Again these are just theory but even so they are intriguing. Also, his radio show is great but his callers are often daft. He has quiz questions that people can call in and attempt to answer sometimes winning books and other things. His approach is very original creating metaphors for advanced principals. Wormholes were explained as worms living on a 2d plain then one called Columbus discovered that their universe was curved in a 3rd spatial dimension. After that a wormhole could be bored through the center of the 2d plain and travel between points in a quick manner. It really frustrates me that there could be 10 dimensions and we can only visually understand three of them. Could 4d objects exist in our world as their 3D projections? There is some hocus pocus but I see nothing wrong with making educated guess as to what the universe might be like in hyperspace.
