This was a fun book. I won't claim that it is cosmically significant, but sometimes I enjoy relaxing with a book that is fun to read, and this book was that for me. Michio Kaku is one of those people that is always fun to follow. You may have seen him on TV where he has a show that is similar to this book.

The ideas is that he takes a number of ideas familiar from Science Fiction, and asks if they are possible, or truly impossible. Some things we can't do now, but maybe there is way we can do it in the future without violating the laws of physics as we know them. Other things would require a new understanding that the laws of physics are not quite what we think. That has happened before, and there is no a priori reason to think it can't happen again.