Excerpt from Book of Worlds
As far as timing goes, it was impossible to predict whether any given world was going to be fast or slow. I soon became confident, however, that there was little danger of my stumbling on a world that was, for example, a million years to one Earth second, or vice versa. This is unlikely because of the rule I mentioned in the previous chapter, that any world you enter will be similar to the one you enter it from.
Such time differences do exist, I am sure, but they are only reachable through many chains of other worlds. If one was to enter fast world after fast world from one to the other, one would probably eventually arrive in a place where one earth second amounted to many years. Alternatively, you could go from slow world to slow world and essentially travel through time and return to earth millenniums later.
But timing, as my next adventure will illustrate, was the least of my worries. As a human man, I have evolved on earth, and so everything in my genes, my instincts, behaviours and thought processes, have evolved to help me survive on Earth.
In other worlds, however, it is sometimes necessary to do things against every survival instinct in your body to survive. In addition, the dangers you face are nothing like those that your evolution has prepared you for, and so you must prepare yourself for them. If you ever mean to travel the worlds in the interests of exploration, as I have, you must be a survivor in every aspect, and able to adapt to your surroundings in the blink of an eye. Your survival away from Earth depends entirely on this: your ability to change.