Since the first edition was very well received, it was decided to prepare a second edition that would incorporate a variety of new results.
Without changing the general structure of the book a number of improvements, corrections, and explanations have been introduced in the first chapters. The last chapters, 21 and 22, are completely new and are concerned with the line of research followed by the author during the last few years. Some new problems are introduced. The role of errors in scientific observations is reexamined and leads to a critical discussion of the idea of "determinism." Scientists believe in determinism, but they are completely unable to prove it, because their experiments always lack in accuracy.
The lack in accuracy is also of very special importance in the definition of very small distances. Here, the experimenter or the mathematician violently disagree; the experimenter refuses to consider discussion of things he cannot measure. This operational viewpoint leads to some curious consequences which are discussed in the last chapter [from author's Preface to the 2nd edition].