Quantum mechanics is a very successful theory that has impacted on many areas of physics, from pure theory to applications. However, it is difficult to interpret, and philosophical contradictions and counterintuitive results are apparent at a fundamental level. In this book, Laloë presents our current understanding of the theory. The book explores the basic questions and difficulties that arise with the theory of quantum mechanics. It examines the various interpretations that have been proposed, describing and comparing them and discussing their success and difficulties. The book is ideal for researchers in physics and mathematics who want to know more about the problems faced in quantum mechanics but who do not have specialist knowledge in the subject. It will also interest philosophers of science, as well as all scientists who are curious about quantum physics and its peculiarities.
A popular objection to the Many-worlds interpretation of Quantum Mechanics is that it allows for quantum suicide where an experimenter creates a device that instantly kills him or leaves him be depending the output of a quantum measurement, since he has no experience of the device killing him he experiences quantum immortality. This is considered counterintuitive and absurd. Presented here is a speculative argument that accepts counterintuitiveness and proposes it as a new approach to physical theory without accepting some of the absurd conclusions of the thought experiment. The approach is based on the idea that the Universe is Fragile in that only a fraction of the time evolved versions retain the familiar structures of people and planets, but the fractions that do not occur are not observed. This presents to us as a skewed view of physics and only by accounting for this fact (which I propose calling the Continual Anthropic Principle) can we understand the true fundamental laws.
The Everett interpretation of quantum mechanics - better known as the Many-Worlds Theory - has had a rather uneven reception. Mainstream philosophers have scarcely heard of it, save as science fiction. In philosophy of physics it is well known but has historically been fairly widely rejected. Among physicists (at least, among those concerned with the interpretation of quantum mechanics in the first place), it is taken very seriously indeed, arguably tied for first place in popularity with more traditional operationalist views of quantum mechanics. In this article, I provide a fairly short (15,000 words) and self-contained introduction to the Everett interpretation as it is currently understood. I use little technical machinery, although I do assume the reader has encountered the measurement problem already (at about the level of the well-known discussions by Penrose or Albert).