Introducing the subject of superfluid helium three and polarized liquid helium three, this book is devoted to modern problems in many body physics specific to the quantum fluid helium three. Relationships between properties of helium three and topics in other fields are established including superconductivity, non-linear dynamics, acoustics, and magnetically polarized quantum systems.Among the chapters in this collection one finds valuable reference material and original research not published elsewhere. Advanced research topics are presented in a pedagogical manner, in considerable depth, and with appropriate introductory material sufficiently general to be suitable to the non-specialist.