Physicists explore the Universe. Their investigations range from particles that are smaller than atoms to stars that are millions and millions of kilometres away. As well as having to find the facts by observation and experiment, physicists also must try to discover the laws that summarise these facts (often as mathematical equations). They then have to make sense of the laws by thinking up and testing theories (thought-models) to explain the laws. The reward, apart from satisfied curiosity, is a better understanding of the physical world. Engineers and technologists use physics to solve practical problems for the benefit of people, though, in solving them, social, environmental and other problems may arise. In this book we will study the behaviour of matter (the stuff things are made of) and the different kinds of energy (such as light, sound, heat, electricity). We will also consider the applications of physics in the home, in transport, medicine, research, industry, energy production and electronics. Shows some examples. Mathematics is an essential tool of physics and a ‘reference section’ for some of the basic mathematics is given at the end of the book along with suggested methods for solving physics problems.
This new edition has been updated and includes a discussion of information theory and descriptions of CT scan, endoscopy, MRI and fMRI imaging, techniques that were not available at the writing of the earlier editions. A word about units. Most physics and chemistry textbooks now use the MKS International System of units (SI). In practice, however, a variety of units continues to be in use. For example, in the SI system, pressure is expressed in units of pascal (kg/m2). Both in common use and in the scientific literature one often finds pressure also expressed in units of dynes/cm2, Torr (mm Hg), psi, and atm. In this book I have used mostly SI units. However, other units have also been used when common usage so dictated. In those cases conversion factors have been provided either within the text or in a compilation at the end of Appendix A.
