Biomedical applications of introductory physics

Abstract

Bill Clinton's now (in)famous remark that the 20th century was that of physics but the 21st century would be that of biology has been widely quoted and discussed. However many advances in biology and medicine have required applications and discoveries in fundamental physics. For example, the positron emission tomography (PET) and magnetic resonance imaging (MRI) scanners were developed from a fundamental understanding of molecular and nuclear physics. Today many physical scientists are seeing new challenges and opportunities in the application of their research to the biosciences; the adaptation of laser spectroscopy to bioimaging, the use of scanning tunnelling and atomic force microscopes to study DNA and the new opportunities made available by the development of nanotechnology all show that the continuing symbiotic relationship between physics, biology and medicine will be key to the scientific advances of the 21st century. The list of physicists who have applied themselves to research in the biosciences is a long and impressive one: Crick, Schrödinger, Hodgkin and Huxley being but a few Nobel Prize winners whose physics background allowed them to make significant advances in the life sciences. However for many physical scientists, and perhaps for most physicists, biology and medicine remain unexplored land. In part this may be ascribed to the different languages used by the two communities such that communication between the disciplines is often fraught with misconceptions. Many physics students have consciously decided to stop studying biology prior to going to university, maths and chemistry being viewed as more relevant to their graduate studies. Thus many physics students (and faculty) fail to appreciate how many of the most basic laws and principles of physics are applicable to biological systems. It is thus a pleasure to read a book that seeks to demonstrate how basic physics may be applied to biomedicine. Arranged in 31 short chapters, each of which discusses a basic law or principle of fundamental physics, the text is predominantly a series of worked examples. Many of the examples provide a fascinating insight into the workings of the human body. For example, the book provides examples of the application of Newton's laws to the human jaw, electrical signal transmission through the neural network and how the human heart beat is regulated by electrical impulses, and the quantum nature of the response of the human eye and how it is degraded by age and illness. This book shows that a knowledge of fundamental physics is necessary if we are to understand the underlying biology of all life and demonstrate the folly of teaching science subjects as separate entities. This is a book that is ideally suited for use in small tutorial classes. The many worked examples may be used as the basis of discussion and analysis in class while some of the other questions may be set as a task for private study or used as questions in many undergraduate courses to illustrate the application of physics. In conclusion, I would recommend that all physics-related academic staff have a copy of this book on their bookshelf, and use it to show that physics is as relevant to the biological and medical world as it is to astronomy and cosmology. Equally, for many life scientists it provides a timely reminder that fundamental laws are just that - fundamental - and that without a knowledge of such laws and principles, advances in medicine will not occur. Perhaps God is, after all, first and foremost a physicist... N Mason