The relationship between physics and other fields of science

You probably recognize science as being divided into different fields. For example, biology is the study

of living things. Chemistry is the study of how atoms and elements create the world we experience.

Astronomy is the study of stars, galaxies, and the vast universe of which the Earth is a part. The

division of science into separate fields was done to help people organize scientific knowledge.

However, the concepts in all of the divisions of science are interrelated.

Physics is sometimes called the fundamental science because it provides the conceptual framework that

underlies all of science. Physics breaks down nature into its simplest processes such as the force

between two objects. In contrast, chemistry, biology, and astronomy study complex interactions, such

as the growth of an animal, the formation of a star, or the combustion of gasoline in air. The complexity

of the universe is why it is important to understand the basic principles across different fields of

science. Biology can tell you how things living grow. Physics tells you that all the processes that occur

during living and growing obey the laws of physics even though we may not know the details of how

those processes actually work.

Any natural process or technology must obey the laws of physics. There is no exception. In many cases,

physics can tell you whether an explanation might be right or has no chance of being right. If the

explanation violates one of the laws of physics, it cannot be right, no matter whether it is biology,

chemistry, astronomy, ecology, or any other science. Still, knowing that everything depends on physics,

and proceeding from physics to understanding biology are two very different things. Physics can tell us

how two atoms interact with each other. But there are so many atoms in an animal that physics is nearly

useless for understanding large-scale behavior, such as how animals grow, or how they reproduce.

Physics is often considered the least complex of the basic sciences because it describes how a few

particles and four forces create the elements and fundamental interactions in the universe. Chemistry is

concerned with more complex systems than physics. Our world contains millions of chemicals made

from the basic elements and even more interactions between the chemicals. Biology is the most

complex of the sciences because it describes the physical processes that occur in life. Even a small

living creature such as a bacteria, is an organization of thousands of chemicals and interactions between

chemicals. This book is designed to help you make connections between physics, chemistry, and

biology (Figure 1.20).