Why Do We Believe What Science Says? 17 



describing the world in terms of numbers is that it makes 

 it possible to describe relationships between objects in 

 terms of mathematical formulas. Although many young 

 people find numbers rather frightening and difficult to 

 learn, the fact of the matter is that the language of mathe- 

 matics is the easiest and most convenient way of describing 

 certain kinds of relationships. 



One of the most famous examples of the power of 

 mathematics to give a neat and convenient way of de- 

 scribing relationships is the work of Sir Isaac Newton in 

 formulating the laws of motion. Galileo had provided many 

 of the original observations on which Newton's work was 

 based. The kinds of questions they were interested in 

 answering ran somewhat as follows: How far will a bullet 

 go when it is fired from a cannon? How long will it take 

 a stone to reach the earth when dropped from a given 

 height? Why does the earth go around the sun faster 

 than the planets which are farther away? Is there some 

 overall relationship between these different types of events? 

 Newton found that there was such a basic relationship 

 and stated it as follows: F ^ Ma. This is a simple way 

 of saying, "All objects, no matter what their size or shape 

 or what they are made of, tend to move at increasing 

 speeds if you push steadily on them. The rate at which 

 they accelerate is directly proportional to the strength of 

 the push and inversely proportional to something I am 

 going to call the mass of the object." (I shall have some- 

 thing more to say about the last phrase in this sentence 

 in a later chapter. It is more significant than it looks.) 



It is important to notice that the equation was designed 

 to take care of all objects acted on by any forces and 

 at all speeds. This is what we mean when we say that 

 science is interested in making general statements about 

 the world. In its essence, the process is the same as that 



