The Scientists

From the Introduction

My aim is to outline the development of Western science, from the Renaissance to (roughly) the end of the twentieth century. This means leaving to one side the achievements of the Ancient Greeks, the Chinese, and the Islamic scientists and philosophers who did so much to keep the search for knowledge about our world alive during the period that Europeans refer to as the Dark and Middle Ages. But it also means telling a coherent story, with a
clear beginning in both space and time, of the development of the world view that lies at the heart of our understanding of the Universe, and our place in it today. For human life turned out to be no different from any other kind of life on Earth. As the work of Charles Darwin and Alfred Wallace established in the nineteenth century, all you need to make human beings out of amoebas is the process of evolution by natural selection, and plenty of time.

All the examples I have mentioned here highlight another feature of the story-telling process. It is natural to describe key events in terms of the work of individuals who made a mark in science ­ Copernicus, Vesalius, Darwin, Wallace and the rest. But this does not mean that science has progressed as a result of the work of a string of irreplaceable
geniuses possessed of a special insight into how the world works. Geniuses maybe (though not always); but irreplaceable certainly not. Scientific progress builds step by step, and as the example of Darwin and Wallace shows, when the time is ripe, two or more individuals may make the next step independently of one another. It is the luck of the draw, or historical accident, whose name gets remembered as the discoverer of a new phenomenon. What is much more important than human genius is the development of technology, and it is no surprise that the start of the scientific revolution `coincides' with the development of the telescope and the microscope.

I can think of only one partial exception to this situation, and even there I would qualify the exception more than most historians of science do. Isaac Newton was clearly something of a special case, both because of the breadth of his scientific achievements and in particular because of the clear way in which he laid down the ground rules on
which science ought to operate. Even Newton, though, relied on his immediate predecessors, in particular Galileo Galilei and Rene´ Descartes, and in that sense his contributions followed naturally from what went before. If Newton had never lived, scientific progress might have been held back by a few decades. But only by a few decades.

Edmond Halley or Robert Hooke might well have come up with the famous inverse square law of gravity; Gottfried Leibniz actually did invent calculus independently of Newton (and made a better job of it); and Christiaan Huygens's superior wave theory of light was held back by Newton's espousal of the rival particle theory.

None of this will stop me from telling much of my version of the history of science in terms of the people involved, including Newton. My choice of individuals to highlight in this way is not intended to be comprehensive; nor are my discussions of their individual lives and work intended to be complete. I have chosen stories that represent the
development of science in its historical context. Some of those stories, and the characters involved, may be familiar; others (I hope) less so.

But the importance of the people and their lives is that they reflect the society in which they lived, and by discussing, for example, the way the work of one specific scientist followed from that of another, I mean to indicate the way in which one generation of scientists influenced the next. This might seem to beg the question of how the ball got rolling in the first place ­ the `first cause'. But in this case it is easy to find the first cause ­ Western science got started because the Renaissance happened. And once it got started, by giving a boost to technology it ensured that it would keep on rolling, with new scientific ideas leading to improved technology, and improved technology providing the scien- tists with the means to test new ideas to greater and greater accuracy.

Technology came first, because it is possible to make machines by trial and error without fully understanding the principles on which they operate. But once science and technology got together, progress really took off.

I will leave the debate about why the Renaissance happened when and where it did to the historians. If you want a definite date to mark the beginning of the revival of Western Europe, a convenient one is 1453, the year the Turks captured Constantinople (on 29 May). By then, many Greek-speaking scholars, seeing which way the wind was
blowing, had already fled westwards (initially to Italy), taking their archives of documents with them. There, the study of those documents was taken up by the Italian humanist movement, who were interested in using the teaching found in classical literature to re-establish civilization along the lines that had existed before the Dark Ages. This does rather neatly tie the rise of modern Europe to the death of the last vestige of the old Roman Empire. But an equally important factor, as many people have argued, was the depopulation of Europe by the Black Death in the fourteenth century, which led the survivors to question the whole basis of society, made labour expensive and encour- aged the invention of technological devices to replace manpower.

Even this is not the whole story. Johann Gutenberg's development of moveable type in the mid-fifteenth century had an obvious impact on what was to become science, and discoveries brought back to Europe by another technological development, sailing ships capable of crossing the oceans, transformed society.

Dating the end of the Renaissance is no easier than dating the beginning ­ you could say that it is still going on. A convenient round number is 1700; but from the present perspective an even better choice of date might be 1687, the year Isaac Newton published his great work Philosophiae Naturalis Principia Mathematica (The Mathematical
Principles of Natural Philosophy) and, in the words of Alexander Pope, `all was light'.

The point I want to make is that the scientific revolution did not happen in isolation, and certainly did not start out as the mainspring of change, although in many ways science (through its influence on technology and on our world view) became the driving force of Western civilization. I want to show how science developed, but I don't have space to do justice to the full historical background, any more than most history books have space to do justice to the story of science. I don't even have space to do justice to all of the science here, so if you want the in-depth story of such key concepts as quantum theory, evolution by natural selection or plate tectonics, you will have to look in other books (including my own). My choice of events to highlight is necessarily incomplete, and therefore to some extent subjective, but my aim is to give a feel for the full sweep of science, which has taken us from the realization that the Earth is not at the centre of the Universe and that human beings are `only' animals, to the theory of the Big Bang and a complete map of the human genome in just over 450 years.