To Explain the World: The Discovery of Modern Science

by Steven Weinberg

Where my own past writing has touched on history, it has been mostly the modern history of physics and astronomy, roughly from the late nineteenth century to the present.

Although in this era we have learned many new things, the goals and standards of physical science have not materially changed.

but the idea of seeking mathematically formulated and experimentally validated impersonal principles that explain a wide variety of phenomena would have seemed quite familiar.

when the goals and standards of science had not yet taken their present shape.

As is natural for an academic, when I want to learn about something, I volunteer to teach a course on the subject.

This book grew out of the lecture notes for those courses.

it is the perspective of a modern working scientist on the science of the past.

I have taken this opportunity to explain my views about the nature of physical science, and about its continued tangled relations with religion, technology, philosophy, mathematics, and aesthetics.

Before history there was science...

At any moment nature presents us with a variety of puzzling phenomena: fire, thunderstorms, plagues, planetary ...

Observation of the world led to useful generalizations: fires are hot; thunder presages rain; tides are highest when t...

But here and there, some people wanted more than just a collection of facts. They wan...

more important, they did not have anything like our ideas of what there was to know about the world, and how to learn it.

a novel of L. P. Hartley put it, “The past is a foreign country; they do things differently there.”

My focus in this book is a little different—it is how we came to learn how to learn about the world.

I am not unaware that the word “explain” in the title of this book raises problems for philosophers of science.

They have pointed out the difficulty in drawing a precise distinction between exp...

By explanation I mean something admittedly imprecise, the same as is meant in ordinary life when we try to explain why a horse has won a race or why an airplane has crashed.

After all, science could hardly exist without human beings to practice it.

I chose “Discovery” instead of “Invention” to suggest that science is the way it is not so much because of various adventitious historic acts of invention, but because of the way nature is.

With all its imperfections, modern science is a technique that is sufficiently well tuned to nature so that it works—it is a practice that allows us to learn reliable things about the world. In this sense, it i...

Thus one can talk about the discovery of science in the way that a historian can talk about the d...

because its practices are sufficiently well tuned to the realities of biology so that it work...

this book will emphasize physics and astronomy.

It was in physics, especially as applied to astronomy, that science first took a modern form.

Of course there are limits to the extent to which sciences like biology, whose principles depend so much on historical accidents,...

development of scientific biology as well as chemistry in the nineteenth and twentieth centuries followed the model of the revolution ...

Science is now international, perhaps the most international aspect of our civilization, but the discovery of modern science happened i...

Modern science learned its methods from research done in Europe during the scientific revolution, which in turn evolved from work done in Europe and ...

and ultimately from the precocious science...

The West borrowed much scientific knowledge from e...

geometry from Egypt, astronomical data from Babylon, the techniques of arithmetic from Babylon and India, the magnetic...

but as far as I know, it did not import the methods o...

by showing how far these very intelligent individuals were from our present conception of science, I want to show how difficult was the discovery of modern science,

how far from obvious are its practices and standards.

This also serves as a warning, that science may not yet be...

we may today be repeating some of the errors of the past.

I will instead make a point of using present knowledge to clarify past science.

For instance, though it might be an interesting intellectual exercise to try to understand how the Hellenistic astronomers Apollonius and Hipparchus developed the theory that the planets go around the Earth on looping epicyclic orbits by using only the data that had been available to them,

this is impossible, for much of the data the...

But we do know that in ancient times the Earth and planets went around the Sun on nearly circular o...

and by using this knowledge we will be able to understand how the data available to ancient astronomers could have suggested...

there are “technical notes” at the back of the book.

Science is not now what it was at its start. Its results are impersonal. Inspiration and aesthetic judgment are important in the development of scientific theories,

but the verification of these theories relies finally on impartial experimental tests of their predictions.

science is not a branch of mathematics, and scientific theories cannot be deduced by purely mathematical reasoning.

Science and technology benefit each other, but at its most fundamental level science is not undertaken for any practical reason.

Though science has nothing to say one way or the other about the existence of God or an afterlife, its goal is to find explanations of natural...

Science is cumulative; each new theory incorporates successful earlier theories as approximations, and even explains why these ap...

None of this was obvious to the scientists of the ancient world...