Nobel-winning physicist

Steven Weinberg

is often called one of the most influential living scientists in the world. Besides his seminal work on particle physics and several other books on science, the 82-year-old American has just come out with an account of the birth of

titled 'To Explain the World'. He talks to

Subodh Varma

about the tension that exists between religious belief and science:

Many people believe that much of modern science already exists in ancient texts or teachings of their respective religions. In India, for example, the Hindu rightwing claims that many scientific and technological achievements of modern times like the aircraft, nuclear bombs, plastic surgery, etc were discovered 3,000 to 10,000 years ago. Is that possible?

What is the difference in the 'science' of ancient times and modern times?

Why did modern science arise in the 17th century? Why not earlier or later?

Despite stupendous advances in science, its acceptance still seems to be limited in society. In fact, you have publicly taken on antiscience lobbyists like climate change deniers or anti-evolutionists…

Does a person have to abandon religion in order to become a scientist?

You have earlier written about the 'beauty' of science. What does that mean?

It is nonsense to suppose that modern scientific and technological knowledge was already in the hands of people thousands of years ago. Though much has been lost, we have enough ancient texts from Greece, Babylon, India, etc to show not only that early philosophers did not know these things, but that they had no opportunity to learn them.We have learned to keep questioning past ideas, formulate general principles on the basis of observation and experiment, and then to test these principles by further observation and experiment. In this way, modern physical science (and to an increasing extent, biological science as well) has been able to find mathematical laws of great generality and predictive power. Our predecessors in the ancient and medieval world often believed that scientific knowledge could be obtained by pure reason, and where they understood the importance of observation, it was passive, not the active manipulation of nature that is characteristic of modern experiment.Further, their theories of the physical world were often muddled with human values or religious belief, which have been expunged from modern physical science.It is impossible to say why the scientific revolution occurred precisely when and where it did. Still, we can point to several developments in former centuries that prepared the ground for the scientific revolution.One was the Renaissance of the 15th and 16th centuries, which led to an increased concern with the real world and a turning away from scholastic theology. Another was the invention of printing with moveable type, which made it possible for the books of scientists such as Copernicus and Galileo to circulate rapidly throughout Europe.Looking further back, we can point to the growth of universities from the 13th century onward. Although these grew out of schools associated with Christian cathedrals, they became havens for secular scientific research, for Buridan and Oresme at Paris, for Galileo at Padua and Pisa, and for Newton at Cambridge.There are few people today who will deny the value of science, but there are many who are terribly confused about the content of scientific knowledge. They doubt the conclusions of geophysicists regarding global warming, and they think that it is still an open question whether evolution through natural selection is responsible for the origin of species. It is good to keep an open mind, even about the conclusions of experts, but there comes a point at which issues become settled. It is silly to keep an open mind about whether the Earth is flat.Certainly not. There are fine scientists (though not many) who are quite religious. But there is a tension between science and religious belief. It is not just that scientific discoveries contradict some religious beliefs. More importantly, when one experiences the care and open-mindedness with which scientists seek truth, one may lose some respect for the pretensions of religion to certain knowledge.By seeking scientific knowledge over many centuries, we have developed a sense of the sort of scientific principle that is likely to describe nature, and we have come to think of such principles as beautiful, in the same way that a designer of sailboats develops a sense of the sort of design that will sail well, and comes to think of such sailboats as beautiful. There is no simple prescription for the beauty of a scientific theory, but it surely includes rigidity, the property that the details of the theory cannot easily be altered without destroying the consistency of the theory.