Second, science progresses by making mistakes. I have heard scientists claim that their work is a search for “truth.” When I hear this, I am always tempted to ask if “truth” is absolute or is it relative — a sort of “situation ethics.” To most scientists, the word “truth” smacks of dogmatism, which defies all that science represents; dogmatism is rigid, science is not. We can defend our observations and data, but we cannot claim they are truth as most persons usually understand it (as absolute). When scientists wander “off key,” slip up, and use the word “truth” in this context, they refer loosely to what most of us would call “fact,” something that is supported by the weight of current evidence.
To cite a classic example, Copernicus realized that his observations of the heavens did not jibe with Aristotle’s view that the earth is the center of the universe, with the sun revolving around the earth. At that time the Church agreed with Aristotle, and held that the earth does not move – one can read the supporting verse of Scripture in Psalm 104:5: You set the earth on its foundations, so that it shall never be shaken (New Revised Standard Version). Galileo’s observations and his skill in mathematics convinced him that Copernicus was correct, and called down the wrath of the Catholic Church and the Inquisition on his head. Others, including Kepler and Newton, provided convincing evidence that our solar system is heliocentric, not geocentric.
Later generations of scientists have shown that the earth is a small planet far out on one arm of a run-of-the-mill galaxy in an expanding universe, in what may even be only one of many universes. As a post-script to this drama, the Vatican took nearly four hundred years to promote Galileo from heretic under permanent house arrest to hero. In explaining its change of heart, the Vatican chose to view Galileo as a man of both faith and reason, as indeed he was. But he sharply separated his theology from science when he said, “The Bible is a book about how to go to heaven, not how the heavens go.”
Third, science is “self-correcting”: As new evidence appears, earlier interpretations may be fine-tuned or even jettisoned if there is overwhelming evidence to do so. I vividly recall sitting in a lecture hall, excited by at last being on my way to becoming a scientist, when the professor – a distinguished chemist – declared that “Science is one damned lie after another.” His language disturbed me far less than his view of science. How could a scientist make such an outlandish claim? It took a few years, but delving into the history of science convinced me that my professor was correct, even if his way of expressing his view was a bit over the top.
A familiar example of this attribute of science is classical Newtonian physics, which served us so well for more than three hundred years, and continues to do so. Not only did it explain such phenomena as motion and energy, but its scientists developed an approach to problem-solving that became a model for their colleagues in the other natural sciences. Near the end of the 19th Century, the scope of physics began expanding beyond our wildest imagination to include quantum physics, and special and general relativity; we realized that Newtonian or classical physics is a part, rather than the whole, of something much more inclusive than was known more than three hundred years earlier.
Science is self-correcting, thanks in part to “peer review,” where other scientists scrutinize and criticize the way one designs and conducts experiments, and how one interprets the results. Mistakes are caught, conclusions weighed. Science is one of the most transparent of human endeavors. Many of us may work alone in our laboratories or in the field, but for science to progress we must disclose our findings to the world at large. Unshared results are essentially useless results. A few years ago, two researchers announced that they had achieved “cold fusion” in the laboratory. That was big news: If those experiments could have been reproduced and confirmed, they might have revealed a source of cheap, abundant energy. Other scientists followed the same methods but could not reproduce – and thus could not confirm — the earlier results. The idea of cold fusion as it was attempted and described died with a whimper. It did not meet the rigorous standards imposed by peer review.