Holy Wars

Natural History, Oct, 1999 by Neil de Grasse Tyson

At nearly every one of my public lectures on the universe, I try to reserve time for questions. The succession of subjects is predictable. The first questions relate directly to the lecture. Then come the sexy topics such as black holes, quasars, and the big bang. If I have enough time to answer everybody, and if I have delivered the talk in the United States, the subject of God eventually comes up. I am typically asked, Do scientists believe in God? Do you believe in God? Do your studies in astrophysics make you more or less religious?

Publishers have learned that there is a lot of money in God when the author is a scientist and the book title directly juxtaposes scientific and religious themes. Successful examples include Robert Jastrow's God and the Astronomers, Leon Lederman's God Particle, Frank J. Tipler's Physics of Immortality, and Paul Davies's books God and the New Physics and The Mind of God. Even Stephen Jay Gould has joined the parade with his recent work Rock of Ages: Science and Religion in the Fullness of Life.

Except for Gould, who is a paleontologist and a historian of science, all these authors are accomplished physicists and astronomers, and while the books are not strictly religious, they do encourage the reader to bring God into conversations about astrophysics. Tipler's Physics of Immortality suggests that the laws of physics could allow you and your soul to exist long after you are gone from this world, and the author's book tour included many lectures to Protestant religious groups.

This lucrative publishing sub-industry has further blossomed because of efforts by the mutual-fund maven John Marks Templeton to develop a constructive dialogue between science and religion. In addition to sponsoring workshops and conferences, the John Templeton Foundation has singled out several religion-friendly scientists to receive its huge annual cash award.

Let there be no doubt that, as they are currently practiced, science and religion have no common ground. The late-nine-teenth-century tome A History of the Warfare of Science With Theology in Christendom, by Andrew White, a historian and one-time president of Cornell University, documents a long and combative relationship between religion and science. As in hostage negotiations, it's probably best to keep the dialogue going, but the schism did not come about for want of attempts to bring the two sides together. Great scientific minds, from Ptolemy in the second century to Isaac Newton in the seventeenth, attempted to deduce the nature of the universe from statements and philosophies contained in religious writings. Indeed, by the time of his death in 1729, Newton had penned more words about God and religion than about the laws of physics, all in a futile attempt to use biblical chronology to understand and predict events in the natural world. Had these efforts succeeded, science and religion today might be one and the same.

But they aren't, and the reason is simple. I have yet to see a successful prediction about the physical world that was inferred or extrapolated from the content of any religious document. Indeed, I can make an even stronger statement: whenever people have used religious documents to make predictions about the natural world, they have been famously wrong. A scientific prediction is a precise statement about the untested behavior of objects or phenomena in the universe--a statement that should be logged before an event takes place. When your model predicts something only after it has happened, then you have instead made a "postdiction." Postdictions are the backbone of most creation myths and, of course, of Rudyard Kipling's Just So Stories, in which fanciful accounts of everyday phenomena explain what is already known. In the business of science, however, a hundred postdictions are hardly worth a single successful prediction. Topping the list of religion-based predictions are the perennial claims about when the world will end, none of which have yet proved true. And at times, religion's failure to acknowledge valid predictions has actually stalled or even reversed the progress of science. We find a leading example in the trial of Galileo (which gets my vote for the trial of the millennium), during which he showed the universe to be fundamentally different from the Earth-centered system recognized by the Catholic Church.

In all fairness to the Inquisition, however, the geocentric universe still made a lot of sense observationally. With a full complement of epicycles to explain the peculiar motions of the planets against the background stars, this model conflicted with no known observations, even though Copernicus had introduced his heliocentric model of the universe a century earlier. The geocentric model was consistent with the teachings of the Catholic Church and with the Bible, wherein Earth, as described unambiguously in the first several verses of Genesis, is created before the Sun, the Moon, and the stars. If you were created first, then you must be at the center of all motion. Where else could you be? Furthermore, the Sun and the Moon were presumed to be smooth orbs. Why would a perfect, omniscient deity create anything else?