[Newton assumed] that the universe needs God's intervention from time to time to stabilize it. For example, the orbits of the planets exhibit irregularities when they pass close to other planets or to comets. Newton feared that over time these fluctuations would accumulate and cause chaos, and the solar system would collapse. Therefore, he argued, God must step in periodically and set things right again. If the universe is a clock, then it is a clock that on occasion needs to be repaired and rebuilt. (The Soul of Science: Christian Faith and Natural Philosophy, p. 91).
For his part, astrophysicist and science popularizer Neil deGrasse Tyson (1958- ) clearly sees this explanation of Newton's as an example of belief in God acting as a "science stopper." In his TV series Cosmos, he comments:
What concerns me is, even if you're as brilliant as Newton, you reach a point where you start basking in the majesty of God, and then your discovery stops. It just stops. You're no good anymore for advancing that frontier. You're waiting for someone to come behind you who doesn't have God on the brain and who says "that's a really cool problem, I want to solve it." And they come in and solve it. (as quoted by J. Warner Wallace at crossexamined.org)
However, the Australian cosmologist Luke Barnes notes a number of problems with Tyson's (and Pearcey and Thaxton's) view of Newton. For one thing, the claim that Newton evoked God to explain why the irregularities in planetary orbits (known as perturbations) don't "accumulate and cause chaos" (to quote Pearcey and Thaxton) is based on single sentence in his work Opticks, published in 1704. And yet, Newton says nothing about God's intervention in the workings of the universe in his General Scholium, which Barnes describes as "the definitive statement of his theological conclusions drawn from physics," which was first published in 1713. Second, there are a number of questions about that single sentence in the Opticks, which make it difficult to know how much weight should be placed upon it. Third, Newton did try to develop a scientific explanation of why planetary perturbations do not create "chaos"--although he was ultimately unsuccessful. This leads to our fourth point--the reason Newton was unsuccessful is that he lacked the necessary mathematical tools to develop an adequate explanation. Fifth, the French mathematician Pierre Simon de Laplace (1749-1827), who did develop a successful explanation of planetary perturbations, had a lot of help from those mathematicians who followed Newton and proceeded Laplace. In short, what Pearcey and Thaxton AND Tyson say about Newton's explanation of planetary perturbations is at best debatable.
Perhaps an even more important point to make is that Newton, despite having "God on the brain," was amazingly productive as a mathematician and scientist. He invented calculus (although Gottfried Leibniz developed it independently), developed a universal law of gravitation and his laws of motion, and advanced our understanding of optics. Thus, Newton's belief in God (although the nature of that belief has been a subject of debate, with Newton being variously portrayed as a deist, an Arian, or an orthodox Christian) doesn't seem, in fact, to have been much of a "science stopper."
However, to be fair, belief in God can be a "science stopper"--depending on what sort of God one believes in. This can be clearly seen in the case of the one of the most celebrated scientists in history--Albert Einstein (1879-1955). The Belgian Georges Lemaitre (1894-1966) was a Catholic priest, theoretical physicist, mathematician, and astronomer. He was also the first to theorize that the fact that galaxies appear to be moving away from each other is due to an expanding universe. In other words, the universe is not static, but had a beginning--the so-called Big Bang. However, Einstein rejected Lemaitre's theory, despite acknowledging that the mathematical calculations underlying it were correct. In a recent article at evolutionnews.org, Jean-Pierre Luminet, paraphrasing another author, Dominque Lambert, explains why:
This reaction came from the fact that Einstein's implicit philosophy was inspired by [Baruch] Spinoza [(1632-1677)]. For the Dutch philosopher, "God" (Deus) was identified with "Nature" (Natura)...Consequently, due to the immutability of God, one could not accept any motion or evolution of Nature itself. Einstein thus rejected the idea of an evolving universe, i.e., a world with a real history. This "theological prejudice" led him also to criticize the idea of expanding (and contracting) universes put forward by [Alexander] Friedmann [another scientist] and Lemaitre.
In other words, Einstein rejected the idea of an expanding universe because of his conception of God. Instead, according to APS News, Einstein "introduced a mathematical 'fudge factor' into his equations, known as the cosmological constant...It implied the existence of a repulsive force pervading space that counteracts the gravitational attraction holding matter together. This balanced out the "push" and "pull" so that the universe would be indeed static." However, a number of years later, American astronomer Edwin Hubble (1889-1953) discovered evidence that strongly suggested that the universe was expanding, and Einstein was forced to acknowledge that his notion of a cosmological constant had been his "greatest blunder." In other words, Einstein was admitting, in effect, that his view of God had been a "science stopper."
It is instructive to contrast Newton's view of God with Einstein's. For Einstein, nature and God are identical. On the other hand, Newton appears to have held to the more traditional theistic view found in Judaism and Christianity that God and nature are separate--in fact, nature (the universe) was created by God. Thus, though Einstein and Newton both believed in the existence of a God, they had very different understandings of His nature. It is interesting to note, furthermore, that Newton's view of God would not have created a theological hurdle to accepting the idea of an expanding universe, unlike Einstein's view.
To conclude, it can be argued that belief in God proves to be a "science stopper" only when a scientist holds to a particular conception of who God is. Theistic belief, in and of itself, is, in fact, not a "science stopper" at all!
Image of Einstein from Wikimedia Commons