The assumption that you have to take a materialist worldview in order to do science is simply wrong. There's nothing about physics, for example, that assumes, much less demands, that view of the universe. In fact, many of the greatest scientists, like Newton, Galileo, and Copernicus, were religious believers.
Despite these facts, philosophical materialism [defined in all dictionaries I've ever consulted as a "philosophical opinion"] has become so identified with science that scientists, and the general public, often have trouble telling them apart, which is why the discoveries that Barr describes come as a surprise, and their implications are resisted by many within the academy.
These implications aren't inconsistent with science, but rather with their dogmatic materialist worldview. Resisting these implications has required ingenious, almost fanciful, attempts to interpret the evidence in a way consistent with the materialist worldview.
Sorry for sprinkling around so many bolds, Phaedrus; but the point Barr makes about materialism not being science needs some "drilling in": A lot of people simply conflate the two -- and it shows. As a result, we often wind up with an "end-justifying-the means" type of science....
This is a very fine book, Phaedrus. I highly recommend it. Thanks so much for the ping. Merry Christmas!