Using different theories at the same time
Scientists, especially astronomers, use several incompatible theories in their calculations. How? And why?
As we mentioned last week, our navigator was out of the office teaching a professor how to use his sextant. Having decades of experience in both the observations and the calculations involved, he certainly has a firm grasp of the subject. But that’s not always the quality you need in a teacher.
Our astronomer and our navigator are away from headquarters at the moment, showing a Professor of Physics how to use his sextant. This style of instrument was the mainstay of nineteenth-century astronomy: made of brass and glass, with precise scales engraved on them for careful measurements. The people who used them had to work in a different way from current astronomers and must have had a different approach to life.
You will have heard of the detection of gravitational waves, just announced this past week. For once the mass media haven’t over-hyped a scientific discovery: this really is an important find. We’re not going to try to explain the science behind it (there are lots of articles on line and offline that do that). It’s the fact of the 100-year gap between the theoretical prediction and the actual observation that tells us something about the nature of science.
Your novel, novella, short story or epic poem has everything:
Shouldn’t you also get the universe right?
Our astronomer begs to be allowed to explain what’s really interesting about KIC8462852.
Our photographic consultant is fond of pointing out to us, with the help of books and magazines, the different styles of great photographers. Clearly part of the variation in the final image is in the subjects they choose: Ansel Adams is famous for mountains and landscapes of the Southwest, quite a different thing from a New York City street photographer catching an instant among people. “But,” he says, “put in exactly the same place, facing exactly the same subject, they’d still come up with different pictures. They just see differently.” Which is true, and much more widely applicable than he meant. Even the same person looking at the same scene can see something entirely different at a different time. A simple exercise can show this.
Science is a part of our culture. It’s not just that the products of science are all around us, in our hands and in our lives; no less, the discoveries of scientists are covered in the mainstream news media (not always well) and the concepts widely known (not always accurately). It’s clear enough by comparing our world with that of other cultures, say in the particular case of astronomy. We have cosmology (the Big Bang and all that); the ancient Greeks, a series of stories about gods and Titans.
Studying humans, even as amateurs, one seeks out similarities across cultures, and so we see cosmology equated to cosmic mythology. This leads to assertions like, “Cosmology is only our way of explaining the universe to ourselves, exactly the same way other cultures use other explanations.” This is just true enough to be seriously misleading.
Our chief consultant writes: It’s time to take up the question again of how a non-expert can evaluate an expert. In a previous post I introduced paradoxers, people from outside the field who claim to have made some highly important advance. Paradoxers are interesting in several ways and we’ll return to them later. Today we consider the case of some undoubted expert, a renowned or at least established scientist, describing something in his or her field. How much of it can you rely on to be true? How far can you actually trust a scientist?
This subversive-looking question occurred to our astronomer a while back. To try to answer it, he looked into the specific case of astronomy over the period 1833-1944, and wound up writing a well-regarded book with his conclusions. It’s 300 pages long, so I’m not going to try to include the whole thing in this post. His depressing conclusion is that even the best and most conscientious scientists may make statements as known fact, that turn out later to be wrong. His encouraging conclusion is that this is very rare, and for almost all scientists almost all the time, their presentations are reliable. In addition, there are a number of clues that help indicate the reliability, or otherwise, of what you’re being told.