In reading many of the comments on Yahoo and Facebook concerning science (usually in the context of climate change) there seems to be a lot of misunderstanding about how science works.
Many people seem to think that once science gets an “answer”, science moves on to other questions. But if an “answer” changes, many people seem to think that the whole concept is bogus. But that is not how science works.
There is never an “answer”. Science is an on-going process, not any fixed set of questions and answers. Scientists work by setting forth a theory, coming up with experiments that seem to test the theory, run the experiments, and see how the results fit (or don’t fit) with the theory. Sometimes, there are no experiments, but just a set of observations. If the theory is sustained by the experimental results or sets of observations — that is, if the theory correctly predicts the results observed — the theory has some experimental support. If the results don’t support the theory, the theory, as proposed, has some sort of flaw. A theory is only weakened and possibly discarded if numerous experimental results and observations fail to support the theory’s predictions. A theory is never fully “proved”. A theory is never the “answer”.
On the other hand, if a large number of different experiments have results that are consistent with the predictions of a theory, although the theory is never “proved” one can say that there is a large body of evidence supporting the theory.
Experiments that come along that seem to provide evidence not consistent with the theory, force researchers to examine the experiment to see if there might be flaws in the experimental design that might explain why the results were inconsistent with the theory, or the theory itself may require modification in a way to better explain the results.
An example of this process is the replacement of Newtonian mechanics with Einsteinien quantum mechanics. When experiments involving the motions of atoms were conducted, the results were not those predicted by Newtonian mechanics. With the theories proposed by Einstein (and related theories proposed by others), the results were suddenly in line with the predictions of the new theories. More and more experiments (and observations) were in line with the predictions of quantum mechanics. Recently, observations of sub-atomic particles such as the Higgs Bosun, and the first observations of what seem to be gravitational waves, lend more evidence that relativity and quantum mechanics seem to be a better fit to what is being observed. Do these findings “prove” quantum mechanics? No, they do not “prove” it, but they lend more evidence for it.
I don’t read as many of the professional science journals as I once did. About the only science-related publication I regularly read these days is “Science News”. Each bi-weekly issue reports on a sampling of articles in the professional journals. These reports cover a wide range of topics. And browsing through some of the recent articles, one can see this incremental advancement of knowledge.
For example, one recent article reported on a study that compared the injuries found in the bones of Neanderthals with current day injuries as reported by hospitals over a five-year period. It had been theorized that some correlation would be found between the injuries sustained by Neanderthals with certain types of modern-day activities, for example injuries sustained by rodeo bronco riders. While some small correlations were found, for the most part the injuries of Neanderthals didn’t seem to have any similarity to injuries caused by current activities. This suggests that the theory about what types of activities were similar to the activities of Neanderthals was incorrect, and that some other explanation (or refinement of the theory) needs to be developed.
To be sure, whatever activities that Neanderthals were performing that caused them injuries isn’t very important in the overall scheme of things, but this is just an example of the process undergone by a scientific theory. If some set of data seems to go against the theory, then the theory gets modified. Nothing earth shattering if the theory gets modified. Indeed, it is almost expected that over time, any theory will undergo modifications.
In the same issue is a report of a retraction of an article in the publication “Science”. The retraction was the result of the activities of an independent review board who found that the original data in the experiment could not be found and that there were questions about the methodology. This is an example of the type of occurrences that have created headlines about “scams” and “forged science”, and that seem to stick in the memory of many people.
In any occupation, from lawyer to barrista to doctor to nurse to teacher to clerk to scientist, there’s always going to be a small fraction who are crooked. The fact that at least in scientific publications fraudulent results seem to be quickly discovered and reported is reassuring. Of more concern to me are recent reports I have seen that show that a growing number of findings reported in clinical trials in medical publications are slanted, if not downright false. Given that many of such studies are funded by organizations with a vested interest in the outcomes, I am not surprised at this reported trend.
Overall, however, I still have confidence in the scientific method. The theories of science are not static. They do change over time. And it has only been within the last two or three hundred years that this philosophical outlook has been widely accepted. People who talk about scientists “clinging” to theories that have been disproven — although as I have said, there really is no such thing as a totally rejected theory — don’t know many current-day scientists. An exception might be those individuals employed by certain industries, but for the most part scientist are independent of as much bias as is humanly possible. That’s the training they’ve had.
There are several theories around that have been sustained over time by observations and experiments: Darwin’s theory of evolution, Einstein’s theory of relativity, and, more recently, the theory of man-caused climate change. To focus on the latter, there certainly shouldn’t be much debate over the question of whether the Earth’s climate changes over time. There are thousands of observations that indicate that the Earth has had ice ages in the past, as well as hot periods.
Observations over the past 100 to 150 years show that temperatures over the Earth have been rising. There is also evidence of the warming trend in terms of the shrinking of the polar ice fields and the retreat of most glaciers. These most recent temperature changes seem to be occurring at a much faster rate than changes observed over longer periods, with observations of this coming from seabed cores, tree ring studies, and polar ice cores, and other items. The question is what might be causing this accelerated warming.
It has also been observed that the level of CO2 gas in the atmosphere has been increasing rapidly over the past years for which observations are available. Studies of the CO2 concentrations indicate that while significant amounts do come from naturally occurring sources, another big chunk comes from man-related activities. Many experiments and observations, such as observing the nearby planet Venus, support the theory that CO2 is a greenhouse gas that traps solar heat in the atmosphere.
While correlation does not prove causation, many scientists have put together the observation that temperatures are rising at a faster-than-historical rate, and that CO2 levels are rising faster than in the past due to the output of man-made CO2, and have come up with the theory that the temperature rise can best be attributed to human activity on this planet: hence, the theory of man-caused climate change.
Given the scale of the Earth, it is unfeasible to come up with a controlled experiment that one could use to test the hypothesis of man-caused climate change. So one must rely upon purely observational data, however fraught with issues about sample size, sampling bias, and observational accuracy that are inherent in such data. And the vast majority of climate scientists who have looked at this data have concluded that it supports the theory of man-caused climate change.
The process of science gives us a constantly changing landscape of understandings of how the universe functions. The understandings are constantly being modified, usually in small increments, but sometimes in sweeping changes. For myself, I like the fact that scientific theories can change over time. If anything is a slave to the past, one only has to look at religions that espouse one fixed set of rules that were laid down thousands of years ago.
Thoughts from a Bearded Collie owner 