Distinguishing Fact and Theory

A recent Facebook, BFSU discussion involved the distinction between fact and theory. This essay is my contribution to that discussion.

I find it humbling to recognize how much “scientific fact” is really highly refined theory. Take our solar system for example. Even with all modern technology, it not yet been possible to get a photograph, much less direct observation, that gives us direct proof of our solar system. Hence, our solar system and the way it behaves is basically theory. Yet, we make models of it and teach it as fact.

How does a theory get to be fact? Our solar system provides a good example. Early in history (prior to the 1500s) it was thought that the Earth was the center of the universe and the sun, and all the stars circled the earth. However, there were numerous observations that didn’t jib with this concept, particularly certain “stars” (called planets) seemed to “wander” among the other stars.

Copernicus, in the early 1500s, recognized that the movements of the sun, stars and planets could be explained and made more sense with a different model, namely putting the sun at the center and having the earth and planets orbit the sun. Note that this was a new theory and it was not readily accepted, in fact, it was generally disregarded. Gradually, however, more and more observations were made that supported the Copernicus model. Significantly, Galileo (1610) observed the moons of Jupiter proving that smaller bodies do orbit a larger one proving the feasibility of the Copernicus concept. Still the concept was not readily accepted.

Fast forward, evidence for the Copernicus model continued to accumulate to now we can make such accurate predictions concerning the movement of bodies (everything from planets to rockets) in space that we are able to build rockets that will land probes on Mars. It is along the way that theory becomes fact.

Here is the crux. When a theory enables one to make predictions and those predictions prove to be accurate — that is what leads one to belief that the theory is an accurate description of reality, i.e., a fact.

It might be fun to study the history of science from this point of view. That is, how much of science that we now consider fact, started off as theory. But gathering further evidence and finding predictive value has gradually brought that theory to the status of FACT!

Acceptance of a theory being fact, however, does not happen all at one time. Some people are convinced of the reality of a theory with relatively little supporting evidence; others remain unconvinced regardless of overwhelming supporting evidence.

Climate change is a case at point. The basic theory (increasing CO2 in the atmosphere will cause a warming climate because CO2 traps heat.) was proposed over one hundred years ago. Since that time there has been no evidence that refutes that theory. Now we have (unwittingly) conducted the crucial test. We have increased the atmospheric concentration of CO2, via burning of fossil, by about 60 percent, and we find that climate is warming. For most of us, this is proof positive; others remain in vociferous denial.

Continuing to increase atmospheric CO2, theory predicts, will have catastrophic effects for both humans and the natural world. Do we need to test that as well?

Comments are welcome.