The Apes—Points To Ponder

Are scientific experiments truly repeatable?

The repeatability of experiments is a supremely important criterion for accepting any scientific hypothesis. Some experiments certainly are repeatable. If you mix a given amount of silver nitrate with a given amount of sodium chloride at a specific temperature, you will produce a precipitate of a given amount of silver chloride. You always get the same result. So it is with some scientific experiments. However, there are also many notable failures to repeat “discovered” phenomena.

One famous area of disputed claims is the ESP research of J B Rhine, which suggested experimental “proof of telepathy.” It was never independently verified. Once you enter the area of scientific psychology, you encounter the problem of the experimenter unwittingly influencing the experiment, and the additional problem that one group of subjects is not necessarily equivalent to another. Rhine’s experiments may have suffered from both of these failings. Perhaps J B Rhine and his methods were at fault, and perhaps not.

As Heraclitus noted, “No man ever steps in the same river twice, for it’s not the same river and he’s not the same man.”

The point is that repeatability is not easy to establish, because all the factors that influence the outcome of an experiment may not be known.

Where you do not have repeatability, the scientific method rules itself out—in theory. In practice, that important criteria is not always enforced. Some experiments, notably those carried out in the Large Hadron Collider (LHC) that is buried beneath the France-Switzerland border, escape the “rule of repeatability” because there is only one LHC and the demands for its use far outstrips availability.

Even if you successfully “exactly repeat” an experiment with this equipment, until someone builds another equivalent LHC, you cannot know for sure that there wasn’t some subtle fault in the experimental equipment.