Control Over Experiments - How It Restricts Physics' Vision

So at one level there is no conflict between a physicist's emphasis on repeatable experiments and her interest in being surprised, proved wrong, and forced to learn something new. But this conflict is resolved only at the expense of a restriction of the scientific field of vision, confining one's attention to those things that one can make happen over and over again, at will - i.e. things that are under one's own control. And the fact is that most matters of interest, and those of greatest interest, are not repeatable at all, and would be destroyed by efforts to control them in the way demanded by natural philosophy. Foremost are of course people - each person on this planet is unrepeatable, with his or her own innate dignity, personality, history, will, and feelings. There is no question of repeating a person's intrinsic being, history, or choices, even considering issues of identical twins and cloning. Attempts to control or repeat a person's choices and personality, whether to obtain scientific reproducibility or for any other reason, would be essentially disrespectful and immoral, and if successful would destroy the person in question. Clearly "scientific truth" is very small (not insignificant, just small) compared to the total of what is important and true. For instance, the questions of whether Alison Hinckley down the street is happy, the success of her marriage, her love or neglect of her parents, how she deals with suffering and death of others and in her own life - none of these are the province of scientific truth. Yet these are things of real import.

Control Over Experiments and Scientific Truth

Earlier I said that experiments involve careful observation of nature, trying to see it very accurately, with the overall hope of learning something new and surprising. I also emphasized the fact that nature is external to oneself and not totally under one's own power. Therefore it may seem incongruous that physicists seek experiments that can be repeated at will, under total control.

On one level there is no contradiction: we create experiments that can be repeated - however the first time we run the experiment we are in suspense about what will actually be observed. The certainty and repeatability is in our preparation of the experiment; the surprise is in the experiment's actual outcome, the details or whole of which may be different than expected.

The point of having totally repeatable control over an experiment is that the experiment's outcome should be exactly the same every time it is performed. Once an experiment is done once, the surprises should be over, and further repetitions of the experiment only serve to verify the scientific truth of the original result. In fact the only "truth" that physicists care to recognize while acting as physicists is those observations that can be repeated experimentally, as well as any mathematical techniques whose predictions have been repeatedly checked experimentally. If you repeat an experiment and obtain a different result than what was originally found, this casts doubt on whether the original result actually was "scientific truth."

For instance, the failure by many to reproduce cold fusion is said to have "discredited" the original experiment which observed cold fusion, leading most physicists to think that probably cold fusion did not occur even in the original experiment. Of course it is possible that fusion actually occurred the first time but not other times - but even if this were true it would not be a "scientific truth," simply because it can not be reproduced on demand by everyone. The only ways to establish the truth or falsity of this possibility would be similar to the procedures used when investigating and judging a crime - collection of historical evidence about the equipment that was used in the first cold fusion experiment and the data that was obtained, rethinking how to interpret all that was observed, judgments about the trustworthiness of the scientists, etc. There may also be reasoning based on currently accepted ideas of how the universe works, and efforts to establish whether or not these ideas indicate any possible way that fusion might have happened in the first cold fusion experiment. In any case, the result of this sort of process would not be "scientific truth," simply because it would be confining itself to a particular time, place, and set of scientists and observations. Physics does not deny the the possibility of truths of a particular, non-repeatable nature - the shape of a particular rock, the sound of a specific person's voice, etc. - but neither does it pay much attention to these things.

Control Over Experiments - Hard Sciences vs. Soft Science

It is precisely this repeatability by anybody, at any time, as many times as desired, and under perfect control, that physicists prize in their experiments and consider to be the hallmark of "scientific truth." Conversely, if something does not meet these standards, then we refuse to think about it or discuss it, at least not as physics per se. We leave these questions to other disciplines, and we uses the words "hard" vs. "soft" to describe how well a discipline conforms to the scientific ideals of repeatability and control, with physics on the "hard" end of the spectrum. ("Hard" vs. "soft" has nothing to do with how difficult the fields actually are.) For instance, astronomy has the problem that the stars are not under our control and we can not make them repeat their behavior; however if ten astronomers look at the same star at ten different times they will almost certainly see the same thing, which is a sort of repeatability. There is also a statistical repeatability in astronomy: picking a thousand stars at random, you always find roughly the same number of red giants, white dwarfs, Sun-type stars, etc. So astronomy is not as "hard" a science as physics; we can also say that it is a "softer" science than physics, which means the same thing. Going softer, one can speak of sociology, the study of large groups of people. From a scientific point of view this is worse: not only are world's people out of the scientist's control, but their actions, demographics, characteristics, opinions, etc. change from year to year and even day to day. The only sort of repeatability a sociologist can hope for is by running two or more similar measurements/surveys/censuses at roughly the same time. Softer yet would be psychology/psychiatry, where one finds a few things which recur, like the addict's acquired physical dependence on drugs, or oedipal complexes, but these recurring elements occur in a multitude of variations unique to each subject and constitute only a small portion of the overall field of study.

Then there are many fields which are not properly science at all. Most of these have their roots decidedly outside of philosophy, and emphasize the practical or functional side of things: law, engineering, the arts, history, accounting, etc. These are often called professions. However there are at least three disciplines which are rooted in philosophy and therefore are not in the same class as the practical professions, but are not science either. One is philosophy itself, which has parted ways from natural philosophy by steering away from experiment. Another discipline is theology, which is rooted in philosophy and does emphasize very careful attention and thought about the world around us, but focuses on unrepeatable aspects of that world, namely persons and what they do, say, and write. If natural philosophy is the philosophy of repeatable things, theology is the philosophy of unrepeatable things, of persons. A third philosophical but non-scientific discipline is mathematics, which concerns certain results which can be reproduced on demand, but which are not part of the physical observable world.

Of course a lot of times there is a secret to repeating something; you have to figure out all the necessary preconditions. Finding out how to make something repeat can be part of hard science. For instance a few years ago someone reported observing a fusion reaction occurring fairly slowly, in smallish laboratory. Previously fusion had been observed only in the sun, thermonuclear bombs, and large experiments involving very large amounts of energy and heat, so the new observation was very exciting. Over the next years many many physicists spent a lot of time trying to make fusion happen in their own labs, using similar equipment. Some report that they found evidence for cold fusion, though their evidence was pretty subtle, the sort that requires very special measurement equipment, quite far from nuclear explosions. However many physicists failed entirely to reproduce cold fusion, and this happened so often that the scientific community as a whole remains sceptical of those who continue to report cold fusion in their labs. So here we see that the question - is cold fusion repeatable on demand? - is a valid question for physics. However as it became clear that many skilled researchers are unable to reproduce the original result, cold fusion moved out of the domain of hard science, and the physics community stopped thinking about it. If someday in the future someone did figure out a recipe for reproducing cold fusion on demand, then suddenly it would become again a physics question.