Hypotheses, engineering scientific

As a result, the limited ability of unit processes to create a viable niche for themselves within chemical engineering must ultimately be understood in terms which also involve unit operations. Although the historical resilience of unit processes turned out to be less than that of unit operations, it was no different in its essential elements. Studying the uneasy and ultimately unsuccessful career of unit processes can therefore be easily justified as a way to shed light on the far more successful career of unit operations. In particular, the career of unit processes raises a hypothesis about the evolution of unit operations. The staying power of unit operations was not so much because of the structural coherence of its conceptual elements as its essential links with social and, more specifically, professional groups. As a theoretical entity, unit operations appears far less stable and, in fact, appears quickly threatened by notions which rest on fewer and more fundamental scientific concepts. Ultimately, this threat came to be realized with the advent of transport phenomena, but this is another story. In effect, unit processes can be interpreted as both the attempt to extend the reach of unit operations and a symptom of their conceptual fragility. 

Hypothesis testing is the basis for many decisions made in scientific and engineering work. To explain an observation, a hypothetical model is advanced and is tested experimentally to determine its validity. If the results from these experiments do not support the model, we reject it and seek a new hypothesis. If agreement is found, the hypothetical model serves as the basis for further experiments. When the hypothesis is supported by sufficient experimental data, it becomes recognized as a useful theory until such time as data are obtained that refute it. 

There is another problem which engineering scientists often tend to overlook. Before this century, scientific knowledge was viewed as the proven truth. Philosophers and scientists have now destroyed that idea. All we can now say of any scientific hypothesis is that, it is the best we can do for the moment and it will be revised in due course. It is a description of part of the world, derived to enable prediction it is not the truth about the world. Thus when comparing scientific prediction in an imperfect world (in contrast to the well-controlled confines of a laboratory. Section 10.7) with rules and procedures developed ovei long periods and known to work, then although the parameters may be similar, some humility on the part of the scientist is required. 

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