Discuss quantum physics and how Thi Lam feels the Deductive-Nomological (D-N) Paradigm of Explanation is difficult.
Quantum mechanics is one of the most powerful scientific theories ever established, the interpretations and predictions of which have been confirmed by experiments. It is the perfect cornerstone of scientific physics that describes the existence and behavior of matter and energy at subatomic and atomic stages. The character and behavior of matter and energy at that level is often referred to as quantum physics. Although several people believe that the world is indeterministic, some dispute this belief that the cosmos is deterministic. In quantum mechanics, a value cannot be assigned quantities, instead there, is a particular probability of finding a value when we measure a quantity or quantities.
Quantum mechanics seems to give empirically assessable predictions about the probabilities of realizing specific results in experiments. This theory observes that two systems that are alike can bring about different results hence it is impracticable to make predictions with conviction albeit one being extremely knowledgeable and intelligent. This notion demonstrates that the world is indeterministic, unlike classical mechanics that perceives the world as deterministic. The quantum mechanical view of the world finds the world to be full of paradoxes, uncertainties, Probabilities, and dualities.
Science’s most anticipated role in the society is to accomplish its capacity to explain various phenomena. These capabilities are closely linked to its capacity to tell the unanticipated and unprecedented occurrences and make predictions. Such explanatory ability of science is also a philosophical area of interest. According to Hempel, “to explain a fact is to demonstrate how the fact could be subsumed under a law or several laws together with various antecedent conditions” (246). This is referred to as the covering law theory that can be further broken down to Deductive-Nomological model of explanation.
This model also referred to as Hempel’s model suggests that a phenomenon is explained by construing it from a statement called explicandum. The premises of this statement also called ‘explanans’ are scientific laws combined with other supporting comments (Hempel 247). The accuracy of a scientific explanation depends on the truth in the explanans. According to Deductive-Nomological model, an explicandum should be logical as a corollary of the explanans. This means that an explanation should take the outline of an excellent deductive argument in which the explicandum ensues as an inference from the grounds in the explanans.
Thi Lam thinks that we should not consider a statistical model of explanation as an incomplete version of Deductive- Nomo logical model of explanation as it can depict the essential contingency of probabilistic occurrences (425). Probabilistic events are best regarded as quantum mechanics. Lam observes that Hempel explains the statistical concept of probability as the relative rate with which a given type of incident occurs within a specific circumstance. Similarly, quantum physicist presents same probabilistic perception regarding a lengthy run of quantum events.
Lam argues that there is room for considering probabilistic explanations as not every natural phenomenon relinquishes themselves to the Deductive-Nomological model of explanations. He claims that as much as he does not know whether the fundamental nature of physical reality is deterministic or indeterministic, he thinks that it is no longer within the jurisdiction of philosophical or religious speculation, “but it is rather an empirical issue that can be solved by empirical means” (425). The physical world when scrutinized by empirical means displays both deterministic and indeterministic characters that can be justified by indeterministic explanatory model or a deterministic one depending on the circumstances. Lam notes that deductive-Nomo logical model is incomplete and cannot account for those phenomena that are indeterministic thus quantum physics fill the gap that has existed in explanatory science.
2. Which model of scientific explanation, statistical or D-N, do you find to be more persuasive and why?
Contrary to Lam, I find the probabilistic statistical model of scientific explanation to be more persuasive compared to its counterpart, D-N model of explanation. Even though both rely on the presence of some laws, statistical model relaxes the deterministic requirements of its premises to a high probability requirement. The stiff laws the D-N model rely on cannot be applicable in all circumstances. I think that proving the accuracy of the D-N’s model is quite a difficult task. There are some unseen variable that are responsible for different results in different circumstances that had same systems. As much as I may agree with Lam that D-N model is very good at explanations, I tend to point out at those weakness that makes it incomplete. Otherwise, it is a good model of scientific explanation.
3. Explain what Lam means when he says that “general laws confer a sense of ‘scientific legitimacy’ onto an explanation” in D-N models.
Lam maintains that general laws are needed and adequate in explanatory accounts of deterministic explicandum-events. Conversely, statistical rules are not required for justifying probabilistic explicandum events. By Lam saying that general laws bestow a sense of scientific authority and legitimacy onto an explanation in D-N models, he means two things. One, he implies that the only way an explanation to phenomena can acquire a scientific credibility is by is by imploring a covering law under which it incorporates the explicandum-event (427). He believes that there are various explanatory accounts an event or phenomena would embrace if they were not considered under the ingrained laws.
The law outlines how nature will act by asserting an anomic symmetry between particular antecedent conditions and their conforming ensuing state of affairs. By subsuming a specific spatial-temporal occurrence under laws of universal nature, we are suggesting that phenomena of the kind defined by the law will act in agreement with every other incident of the kind excluding extraterrestrial intervention (Lam 428). What confines people into giving accurate explanations on events and phenomena is the presence of laws that would otherwise allow them to give other wrong statements on these events.
Secondly, he means that by incorporating the explicandum-event under the law, people link the incident to a more significant engrained body of scientific knowledge. For people to articulate that an event or phenomena will proceed in a given manner, there must be the capacity to see how it will be explained through general laws, by the presently accepted scientific model of the time. Lam believes that to explain an event is to exhibit it as occupying its place in the discernible patterns of the world (428).
Having critically analyzed these two theories of explanation, I am convinced that our physical world displays both deterministic and indeterministic features that can be explained by both D-N and statistical explanation models. If an explicandum or a statement illustrates a phenomenon that is deterministic, then the D-N model is the best explanatory model to account for the event. If the statement describes a phenomenon that is indeterministic, the best descriptive model to implore is the probabilistic statistical model (Lam 427). Salmon shares the same thoughts (81).
Hempeî, Carl G. “ASPECTS of SCIENTIFIC EXPLANATION.” (1965).
Salmon, Wesley C. Scientific explanation and the causal structure of the world. Princeton University Press, 1984.