Thermodynamics: What Does Causality Mean?

1. Introduction Every human being tends to try connecting the events by causes and effects. We believe that everything that happens need to have a causal explanation. This is simply how the human mind works. On account of this, causal relationships can also be observed in every branch of science. For instance, medical specialists search causes of the diseases. Similarly, physicists observe causes of the effects on the nature. This is a reason why even the simplest laws of physics have causal relationships. When a force applied to a spring, a displacement is observed. We know that the displacement is occurred just because of the force we applied. In other words, the force is the cause of the displacement which is effect in this case. In this …show more content…
What Does Causality Mean? The simple answer which would be given to this question is following. Causality is a relationship between causes and effects. However, simplicity does not bring clarity. Therefore, in order for us to understand clearly, we need to dig deep. The greatest definition, in my opinion, to the question is made by famous philosopher J.L Mackie. He defines causation as follows: "Causation as we observe it in 'objects' of any kind--physical processes, mental processes, the transition from willing to bodily movement, or anywhere else--is something that we might roughly describe as regular succession. Exactly what it is or may be, within the bounds of this rough description, does not matter for the present purpose. All that matters is (i) that it should be something that could, in those cases in which we form our idea of causation, give rise to a suitable association of ideas and hence, in accordance with my psychological theory of belief, to belief in the effect when the cause is observed or in the cause when the effect is, and (ii) that it should not be anything in which there is an observable necessity (or efficacy or agency or power or force or energy or productive quality) or anything at all that could supply a rival explanation of our idea of necessity, competing with the explanation given in terms of association, belief, and …show more content…
This belief ended when Rolf Landauer introduced the concepts which are called logical irreversibility and memory erasure. He is originally a famous computer scientist and the logical irreversibility is about information discarding process happens in computers. However, these ideas are introduced as a new solution to the problem which is created by Maxwell’s Demon. Let’s take a look how he has done this. At the first, we assumed that Maxwell’s Demon has not experienced any temperature change and neglected other effects. In order for the demon to process cycling, demon’s memory has to be erased. However, the following passage which mentions Landauer’s logical irreversibility states that erasure of the memory of the demon cause a temperature change. “Memory erasure, which takes a computer memory from an arbitrary existing state A, to a unique, standard reference state R discards information in a logically irreversible way. Logical irreversibility means that the prescription ‘Map the existing state A to the state R’ has no unique inverse because state A can be any of many possible states in the computer’s memory. Landauer argued that to each logical state there must correspond a physical state. Logical irreversibility carries the implication of a reduction of physical degrees of freedom, resulting in