Post by cjm on Jul 21, 2019 11:51:45 GMT
5.7. The Principle of Uncertainty against Determinism
Quantum mechanics is accepted as a basic and universal theory of physics that is candidate for description of physical world. The conceptual frame drawn by this theory is quite dissimilar to that of classical physics. In fact moving from classical physics to quantum mechanics is a revolution for our understanding and comprehending of the world. The main difference between these two is that classical mechanics anticipates that exact simultaneous values can be applied to all physical quantities. (Hilgevoord and Uffink, 2008)
In the classical theories of physics, statistical considerations are introduced in order to deal with large aggregates of elementary particles, but it is not thought that there are any essential theoretical limitations to the fineness of possible observations on the individual elementary
particles. In quantum theory on the other hand, we have at the basis Heisenberg‟s principle of uncertainty, which by a close analysis of methods of observation shows that there are essential theoretical lower limits to the accuracy with which we can measure the dynamical variables ( e.g. position and momentum) connected with the individual elementary particles. More precisely, the uncertainty principle formulates the disturbance of states by observations, by affirming that (a) it is impossible to measure simultaneously “complementary” or “non- commuting” variables, such as the position q and momentum p of a particle, and (b) that the more precisely we measure q, the less precisely can we predict p. (Moyal, 1949, p.315)
particles. In quantum theory on the other hand, we have at the basis Heisenberg‟s principle of uncertainty, which by a close analysis of methods of observation shows that there are essential theoretical lower limits to the accuracy with which we can measure the dynamical variables ( e.g. position and momentum) connected with the individual elementary particles. More precisely, the uncertainty principle formulates the disturbance of states by observations, by affirming that (a) it is impossible to measure simultaneously “complementary” or “non- commuting” variables, such as the position q and momentum p of a particle, and (b) that the more precisely we measure q, the less precisely can we predict p. (Moyal, 1949, p.315)
The classical causality in macro level had been meaningless in micro level. For instance the moving of electrons form one trajectory to the other couldn‟t be predetermined and accounted for. How only a certain percentage of particles of great number will act could be mentioned. This is not about the classical determinism in causality but shows a relation of probability. (Yıldırım, 1979) In 1927, Heisenberg put forward the principle of uncertainty which devastated deteminism.
“The uncertainty principle (for position and momentum) states that one canot assign exact simultaneous values to the position and momentum of a physical system.”
He mentions that in order to predict the place of a particle in the future, its starting conditions should be known and this isn‟t possible in micro level.The more precisely the position of the particle is determined, the less precisely its momentum is determined. (Hilgevoord and Uffink, 2008)
The difficulty mentioned here is that [of] measurement and can not disprove the classical principle of causality. Classical determinism relates the designation of an object at a moment to its faultless measurement of its starting conditions. In cases when we cannot determine its starting conditions, the inadequacy of our measurement method or tools of measurement will be in question. But it is wrong to explain the uncertainty principle with an impossibility of measurement because this principle is relevant to the interaction between the process of measurement and the object measured. (Yıldırım, 1979)
It also seems that determinism has scored another recent point:
link
Scientists from Yale University conducted an experiment that makes use of an ‘artificial’ quantum particle, made from an electrical circuit and a special type of insulating fence. By exposing this particle to radiation, the scientists were able to reverse what is called a quantum jump (when two particles interact with each other). This means that not only do scientists have a way of reversing a particle’s reaction to another molecule, but they have found a way to predict what kind of reaction that they will have. This can lead to a whole new batch of scientific and technological innovations.