The Principle of Complementarity


The discovery of quantum particles to exhibit apparently opposite features, like particles and their antiparticles or particles and the dual nature of particles as waves and particles, leads the Danish physicist Neils Bohr to advance in 1927 his so-called “principle of complementarity,” in which he maintains that isolated material particles can only be defined and observed through their interaction with other systems (1958:57). In his notion of complementarity, Bohr also sees the particle and wave dimensions as complementary representations of the same reality and both descriptions, according to him, are needed to complete the whole picture. Heisenberg (1958:107) later comments that as a result: “The world thus appears as a complicated tissue of events, in which connections of different kinds alternate or overlap or combine and thereby determine the texture of the whole.” It now appears that quantum theory reveals a fundamental reality, which physicist David Bohm (1917-1992) calls “unbroken wholeness,” clearly suggesting that we cannot decompose the world into independently existing smallest units. In the words of Bohm and Hiley (1974, 1975:96,102):

“Parts” are seen to be in immediate connection, in which their dynamical relationships depend, in an irreducible way, on the state the whole system (and, indeed, on that of broader systems in which they are contained, extending ultimately and in principle to the entire universe). Thus, one is led to a new notion of unbroken wholeness which denies the classical idea of analyzability of the world into separately and independently existent parts.

As American physicist, Barbara Brennan, states in her book The Hands of Light: “Quantum physics is beginning to realize that the Universe appears to be a dynamic web of interconnected and inseparable energy patterns. If the universe is indeed composed of such a web, there is logically no such thing as a part. This implies we are not separated parts of a whole but rather we are the Whole." The interconnectedness of all matter in the physical universe also reflects the so-called non-locality phenomenon (attributed as the Bell’s theorem) which advances the view that occurrences on one side of the Cosmos can instantly effect 'matter' on the other side of the Cosmos. In simpler words, an event which happens in one place instantaneously causes an influence or effect of another event in some place elsewhere in the Cosmos. This theory is discovered in 1935 when Einstein, Podolsky, and Rosenberg (EPR) theorize that the simple act of measuring a particular particle at one particular location instantly influence another particle far away, an event which Einstein calls “spooky actions at a distance.”

Almost after 30 years later, Irish experimental physicist John Stewart Bell (1928-1990) conducts an experiment following the EPR theory, the results of which prove the latter to be true. Fritjof Capra interprets this feature in the quantum world in terms of unity, interconnectedness, and mutual interrelation of all things and events that arise in the quantum world. This sort of interpretation, he refers to as the “metaphysics of quantum theory.” In his words (1975:124): “Quantum theory ... reveals an essential interconnectedness of the universe. It shows that we cannot decompose the world into independently existing smallest units.” Particle scientists discover that atoms can now be divided. But, strangely enough, the resulting elements are also atoms of the same nature as the original atom, consisting primarily of the three major elements: protons, neutrons, and electrons, composed of matter (dense part) and energy (the subtle part).