When one talks about what an electron is “doing”, one implies what sort of a wave function is associated with it. But the wave function is not a physical object in the sense a proton or an electron or a billiard ball. In fact, the rules of quantum theory do not even allot a unique wave function to a given state of motion, since multiplying the wave function by a factor of modulus unity does not change any physical consequence. Thus, Heisenberg opined that “the atoms or elementary particles are not as real; they form a world of potentialities or possibilities rather than one of things or facts”. This shows the helplessness of the physicists to explain the quantum phenomena in terms of the macro world. The activities of the elementary particles appear essential as long as we believe in the independent existence of fundamental laws that we can hope to understand better.
Reality cannot differ from person to person or from measurement to measurement because it has existence independent of these factors. The elements of our “knowledge” are actually derived from our raw sense impressions, by automatically interpreting them in conventional terms based on our earlier impressions. Since these impressions vary, our responses to the same data also vary. Yet, unless an event is observed, it has no meaning by itself. Thus, it can be said that while observables have a time evolution independent of observation, it depends upon observation for any meaningful description in relation to others. For this reason the individual responses/readings to the same object may differ based on their earlier (at a different time and may be space) experience/environment. As the earlier example of the cat shows, it requires a definite link between the observer and the observed – a split (from time evolution), and a link (between the measurement representing its state and the consciousness of the observer for describing such state in communicable language). This link varies from person to person. At every interaction, the reality is not “created”, but the “presently evolved state” of the same reality gets described and communicated. Based on our earlier experiences/experimental set-up, it may return different responses/readings.
There is no proof to show that a particle does not have a value before measurement. The static attributes of a proton or an electron such as its charge or its mass have well defined properties and will remain so even before and after observation even though it may change its position or composition due to the effect of the forces acting on it – spatial translation. The dynamical attributes will continue to evolve – temporal translation. The life cycles of stars and galaxies will continue till we notice their extinction in a supernova explosion. The moon will exist even when we are not observing it. The proof for this is their observed position after a given time matches our theoretical calculation. Before measurement, we do not know the “present” state. Since present is a dynamical entity describing time evolution of the particle, it evolves continuously from past to future. This does not mean that the observer creates reality – after observation at a given instant he only discovers the spatial and temporal state of its static and dynamical aspects.
The prevailing notion of superposition (an unobserved proposition) only means that we do not know how the actual fixed value after measurement has been arrived at (described elaborately in later pages), as the same value could be arrived at by infinite numbers of ways. We superimpose our ignorance on the particle and claim that the value of that particular aspect is undetermined whereas in reality the value might already have been fixed (the cat might have died). The observer cannot influence the state of the observed (moment of death of the cat) before or after observation. He can only report the “present state”. Quantum mechanics has failed to describe the collapse mechanism satisfactorily. In fact many models (such as the Copenhagen interpretation) treat the concept of collapse as non-sense. The few models that accept collapse as real are incomplete and fail to come up with a satisfactory mechanism to explain it. In 1932, John von Neumann showed that if electrons are ordinary objects with inherent properties (which would include hidden variables) then the behavior of those objects must contradict the predictions of quantum theory. Because of his stature in those days, no one contradicted him. But in 1952, David Bohm showed that hidden variables theories were plausible if super-luminal velocities are possible. Bohm’s mechanics has returned predictions equivalent to other interpretations of quantum mechanics. Thus, it cannot be discarded lightly. If Bohm is right, then Copenhagen interpretation and its extensions are wrong.
There is no proof to show that the characteristics of particle states are randomly chosen instantaneously at the time of observation/measurement. Since the value remains fixed after measurement, it is reasonable to assume that it remained so before measurement also. For example, if we measure the temperature of a particle by a thermometer, it is generally assumed that a little heat is transferred from the particle to the thermometer thereby changing the state of the particle. This is an absolutely wrong assumption. No particle in the Universe is perfectly isolated. A particle inevitably interacts with its environment. The environment might very well be a man-made measuring device.
Introduction of the thermometer does not change the environment as all objects in the environment are either isothermic or heat is flowing from higher concentration to lower concentration. In the former case there is no effect. In the latter case also it does not change anything as the thermometer is isothermic with the environment. Thus the rate of heat flow from the particle to the thermometer remains constant – same as that of the particle to its environment. When exposed to heat, the expansion of mercury shows a uniform gradient in proportion to the temperature of its environment. This is sub-divided over a randomly chosen range and taken as the unit. The expansion of mercury when exposed to the heat flow from a particle till both become isothermic is compared with this unit and we get a scalar quantity, which we call the result of measurement at that instant. Similarly, the heat flow to the thermometer does not affect the object as it was in any case continuing with the heat flow at a steady rate and continued to do so even after measurement. This is proved from the fact that the thermometer reading does not change after sometime (all other conditions being unchanged). This is common to all measurements. Since the scalar quantity returned as the result of measurement is a number, it is sometimes said that numbers are everything.
While there is no proof that measurement determines reality, there is proof to the contrary. Suppose we have a random group of people and we measure three of their properties: sex, height and skin-color. They can be male or female, tall or short and their skin-color could be fair or brown. If we take at random 30 people and measure the sex and height first (male and tall), and then the skin-color (fair) for the same sample, we will get one result (how many tall men are fair). If we measure the sex and the skin-color first (male and fair), and then the height (tall), we will get a different result (how many fare males are tall). If we measure the skin-color and the height first (fair and tall), and then the sex (male), we will get a yet different result (how many fare and tall persons are male). Order of measurement apparently changes result of measurement. But the result of measurement really does not change anything. The tall will continue to be tall and the fair will continue to be fair. The male and female will not change sex either. This proves that measurement does not determine reality, but only exposes selected aspects of reality in a desired manner – depending upon the nature of measurement. It is also wrong to say that whenever any property of a microscopic object affects a macroscopic object, that property is observed and becomes physical reality. We have experienced situations when an insect bite is not really felt (measure of pain) by us immediately even though it affects us. A viral infection does not affect us immediately.