We are almost up to date but throughout this hurried history of Quantum Mechanics, I might have given the impression that the Copenhagen Interpretation is the only show in town. Not so. Although it remains the orthodox approach, there are many competing interpretations. I’ll mention a few here and provide links for further reading if your interest is stimulated. Indeed, this link …
Quantum Reality (not to be confused with Nick Herbert’s work of the same title).
… really does the job for me.
In its own way, each of the above is somewhat controversial. We have already discussed Einstein’s objection to Copenhagen and many other scientists, to this day, feel a strong affinity with Einstein’s view. Nevertheless, this is still the “textbook” interpretation.
“Many Worlds”, originally proposed by Hugh Everett in the 1950′s in an attempt to resolve the much debated measurement problem and the fate of Schrödinger’s cat. According to Everett the cat would have – not nine – but as many lives as there are probabilities arising from the measurement experiment. In other words, if a decision can have a thousand probable outcomes, then a thousand new worlds are created to realise each and every one of them. At first this theory was derided as being too fantastical to deserve consideration but by 1995 this online Many Worlds FAQ was claiming outright support from 58% of a poll of 72 leading scientists.
I could go into a long analysis of each interpretation in turn, rehashing the information available if you follow the links I have provided. But I won’t. The general point to be made here is that the interpretations fall into two camps: the realist and the anti-realist (we could add another labelled “don’t ask”). Those eminent scientists, mathematicians and philosophers who have what they would call a rational, common-sense view of reality would likely opt for the more realist interpretations such as Consistent Histories or Transactional. This group doesn’t feel comfortable with paradoxes such as nonlocality. They insist that electrons are little lumps of matter – not metaphysical wave packets that only achieve physical reality once an observer happens across it. They would probably be keen to adopt Albert Einstein as their patron.
David Bohm’s Implicate Order theory is quite an odd one to box and label. Bohm himself was a materialist and disliked the idea of dice throwing just as much as did his mentor, Einstein. Thus, Implicate Order is a realist theory complete with the hidden variable that Einstein suggested must be present to make Quantum Mechanics a complete theory.
Yet it is this theory that is probably most popular among New Age thinkers – the very people who would naturally select the anti-realist stance. In my view it is the holistic emphasis of the theory that appeals to the more idealist among us. Whatever the attraction may be, it is true that Bohm’s philosophy has inspired several best sellers which, according to your viewpoint, either fall into the category of popular science or New Age (or both). These include Michael Talbot’s book The Holographic Universe, Gary Zukav’s The Dancing Wu Li Masters and Fritjof Capra’s The Tao of Physics.
Last, but not least, is the interpretation that draws the most flak from the scientific establishment: the one which says that a conscious observer is required to collapse the wave into a “real” particle. The argument against it is simple and, to most, self-evident: if it has taken evolution billions of years to produce a self-aware, sentient being, then who was around in the universe to play the role of conscious observer while evolution was doing its thing? Well, religious people would say that the answer to that is obvious: God. Others, such as Amit Goswami, hold that the universe itself is conscious or, to be more precise, that consciousness is the prime cause; that physical reality is a product of this primary consciousness