Monday, 17 August 2015

The debt we all owe Bernard d’Espagnat (1921-2015)

It was only in the last few weeks that Bernard d’Espagnat died. Sadly, not many people were aware of this… nor of his contribution to what we now know about quantum reality. And this is because despite what he (and others) have revealed in their lifetimes, people still believe the Materialism world-view is the de-facto accepted nature of reality. This is thanks to the evangelistic fervour of über-atheists (such as Richard Dawkins etc.) whose world-views have long since fallen apart ardently dis-informing the public of what scientists, through the work of d’Espagnat, know to be the fabric of all reality… and it isn’t Materialism.
d’Espagnat (theoretical physicist and philosopher) was born in 1921 in Fourmagnac, and established himself as a major voice in the field of Quantum Mechanics (working alongside Fermi, Bohr and Bell). And when in 1979 wrote “The doctrine that the world is made up of objects whose existence is independent of human consciousness turns out to be in conflict with quantum mechanics and with facts established by experiment” he paved the way for his description of physical reality as a ‘veiled reality’ in the context of Quantum Mechanics and his experiments with Bell's inequalities he furthered this concept of veiled reality and won the attention of the John Templeton Foundation to become the 2009 Templeton Prize winner for his "work which acknowledges that science cannot fully explain 'the nature of being.'”
But it is for something else for which we owe so much to d’Espagnat, because his work sprang from his issues with his fellow scientists. He remained, till he died, troubled by the scant attention most physicists paid to the interpretational questions raised by quantum mechanics, as he wrote in the Guardian newspaper in 2009:
And then a real breakthrough took place in that John Bell, a colleague of mine at Cern, published his famous inequalities, which - for the first time - opened a possibility of testing whether or not entanglement-at-a-distance had experimentally testable consequences.
“The outcome confirmed my anticipations. Entanglement-at-a-distance does physically exist, in the sense that it has physically verifiable (and verified) consequences. Which proves beyond a shadow of a doubt that some of our most engrained notions about space and causality should be reconsidered.
It was way back in 1965 (showing my age here) that his first book, Conceptions of Contemporary Physics (1965), asked these questions and sketched possible resolutions, underscoring his insistence that scientists face the issues raised by their own pursuits. And yet, even in 2009 he felt that scientists were ignoring the real issues of science, as he explained in his address upon winning the Templeton Prize
When all is said and done I therefore consider that the – apparently so sensible and self-evident – world view we called transcendental realism is to be dropped after all. I think that our scientific knowledge finally bears, not on reality-in-itself – alias “the Real,” alias “the ground of everything” – but just on empirical reality, that is, on the picture that, in virtue of its structure and finite intellectual capacities, human mind is induced to form of reality-in-itself. And, account being taken of the hidden wholeness I mentioned before, I even claim that we must drop the view according to which objects, be they elementary or composite, exist by themselves and are at any time at some definite place is space. To state that we see them so because the structure of our senses makes us perceive the Real in this form seems to be nearer to the truth. Admittedly this conception of mine is not the one the bulk of the scientists’ community favors. Note however that it is quite far from just being my personal one. On the one hand it meets with the views of outstanding contemporary neurologists specialized in cognition theory. And on the other one it obviously bears quite a definite relationship with the main Kantian views, which were adhered to by a great many philosophers as well as by some physicists such as Henri Poincaré.
Because of his insights during the ‘60s, and his work with more recognised quantum scientists like Bell and Bohr, d’Espagnat was an early interpreter of the deep philosophical significance of experimental research agenda in quantum physics. He encouraged physicists and philosophers to think afresh about questions long considered marginal but which today serve as the foundation for new fields of research into the nature of reality. And in ‘Le réel voilé, analyse des concepts quantiques’ (Veiled Reality, An Analysis of Present-Day Quantum Mechanical Concepts), he coined the term “veiled reality” and explained why significant experiments over the past decade had not restored conventional realism. And when he published ‘On Physics and Philosophy’ (published in France in 2002 as Traité de physique et de philosophie) it was hailed as “surely the most complete book to have been written on this subject and one likely to last a long time…” by Roland Omnès.
His contribution to science should not be forgotten, lest we want science to continue to stagnate and feed the monster that is Materialism. And although he did not describe himself as a monistic idealist, maybe because his philosophy had never been tested to his satisfaction (although Bohr and Heisenberg, the two founding fathers of the Copenhagen interpretation, clearly leaned towards monistic idealism in some of their writings).
d’Espagnat recognised that Quantum Mechanics gives us a revolutionary view of reality, a view radically different from the deterministic, causal, continuous, and objective view of the world with which classical mechanics mesmerises us. Quantum Mechanics depicts the world of appearance as a succession of discontinuous events, and what’s more disconcerting to the classical physicist, it seems to say that no event is an event unless it is an observed event. This appears to invite subjects, observers, into the affair of objects, the observed; and if subjects and objects get mixed up, then the traditional doctrine of strong objectivity – the observer independence of objects – doesn’t hold. And more recently Bell’s theorem and Aspect’s experimental demonstration of EPR-Bohm non-locality have challenged the doctrine of strong objectivity even further.
The subject-object mixing and non-locality form the core of the quantum mechanical measurement problem. In the standard Copenhagen interpretation, the assumption of collapse of the wave function upon observation (the reduction postulate) is introduced in order to connect theory and experiment, but the question of what constitutes a measurement has been left unanswered. And in view of the EPR-Bohm non-locality, the collapse is clearly non-local, yet the ontological implication of non-local collapse has still not been studied.
Any explicit role of the subject is avoided in the standard interpretation, but the price is the baffling quantum/classical dichotomy. This dichotomy finds a straightforward resolution if we assume as von Neumann and Wigner have done, that consciousness, the observing subject, collapses the state function of a quantum system, not the “classical” measuring apparatus. Unfortunately, at least two major objections can be raised against the von Neumann-Wigner hypothesis. The first is the question of mind over matter, and the second is solipsism. But this subject is for another post. For now, let us remember the man without whom these questions might not have been heard today.
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