Brian Cox — co-author with Jeff Forshaw of The Quantum Universe (And Why Anything That Can Happen, Does) (Da Capo Press, 2012) — has posted an article titled Why Quantum Theory Is So Misunderstood in the Wall Street Journal’s Speakeasy blog. There he defends his claim that according to quantum mechanics “everything is connected to everything else”, and that “this is literally true if quantum theory as currently understood is not augmented by new physics,” which for the moment (and probably for a long time to come) it isn’t. “This means that the subatomic constituents of your body are constantly shifting, albeit absolutely imperceptibly, in response to events happening an arbitrarily large distance away…”
That this statement received some well-deserved criticism in scientific circles wasn’t, according to Cox, because it is wrong but because “it sounds like woo woo, and quantum theory attracts woo-woo merde-merchants like the pronouncements of New Age mystics attract flies.”
Cox goes on to inform us (“for the record”) that “the subtle interconnectedness in quantum theory cannot be used to transmit information.” Wait a minute. Haven’t we just been told that the subatomic constituents of our bodies are constantly shifting in response to events happening an arbitrarily large distance away? If this were true, the response would depend on what happened a large distance away — otherwise we couldn’t say that it was a response to what happened there. But if what happens here depends on what happens there, then what happens here contains information about what happens there.
I am not saying that the “subtle interconnectedness in quantum theory” can be used to transmit information. It cannot. What I am saying (in agreement with the critics) is that blather about subatomic constituents constantly shifting in response to arbitrarily distant events is not the right way to illustrate the subtle interconnectedness that exists in quantum theory. Rather, it is precisely the kind of thoughtless talk that fires up the wooly masters of the New Age. Nor does saying that the constant shifting takes place “absolutely imperceptibly” explain why it cannot be used to transmit information. This qualifier is nothing but the second of two wrongs that pretend to make a right.
Cox accepts partial responsibility for the “cataclysmic tosh” purveyed by writers who cannot “possibly have the faintest idea how to use quantum theory to calculate the energy levels in a hydrogen atom” but tries to defend the use of his shifty metaphor, with scant success. Along the way he cites scientific questions — Is the climate warming and, if so, what is the cause? Is it safe to vaccinate children against disease? — whose answers “are independent of the opinion, faith or political persuasion of the individual.” I wish the tosh purveyed by those who know how to calculate the energy levels in a hydrogen atom were equally independent of their faiths or opinions. (Political persuasion may not be a factor here.)
The fact of the matter is that the mathematical formalism of quantum physics is a probability calculus. It serves to assign probabilities to the possible outcomes of measurements yet to be made, on the basis of measurement outcomes already obtained. This calculus, moreover, is the only testable part of the theory. It is all that experimental physicists need to know and most of them care to know. How, if not by way of faith or opinion, does one get from here to balderdash like the following?
“Quantum theory tells us that the universe we experience emerges from a bewildering, counterintuitive maelstrom of interactions between an infinity of recalcitrant sub-atomic particles. To understand something as simple as a rainbow, we have to allow each single particle of light to explore the entire universe on its journey through the rain.”
For a significantly more insightful discussion of quantum mechanics and its popularization I strongly recommend an article by philosopher of science Dennis Dieks, which appeared in the first issue of AntiMatters.