Review of Einstein's Entanglement by W. M. Stuckely, Michael Silberstein & Timothy McDevitt

Quantum entanglement is a phenomena explained by quantum theory. Take an atom or ion from a group of atoms or ions, or split a laser into two beam, and the pairs of atoms, ions, or laser photons are said to be entangled. That is to say alter the property measured on one of the pair, such as the spin or polarisation of the particle, and a measurement of the property on the other will be found to be perfectly correlated. The thing is that theory has it that this correlation takes place instantaneously. However, Einstein's special relativity says that nothing travels faster than the speed of light and so he dismissively called the phenomena 'spooky actions at a distance'. The reason that quantum entanglement does not conflict with special relativity is that no information is transmitted from the first particle to the second (so the phenomenon cannot be used for faster than light communication for example). Nevertheless, the quantum state of the second is changed – in theory instantaneously – by the alteration of the measurement made on the first

That this 'conveyance' through entanglement takes place at the least nearly instantly was demonstrated in 2008 by physicists from the University of Geneva. They created entangled photons and passed them through fibre-optical cables of equal length to receiving stations in the villages of Jussy and Satigny, which lie 11 miles (18km) apart, respectively east and west of Lake Geneva. They found that the speed of entangled signal was instant to within experimental error. Taking into account of experimental error the signal passing between the entangled photons was travelling at least ten thousand times faster than light.(1, 2)

Now, it should be pointed out that this is a 'quantum signal' and not a 'classical signal' and so no information other than measurement had taken place had passed between the entangled particles. (Theory has it that entanglement cannot be used for faster-than-light (FTL) communication, even though that is a science fiction dream. And, while FTL entanglement communication cannot be completely ruled out, the prevailing view among physicists is that it is impossible.)

Yet entanglement is real and may have practical purposes such as using entangled photons as encryption keys.

Nonetheless, the actual 'mechanism' by which such teleportation of properties takes place remains elusive: we have the theory and we have the maths, but not the how. Could our understanding of quantum mechanics be incomplete? (This is what Einstein thought.) Could the world work according to 'spooky actions at a distance? Could causes from the future create effects in the present? Could there be some sort of superdeterministic explanation? Yet entanglement is real, so perhaps – as is attributed to Richard Feynman in the context of quantum mechanics – best just to 'shut up and calculate'…

That quantum entanglement is recognised as being so intriguing is evidenced by it being the subject of research by those who won the Nobel Prize for Physics in 2022. What Stuckely, Silberstein and McDevitt have done in Einstein's Entanglement is attempt to come up with an explanation that basically refutes all the questions posed in the preceding paragraph. They say that entanglement can be explained employing the same language – chain of thought – Einstein himself used when formulating his theory of relativity.

If what the authors claim to have done is true, then it would be a truly impressive feat.

The authors state that their book will be understandable to both experts (quantum mechanics researchers) and beginners (physics undergraduates who have completed modules in quantum mechanics and relativity).

Alas, though I thought I was 'beginner' (a scientist who was not a physicist but has a lay interest in physics) I have not taken any undergraduate physics course modules the book's authors say their readers need. (My expertise is that of an environmental scientist who has had a career in conveying and analysing bioscience policy and who has also spent decades of working on climate change science and recent years on the deep-time evolution of biology and the Earth system: I left the formal study of physics after passing a school A-level in the subject.) In short, as per the authors' definition of 'beginner', I am not equipped to properly digest this book and, indeed, I did find it hard work.

Along the way to their rationalisation of the phenomena, the authors do provide an interesting exploration as to how past explanations have come and gone over the decades. And they do come up with a non-preferred reference frame explanation; though not one used when considering relativity, but one that involves Max Planck's physics!

By now you will have gathered that I am not qualified to pass judgment as to the merit of the authors' idea and so consequently am passing this book on to one of the physicists on the SF² Concatenation team. I would, though, say that if this book does pass muster then it will be a must-read for physics undergraduates. As for the rest of us, if the authors really have come up with a sound way to explain entanglement then I hope they can describe it in a way that is comprehensible to scientists outside of physics and even to the lay public with an interest in science. This is too fascinating a topic for physicists to keep to themselves and if their idea has legs, then a popular science book would be welcome.

Non-Fiction Reviews

Einstein's Entanglement