# Book review: “Entanglement. Il più grande mistero della fisica”

By Amir D. Aczel

A wonderful book explaining the basic idea behind the most incredible and mind blowing fact of quantum physics, the entanglement! The book follows also the historical path of this phenomenon and its understanding and experimental evidence, starting from the seminal EPR paper up to the quantum teleportation being possible thanks to the nature of the entanglement.

The understanding of the Nature and of our fundamental idea were challenged more than once in our history; think about the concepts of absolute space and time destroyed by Einstein’s theories of special and general relativity or the fact that the fundamental laws of quantum physics have an intrinsic probability aspect so that pure determinism is trashed. Again Einstein in the EPR paper stated the impossibility for quantum physics to be a complete theory assuming impossible to doubt about the locality of the reality, i.e. it should be impossible to have objects in real life correlated between them regardless their mutual distance, so that doing something on an object here would cause something instantaneously on another object wherever else. But John Bell many years later entered the game introducing a famous theorem that could be experimentally verified to discriminate if Einstein was right or not. Years later other people were capable to implement such experiments in many different ways closing definitively the puzzle. Einstein was wrong! The entanglement is a real and observable fact and it implies we have to abandon even the concept of locality!

Sad to not have been in the optics laboratories of my department during the years of my physics university studies because in that years De Martini research group was one of the two all over the world capable of doing quantum teleportation and so being able to “see” entanglement at work!