Shadows of the Mind

« Shadows of the mind : A search for the missing science of consciousness» is one of the first books written by Roger Penrose.

The book consists of two parts :

- The first part is dedicated to demonstrating that a computer (that Penrose calls "Turing machine") can not possibly attain such a degree of perfection so that it becomes capable of fully replacing human consciousness.

- On the other hand, the second part of the book is absolutely passionate: Roger Penrose very elegantly and with convincing arguments demonstrates that human consciousness arises from a coherent quantum state in the microtubules of the cytoskeletons of neurons.

He also notes a remarkable example, that of the amoeba, a unicellular organism that does not posses a brain but that has microtubules in its cytoskeleton, that allow for it to achieve a certain degree of consciousness and to facilitate such functions as motion, to search for nutrients and to avoid obstacles.

Roger Penrose points out that anesthetizing a human or an amoeba, as well as any organism of the spectrum of animal life between this two extremes, is to act on the microtubules of the cytoskeleton and impede the sustainment of quantum coherence.

Roger Penrose talks of a proto-consciousness that exists even in elementary particles, from which animal and human consciousness is progressively build by the complexification of spacetime.

Written by Roger Penrose (Oxford University Press 1996)

Time Reborn

This is the last book by Lee Smolin. In this book, Smolin rejects the idea defended by many scientists, that the common sense view of time is contradicted by the results of contemporary physics. He defends the idea that the natural concept of time must remain a priority for understanding the world.

Lee Smolin advances the following thesis, inspired by what Edmund Husserl called the « mathematisation of Nature » : the reason physicists have come to reject the reality of time is that they have been bewitched by the beauty and success of the mathematical models they use into mistaking those models for reality.

As Lee puts it : "Useful as mathematics has turned out to be, the postulation of timeless mathematical laws is never completely innocent, for it always carries a trace of the metaphysical fantasy of transcendence from our earthly world. Either the world is in essence mathematical or it lives in time."

To make time real, he also puts forward an unconventional idea, “the principle of precedence”: that repeated measurements of a certain phenomenon yield the same outcomes not because it obeys a law of nature but simply because this principle holds. That is, determinism arises as the accord between results of identical past and future experiments but “new measurements” can yield new outcomes, not predictable from knowledge of the past.

With “new measurements” Lee Smolin has in mind measurements on entangled states, because an entangled system has properties that cannot be attributed to its constituent parts alone and in this sense has “new” properties. Lee argues that the laws themselves that explain this “new” phenomena must then evolve in a way that mimics biological evolution.

For Lee timeless laws, as are the current laws of physics that we use to describe physical reality, are and will remain inexplicable. This novel point of view would make physical laws explainable in the same way that features of life can be explained as a result of them providing an evolutionary advantage. In the words of Lee: “This can make laws explainable : If we want to understand law then law must evolve, law must change, law must be subject to time. Law then emerges from time and is subject to time rather than the reverse.”

Written by Lee Smolin (Houghton Mifflin 2013)

Par-delà le visible : La réalité du monde physique et la gravité quantique

This book is for those wanting to understand the questions undertaken by research in quantum gravity. The book covers a grand historical arc, starting from ancient atomism, in order to arrive to the contemporary questions on the reality of space and time. The book also contains reflections on the nature of scientific research.

Written by Carlo Rovelli (Odile Jacob 2015)

Seven brief lessons of physics

Simple and readable exposition of the main advances in theoretical physics during the twentieth century, and the questions and the mysteries that these advances have raised. The first six lessons are dedicated to: (i) general relativity, (ii) quantum mechanics, (iii) cosmology, (iv) elementary particles, (v) quantum gravity, (vi) heat, black holes, and time. The last chapter is a reflection on what are we, human beings, in the great fresco of modern physics: parts of this nature, not outside of it.

Written by Carlo Rovelli

Quantum: Einstein, Bohr, and the great debate about the Nature Of Reality

This book is a fascinating presentation of the birth of quantum mechanics and the first debates on the meaning of the theory and what it tells us about reality. The book describes in particular the reasons for which Einstein was never happy with the prevailing interpretation of the theory, and the famous debate with Niels Bohr on his topic.

Written by Manjit Kumar