When I first saw this book it instantly appealed to me and my sense of the pursuit of cutting edge science. Some of the writers I was familiar with, such as Roger Penrose, Alain Connes and John Polikinghorne. The other writers were less known to me, but the inclusion of the above names on the topic of Space & Time meant that this wasn’t one to be missed.
In truth, the book is dominated by Shahn Mahjid. He writes the introduction and his chapter is by far the longest in the book.
Andrew Taylor – The dark Universe
This first essay introduces some of the big issues in cosmology, including dark matter and dark energy. However, the chapter doesn’t shy away from the details. In this respect it is extremely hard going. It may have something to do with the fact that I was a theoretician, rather than an experimentalist, but it struck me as being far too technical for the non-expert reader.
Shahn Majid – Quantum spacetime and physical reality
With Taylor having laid the groundwork in experimental evidence, Majid picks up the mantle and takes us back into theoretical physics. Again, though, he goes down a very narrow road where few can follow him. I have heard it said than expert is someone who knows more and more about less and less, until they know everything about nothing. In this case, you have to know an awful lot about very little in order to fully follow Majid. I think I got stuck in the passageway about a third of the way down it.
The general thrust of the essay is on the potential solutions to how we might think about quantum spacetime and the implications that may have on how we think of the rest of reality. For example, while calculus has been an enormously helpful tool in physics, we may have to ditch it as a tool if we are to penetrate to the heart of reality.
Roger Penrose – Causality, quantum theory and cosmology
Of all the writers in this compilation, Penrose is by far and away the best communicator. In his essay, he gives an outline of some of the problems that thermodynamics poses to the issue of space and time, particular with relation to causal structure. He then goes on to give a description of his theory of Conformal Cyclic Cosmology (CCC). If you have read his Cycles of Time, then much here will be familiar, even if it remains at the very cutting edge of science.
Alain Connes – On the fine structure of spacetime
Connes is most famous for his work on noncommutative geometry, so it is no surprise that this is the subject of his essay. He starts off easily enough and does scare the reader somewhat by giving a complete Lagrangian of the standard model displayed on a slide, which is a gargantuan formula. This is merely to demonstrate that perhaps another approach is needed. Connes’ outline of noncommutative geometry starts off accessible enough, but quickly goes out of sight of the non-expert reader, much as Majid’s essay did.
Michael Heller – Where physics meets metaphysics
Heller is a catholic philosopher whose essay marks a radical change in the tone of the book. Instead of focusing on the physics, the emphasis is on the metaphysical implications of the theories discussed. For someone picking this up off the shelf, imagining it to be a book purely on physics, then Heller’s essay may be a disappointment. I, however, found it a welcome break from the intensity of the preceding chapters, as it was eminently readable and understandable to non-expert like me.
He gives a helpful, though not devastating, critique of the idea of “God of the gaps” which is an idea I have personally grown out of. He also looks at the idea of non-locality (an idea discussed in detail elsewhere in the book, and is mooted as a potential answer to the problem of action at a distance) and how that might then go on to inform and reform our understanding of philosophy and theology.
John Polkinghorne – The nature of time
Christian theologian, and former particle physicist, Polkinghorne gets the shortest essay tucked at the back of the book, which is just 6 pages long. As such, there is very little here, apart from an advertisement for Exploring Reality which Polkinghorne had published in 2005. The core of his argument may be found at the end, where he proposes that when it comes to studying time, physics, metaphysics and theology all have a role to play. This may be seen as a provocative statement by some positivists, though that would be testament to their lack of understanding of metaphysics.
The last 2 essays are very distinct from the rest of the book, which could be perceived by a purist physicist as spoiling it slightly. Instead, I think it adds a different dimension to the book which is quite welcome. The extremely hypothetical nature of the book is what appeals, though to get to grips with it all, you will need a PhD in theoretical physics. Where it is accessible, it is highly thought-provoking and will be interesting to return to it in the years and decades to come to see what, if any, becomes mainstream science and what may be discarded as hypotheses that failed to get off the ground.