Time Resurrected – A Review of the Book By Lee Smolin
Time Reborn – From the Crisis in Physics to the Future of the Universe by Lee Smolin, Houghton Mifflin Harcourt, 2013, pp: 319 ISBN 978-0-547-51172-6
Prof. Lee Smolin is a well-known Theoretical Physicist and author. He is a founding senior faculty member of the Perimeter Institute of Theoretical Physics in Waterloo, Canada, and is also a Professor in the Philosophy department at the University of Toronto. He has just published his fourth book. It is on the reality of time. There is, yes, physics in it but not addressed to Physicists. There are deep philosophical thoughts expressed in it but not meant for academic Philosophers. It is a book for all thinking people, the non-specialists interested in modern science and ancient wisdom.
Smolin talks about the latest developments in Quantum Mechanics, Relativity and the Standard Model of Physics in an easy relaxed manner - no intimidating complex theoretical nuances or formidable mathematical equations - as if you are chitchatting the state of the nation over a cup of tea on a beach resort. He traces the historical trends in the scientific process of analysis leading to the present impasse in the search for an all-encompassing “Theory of Everything.” He laments how the best of brains have been spending their time unsuccessfully for over nine decades in their effort to unify the four forces of nature under one formula. And mind you, he himself made very significant contributions to this field. So he asks, is there not something fundamentally wrong in the basic conceptual structure of Physics?
Right from the ancient times, man has placed an unchanging celestial power up in the Heavens, beyond time and space. The earth and the earthlings are considered to be destined to suffer being subjected to change at the mercy of “time.” The philosophers looked for the divine hand that writ their fate. The scientists went in search of the processes that are not ravished by time. They invented mathematical structures believed to be outside the realms of time and extended their application to physical processes. The scientists discovered formulae in physics that are invariant in time. They could eliminate ‘time’ from their equations, more by a sleight of hand than a holistic appraisal, whether it was Newtonian or Einstenian physics. The advances in quantum mechanics and particularly in quantum cosmology hammered the final nail into the coffin of ‘time.’ The concept that “time is an illusion” caught up with physicists as a gospel truth.
All the theories in physics are based on observing a little chunk of the world and then extending them to the whole universe. They present the laws of physics as eternal and unchanging. But what if it’s all wrong?
Suppose ‘Time’ is real and not an illusion. Suppose it is ‘space’ which is illusory and an emergent phenomenon. And suppose that physical laws ‘evolve’ in time following a Darwinian process of natural selection. How then will the whole physics get re-written? What impact it will have on other fields of life like philosophy or even economics?
Smolin lets his imagination go wild in answering those questions – many times backed by good logic but speculative and unproven physics to the consternation of academically bent physicists. The book presents his thoughts which had been incubating in his fertile brain for several years – for example many of these ideas come in seed form in his TED lecture in 2003.
The first part of the book extending up to 90 pages is a good and enjoyable read for those interested in the developments of moderns physics described in a racy style by an expert having a thorough grip and deep understanding of the subject. It establishes how ‘time’ got expelled from physics. The second part is over 150 pages and tries to resurrect time by pointing out the various fallacies in the theories of quantum physics, cosmology, relativity, thermodynamics and so on. The title of the book comes from this part.
I give below an excerpt from the book, to show as an example, the clarity and simplicity with which Smolin presents even highly complicated concepts like that of Dr. J. Barbour’s theory on the illusory nature of time – a theory of unfailing interest for all students of advatia.
*****
From Pages: 85-87:
The best thought-through approach to making sense of the quantum cosmology framed by Wheeler-DeWitt equations has been proposed by the British physicist and philosopher, Julian Barbour. He asserts that all that exists, fundamentally, is a vast collection of frozen moments. Each moment has the form of a configuration of the universe. Each configuration exists – and is experienced by any beings caught in that configuration – as a moment of time. Barbour calls the collection of all the moments “the heap of moments.” The moments in the heap don’t follow each other, one after the other. There’s no order to them. They simply are. In Barbour’s metaphysical picture, nothing at all exists except these pure moments of time.
According to Barbour, we do not experience time passing. All any of us experience, he insists, is moments – snapshots of experience. Snap your fingers – that was one snapshot, one moment in the heap. Snap your fingers again – that’s another moment. You have the impression that the second followed the first, but that’s an illusion. You think so because in the second moment you have a memory of the first moment. But that memory is not an experience of time passing (which Barbour says never happens); it’s just the memory of the first moment is part of the experience of the second moment. All we experience – and all that‘s real, according to him, are the individual moments in the heap.
However, there’s one bit of structure in the heap. Moments can be represented more than once. You can then speak of the relative frequency of moments; one moment may be present a billion times more than another moment. These relative frequencies of moments are what the probabilities given by the quantum state refer to. Two configurations have a relative probability to appear in the heap, given by their relative probability in the quantum state.
That’s all there is. There’s one quantum universe, described by one quantum state. That universe consists of a very large collection of moments. Some are more common than others.
Some of the configurations in the heap describe a moment of time in a universe filled with a gas of photons or a gas of hydrogen atoms. Barbour says that in the actual quantum state of the universe, most of such configurations have small volume. Other configurations in the heap are full of complexity, with living beings like ourselves living in planets orbiting stars in galaxies, which are themselves arranged in sheets and clusters. The property of being full of complexity and life correlates with large volume.
Barbour asserts that in the right quantum state, the most common configurations have structures that refer implicitly to other moments. These references are what Barbour calls “time capsules.” They are memories, books, artifacts, fossils, DNA, and so on. They tell a story open to interpretation in terms of a sequence of moments in which things happened that built on each other, leading to complexity. That is, the time capsules support the illusion that time is passing.
According to Barbour’s theory, causality, too, is an illusion. Nothing can be the cause of anything, because in actuality nothing is happening in the universe. There’s a vast pile of moments, some of which are experienced by beings like ourselves. In reality, each experience of each moment is only that – unconnected to the rest. There are moments, but there is no ordering of them, no passage of time.
But the Wheeler-DeWitt equations do allow approximate notions of order and causality to emerge, so that there are correlations among the most common moments – correlations that make it appear as if there were a succession of moments in time, between which causal processes could operate. To a high degree of approximation, the story of a succession of moments can be helpful for explaining the structures that occur in the moments. But it is not a fundamental story, and when looked at closely enough, there is no order and no causality, just a pile of moments.
Barbour’s theory neatly solves the problem of what probabilities in quantum cosmology can refer to. There’s only one universe, but it contains many moments. The quantum probabilities are real relative-frequency probabilities for moments to exist as part of reality. To the extent that Barbour’s scheme works in detail, it explains how the impression emerges that the world has a history during which causal processes contribute to building complex structures. This proposal also explains the apparent directionality of time: There is a preferred direction in configuration space, which is away from the configurations of small volume and toward larger volumes. When time emerges, increasing volume correlates well with increasing time, so this explains why the universe appears to have an arrow of time.
