The End of Time: The Next Revolution in Our Understanding of the Universe by Julian Barbour
My rating: 5 of 5 stars

Plato Rules OK?

I suspect that most of us have thought at some point about the mystery of time. But very few have considered seriously what it might be. And only a handful, perhaps, could explain in a comprehensible way how time is constructed. And, I’m sure, there are less than a handful who with any plausibility deny its existence entirely - Julian Barbour is one of these. And he makes an interesting case.

According to Barbour, time is a constructive illusion, a concept without any extra-linguistic existence. We use it like a ‘god of the gaps’ to explain that for which we have no other theory. The illusion is the sensory equivalent of a flat earth or the appearance of instantaneous gravitational action at a distance. What we experience, or name as experience, is our interpretation of various states of entropy, a measure of the disorder of the cosmos.

Time then is really the feeling of progression from states of lower to states of higher entropy, from relative order to disorder. Such a concept might seem a scientific splitting of hairs, except that it has a profound Implication: the ‘direction’ of time depends on what ‘side’ of successive entropy states one happens to be. Successive states might be ‘before’ or ‘after’ each other depending on the perspective of the conscious being involved. Since the past is always the domain of lesser entropy, time, the gradient of entropy, can run in opposite directions simultaneously. The past is a conjecture, a supposition made on the basis of incomplete information, not a fact.

Barbour believes that there are evolutionary reasons for our creation of the idea of time. We are programmed to detect ‘records’, sequences of entropic states, at the expense of other perceptual sensitivities. We are able to manipulate, really order, these records through consciousness to great effect in finding food, establishing social structures, in ‘anticipating’ consequences. In short, time is a survival tactic, an expediency which may no longer be expedient. What it is not is a physical reality.

Perhaps the principle reason I am attracted to Barbour’s theory (in addition to its sheer provocation) is that it vindicates much of Platonic thinking. Plato’s ‘forms’ for example have a credibility inside a timeless universe which had been lost in the methods of Aristotelian science. Instants, what Barbour calls Nows, are things. Space and time are not more fundamental than things, in which things mysteriously float; they are part of the ‘configuration’ of things as they exist. This highly technical term of configuration seems remarkably similar, if not equivalent, to the Platonic ‘eternal ideas’.

The End of Time is challenging, but not because Barbour’s exposition is flawed or interrupted by technical scientific and mathematical proof texts. It is challenging because it reveals the depth of presumption about the world that we carry around with us nonchalantly. Exposing these unwarranted presumptions is often a matter of confronting not just common sense but an entire culture of thought that has worked reasonably well. In a sense, what Barbour is doing is equivalent to Luther’s nailing of his theses on the door of Wittenberg Cathedral. Neither Luther nor Barbour could have a clear idea of the consequences. Nevertheless, they’re bound to be exciting.

Postscript: for a good short summary of much of Barbour see: https://www.lesswrong.com/posts/rrW7y...

To see how badly the subject can be written about, consult this academic text on time. Its lack of literary skill, I’ll wager, is matched by its opaqueness of thought: https://www.goodreads.com/review/show...

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