Saturday, October 13, 2012

Raymond Tallis - Did Time Begin With A Bang?

Raymond Tallis is writing a new book to "rescue our thinking about time (and a good deal of metaphysics) from the domination of physics." In this column from Philosophy Now, he explains a little bit of where he is heading in the new book.

Did Time Begin With A Bang?

Raymond Tallis doesn’t know, at present.

I am half way through writing Of Time and Lamentation, an attempt to rescue our thinking about time (and a good deal of metaphysics) from the domination of physics. I justify this shameless self-promotion by presenting it as a warning: you must expect your columnist, over the next year or so, occasionally to share with you some of his puzzles about the nature of time. The one that is preoccupying me at present is the question of whether time does or does not have a beginning. It’s an issue that has wandered through Western thought on the border between philosophy and theology for millennia, and no end seems to be in sight.

Some of you will be familiar with Kant’s cunning argument in The Critique of Pure Reason (1781), in which he demonstrates to his own satisfaction that time cannot be something in the world out there, a property of things in themselves: on the contrary, he says, time belongs to the perceiving subject. (For those who don’t feel up to reading the original, Robin Le Poidevin’s discussion in his brilliant Travels in Four Dimensions: The Enigmas of Space and Time is an ideal starting point.) Kant’s argument revolves around the question of whether or not the world has a beginning in time. He shows that we can prove both that the world must have and that it can’t have a beginning in time, so there must be something wrong with the idea. This is the first of his famous four ‘antinomies’ – philosophical problems with contradictory but apparently necessary solutions – the others relating to atoms, freedom, and God.

The world, Kant says, must have a beginning in time, otherwise an infinite amount of time – an ‘eternity’, as Kant called it – would have already passed in this world – but no infinite series can be completed. On the other hand, the world can’t have had a beginning in time, because this would imply a period of empty time before the world came into being, and nothing (least of all a whole world) can come into being in empty time, as there isn’t anything to distinguish one moment in empty time from another. To put this another way: since successive moments of empty time are identical, there would not be a sufficient reason for one moment to give birth to the world while its predecessors were sterile.

One current standard response to Kant’s Antinomy of Time is to say that the world did have a beginning – at the Big Bang, 13.75 billion years ago – but that it was not a beginning in already-existing empty time, since the beginning of the world also started time itself. This solution echoes St Augustine’s assertion that “the world was made, not in time, but simultaneously with time”: God brought the world and time into being together, so that the question of (say) what God was doing before the Creation does not arise. Kant’s First Antinomy is therefore based on a false premise. Job done. Tick in box. Next question please.

Not so fast. Let us look at the claim that time and the world began with the Big Bang 13.75 billion years ago. This is claiming two rather remarkable things: that time began at a particular time; and that time and the world began at the same time. Let us look at these assumptions, starting with the assertion that time began at a particular time.

Time Zero

Since the Big Bang can be assigned a date, Something must have come out of Nothing at a particular moment. What was special about a specific moment 13.75 billion years ago? The cosmologists say that there was nothing special about it: the universe is a random event that happened for no particular reason. It grew out of a quantum field – the ‘inflaton’ – which found itself in a false vacuum – temporarily stable, but not in the lowest energy state. Random fluctuation (uncaused, as things are in the quantum world) sent the inflaton tumbling into a true vacuum, which generated an equal amount of positive energy (matter) and negative energy (gravity). Thus the Big Bang didn’t need causes to bring it about because no net stuff is created. Far from solving the problem of creation, this has multiplied the problems beyond those the physicists were struggling with: an energetic quantum vacuum – a fidgety Nothing – looks a little dodgy, for a start.
Never mind, that’s quantum physics for you. What seems more vulnerable is the idea that we can finesse Something out of Nothing by the generation of equal amounts of positive and negative energy, so that the universe has zero total energy. This seems to be somewhat literal-minded, taking the pluses and minuses in an equation for reality. Worse, it looks as if in pursuit of an explanation we have doubled the number of unexplainables: we have to explain two lots of energy. In short, Kant’s problem of explaining why one moment of empty time should be privileged to deliver a universe is not solved by appealing to random fluctuations, because fluctuations in Nothing – even if they generate pairs of virtual particles (virtual particle plus virtual antiparticle) – don’t seem likely to help us to explain Something.

Some scientists have given up on the idea that the Big Bang is at the beginning of time (and space); rather, it is but a recent event in a much longer history. (See for example, ‘Bang Goes The Theory’, New Scientist, 30th June 2012.) Instead of one Big Bang, there is a series of big bangs livening up a cosmos that has been around forever. This, of course, only displaces the problem of the emergence of Something out of Nothing, and Kant’s problem of an infinite time having already passed is back.
Meanwhile, there are variants of the Big Bang theory in which it is suggested that time doesn’t arrive on the scene at once; or rather, it behaves at first like another dimension of space – in the earliest universe there is a period in which it is too early for time. If so, we have to ask what ‘too early’ could possibly mean in this context. Are we referring to a time before time exists – before it makes sense to speak of ‘before’?

There is something dubious about dating the beginning of time in any case. Allocating a time to the beginning of time is like allocating a time to any moment in time. Saying that a time t1 took place at a particular time t1 seems like a harmless tautology, but it is actively misleading, because it treats a moment in time as if it were itself a kind of occurrence in time, as opposed to part of the framework within which things can occur. To say that time began at tbeginning is thus to treat the beginning of time more like a kind of occurrence. This impression is confirmed when it is asserted that tbeginning occurred 13.75 billion years ago.

Those who want to defend the notion of a moment in time as being like an occurrence, might be tempted to say we often think this way when we talk about stretches of time. For example, there is nothing wrong with saying that Wednesday – not in itself an event, but simply a holder for events – began, came into being, at twelve midnight on Tuesday. The analogy is not sound, however. Tuesday or Wednesday are not time in itself, but divisions placed upon time. However, the Big Bang is supposed to be both timeless and at a particular time: at the beginning of, and yet not part of, the series that it begins.

The problem with saying that time began at a particular time is highlighted by this obvious question: If it is perfectly valid to speak of 13.2, 13.3 and 13.75 billion years ago, why is it not valid to talk about 13.8, 13.76 or even 13.755 billion years ago? Steven Hawking addresses this question by arguing that to talk of time before the Big Bang is like talking about points north of the North Pole. Once you have got to the North Pole, it makes no sense to imagine you can go any further north.
This analogy does not work. As mathematical philosopher J.R. Lucas has pointed out, there is a deeper, astronomical sense of north which allows a line pointing in that direction to be extended indefinitely. North is a direction that has no terminus: you can be north of the North Pole. So the question still stands.

What about the second assumption: the supposed simultaneity of the beginning of the universe and the origin of time? How can we think of the start of time itself (as opposed to the time of something) being at the same time as an event (the creation of the universe)? There is no ‘at the same time as’ until the universe has differentiated to the point where one event can be temporally related to other events via an observer. What’s more, once the universe has come into being, and more than one event has occurred, the notion of simultaneity as absolute and observer-independent is invalidated by the Special Theory of Relativity. Finally, there is a mismatch between a universe, whose coming-into-being is extended over time, and time itself, whose coming into being is presumably instantaneous, or at least not extended through time.

Haunted By Kant

So Kant’s First Antinomy still haunts us. But we have good reason not to jump from its problems to Kant’s conclusion that time is somehow internal to the human mind. If time were only a property of human minds, we would not be able to make sense of what in After Finitude (2008) the French philosopher Quentin Meillassoux called ‘ancestrals’. Ancestrals are those realities that pre-date human consciousness and yet have a clear temporal order. For example, the Earth came into being 4.56 billion years ago, before life on Earth originated (3.5 billion years ago) and before conscious humans began emerging (several million years ago). So if we believe what evolutionary science tells us, we cannot reduce time to one of Kant’s two ‘forms of sensible intuition’ (roughly, modes of human perception, the other form being space).

However, this conclusion, too, can be challenged, by arguing that the allocation of events to past dates is itself internal to the calendar time that humans have invented – that we project the framework we have established to structure our time beyond the situation within which it arose: that the very idea of ‘ago’ is established with respect to a system that has been built up by humans and extrapolated from ways of seeing that serve us well but do not necessarily reveal truths about how the universe is in itself, beyond our manner of perceiving it. On this matter, the jury remains out.

Many physicists despise the kinds of arguments I have presented. Their feeling about philosophers (or even physicists) who want to make other than mathematical sense of what physics tells us about the fundamental nature of things could be summarised in David Mirmin’s “Shut up and calculate!” And Steven Hawking has dismissed philosophers as poor sods who haven’t kept up with physics. It is important not to lose one’s nerve and to note that physicists who dismiss philosophy are often doing philosophy themselves, but very badly.

The question of whether time has a beginning is far from resolution. Equally vexing is the opposite question, as to whether it has an end. Another time, perhaps.

© Prof. Raymond Tallis 2012

Raymond Tallis is a physician, philosopher, poet, broadcaster and novelist. His latest book, In Defence of Wonder, is out now from Acumen.
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