How to Make a Human Being: A Body of Evidence

The more the universe seems comprehensible, the more it also seems pointless.

Steven Weinberg, theoretical physicist

Not for us and not by the gods was this world made; there’s too much wrong with it.

Lucretius (c.99–55 BC), Roman poet and philosopher

3 | ‘I accept the universe’ was a favourite phrase of the transcendentalist Margaret Fuller. ‘Gad! She’d better,’ said Thomas Carlyle.

4 | There are those who are emphatic that the universe has no purpose, but I do not know how they know. The scientific method doesn’t do purpose, so it can hardly come as a surprise that the universe science describes is purposeless. What it all means is not a story scientists can tell. Science attempts to answer the question ‘What is it like?’ Not the question ‘What is it?’ If the point is what you are after, look elsewhere, not to science.

5 | Science describes a universe full of meaning. If there was no meaning there could be no science, and yet science has nothing to say about what that meaning means. We can know the facts, but why they mean anything is outside the remit of the scientific method. What if the world is evil? What if the world is a world of love? These are other kinds of investigations that human beings may undertake, but not when they are in the laboratory.

6 | Are the stars indifferent as they toil to make the ingredients necessary for life? Or is their seeming indifference an inevitable consequence of the way we tell stories and the way we do science: lineally from start to finish? In any case, our cosmologies are no longer stories of love, nor stories of intention. For those we must look elsewhere. The stars may be indifferent, but it is not their job to care: that is our human task.

7 | Perhaps the universe is pointless, but set as a dogma even pointlessness can be turned into purpose of a kind.

8 | Why should we suppose the universe inhospitable? Why not hospitable, because we are here? If this patch of the multiverse is an oasis, and if the earth is an oasis within this patch of the universe, well, we are in the oasis, and from this perspective – home – why should we be fearful of the desert? The universe is only inhospitable if we are against it. Why would we want to be against what has produced us, one of its most sophisticated products?

9 | The universe has the curious quality that it appears to be whatever we think it is: loving to the loving, fearful to the fearful, a world of anger to the angry, depressing to the depressed. When you’re smiling, when you’re smiling, the whole world smiles with you. When you’re laughing, when you’re laughing, the sun comes shining through. Like the Oracle, the universe is only as powerful as the questions asked of it. What would the world look like if it were rational?, is what science asks. Clearly a powerful way of questioning the world; the material world we live in being continuing evidence of that power.

There is nothing either good or bad, but thinking makes it so.

Hamlet

Any universe simple enough to be understood is too simple to produce a mind able to understand it.

John Barrow’s First Law

10 | The cosmologist Brian Greene has argued that if eternal inflation really did happen, then there must be an infinite number of copies of you somewhere out there.

The argument goes like this:

i The ‘visible’ universe – as far as we can see, using our best physical theories and best measuring instruments – circumscribes a fixed amount of stuff, and that stuff is made out of particles. Add up what is out there and the visible universe is fashioned out of some 10

particles.

ii If space is infinite (we do not know if it is or it is not, but most cosmologists believe that it is), then there is an infinite number of regions that circumscribe 10

particles.

iii Quantum mechanics puts a limit on how reality is measured, with the consequence that there is a finite number of possible states that any finite number of particles can take. And so, logically, if the universe is infinite, there must be an infinite number of universes like ours, made out of 10

particles, because anything that is finite endlessly repeated within something infinite must also be infinite.

11 | Brian Greene says that he takes comfort from knowing that there are other selves living out all possible versions of his life in far-flung reaches of the universe. The cosmologist Lee Smolin, however, finds such an idea horrifying, and wonders why he should care about the consequences of the choices he makes if all other possible choices (moral and immoral) are being made by an infinite number of Lee Smolins elsewhere.

I’m with Smolin.

I neither feel sorry for my other selves not making such good choices as I have made, nor envious of those that have made better ones. Why, anyway, would I choose to think of those universes that have me in them in some recognisable form and not all those other universes that do not, except to acknowledge that only the power of my imagination takes me to these far-flung parts of the multiverse?

Of all the millions of ways Trim might have dropped his hat to signify the death of his master’s nephew, there was this one and not the others.

Laurence Sterne (1713–68), Tristram Shandy

12 | Trim doesn’t exist, but he seems more real to me than the infinite number of copies of me out there in the multiverse, an infinite number of whom are writing this book and an infinite number of whom are not.

13 | Then there are other days: when I am willing to make the leap of faith that the mathematics offers and the physics requires, when I remember that cosmologists’ flights of fancy call the scientific method to their defence, and accept that these other worlds do actually exist. On those days the flying carpets of imagination seem no more exotic, no less real, than the supposed realities of particle physics. Hurrah for a physical reality grown so cloudy.

You don’t like it? Go somewhere else. To another universe, where the rules are simpler; philosophically more pleasing, more psychologically easy.

Richard Feynman

‘Imaginary’ universes are so much more beautiful than this stupidly constructed ‘real’ one.

G.H. Hardy (1877–1947), mathematician

14 | According to the theoretical biologist Stuart Kauffman, the world is more constrained than we suppose. Kauffman has called the constraints ‘the adjacent possible’. Only certain next steps are available. Leibniz called it ‘the compossible world’. Leibniz’s insight was marred by his declaration that this world that we are experiencing is not only the only possible world, but the best of all possible worlds, a claim that was famously parodied by Voltaire in Candide.

15 | There are many things that are not possible in a particulate world. It is not possible, for example, to stand and run at the same time. The restraints on what forms the various island universes like ours can take may constrain them severely. The infinite may yet collapse into the few or even the one.

For Macbeth’s rhetoric about the impossibility of being many opposite things in the same moment, referred to the clumsy necessities of action and not to the subtler possibilities of feeling. We cannot speak a loyal word and be meanly silent; we cannot kill and not kill in the same moment; but a moment is wide enough for the loyal and mean desire, for the outlash of a murderous thought and the sharp backward stroke of repentance.

George Eliot, Daniel Deronda

16 | There is something circular about our physical descriptions of the universe. We suspect the universe might well be infinite beyond the horizon of the visible universe, and yet the laws of nature that underpin that understanding are derived precisely out of the limit of how far we can see. The finite speed of light, the fixed amount of time that has passed since the Big Bang, and the set number of particles out of which the contents of this region of the universe are fashioned obey laws that we only understand in the form that we understand them because we cannot see further than we do. If we could see further, we might discover, for instance, that the speed of light is not a constant after all.

Nor would the laws of physics as we understand them necessarily apply to universes with different numbers of particles in them. Nothing could be predicted if the universe had only a few particles in it. Even the so-called laws of nature have something statistical about them. The laws of nature, as we understand them to be, are what we uncover in a universe of this kind, with this many particles in it, seen from this perspective.

17 | We have forged our idea of reality out of what we can see. Nature crooks a finger and draws us on, and we follow in the hope of finding out things truer than those we knew before; revelation follows revelation, curtain after curtain is pulled aside – this, then this, then this – but there is no inner sanctum. There are days, most days, when I believe that the universe will not be outrun, not by the scientific method, imagination, moral intuition, religious insight, nor any methods or combinations of methods of truth-seeking available to us.

We never get to the bottom of our understanding of the universe; there is always something more universal, more encompassing. We reach out to things truer but never arrive at the truth because there is no final destination. The starting conditions of the universe hold within them everything we don’t know about the physical universe moved to the edges of time and space.

18 | It requires a certain kind of stubbornness not to see, in the fine measurements that science makes, confirmation of the existence of an external reality. But there are days when I find that I am that stubborn. How can we be separate from reality? Reach out and you reach into the Big Bang everywhere about you. The universe and we its observers have grown up together from the one stuff. What could we be separate as?

SECTION 7 (#ulink_960ac252-b5c0-5530-984e-9c53be25f89c)

Evidence for the existence of an external world (#ulink_960ac252-b5c0-5530-984e-9c53be25f89c)

1 | That science works – it creates what we mean by progress – is proof and evidence enough for most of us that there is a world out there, separate from us and full of things that have separate existences. And then there is mathematics, the strongest evidence of all.

2 | For the philosopher René Descartes the only certainties were mathematics and theology.

The mathematics appear to be there in the behaviour of physical things and not merely imposed by us.

Roger Penrose, mathematical physicist and philosopher

3 | Roger Penrose believes that mathematics has real existence in a kind of Platonic world parallel – but somehow connected (by what mechanism is not known) – to our world of experience.