The Beginning of Infinity: Explanations That Transform the World (13 page)

It is going to be removed from the bottle if and when SETI succeeds in its mission to detect radio signals transmitted by an extraterrestrial intelligence. Hence, if you were to keep a careful watch on the cork, and one day saw it popping from the bottle, you could infer that an extraterrestrial intelligence exists. The configuration of the cork is what experimentalists call a ‘proxy’: a physical variable which can be measured as a way of measuring another variable. (All scientific measurements involve chains of proxies.) Thus we can also regard the entire Arecibo observatory, including its staff and that bottle and its cork, as a scientific instrument to detect distant people.

The behaviour of that humble cork is therefore extraordinarily difficult to explain or predict. To predict it, you have to know whether
there really are people sending radio signals from various solar systems. To explain it, you have to explain how you know about those people and their attributes. Nothing less than that specific knowledge, which depends among other things on subtle properties of the chemistry on the planets of distant stars, can explain or predict with any accuracy whether, and when, that cork will pop.

The SETI instrument is also remarkably finely tuned to its purpose. Completely insensitive to the presence of several tonnes of people a few metres away, and even to the tens of millions of tonnes of people on the same planet, it detects only people on planets orbiting other stars, and only if they are radio engineers. No other type of phenomenon on Earth, or in the universe, is sensitive to what people are doing at locations hundreds of light years away, let alone with that enormous degree of discrimination.

This is made possible in part by the corresponding fact that few types of matter are as prominent, at those distances, as that type of scum. Specifically, the only phenomena that our best current instruments can detect at stellar distances are (1) extraordinarily luminous ones such as stars (or, to be precise, only their surfaces); (2) a few objects that obscure our view of those luminous objects; and (3) the effects of certain types of knowledge. We can detect devices such as lasers and radio transmitters that have been designed for the purpose of communication; and we can detect components of planetary atmospheres that could not be present in the absence of life. Thus those types of knowledge are among the most prominent phenomena in the universe.

Note also that the SETI instrument is exquisitely adapted to detecting something that has never yet been detected. Biological evolution could never produce such an adaptation. Only scientific knowledge can. This illustrates why non-explanatory knowledge cannot be universal. Like all science, the SETI project can conjecture the existence of something, calculate what some of its observable attributes would be, and then construct an instrument to detect it. Non-explanatory systems cannot cross the conceptual gap that an explanatory conjecture crosses, to engage with unexperienced evidence or non-existent phenomena. Nor is that true only of fundamental science:
if
such-and-such a load were put on the proposed bridge it would collapse, says the engineer, and
such statements can be true and immensely valuable even if the bridge is never even built, let alone subjected to such a load.

Similar champagne bottles are stored in other laboratories. The popping of each such cork signals a discovery about something significant in the cosmic scheme of things. Thus the study of the behaviour of champagne corks and other proxies for what people do is logically equivalent to the study of
everything
significant. It follows that humans, people and knowledge are not only objectively significant: they are by far the most significant phenomena in nature – the only ones whose behaviour cannot be understood without understanding everything of fundamental importance.

Finally, consider the enormous difference between how an environment will behave spontaneously (that is to say, in the absence of knowledge) and how it behaves once a tiny sliver of knowledge, of just the right kind, has reached it. We would normally regard a lunar colony, even after it has become self-sufficient, as having originated on Earth. But what, exactly, will have originated on Earth? In the long run, all its atoms have originated on the moon (or the asteroids). All the energy that it uses has originated in the sun. Only some proportion of its
knowledge
came from Earth, and, in the hypothetical case of a perfectly isolated colony, that would be a rapidly dwindling proportion. What has happened, physically, is that the
moon
has been changed – initially only minimally – by matter that came from the Earth. And what made the difference was not the matter, but the knowledge that it encoded. In response to that knowledge, the substance of the moon reorganized itself in a new, increasingly extensive and complex way, and started to create an indefinitely long stream of ever-improving explanations. A beginning of infinity.

Similarly, in the intergalactic thought experiment, we imagined ‘priming’ a typical cube, and as a result intergalactic space itself began to produce a stream of ever-improving explanations. Notice how different, physically, the transformed cube is from a typical one. A typical cube has about the same mass as any of the millions of nearby cubes, and that mass barely changes over many millions of years. The transformed cube is more massive than its neighbours, and its mass is increasing continuously as the inhabitants systematically capture matter and use it to embody knowledge. The mass of a typical cube is
spread thinly throughout its whole volume; most of the mass of the transformed cube is concentrated at its centre. A typical cube contains mostly hydrogen; the transformed cube contains every element. A typical cube is not producing any energy; the transformed cube is converting mass to energy at a substantial rate. A typical cube is full of evidence, but most of it is just passing through, and none of it ever causes any changes. The transformed cube contains even more evidence, most of it having been created locally, and is detecting it with ever-improving instruments and changing rapidly as a result. A typical cube is not emitting any energy; the transformed cube may well be broadcasting explanations into space. But perhaps the biggest physical difference is that, like all knowledge-creating systems, the transformed cube corrects errors. You would notice this if you tried to modify or harvest the matter in it: it would resist!

It appears, nevertheless, that most environments are not yet creating any knowledge. We know of none that is, except on or near the Earth, and what we see happening elsewhere is radically different from what would happen if knowledge-creation were to become widespread. But the universe is still young. An environment that is not currently creating anything may do so in the future. What will be typical in the distant future could be very different from what is typical now.

Like an explosive awaiting a spark, unimaginably numerous environments in the universe are waiting out there, for aeons on end, doing nothing at all or blindly generating evidence and storing it up or pouring it out into space. Almost any of them would, if the right knowledge ever reached it, instantly and irrevocably burst into a radically different type of physical activity: intense knowledge-creation, displaying all the various kinds of complexity, universality and reach that are inherent in the laws of nature, and transforming that environment from what is typical today into what could become typical in the future. If we want to, we could be that spark.

Person
   An entity that can create explanatory knowledge.

Anthropocentric
   Centred on humans, or on persons.

Fundamental or significant phenomenon
:   One that plays a necessary
role in the explanation of many phenomena, or whose distinctive features require distinctive explanation in terms of fundamental theories.

Principle of Mediocrity
   ‘There is nothing significant about humans.’

Parochialism
   Mistaking appearance for reality, or local regularities for universal laws.

Spaceship Earth
   ‘The biosphere is a life-support system for humans.’

Constructor
   A device capable of causing other objects to undergo transformations without undergoing any net change itself.

Universal constructor
   A constructor that can cause any raw materials to undergo any physically possible transformation, given the right information.

– The fact that everything that is not forbidden by laws of nature is achievable, given the right knowledge. ‘Problems are soluble.’

– The ‘perspiration’ phase can always be automated.

– The knowledge-friendliness of the physical world.

– People are universal constructors.

– The beginning of the open-ended creation of explanations.

– The environments that could create an open-ended stream of knowledge, if suitably primed – i.e. almost all environments.

– The fact that new explanations create new problems.

Both the Principle of Mediocrity and the Spaceship Earth idea are, contrary to their motivations, irreparably parochial and mistaken. From the least parochial perspectives available to us,
people
are the most significant entities in the cosmic scheme of things. They are not ‘supported’ by their environments, but support themselves by creating knowledge. Once they have suitable knowledge (essentially, the knowledge of the Enlightenment), they are capable of sparking unlimited further progress.

Apart from the thoughts of people, the only process known to be
capable of creating knowledge is biological evolution. The knowledge it creates (other than via people) is inherently bounded and parochial. Yet it also has close similarities with human knowledge. The similarities and the differences are the subject of the next chapter.

The knowledge in human brains and the knowledge in biological adaptations are both created by
evolution
in the broad sense: the variation of existing information, alternating with selection. In the case of human knowledge, the variation is by conjecture, and the selection is by criticism and experiment. In the biosphere, the variation consists of mutations (random changes) in genes, and natural selection favours the variants that most improve the ability of their organisms to reproduce, thus causing those variant genes to spread through the population.

That a gene is
adapted
to a given function means that few, if any, small changes would improve its ability to perform that function. Some changes might make no practical difference to that ability, but most of those that did would make it worse. In other words good adaptations, like good explanations, are distinguished by being hard to vary while still fulfilling their functions.

Human brains and DNA molecules each have many functions, but among other things they are general-purpose information-storage media: they are in principle capable of storing any kind of information. Moreover, the two types of information that they respectively evolved to store have a property of cosmic significance in common:
once they are physically embodied in a suitable environment, they tend to cause themselves to remain so
. Such information – which I call
knowledge
– is very unlikely to come into existence other than through the error-correcting processes of evolution or thought.

There are also important differences between those two kinds of knowledge. One is that biological knowledge is non-explanatory, and therefore has limited reach; explanatory human knowledge can have
broad or even unlimited reach. Another difference is that mutations are random, while conjectures can be constructed intentionally for a purpose. Nevertheless, the two kinds of knowledge share enough of their underlying logic for the theory of evolution to be highly relevant to human knowledge. In particular, some historic misconceptions about biological evolution have counterparts in misconceptions about human knowledge. So in this chapter I shall describe some of those misconceptions in addition to the actual explanation of biological adaptations, namely modern Darwinian evolutionary theory, sometimes known as ‘neo-Darwinism’.

Creationism is the idea that some supernatural being or beings designed and created all biological adaptations. In other words, ‘the gods did it.’ As I explained in
Chapter 1
, theories of that form are bad explanations. Unless supplemented by hard-to-vary specifics, they do not even address the problem – just as ‘the laws of physics did it’ will never win you a Nobel prize, and ‘the conjurer did it’ does not solve the mystery of the conjuring trick.

Before a conjuring trick is ever performed, its explanation must be known to the person who invented it. The origin of that knowledge is the origin of the trick. Similarly, the problem of explaining the biosphere is that of explaining how the knowledge embodied in its adaptations could possibly have been created. In particular, a putative designer of any organism must also have created the knowledge of how that organism works. Creationism thus faces an inherent dilemma: is the designer a purely supernatural being – one who was ‘just there’, complete with all that knowledge – or not? A being who was ‘just there’ would serve no explanatory purpose (in regard to the biosphere), since then one could more economically say that the biosphere itself ‘just happened’, complete with that same knowledge, embodied in organisms. On the other hand, to whatever extent a creationist theory provides explanations about how supernatural beings designed and created the biosphere, they are no longer supernatural beings but merely unseen ones. They might, for instance, be an extraterrestrial civilization. But then the theory is not really creationism – unless it proposes that
the extraterrestrial designers themselves had supernatural designers.

Moreover, the designer of any adaptation must by definition have had the
intention
that the adaptation be as it is. But that is hard to reconcile with the designer envisaged in virtually all creationist theories, namely a deity or deities worthy of worship; for the reality is that many biological adaptations have distinctly suboptimal features. For instance, the eyes of vertebrates have their ‘wiring’ and blood supply
in front
of the retina, where they absorb and scatter incoming light and so degrade the image. There is also a blind spot where the optic nerve passes through the retina on its way to the brain. The eyes of some invertebrates, such as squids, have the same basic design but without those design flaws. The effect of the flaws on the efficiency of the eye is small; but the point is that they are wholly contrary to the eye’s functional purpose, and so conflict with the idea that that purpose was intended by a divine designer. As Charles Darwin put it in
The Origin of Species
, ‘On the view of each organism with all its separate parts having been specially created, how utterly inexplicable is it that organs bearing the plain stamp of inutility . . . should so frequently occur.’