The great German poet Johann von Goethe (1749–1832) once said that because people can speak they think they are entitled to speak about language.1 The point he was making is that because we have language we think we have the necessary knowledge to make pronouncements on language. However, this is not true. In order to make objective statements about the structure and use of language one needs training as a linguist. So why does one need technical vocabulary when talking about language? The reason is that, although we all speak our native language effortlessly, there is a lot of internal structure involved in this process and we are normally unaware of this. To describe all facets of language one needs an array of technical terms. Bear in mind that most of our knowledge of language is unconscious, like an iceberg where nine-tenths are hidden below the water’s surface.

Humans are mammals, a group of vertebrate animals with backbones, an internal skeleton and a nervous system controlled by a brain. However, the essential feature of mammals is that they give birth to live young, as opposed to other animals1 like reptiles and birds, from which we split off about 300 million years ago (mya), and which lay eggs from which their young later hatch. The word mammal derives from Latin mamma ‘breast’ and refers to the fact that the females of these animals breastfeed their young to begin with. This system is typical of cognitively advanced animals and there is probably a causal connection here. Live birth and breastfeeding result is a greater attachment between mother and young than does egg laying, adding an increased emotional dimension to the lives of the animals in question and thus providing a positive feedback loop for further cognitive development.

The discussions in this book so far have been about how life evolved on Earth and what paths it took, with the possible situation beyond Earth considered at regular intervals against this background. Some might say this approach is too conservative and that we should think outside the box for a while. After all, life could not just look, but also be very different, in principle, from life on Earth.

Is this really the case? Let’s recap on some of the preconditions for life discussed in previous chapters. To reach the level of molecular sophistication, which we observe on our own planet, the biology of an exoplanet would most likely have to be carbon-based because no other element has the same potential to form such a huge array of different molecules. Another point to remember is that high-level functions, like those humans exhibit, with their large brains and intricate physiologies, would require a complex physical substrate.

The language faculty, the ability to understand and acquire human language, is a feature of our neurobiological make-up which has been passed down through the generations in every human being as part of our genetic endowment.1 It is the language faculty which allows us to acquire any language as long as we are exposed to it in our early childhood. Although it cannot be directly observed, the language faculty imposes structural conditions which must be met by all the languages of the world, that is, it provides limits to what can occur in a human language by containing a framework within which language variation can arise.

The options for space travel will determine how much of our corner of the Milky Way we might explore in the future. Whether exobeings will have crossed the frontiers we recognise in this field now is an open question. The speed of light will be the same absolute barrier for them as it is for us. Indeed, reaching a significant fraction of this speed will represent an immense technological challenge. This means that, for all practical purposes, the search for life elsewhere is, and will be in at least the near future, limited to our corner of the Milky Way galaxy. Life can only arise on planets (leaving moons aside for a moment) and these are relatively small compared to stars. And, of course, they only reflect light from the latter so that detecting planets in other galaxies is presently out of the question, despite advances in technology.

Would exobeings have language? The answer to this question without a doubt is: ‘Yes’. They would have language in the sense of a powerful and flexible means of communicating thoughts and ideas between individuals. Why? Complex societies arise through continual differentiated interaction among their members. While many non-human animals do live in communities whose members engage in considerable interaction this does not reach anything like the level characteristic of humans. Furthermore, no beings can acquire all the knowledge of a complex society from scratch on their own. Each generation of a society builds on existing knowledge, which is transferred from generation to generation by being documented using language. To build a technologically advanced society, language would need to be documented in some fixed form, which on Earth means using one of the many writing systems, captured physically, usually on paper, or digitally as bits and bytes in computer storage.

Language is a unique property of humans. It is located in our brains and is intimately connected with our experience of consciousness. Our interaction with other humans via language is the main means by which we can be sure that others experience levels of consciousness like ourselves. However, many animals have communication systems which in principle are similar to language, that is, they are used to convey information between members of a species, though not always by means of sounds. For instance, bees use a special set of movements in which information about a source of nectar, its size and distance from the hive, is transmitted by movements in space by the bees, their ‘dance’. Whales use noises sent out beneath the water to other whales. Other senses can and have been used for communication. For example, many insects exude pheromones, scents with a certain signal value for a member of a species, normally to attract females.

In discussions about the search for life beyond Earth two basic possibilities have been proposed: either we will discover signs that biology exists on other planets through atmospheric analysis or we will detect an unambiguous radio (or maybe laser) signal from outer space which does not have a natural source and hence can be assumed to originate from an exoplanet. The former discovery would be via a biosignature, such as abundant oxygen in the atmosphere of an exoplanet. The reason why this is a good bio-indicator is that free oxygen (as a diatomic gas, O2) is highly reactive and if it existed in the atmosphere of an exoplanet it would disappear quickly by forming molecules like carbon dioxide or water, or rust with iron, unless it were continuously replenished by some biological source, like trees and plants on Earth, which release oxygen into the atmosphere during photosynthesis.

You have already performed the greatest feat of your life, although you most likely are unaware of it. This is the acquisition of your native language. Within the first few years of your life, you went from nothing to a fully competent speaker of the language(s) you were exposed to. That happens unconsciously, without any instruction,1 in a very short time, with native-speaker competence as the result.

Would the same hold for exobeings? Indeed, would it be valid to assume that exobeings have a division of their lifespans into childhood and adulthood as with humans? Recall that for Darwinian evolution to occur there must be some way for an organism to reproduce and be gradually subject to natural selection. If sexual reproduction applied in the animal world of an exoplanet, reaching sexual maturity would be a feature of animal life.

The long pathway from simple cells to intelligent beings, capable of developing digital technology, will have been traversed on any planet with such beings. So it makes sense to consider how the development panned out on Earth. Up to about seven million years ago (7 mya), about 99.85 per cent of the age of our planet, there were no animals walking the Earth which looked like us. Yes, there was great biodiversity on land and in the sea. But there were no species which were in any way capable of reflecting on the larger world in which they lived, beyond their own environment, let alone reflecting on Earth as a planet and its admittedly very modest role in the cosmic scheme of things. If any exobeings had by chance taken a closer look at our planet, they would not have been motivated to investigate it in any detail.

Linguistics is the study of the human language faculty and the languages it engenders. It enjoys interfaces with other sciences such as cognitive psychology, neurobiology and physiology. The borders between linguistics and other sciences are fluid and have shifted with increasing research in the field. Where we draw the lines is a matter of debate among scientists, but we do draw them because science compartmentalises reality for the purpose of inquiry and analysis.1

For some two centuries linguistics has been an established branch of science, and considerable strides have been made in researching how humans speak, how they acquire their native language and in documenting the known languages of the world. This knowledge has been arrived at by devising means for analysing human language and by adopting approaches based on notions which are likely to be quite different from the views which non-linguists will have about the subject.

We know that life has arisen at least once in our universe. This simple fact testifies to an extraordinary feature of the building blocks of the universe – subatomic particles, atoms and molecules – the ability to aggregate to form immensely complex entities, which display a vast array of emergent structural properties. One of the pinnacles of this potential (on Earth) is the human brain, with the consciousness it engenders (see Chapter 17 for a detailed discussion).

When examining the building blocks of the early universe there is no indication whatsoever that these elements – initially hydrogen with some helium – would ever give rise to beings capable of reflecting on the nature of the universe and mulling over its origin and possible future. It would seem that all one needs are suitable conditions and enough time.

As exobeings can only arise through evolution the roots of their sociality would lie in earlier stages of their biological development. From Earth, we know that animals bond and form communities in different ways, with the common purpose being the survival of the species. This is the basis of their very divergent kinds of behaviour. There is no reason why this should not be the case on an exoplanet as well.

Animals differ widely in the extent to which they interact with each other. Some animals, like certain types of birds, such as albatrosses, remain together as couples to rear their young and return to each other every year; others do not, with the male leaving once mating has occurred.