Words Across Space

If I were to send a message directed at hypothetical aliens about which we know absolutely nothing, I would not send words. Words are too anthropocentric. Even among Earthly creatures, words are unique to humans. Most animals communicate with each other, but not with words. Many communicate with sounds, but their sounds are not structured as anything wordlike – and even sound communication can be totally alien to us, like the recent discovery that dolphins can send sonar “images” as echo patterns to each other.

Some squid can control their skin color like chameleons, and use this for communication – their entire body surface is used as a color display to show meaningful patterns. Ants organise their communities using trails of chemical signals. Some fishes use modulated electric fields to communicate, something we need sensitive instruments to even detect, much less interpret. What is it like to be an electric eel?

What is it like to be an alien? We have really no idea. Quite possibly there are aliens out there that are so unimaginably alien that we won’t even notice each other as intelligent beings. But beings with which we have any remote hope of communicating will have some recognizable way of perceiving its surroundings. Whether they perceive some kind of radiation (light, radio waves…), vibrations in a medium (sound), by active scanning (sonar, radar, electrosense…), by chemicals, or simply by touch – or by some sense we can’t imagine – depends on their environment and evolutionary history. But they will have some way of perceiving objects. If we are to communicate across space, the aliens should also be able to perceive somehow that there is space beyond their habitat, be it a planet or some other substrate.

Only a small fraction of conceivable aliens – and a much smaller fraction of the inconceivable ones – would be able to perceive words. I would not send records like on the Voyager spacecrafts. The Pioneer plaques are better: they make less assumptions about alien perception, as they work with both vision, touch and some active-scanning senses. But they do assume that the aliens can make sense of twodimensional representations of threedimensional objects, which is not self-evident; not all animals can.

The most reliable sense-independent way of sending ‘words’ across space may be to send actual threedimensional objects. Figurines of people rather than engraved images. We can trust the aliens to perceive the figurines at least – but will they understand that the figurines represent us?

If they do – will we understand, or even perceive, whatever they send us in return?