Communication requires energy to be transferred from one place to another. Whether through speech — as a disturbance in air — or visual signals — as electromagnetic radiation — an energy transfer must take place. This means, except for uncontrollable quantum phenomena, information cannot move faster than the speed of light. This creates a conversational time lag equal to the alien’s distance.
In the movie Contact, the ETs’ communications came from a spot near Vega, 25 light-years away. If we received a hello from them today and immediately replied, “Well, hi there, who are you?” it would get to them in 25 years. Their further response, “We’re Vegans. What’s up?” would arrive here in 2056. Our answer, “Nothing much, you?” would reach the vegetarians in 2081.
This, of course, assumes we communicate the way we think and speak, by relying on symbolism. We say “field of sunflowers” to convey a basic concept. But the actual observation entails impossibly complex patterns of countless swaying flowers. There’s no way to disclose the scene with words.
Although we use symbolism and animals don’t, we’re nonetheless not isolated from the life-forms around us. Each species does its thing, and it all works out. We stick with verbal skills and yell, “Stop that!” when we see Spot ripping up the garbage, but our tone, more than the words, lets him know how unhappy we are with him. Meanwhile, the dog speaks without symbology. He stares at us as if thinking, “What part of woof don’t you understand?”
Sci-fi assumes aliens will, at minimum, possess the communication skills of mammals. But even lower-order animals communicate, and perhaps even bacteria do. The farther away from the mammalian realm, the more indecipherable to us is an animal’s method of information-sharing. So, exchanges with ETs may be a bigger challenge than we imagine.
We start out suspecting, probably correctly, that if they’re flying through the cosmos or transmitting electromagnetically, they resemble our own technological mind-set rather than taking after species like whales that are smart but bad at soldering. We presume aliens are nerdy and would enjoy techno-babble. We might hold their interest just by faxing them a Radio Shack catalog. But after that, what?
Would they bother to be diplomatic? Or, would they get right to the point? (“We need all your cardboard right now!”) Maybe we should first uncover their motives. Why are they reaching out? Is it intellectual curiosity or benevolence, or might they be after something? Should we be initially wary of beings who don’t just stay put and mind their own business?
Another prospect is that communication might be impossible. If they moved through time at a different rate than we do, they could be as imperceptible to our senses as neutrinos. For any of a hundred reasons, there might not be anything to say.
But if we both desired an exchange, the standard paradigm is that math and physics would provide starting points. We always assume aliens would know about circles and pi, and realize hydrogen is the element that dominates the universe, even though most humans don’t know these things.
The flavor of exchanges might be revelatory, too. The dialogue could be as neutral as math, but if we are lucky, we might perceive some hint of the senders’ mind-set, letting us know if they are awkward, wary, upbeat, tense, peaceful, or trustworthy. Human conversations are accompanied by nonverbal tones, emphases, and feelings that convey important information obvious to the listener. Might such subtle tones be available with aliens, too?
It’s so unpredictable, speculation is pointless. In fact, don’t waste your time reading this. Oops, too late.