There is a forest valley surrounded by impassable mountains on every side. In it lives a single tribe of hunter-gatherers. How they got into the valley is lost in time and they have never had contact with any people outside of their tribe.
The tribe believes itself to be alone and that there are no other inhabited valleys. It is the duty of the shaman of the tribe to prove they are alone and thereby confirm their creation story. So every morning he wakes up early, climbs a tall tree and scans the valley for smoke from a campfire. He reasons that since his tribe always builds up their fire at sunrise this would be the best time to look for other tribes’ fires.
After a period of time the shaman realizes that he isn’t scanning the entire valley. He desires improvement in his observations so he can conclude whether the tribe is truly alone. His crafter is able to build a primitive telescope and the shaman uses it to scan the valley better and further than before. With the telescope he can scan the entire valley for smoke.
Eventually he sees some fires. To ascertain whether the fires are natural or artificial he turns to the hunter and learns how to make longer and longer trips throughout the valley. Soon, he has been to every part of the valley and verified that no artificial fires have ever been seen.
At the same time, a group of anthropologists became aware of the tribe’s existence through aerial reconnaissance. They decided to study the valley tribe for its scientific value toward understanding of humankind’s primitive roots. They considered several courses of action for their first contact with the tribe.
They could simply fly into the valley and approach the tribe’s members. But they were concerned that this would seem alien and cause fear. And if the contact lasted and the tribe were shown modern technological items, the anthropologists might be considered gods.
Further, the tribe’s own inventiveness be stifled. The tribe would turn to quickly appropriating modern technology rather then slowly developing their own. The tribe’s telescope would be their last innovation.
The anthropology team was also concerned that if modern societies were revealed to the tribe then the tribe’s own society would be destroyed. As a primitive hunter-gatherer tribe of related individuals they had a communal and patriarchal social system. And if they must simultaneously deal with democracy, women’s rights and many other modern ideas the tribe would be torn apart.
In another approach, a small group of scientists could shed all evidence of their advanced civilization, even their clothes. They then would dress as the tribe dressed and could make an introduction in a low key gradual manner, perhaps with a single tribe member at first.
The pitfall of this approach was that the presence of any visitors, no matter how cleverly disguised, would affect the tribe. They tribe’s belief in their aloneness had become codified in their religion and law. Destroying this belief would profoundly affect the tribe. The anthropologists decided they must limit their impact if the valley tribe were to be scientifically studied.
Finally, the anthropologists decided to remain unobserved and yet study the tribe in close quarters. They would listen to the tribe’s private conversations, study their behaviors and come to understand their tribal society better than any of the tribe understood it themselves.
Toward this end, they introduced a small group of field anthropologists trained in jungle survive and evade tactics. Then they supplemented them with miniaturized microphones and video cameras that were placed around the valley and especially near the tribe’s encampment. Next, miniaturized video drones, disguised as flying insects, were deployed to the trees to follow the foraging parties. The team could even use anesthetic gas or drugged food to render the entire tribe unconscious for the purpose of drawing blood and tissue samples. And as a final precaution, the team would eavesdrop on the tribe in order to track where and when the tribe might look for them, should its members become suspicious that they were being observed.
Upon reflection, one can see we are much like this isolated tribe of people, if the valley is the Earth and solar system. We have traveled to every part of the Earth and soon will have investigated all of the solar system. Yet no evidence of ETI existence has ever been found. We can not escape the solar system because the speed of light makes interstellar travel unfeasible. This constraint is represented by the mountains, a barrier we can barely even conceive of surmounting.
The artificial radio waves from other distant civilizations is like the smoke from another tribe’s encampment. Our massive radio telescopes are becoming more and more sensitive but at the current time still can not look for our level of radio emissions outside of the solar system.
The ETIs for whom we are searching are represented by the anthropologists. Their desire to remain unobserved while observing is a basic tenet of scientific field research. Their technology is so advanced it can not be fully comprehended by their study subjects.
Once we accept that we are in the valley then it is a short step to believing we are probably being observed by surreptitious and remote means. We can not initiate contact any other people because of the limitations of our technology. We therefore are at the mercy of the more advanced civilizations. The lack of negative impact from them indicates they are at least tolerant of us, if not benevolent. Our continued existence shows that the more advanced civilizations are not a threat, at least not in the way we are a threat to our less advanced societies.
When the team of anthropologists did enter the valley to observe, the tribe members had to be prepared medically. They were rendered unconscious and then immunized against all of the diseases modern people carry. Some time later, a disease passed from the animals in the valley to the tribe and starting wiping out the tribe members, one by one.
The anthropologists had to make a scientific evaluation before proceeding. First, if the did nothing they would have the chance to observe an entire people losing out to natural selection. This was considered to be of some potential scientific benefit but was less important than studying a tribe untouched by the modern world. Finally, they asked the question: “Do we have a moral obligation to intercede and save our fellow humans beings?”
Again the tribe was rendered unconscious and blood was drawn. The sample was airlifted at night to a medical lab to identify the pathogen and formulate a cure. The resulting drugs were transported back to the valley and the scientists administered the cure. All of this was unknown and unknowable to the tribe, it was simply too far ahead of them to be comprehended.
This is not to say the entire population of Earth could be rendered unconscious. Rather it is a simply stating that ETIs may have prepared the Earth for us or that they may have maintained its habitability during our early development. We have no way of knowing whether or not this happened.
At the current time, there is no direct evidence of other civilizations outside of Earth. Therefore, our view must be that while ETIs most certainly exist, we should proceed as though they don’t. We are alone for as long as the ETIs choose not to reveal themselves.
From this story it is clear that we will not have contact with ETIs until we find a transport method that exceeds the speed of light. At that point we may find an ETI at or below our level of civilization. By beginning contact with a primitive ETI we would force the more advanced ETIs to reveal themselves — if they chose to enforce the isolation to which we have been subjected.