In my last article, I talked about the existence of extraterrestrial life, and where and how we may find it. In this one, I speculate what may happen if we discover it.
To start out, what exactly is “life”? This itself is a hotly debated topic and there are lots of definitions and debates. A good source of information on this topic is a series of lectures titled “Origins of Life” by Robert Hazen, available through The Great Courses. According to him, here is the definition used by NASA: “Life is a self sustained chemical system capable of Darwinian evolution”. So, a key question in research being done on origin of life is — -How did a geochemical world with ocean, air and rocks containing organic molecules transfer itself into a biochemical world containing self-replicating chemical molecules that compete and evolve? At this point no one knows for sure how this happened but there are three scenarios, according to Professor Hazen: metabolism first scenario, genetic first scenario and a cooperative scenario (which combines the previous two). No need to go into details but the fact that we are down to just three possible scientific explanations is quite heartening.
There are two reasons why I mention all this. First, since we still have not found out exactly how life began on earth, there is still a possibility that life has emerged only once in the universe, just on earth, because the final step is so complex, and requires so many preconditions. I think this is highly unlikely, but it is possible. The second reason is that since we are so close to finding scientific theory of how life emerged from a bunch of chemicals; it is highly unlikely that there was a supreme being involved in creating us, “in his image.”
Finding life outside of earth will put an end to both these debates. Even though the exact transition from geochemical to biochemical may remain a mystery for a few more years, the fact that there is life elsewhere would prove that the final step is not that complex and the universe may be teeming with life. Also, the religious people may need to rethink some of their assumptions.
The most likely place where we would find evidence of primitive life would be Mars. It is likely to be microbes or their fossils, not Martians. If they look like our microbes, there are two possibilities. One is that the same process that created life on earth did so on Mars. Also, it is possible that life emerged on Mars and came to earth on a meteorite that originated on Mars. If that turns out to be the explanation, we would be back to square one on the question of life’s existence elsewhere, besides Mars. Of course, if we find similar life on, say Europa or Enceladus, the conclusion of more than one origin of life would be quite conclusive.
As I had mentioned in my previous article, it is highly unlikely that we would find life that is at the same stage of evolution as us. We separated from apes only seven million years ago, and Homo Sapiens have been around for only 200,000 years. In the same amount of time in the future, perhaps much less, we would be unrecognizable. A few million years are nothing in the life of our universe, so how can we expect to find a civilization to looks like ours at this narrow slot of time? Or communicates using electromagnetic signals?
That would explain why the SETI program — -one that listens to signals coming from outer space as evidence of intelligent life — -has yielded nothing thus far. A wonderful book written by Paul Davis, “The Eerie Silence” refers to that fact.
That means if we don’t find microbes, we will find life at another extreme…so advanced and sophisticated that we cannot even imagine. These are the stages that are not as transient as our current one.
In his above referenced book, Paul Davis cites three Types of civilization as defined by a Russian astronomer, Nikolai Kardashev. These Types, based simply on energy consumption are: Type I that uses all energy resources from its home planet, Type II which requires total energy output from its parent star, and Type III, from whole galaxy. One would be able to detect Type II and III civilizations based on the energy footprints they leave.
Of course, it is entirely possible, according to Davis that “biological intelligence is only a transitory phenomenon, a fleeting phase in the evolution of intelligence in the universe. If we ever encounter extraterrestrial intelligence, it is overwhelmingly likely to be post-biological in nature.” It is not clear what impact such intelligence would create on its physical surroundings and how we would be able to detect it. In fact, it does not even fit the definition of life that NASA is using in its search.
The most likely scenario is that we will find such advanced civilizations not the other way around. I do not believe in UFOs and curious aliens snooping around. Why would they? We are an insignificant planet of an insignificant star, virtually undetectable. Sure, we have been emitting TV and radio signals for a few decades, but they have not reached far and are most likely undetectable from noise. That eliminates most of the science fiction type close encounters.
After finding an advanced civilization, it may take forever to establish contact, given how far in the universe they are likely to be, and our ability to emit a powerful enough signal so they would detect us. There are eminent scientists, like Stephen Hawkins, who say that we should not try to contact them. Just stay silent. They may not be benevolent and wipe us out in an instance. He cites what happened to Native Americans as an example of what can happen to us.
So, it may be that we will not have any interactions with aliens even if we detect them. That means we will not befit from their advanced technologies, and the only major impact will on our religious beliefs. That could be significant, but a more important effect such a discovery will be to give us confidence that civilizations of past have been able to survive self-destructive tendencies.
That by itself would be great news.