If, and when, we make first contact with an intelligent alien species, we may find ourselves faced with the daunting task of trying to communicate with beings so perfectly strange in relation to ourselves that it’s nearly impossible. In a nearly infinite universe, the possibilities for life are also nearly infinite.
Life has taken many unique paths throughout the history of evolution on our own Earth. The “tree of life” is filled with branches that have grown on for millions, and even billions, of years, while others have only progressed for a few million or hundreds of thousands of years.
What forms might life take on other planets, in other solar systems across our galaxy?
Life as we know it on Earth is only one version of what life could be, and it’s inherently unique because the precise combination of elements, the qualities of our orbit, sun and moon, are unique to Earth. No other planet would be exactly the same, so what will life be like there?
Carbon-based life seems like it be the most common, as it is the fourth most common element in the universe when measured spectroscopically, at 4,600 parts per million. Ranking just above that is oxygen, at a little over 10,000 PPM. The top two elements are hydrogen and helium, the lightest, produced in the first moments after the Big Bang and making up 74% and 24% of the universe’s baryonic matter, respectively. So, given a moderately wet world that isn’t too hot or too cold, and has a protective atmosphere like Earth’s, most exobiologists agree that life would end up being carbon-based there.
The next two most common elements that are solid at room temperature are iron and silicon. Indeed, silicon can form four bonds just like carbon, but carbon is capable of more stable and varied structures, and is able to incorporate nitrogen and oxygen into complex molecules. Exobiologists believe that silicon-based life might be more possible on worlds more unlike Earth, and at higher temperatures. On our planet, there are some bacteria that are able to metabolize arsenic, which is poisonous to all other life. And the earliest life on Earth is believed to have metabolized sulphur. Life is constantly challenging boundaries.
Scientists also theorize that life may exist in altogether unrecognizable forms, based on other forces (gravity, strong and weak nuclear forces), and even other mediums, like plasma.
Here on Earth, “eyes” have evolved at least 40 different times independently of each instance. Wings are another case of what we call convergent evolution, or the idea that whenever there is a specific need an organism must meet in order to survive, it must adapt to meet that need in whatever way its current form allows. A bat’s wings match some of the function of those of a bird or an insect, but each variation is very different in many ways and evolved on differing paths in order to make an animal that could take to the air at will.
This idea is known as convergent evolution, and it is just as likely to occur elsewhere in the galaxy as it has on Earth. And just as we must see, hear, move, eat, and every other function life takes on, so will the life forms we discover on other worlds. Alien life might be something other than carbon-based, but it will still have many of the same needs.
Types of Intelligence
The idea of convergent evolution might also suggest there would be some “convergent intelligence” — That is, if there tend to be common organic forms evolving throughout the cosmos there would likely also be common ways that these forms react to and think about their environments. A squid-like creature on Gliese 581g, some 20 light years from us, will probably have a similar intelligence capacity to the actual squids found on Earth.
But on Earth, the path to human-level intellect was not a direct one. Unintelligent, and probably mostly non-sentient, animal life existed on our planet for billions of years before a massive natural disaster wiped out the dinosaurs and cleared the way for the explosive evolution of mammals. If that asteroid event had never happened, there is a good chance that nothing much resembling homo sapiens would have developed up to this point.
Communication vs. Language
Many forms of life that evolve throughout the universe will come about in much of the same, or at least similar, environments that life on Earth has. So, as I wrote about above, these life forms will also share similar modes of existence and form.
On our world, communication between individuals or among groups is very common among living things: It occurs in almost every species. It is performed using an immense variety of modes, from sound or vibrations, to scent and pheromones, and also in many visual methods that utilize color and motion.
But communication is very different from language.
Communication is an extension of biological necessities required for creatures that come into contact with others of their kind. And communication consists exclusively of signals rather than containing abstract concepts as language does. A signal can be anything from the various different mewlings of bear cubs that let a bear sow know if her offspring are lost or simply hungry, to the peculiar cries of birds that let other members of their species know when a predator is nearing.
This line blurs somewhat when zoologists study the more complex communication of intelligent animals such as dolphins.
Dolphins communicate using broadband pulses, similar to their echolocation clicks, and also using auditory whistle sounds. The whistles seem to act as a way to identify one another in their groups, a theory which has found agreement in multiple studies. Numerous other studies also support the idea that dolphin communication is linguistic in nature, as well: they use unique sounds in the presence of different dolphins, which might signify “names”; they don’t readily communicate with “foreign” groups; they take turns; and their vocalization patterns seem to follow basic speech patterns found in human languages.
Our nearest relatives, chimpanzees, as well as gorillas such as the legendary, late Koko, also exist somewhere in this limbo between communication and language. While our ape cousins possess similar worldviews and are capable of learning words and communicating via sign language, none of them have developed an actual language that we have been able to uncover in the hundreds of thousands of years we’ve coexisted.
Despite the many decades of study we’ve had with dolphins and apes, however, we still are nowhere close to fully deciphering a dictionary of “dolphinese” or being able to hold true conversations with them. And these are some of our most intelligent fellow beings on THIS planet.
While dolphins and apes are very different from us, from our point of view, on a cosmic scale they are very close kin to humans. We can all subsist from basically the same foodstuffs; we have similar biologies in many ways; we are all placental mammals and share emotional bonds and are social creatures. We’re all Earthlings. What, or who, we find on other planets will not be. They will not have such similar biologies and frames of reference. They may not communicate vocally at all, or even visually.
They will be truly alien.
The earliest known formalized writing system researchers know of is cuneiform, which originated around 5000 years ago somewhere around the area we know today as Iraq. Cuneiform, Egyptian hieroglyphics, and other forms of writing had to have evolved from some earlier system, however, and von Petzinger believes that might be found in the paleolithic some 35,000 years before cuneiform was invented.
Moreover, what von Petzinger came to understand was that while some of the 32 symbols were “fads” that were adopted but later seemed to fade from usage, most were very consistent across the millennia and were even matches for symbols seen across the world, on other continents:
This led to the realization that this kind of symbolic writing had been in use by ancient humans for at least 100,000 years.
What scientists consider a complete writing system, however, is usually not inclusive of these very early collections of symbols. The definition for them is that a written language must allow for the expression of a complete language — encompassing the full language and dictionary of spoken words. But what is most important about these symbols is that their appearance marks a turning point in our evolution: the beginning of our ability to pass knowledge on from generation to generation and to truly become the “masters” of our environment on Earth.
Reaching that point — having the ability to progress using technology — seems to be a very rare occurrence among life, however, more rare than reaching a basic level of intelligence and sentience that we see demonstrated by dolphins and apes. What, then, might the chances be that there is an alien intelligence somewhat comparable to our own?
The Drake Equation
In 1961, the astronomer Frank Drake, with some help from scientists Carl Sagan and John Lilly, devised what would be known as the “Drake Equation”. This string of variables represents the possible number of civilizations in the Milky Way galaxy (that we may be able to communicate with).
N = R* • fp • ne • fl • fi • fc • L
Per author Elizabeth Howell on Space.com:
N = The number of civilizations in the Milky Way galaxy whose electromagnetic emissions are detectable.
R* =The rate of formation of stars suitable for the development of intelligent life.
fp = The fraction of those stars with planetary systems.
ne = The number of planets, per solar system, with an environment suitable for life.
fl = The fraction of suitable planets on which life actually appears.
fi = The fraction of life bearing planets on which intelligent life emerges.
fc = The fraction of civilizations that develop a technology that releases detectable signs of their existence into space.
L = The length of time such civilizations release detectable signals into space.
The original estimates that Drake and his colleagues used were as follows:
R∗ = 1 yr−1 (1 star formed per year, on the average over the life of the galaxy; this was regarded as conservative)
fp = 0.2 to 0.5 (one fifth to one half of all stars formed will have planets)
ne = 1 to 5 (stars with planets will have between 1 and 5 planets capable of developing life)
fl = 1 (100% of these planets will develop life)
fi = 1 (100% of which will develop intelligent life)
fc = 0.1 to 0.2 (10–20% of which will be able to communicate)
L = 1,000 to 100,000,000 years (which will last somewhere between 1000 and 100,000,000 years)
Using the minimum values results in an N of 20. Using the maximum values would give us an N of 50,000,000. Obviously, the range of possibility here is almost too large to be considered worthwhile. There may be so few civilizations with sufficiently advanced technology that the chances of contact over such a vast area as our galaxy approaches zero, or there could be so many that me might expect contact to occur sometime in the next few decades.
Based on this wide variance, Drake says that we might reliably only state that the value of N is somewhere between 1,000 and 100,000,000, or roughly that N = L.
However, more recent data suggests that the range of possibilities may be much narrower: Somewhere between 12,000 and 96,000 potential civilizations might exist in our galaxy. For more detail on these updated variables, see my article here.
Out there…Somewhere
Even though these figures seem very large, on the vast scale of the galaxy these other intelligences are still very spread out, all separated by tens of light years at a minimum. A great majority of those civilizations would currently exist at technological levels centuries more primitive than our own or might have reached a point where their actions have devastated their advancement and taken them off of the track to being spacefaring. Others may be thousands of years more advanced (or perhaps millions of years), and might not even be interested in communicating with a “backwards” world such as Earth.
If, and when, we make contact with an intelligence on par with our own, these new acquaintances will be very different. But there will be some commonalities, and we will need to strive to fashion an understanding between us so that a future can be forged. When we discover other beings who are exploring the universe with a curiosity much like our own, not only will we finally know that we are not alone — we will also multiply our knowledge of the cosmos and become part of a multiplanetary kinship.
A new chapter in the life of Earth will begin.
Thank you for reading and sharing!
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