Cosmology and our View of the World
Are We Alone?
Lead: Jonathan Wurtz & Jeffrey Duchesne
Summary by Connor Dieter-Leeds
Are We Alone? – Life and Civilizations in the Universe
Whether Earth is the lone refuge of life in this universe is a question that has intrigued humans (at least) for quite some time. On the evening of March 26, 2014, Jon and Jeff led us through a thorough discussion of this seemingly simple question. We began by examining the common conceptualization of extra-terrestrial life in our society and imagining likely first contact scenarios. We then briefly discussed how we define life, which quickly led to the idea of exotic life forms. After that we considered the Drake Equation as an estimate of how many technologically advanced societies may exist in our galaxy. Even if we assume the universe is full of life, there remains Fermi’s paradox (if the Universe is full of life, where is it all?), which we proposed multiple solutions to. The last portion of the discussion was just a presentation on the ongoing searches for other life in our universe.
The idea of aliens is pervasive in popular culture, but so many of our creations seem very anthropomorphic. It is highly unlikely that any life we will encounter will bear such striking resemblance to us or Earth-life, for that matter. This drastic difference makes it even more interesting to consider the eventual first contact. In our discussion, the general sense of things seemed to be that first contact implied two civilizations of sentient beings who both previously thought themselves alone encountering the other for the first time, but the phrase “first contact” implies neither sentience nor solitude. We could just as likely find a life form resembling bacteria as we could be contacted by a longstanding galactic civilization with protocols for including new species. But I repeat: the scenario we seemed focused on humanity’s first encounter with sentient beings, mainly on the point of how we would react to this first contact.
The majority seemed to think that first contact would be closely followed by violence, citing history’s dismal track record of the first meeting of two human civilizations. The sentiment that humanity is young still was voiced, “It looks grim, we are still children growing up with toys we don’t know how to handle” as Rich put it. Echoing this idea was the thought that we would react defensively and primitively if we encountered alien life here on Earth. But we weren’t all so jaded! There was one vote for peace, suggesting that the “contactors” would most likely be explorers, scientists, and diplomats rather than conquerors and warriors.
In the case of either contact, be it the simple discovery of bacteria, or the clash of two technological powers, it was the general consensus that there would be drastic sociological repercussions, but it would take a long time. People would be reluctant to give up on what they held to be true for the entirety of history up to the encounter. The Earth and its inhabitants would no longer be a unique entity. Among our class, although we would no longer be our previously established form of special beings, the presence of life elsewhere in the universe would not shake the faith or mean drastic overhauls to religious views.
It is difficult to discuss whether we are alone without having a proper definition of life. Anything becomes exclusive if the definition is too strict. A common definition, and the one being used here, includes a condition distinguishing organic from inorganic matter. Some of the characteristics attributed to life are growth, reproduction, functional activity, and continual change before death. But this already seems like a fairly strict definition, meaning that if we are only searching for this, we are searching only for Earth-like life, which may exclude beings that consider themselves alive. I honestly have been struggling to come up with ideas of what that could mean, so maybe it isn’t so awful to be searching for Earth-like life.
Perhaps a more interesting idea is what it would take for us to consider extra-terrestrial people. This questions digs out the characteristics we associate with consciousness, for I would consider all conscious life people. This may even be more difficult to define than ‘life’, but I’m still optimistic that if encountered, we would be able to make the correct distinction.
The organic condition for life isn’t without its challengers. Just because Earth life is carbon based doesn’t imply that all life is so. Exotic forms of life cannot be rule out, and by removing the organic condition it’s possible that there exist other entities that meet the rest of our hazy definition for life. There could be non-carbon based life-forms, perhaps based instead on phosphorous, silicon, or germanium. At the moment, silicon seems like the next best option, but since carbon is lighter, can bond more easily, and is much more flexible, here on Earth silicon is inferior. Then there is the idea of synthetic life. Although that wouldn’t necessarily be alien, it would certainly be a paradigm-altering creation.
Now we come to the Drake Equation, which is an estimate of the number of technological civilizations that may exist “among the stars”. It relates factors such as the formation rate of stars and planets to the number of planets with intelligent life and the time they have had to output signals. An admirable idea, but it suffers a few crucial limitations; the first being that most of the inputs about celestial bodies are wild approximations, which get compounded with each additional term. Secondly, we hardly have a working definition for life, and the distinction we make between life and intelligent life is even less well defined. We only have the smallest sample of all the inputs to the equation and the scale we are working with is immense. Trying to extrapolate from our tiny sample to the scale of the galaxy is challenging.
Fermi’s paradox can be summed up nicely in this simple question, “If the universe is full of life, where is everyone?” There are many resolutions to this apparent paradox, some more dreary than others. First, there’s the possibility that we are actually alone. Assuming the universe is infinite, this seems highly unlikely, but until we find any other life-form, it will remain a frightening (yes, really) possibility. Perhaps an even more frightening prospect is that sentience is destructive, meaning that sentient beings never get the chance to interact because we annihilate ourselves before we get the chance. Another bleak possibility is that the universe is destructive; it’s just too hazardous a place for fragile creatures like us to last long enough to contact each other. Then there is the idea that other life is too alien for us to recognize as life. We can’t see the signs of these life forms, leading us to conclude that there’s nothing else out there. We have been assuming that other beings will be equally as eager to contact us as we are to hear from them; this may not be the case. Other life forms may not be technologically advanced enough to try to contact us, or it’s possible that they are and they’ve chosen not to. I want to believe that life is just scarce and too far apart for us to have any meaningful interaction with at the moment, all the other options are depressing (Again, yes really). Our options are being ignored, being destroyed, or being alone in what may be an infinite, eternal universe; yes I find that prospect somewhat frightening and depressing.
These pessimistic thoughts were not enough to deter the search for extra-terrestrial life. There are a few possibilities worth exploring in our own solar system, including Mars (though mostly for remnants of life) and moons of Jupiter and Saturn. Ganymede and Europa, the moons of Jupiter are prime candidates due to the apparent abundance of water. Titan, one of Saturn’s moons, is another intriguing possibility because it is thought to have a prebiotic atmosphere similar to the hypothesized environment of early Earth. There are many extrasolar searches as well, including early radio searches (LGM 1-4), SETI, and direct optical searches. It also makes sense to look for planets similar to Earth in all regards in hope that they will also support life.