'Are We Alone?' Janna Levin & Rana Adhikari Talk Other Planetary Life For Oyster #109
We asked two science specialists to talk about alien life and our place in the Universe for Oyster #109: The Tomorrow Issue.
Theoretical cosmologist Janna Levin, Tow Professor of physics and astronomy at Barnard College of Columbia University and director of sciences at NYC nonprofit Pioneer Works, in conversation with Rana Adhikari, Professor of physics at Caltech, on the subject of life on other planets.
Janna Levin: I know you have some pretty inspired ideas about the emergence of life — or actually maybe not its emergence, but how it emerges. What might we really expect if contact is ever made?
Rana Adhikari: You know, who we are — is it really embodied in our bodies that we walk around in? Or is it more true that who I am is something like the sum of ideas or the replicating pattern that keeps my package together while I am walking around? And if it's more like the soul is really the pattern and that keeps the body and the shape after atoms keep going in and out, then you might argue that the real definition of self is something bigger than something that's just a couple of metres tall — more like the full digital collection of your ideas that spreads out and infects other people on the Earth.
JL: Well, there's a million questions that sort of sparks. One is about artificial intelligence, but let's put that on hold for a second. The other is about whether consciousness is something we are always aware of. So for instance, let's say you launch these ideas into this ether — the internet or just the reality of the world and all human beings… Is it possible that all those human beings on Earth are somehow actually a collective consciousness and we're just not aware of it? That there is some other entity that thinks it's a self, and its cells are made up of the seven billion people on the planet?
RA: Yeah, maybe there is no such thing as consciousness, or that every animal at every level thinks it's conscious or has something that is there in order to keep its species reproducing more often.
JL: There are so many time scales that we can't recognise. You know, we see galaxies colliding but we don't actually see them colliding; it's a frozen snapshot in our timescale. It takes billions of years for there to be any visible motion in that collision and we are able to figure it out that they were mid-collision and it was pretty obvious.
RA: When you look at the lifetime of stars, you say they spend most of the time doing this thing — they are yellow or they are orange — but over the course of ten billion years they spend [relatively] very little time exploding in a supernova. So when you look out you find billions of more things that are just normal stars and supernovae and if you think of intelligent civilisations, if they pass through this meatbag stage and if it's only something like one part per billion of their total time then you might never find anything like that. For the same reason that when we travel around going to lunch or something, you don't look down at a crack in the sidewalk and see a weed and say, "I better figure out how to communicate with that weed or else it's going to think it's alone in the universe."
RA: It doesn't really worry us that we weren't contacted when we were apes, right? It's a kind of a brief period. We were [only] apes for a while.
JL: How would we know?
RA: But maybe there was an obelisk. We don't really know if somebody came down and tried to talk to us. You can imagine a scenario — there are, like, two skinny green people who are nude and they have giant heads and big eyes and there's a conversation with some apes, like, "Here we are! We are making contact with you. What do you want to do now?" And the apes just say, "Huh, ungh!" And then the aliens leave; they say, "Alright, so much for that planet!" But then maybe that's never happened because none of the aliens are ever of the green flying saucer kind.
JL: Exactly! We're in a galaxy that's — what, more than 100,000 light years across? And there are probably more planets in the galaxy than there are stars, because if one-fifth of the stars' systems has eight planets — and they all seem to have multiple planets from what we are discovering... By the time a planet evolves life and it starts to get interested in exploring the galaxy, it still has a pretty long trip travelling at our current technology. Like, if we send Voyager into space, it's 35,000 years.
RA: This whole story may already be far out in the weeds... It's a little bit like asking, "What kind of baseball teams will aliens have?" We don't look at neutrons and wonder if there's people living on them; it doesn't make sense to do it. So I guess another question would be… Suppose in the universe there are these forms of consciousness that are really ones that we will never recognise. We did, nonetheless, evolve in this particular way, and so you do have to address: why would we be the only ones in the history of the universe that evolved in this particular way? And so if you go back to the weeds that we were in before, even if they are weeds it's still a place where you do have concrete reason to believe there would be more [beings] like us to some extent — maybe not two eyes and a nose; maybe they look like bacteria or maybe they look like some other kind of organic metabolic physical object made out of ordinary chemicals… So there is a real question: what's the likelihood of something like us evolving that we could recognise, and why doesn't it happen more often? I think that's the famous Fermi paradox, and there are lots of ideas and they are all interesting, but not one of them feels like, "Ahhh, that's it! We stop looking."
RA: I believe in the resolution of the Fermi paradox and the insignificance of humankind — that we are just a thing that's not… not-super rare, not super common, but not significant. I mean, if there's such a thing as a galactic civilisation, a universal civilisation. It's unlikely if you think about just the biodiversity of the Earth.
JL: Agreed. But also our species has not had success in terms of longevity — measured at least in human years compared to other species. Dinosaurs roamed the planet for 250 million years without threatening their own extinction.
RA: Yeah, they never had Academy Awards.
JL: Exactly! So we have some stuff to be proud of and some stuff to be ashamed of, but in a couple of hundred thousand years we have been pretty brutally destructive towards our own survival. So you could make that kind of an argument.
RA: I don't know. Nobody would like to hear this, but it could be that being wildly destructive with the environment is good because it hastens the destruction of humanity and brings about an environment which is more hospitable to the different species.
JL: Yeah, we might literally have just been a failed experiment in the evolutionary chain.