You know what an alien looks like, right? Little guy, big head, bug eyes? If not that, it would certainly have some kind of vaguely humanoid shape, right? Star Trek wouldn’t lie to us.
But would aliens really look like that? Are we actually looking at the idea all wrong?
Stott was the moderator of a World Science Festival 2018 panel titled “Who is out There? Why Alien ‘Life’ May Be Weirder Than We Imagine.” It’s a topic sci-fi fans, and people in general, probably don’t consider all that often. And that’s how we can end up making bad assumptions.
You ask 100 different scientists what life is, and “you’ll get 100 different answers,” Scharf said. “What we call life is a confluence of multiple phenomena.” Lisa Kaltenegger, astronomy professor and director of Cornell University’s Carl Sagan Institute, didn’t have time for that.
“I’m an astronomer, so I don’t have to give you a real definition,” she quipped. For Kaltenegger, the only thing she needs to look for is the right kinds of gases in the atmosphere, as the 2020-launching James Webb Space Telescope will do. A bunch of oxygen with a little methane? Those are hard things to produce geologically, so that’s likely a good indication.
“That definition encompasses a huge amount of life,” Kaltenegger said.
“I’m a philosopher, so definitions are always a train wreck,” admitted Susan Schneider, Director of the AI, Mind and Society Group at the University of Connecticut. But since all things on Earth are related, realistically meaning we only have ONE instance of life to look at, we may narrow the definition so much that we don’t recognize it when we see it elsewhere.
“I think one of the problems that we often encounter is assuming that life is a chemical phenomenon,” agreed Sara Walker, astrobiologist and theoretical physicist. Maybe life begins chemically, but that doesn’t mean it has to be defined that way. That would exclude artificial intelligence (AI) and all exotic phenomena, so maybe life should be defined by its information processing capability.
“We don’t really see any other kinds of systems that use information in the way that biology does,” Walker said.
The conversation turned to alien climates, and what would be suitable for life. Scharf explained that the fundamental nature of climate is a complex problem — degree of axial tilt, amount of gravity and innumerable other factors play into whether a planet is habitable or not. “We’re trying to come at this problem from multiple directions,” he said.
“Imagine modeling a climate with two suns,” Kaltenegger said. There are a whole lot of potential climates out there, many we probably can’t even think of, and while the so-called “habitable zone” is restrictive, it’s a good place to start. Scharf wasn’t ready to give up on the weird environments, though, mentioning that there’s 13 times more water in the solar system than what’s in Earth’s oceans, so the “solar system could be teeming with life” that’s “locked in these dark oceans.”
“I’ve been intrigued with this idea that life needs to take over an entire planet,” Walker said, casting doubt on potential life on Mars. “Everything about the Earth’s system is defined by life in some sense,” so we should be looking for those kinds of fundamental, sweeping changes on other planets.
Stott asked Scharf about the Fermi pardox, the conundrum that if there is intelligent life out there, why haven’t we seen it? It’s even worse than we think, he said, because the fact that stars and galaxies move and sometimes get closer to each other should actually encourage colonization, even though we don’t see it.
“I think we don’t know what we’re looking for,” Walker said, again suggesting that advanced civilizations may have a sizeable AI component. “We are probably too boring,” Schneider said, putting the search impetus on the aliens. Maybe we’re too young to care about and search out?
Kaltenegger wondered what a civilization’s motivation would even be to become interstellar. It certainly wouldn’t be for resources — if you can already do the nearly impossible, you don’t need to look for fuel elsewhere. Scharf thought there might be other reasons to commune with alien species.
“It’s the way we’re going to learn about ourselves,” he said.
Stott then brought up the difference between intelligent life and conscious life. Schneider noted that slime molds can develop navigation methods. Is that intelligence? It’s certainly not consciousness. Maybe it doesn’t have to be.
Scharf broached two seemingly contradictory ideas — first, that “we may live in an unusual time” when we’re the only intelligence on-planet, now that all the other hominid species have died off. Also, there’s the problem that “we see intelligence in things where there may not actually be any.” Consider the behavior of ants, which looks intelligent, but is really just driven by chemical signals.
Walker drew a slightly different distinction, saying that ants aren’t intelligent individually, “but collectively they are.” And those kinds of collective behaviors are what we should look for when we’re seeking intelligent life, along with other phenomena that might tip off us off about someone’s sophistication. You don’t get satellites if you don’t know the laws of physics, for example.
The discussion became a little scattershot, perhaps understandably, when the topic of “the future of intelligence” came up. “Intelligence is realized in a lot of different ways,” Schneider said, opening Walker to again assert that, to her, a sophisticated AI would be considered alive, even though it’s not subject to Darwinian evolution (which is part of NASA’s definition of “life”). By that token, Scharf noted that the people who do meet extraterrestrials will not actually be “us.”
“There’s this implicit assumption that species remain the same,” he said, but in reality, “we will not be the human beings we are now.”
Watch the whole panel right here!