I’m not sure aboud Drake, but Brownlee and Ward spend chapters on both. Personally, I found their arguments unconvincing, but who am I? The thing is, it takes only one factor to make animal life rare, and they outline at least ten. Even if they’re wrong half the time, it’s still going to be real hard to find our Space Brothers.
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I agree that it’s entirely possible that civilizations are short-lived – but I think the study’s contention that “it is enough that one civilization survives for it to become visible” is rubbish. The books sound fun – I’ll definitely check 'em out!
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They’re important here, but not necessarily everywhere. They’re important here because they create a stable environment, tides, and a shifting supply of nutrients being moved to the surface, and there are other ways of doing those things.
It’s like the puddle saying, “how amazing and unlikely it is that the ground be shaped so perfectly for me”. (credit to Douglas Adams, i think)
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The probability of life developing is likely to be largely dependent on a given planet having the necessary asynchronous weather drivers as the Earth has, in order for there to be enough zillions of ‘Petri dishes’ in tidepools and such for the necessary chemical reactions to occur in a decent sequence. I don’t know if the exoplanet folks can answer this yet, since the images I see of exoplanets on the walls of Steward Observatory are comprised of a few pixels per planet.
The communication thing is unlikely to happen, given the brief time between when transmitting radio waves was invented here, and when it was realized that sending simply-modulated transmissions into space was economically dumb. Modern TV signals look like white noise.
As far as traveling to other solar systems, good luck with that.
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This is actually my personal favorite explanation for the Fermi Paradox: we are if not the first, then at least among the first technologically advanced civilizations, at the very least in this galaxy if not the entire universe. Because let’s face it, we’re in the early days of the cosmos! Universe is about 13.8 billion years old; the stellar era is predicted to run for some 100 trillion years. Even if we discount the deep, deep future beyond that, only one tenth-thousandth of the age of stars has passed!
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Regardless of the possibility of accurately determining the possibility of there being other life out there, the salient point seems to be the seeming likelihood that most or all of us here discussing this now will be dead before we make contact with such life, or before we travel the stars and colonize other worlds (if we ever successfully do so), much like the people who dreamed of flying like birds before we successfully invented mostly reliable air travel.
/bummer
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When I was studying astronomy in college the number of known exoplanets was zero (though one of my professors was convinced that Barnard’s Star was a planet). The amount of new stuff we know is out there has increased dramatically just in my adulthood (not even my lifetime). The amount of new stuff that will be discovered in the next comparable chunk of time (*) will be enormously greater. Articles drawing predictions like this from current data don’t make sense.
(*) Assiming the dominionists ruining running my country don’t destroy the planet.
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Not quite. It speculated on the right questions to ask based on a sample size of precisely one, and even then gave no way to chose values for most of the variables which rigorously reflect evidence, the sole exception at the time being star formation rates and now were beginning to get good data on planetary formation rates.
Now look, I have no problem whatsoever with speculation based on a speculative equation. But it’s fallacious to pretend it’s science and people who confidently offer answers based on speculation about variables plugged into a speculative equation are indulging in science fiction and trying to pass it off as science. That’s deceitful at best and deluded at worst. Since most of these indulgences involve articles in popular science periodicals, it’s also taking advantage of the public for profit at the expense of long-term trust in the actual science it pretends to be.
I support SETI and have participated in SETI@home. I have no problem with the equation as speculation to try and help astonomers decide what to look for since they have to start somewhere (provided they recognize the equation might lead them to ask the wrong questions). I adamantly oppose selling junk science to the inexpert public.
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That one is a classic.
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Add to that the fact that what radio we do broadcast is more and more often encrypted, one of the properties of a good encryption scheme is that it is indistinguishable from random noise. It’s likely that before long our RF emissions will be more notable to the periodicity of the random noise than any actual content.
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Well, we do live far out in the uncharted backwaters of the unfashionable end of the western spiral arm of the Galaxy.
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Looking for civilizations out there like ours, is not the same thing as looking for intelligent life. As important as the Drake equation has become for framing this question, I think Kay’s observation is just as pertinent:
A person is smart. People are dumb, panicky dangerous animals and you know it.
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But… it’s not.
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" Instead, it simply means that we can say with greater confidence – based on what we know – that humanity is most likely the only intelligent species in the Milky Way Galaxy at present."
No! Based on what we know, humanity IS the only intelligent species in the Milky Way Galaxy. Period. Full stop.
Anything beyond that is wishful thinking. Until we get new data.
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“Well, we do live far out in the uncharted backwaters of the unfashionable end of the western spiral arm of the Galaxy.”
So, population-wise, it’s like… Earth is Staten Island and toward the center of the galaxy is Brooklyn.
I think in those terms.
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Sigh. Yes, we’re probably alone, but this paper spends a lot of time straining at a gnat to get to that conclusion, because like most of the people who play with the Drake equation, they don’t seem to understand evolution much at all.
The Drake equation assumes that sapience and civilization are one and the same, and that it’s something like the eye, an innovation with straightforward benefits that can develop slowly and incrementally over time, each step providing a bit more survival benefit. Each of those assumptions is wrong.
Humans are a package deal - we’re smart talky animals, but we’re also possessed of hands, we’re adaptable in terms of habitat and diet, and we have a wanderlust that has driven us to spread across the globe and dream of going to other worlds. For ETs to create a civilization that we could even theoretically detect, they’d have to have a package very similar to our own. Smart elephant ETs would have a lot of trouble creating a technolgical civilization with only their trunks. Gorilla ETs would just stay in their woody homeland and never dream of spreading to other continents, let alone other worlds. Panda ETs would have a very fragile civilization - anything that negatively impacted the bamboo harvest (climate change, bamboo blight, etc) would cause their population to crash. And so on.
To get a world of ETs capable of and interested in broadcasting “we are here” to the universe, they would need not just sapience, but a whole host of adaptations coming together. They’d have to be similar to us in a number of ways large and small. And evolution doesn’t create package deals on purpose, but only by random chance. So the odds of an ET technological civilization evolving are pretty slim, even before we examine the box marked “sapience.”
Some adaptations (land life, flying, etc) happened repeatedly, in different forms in different lineages. The benefits are so broad based and so big that similar adaptations keep showing up over and over. We can confidently predict that a life bearing exoplanet similar to Earth would have land life, flying life, etc.
Other adaptations have happened only once. Human sapience is an only once (so far) adaptation. As explicated by Terrence Deacon in The Symbolic Species, there’s quite a big qualitative difference between the communication systems used by other primates (and all other animals) and human languages. We are a quantum leap in cognition. No other species now existing seems to have even dabbled in the realm of expanding their ability to think in symbolic terms, nor is there any evidence in the fossil record that any species has developed such cognitive abilities in the past. The first step towards sapience must provide only a narrow benefit that our ancestors found useful in their specific situation, but no other species has found it useful enough in their situations for it to catch on. Rewind the tape of history, and smart talky hominids would only evolve once in several million replays.
Which mitigates heavily against life on exoplanets also happening to luck onto sapience as an adaptation for their situation.
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No, if the center of the galaxy is Brooklyn, the solar system is in a suburb of Phoenix.
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And radio… really? We look for aliens by listening for powerful radio communications. That’s a tech that’s dying even here on earth where low power digital spectrum hopping radio is the norm for communication.
It’s as if we decided that if there are aliens, they would be communicating using a tech that even we consider outdated.
I don’t know if there is other life in the universe but I think it’s a good bet that if there are advanced civilizations, they would be using something a bit more advanced and probably something we aren’t even capable of recognizing as a communication medium.
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