Tens for the Tens: Fermi's Paradox
Jan. 2nd, 2010 01:01 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
pmcrayIt is an odd thing that, for all we actually know, the Solar System could be teeming with life. OK, probably not intelligence life of the chimp- or dolphin-type, but we don't even know that for sure. In the 1970s, James Lovelock predicted that the Viking landers would not find life on Mars: the atmosphere is in chemical equilibrium and life is such a fundamental and integrated driver of planetological evolution that any planet that does possess life should posses it obviously. Life has certainly modified the environment on Earth profoundly. But we don't know that that level of impact is a universal. Life might thrive in redoubts - geothermally-heated aquifers or liquid droplets in clouds.
It now also seems that the Martian atmosphere is not precisely in chemical equilibrium: where is that methane coming from? And although we might dismiss the ambiguous results from Viking, we know that Mars was much wetter and warmer in the past. Maybe we really have detected the traces of nanobacteria in Martian meteorites. Perhaps life flourished briefly on Mars and that it has tenaciously maintained a tenuous grip for hundreds of millions or even billions of years. Perhaps the Mars Science Laboratory rover and, if they are ever funded, the Astrobiology Field Laboratory and ExoMars probes will provide evidence unambiguous enough to convince even the most hardened sceptic.
And then there are the mysterious spectra from the upper reaches of Venus's atmosphere. Certainly plenty of opportunity there for complex chemistry - as in the atmosphere of the gas giants and inside all those tidally heated moons: it is not just Europa and Enceladus. Consider Io. There are plenty of hot volatiles there. And do volatiles really need to be hot? What about Titan? Or even Mercury and the Moon. Volatiles in permanently shaded craters over planetological time might get buried, moved, heated (from above and below) and cooked. As on Mars, there could be redoubts on Mercury and the Moon.
Twenty years ago, when I was postgraduate astronomy student, we didn't even know whether there were any planets around other stars. Now we know of hundreds, none of them, as yet, very Earth-like or any of the planetary systems very Solar System-like. One of the interesting things about the Solar System is just how many different kinds of things there are in it. It is just such a pity that it is so difficult to get around the Solar System and that all you can do there are planetological field trips (well, perhaps there will be dolphin-analogues floating in the atmosphere of Saturn, but that is not one for the Tens). And the other planetary systems found so far have been quite different from the Solar Systems, full of exotic objects such as eccentric Jupiters, hot Neptunes and super-Earths. But it is likely that we will find terrestrial planets within the next decade, including ones in the so-called habitable zones. We might even learn something of composition of their atmospheres. Of course, for much for its existence the Earth did not have an oxygen-rich atmosphere, so we will have to look for other signatures (such as, perhaps, methane) as well. Even if we did discover a planet with an oxygen-rich atmosphere, I am sure the chemists would soon produce plausible scenarios for a non-biological origin of the gas. The only way of knowing for sure it is life would be go to there and see for ourselves and we aren't going to be doing that in the Tens. So by the end of the Tens, we might know there is life on Mars and have good evidence for it it, say, in the atmosphere of Venus (I doubt we will have had the chance to uncover lunar redoubts by then).
The main argument for our cosmic solitude is an extension of Lovelock's argument about Mars: the universe does not appear to be out of chemical equilibrium (and we don't see obvious evidence of large-scale engineering works): there seem to be no Kardashev Type II civilisations nearby or Type III ones in our light zone (but then we aren't really looking). Of course, that might be because life is rare or intelligent life is rare or technological civilisations are rare or interstellar travel is difficult or large-scale engineering works are expensive. Given Tens technology how far away from the Solar System could one detect our Tens civilisation (given that we are generally speaking not explicitly broadcasting - or narrowcasting - signals)? The best resolution to Fermi's Paradox is to assume that civilisations "go away" (or are made to "go away") either through a Singularity or some other existential event. I don't think that we are going to detecting the unmistakeable signal of early warning radars from one of the moons of 23 Librae b in the Tens, but pace Charlie in Accelerando, imagine discovering something weird in the signals from the active nuclei of distant galaxies - perhaps in their infrared or millimetre wave emissions. How frustrating to eavesdrop on heavily encrypted messages from the Forerunners, billions of years old.
Martin Harwit in Cosmic Discovery (1981) argues that there is a limit to how much we can know about the universe on information-theoretic grounds. There are only so many modalities that we can detect and there is only so much information that can be conveyed by each modality. Following Harwitt, we could detect signals consistent with biological processes from other planets, but we could never be sure how they had actually been produced. Clearly in the Solar System, we could go to the other planets if we wanted to, but this is not an option for planets in other systems. We are in rather philosophical (or theological) Dick Cheney/Karl Popper territory here - Known Unknowns (one could think of these issues as being undecidable within the system of the world to which one has access) Perhaps xenobiology/bioastronomy will become like string theory - something like that one believes in philosophically (or theologically) rather than scientifically.
The universe might be teeming with life. There might be all sorts of general principles that be derived from a comparative study of biological systems of different kinds (including systems of natural general intelligences). It is possible that such principles must remain forever necessarily unknowable to us. They are likely to remain unknowable to us through the Tens. Unless, of course, we stumbled on an Encyclopedia Galactica feed (not necessarily for our galaxy or epoch). We would I think be happy to have such a thing even if we hadn't been granted edit privileges.
It now also seems that the Martian atmosphere is not precisely in chemical equilibrium: where is that methane coming from? And although we might dismiss the ambiguous results from Viking, we know that Mars was much wetter and warmer in the past. Maybe we really have detected the traces of nanobacteria in Martian meteorites. Perhaps life flourished briefly on Mars and that it has tenaciously maintained a tenuous grip for hundreds of millions or even billions of years. Perhaps the Mars Science Laboratory rover and, if they are ever funded, the Astrobiology Field Laboratory and ExoMars probes will provide evidence unambiguous enough to convince even the most hardened sceptic.
And then there are the mysterious spectra from the upper reaches of Venus's atmosphere. Certainly plenty of opportunity there for complex chemistry - as in the atmosphere of the gas giants and inside all those tidally heated moons: it is not just Europa and Enceladus. Consider Io. There are plenty of hot volatiles there. And do volatiles really need to be hot? What about Titan? Or even Mercury and the Moon. Volatiles in permanently shaded craters over planetological time might get buried, moved, heated (from above and below) and cooked. As on Mars, there could be redoubts on Mercury and the Moon.
Twenty years ago, when I was postgraduate astronomy student, we didn't even know whether there were any planets around other stars. Now we know of hundreds, none of them, as yet, very Earth-like or any of the planetary systems very Solar System-like. One of the interesting things about the Solar System is just how many different kinds of things there are in it. It is just such a pity that it is so difficult to get around the Solar System and that all you can do there are planetological field trips (well, perhaps there will be dolphin-analogues floating in the atmosphere of Saturn, but that is not one for the Tens). And the other planetary systems found so far have been quite different from the Solar Systems, full of exotic objects such as eccentric Jupiters, hot Neptunes and super-Earths. But it is likely that we will find terrestrial planets within the next decade, including ones in the so-called habitable zones. We might even learn something of composition of their atmospheres. Of course, for much for its existence the Earth did not have an oxygen-rich atmosphere, so we will have to look for other signatures (such as, perhaps, methane) as well. Even if we did discover a planet with an oxygen-rich atmosphere, I am sure the chemists would soon produce plausible scenarios for a non-biological origin of the gas. The only way of knowing for sure it is life would be go to there and see for ourselves and we aren't going to be doing that in the Tens. So by the end of the Tens, we might know there is life on Mars and have good evidence for it it, say, in the atmosphere of Venus (I doubt we will have had the chance to uncover lunar redoubts by then).
The main argument for our cosmic solitude is an extension of Lovelock's argument about Mars: the universe does not appear to be out of chemical equilibrium (and we don't see obvious evidence of large-scale engineering works): there seem to be no Kardashev Type II civilisations nearby or Type III ones in our light zone (but then we aren't really looking). Of course, that might be because life is rare or intelligent life is rare or technological civilisations are rare or interstellar travel is difficult or large-scale engineering works are expensive. Given Tens technology how far away from the Solar System could one detect our Tens civilisation (given that we are generally speaking not explicitly broadcasting - or narrowcasting - signals)? The best resolution to Fermi's Paradox is to assume that civilisations "go away" (or are made to "go away") either through a Singularity or some other existential event. I don't think that we are going to detecting the unmistakeable signal of early warning radars from one of the moons of 23 Librae b in the Tens, but pace Charlie in Accelerando, imagine discovering something weird in the signals from the active nuclei of distant galaxies - perhaps in their infrared or millimetre wave emissions. How frustrating to eavesdrop on heavily encrypted messages from the Forerunners, billions of years old.
Martin Harwit in Cosmic Discovery (1981) argues that there is a limit to how much we can know about the universe on information-theoretic grounds. There are only so many modalities that we can detect and there is only so much information that can be conveyed by each modality. Following Harwitt, we could detect signals consistent with biological processes from other planets, but we could never be sure how they had actually been produced. Clearly in the Solar System, we could go to the other planets if we wanted to, but this is not an option for planets in other systems. We are in rather philosophical (or theological) Dick Cheney/Karl Popper territory here - Known Unknowns (one could think of these issues as being undecidable within the system of the world to which one has access) Perhaps xenobiology/bioastronomy will become like string theory - something like that one believes in philosophically (or theologically) rather than scientifically.
The universe might be teeming with life. There might be all sorts of general principles that be derived from a comparative study of biological systems of different kinds (including systems of natural general intelligences). It is possible that such principles must remain forever necessarily unknowable to us. They are likely to remain unknowable to us through the Tens. Unless, of course, we stumbled on an Encyclopedia Galactica feed (not necessarily for our galaxy or epoch). We would I think be happy to have such a thing even if we hadn't been granted edit privileges.
Blogged with the Flock Browser
Another resolution of the Fermi Paradox?
Date: 2010-01-11 05:00 am (UTC)That led me to go around visiting other blogs that mention the paradox. I definitely reject the UFO angle...
That led me to go around visiting other blogs that mention the paradox. I definitely reject the UFO angle...
(Sorry, I won't register for ANY Microsoft service unless I absolutely have to. Actually, I wouldn't even have read this blog if I had known it was Microsoft's. Yes, I know Google is evolving towards evil, too, but at least they haven't caught up with Microsoft yet. I think.)
P.S. That is one stupid spelling check, even for Microsoft. It screws up the HTML, doesn't know such obvious words as "blog" or "Google", and did not check the subject field.