Here’s Seth Shostak pumping up SETI again, and now he’s predicting contact with aliens within 20 or 25 years, or by 2030.
I don’t buy it for a minute, and I think his whole argument is ridiculous.
As these guys always do, they have a small set of arguments. One is the argument from very big numbers: there are 1022 stars in the known universe, and the current data shows that a significant fraction of them have planets, and they’ve even observed a few of them that have earth-like temperatures.
I say, big whoop. The other big numbers we could throw around are the distances of these stars from us and each other, which completely negate the bonus of large numbers. We’re simply not going to get an accidental signal from elsewhere; signal strength is going to drop off as the inverse of the square of the distance, so we’re not going to pick up some broadcast from an alien civilization. They’re going to have to aim a signal at us (one unexceptional star out of 1022), and they’re going to have to invest a significant fraction of the energy output of their star to get the signal to us.
I would ask, from the example of the sole technological society we know about, are we doing that? Why do we expect other civilizations are going to do that, and specifically send a signal to us?
But the most objectionable part to me, personally, is the short section titled “Biology: An Easy Thing?” Life arose very early on Earth, and there is good reason to expect that we are not unusual, and the emergence of life as an outcome of normal planetary chemistry probably is common and likely. Biology is only easy, though, if you’re willing to point to a stromatolite and leap immediately to the conclusion that life will build radios. There’s a rather wide chasm there that Shostak elides. The ubiquity of bacteria in no way implies the ubiquity of technology. The specific kind of intelligent life that builds telescopes and radios and artificial intelligences is going to be really rare: I can understand how an astronomer might get excited about incremental increases in likelihood by discoveries that maybe 70-80% of stars have planets, and maybe planets orbiting red dwarf stars would have habitable zones, but those numbers do not compensate for the fact that in the 4 billion year long history of life on earth, the technology to even dream of collecting signals radiating from other stars is only a century old. Only one 40 millionth of this planet’s existence contains that kind of capability.
Add to that the likelihood that any matching civilization might be a thousand light years or more away, and that their signal (although from our example, they probably aren’t signaling; think instead of thinly scattered civilizations all listening casually and unintently for a bit of patterned electromagnetic radiation) can only be received and echoed back over a time span far greater than the duration of any of our cultures, and that puts Shostak’s 16 or 20 or 30 year bet in perspective. That’s a convenient eyeblink on the scale of the time and space SETI proponents tout as an advantage for their calculations.
I do agree with Shostak’s comments about how science isn’t shackled to the narrow hypothetico-deductive method taught in introductory science courses, and that sometimes fishing expeditions are legitimate components of a research program. But I tend to expect fishing expeditions to have slightly better rationales and expectations of useful results than SETI can provide.
Okay, maybe you’re right but I’d say any thinking about this is necessarily speculative. While it took billions of years for a technological civilization to appear on earth, we don’t know what the typical length of endurance is once they happen. While we’re on the verge of doing ourselves in, one can’t rule out wiser beings that, once they steal the fire of intelligent understanding from the Gods, figure out how to endure for a billion years. If that happens, there could be a lot of them. No particular reason for them to beam a message at us, to be sure, and if they do communicate between stars, they’ll be using masers. But I can’t rule out some perceptible leakage of EMR. Not that I’d be making any bets, for sure. The argument that it’s unlikely is pretty credible.
Our own civilizations radio leakage attenuates to indistinguishable from background only about a light year or so out. So all the talk about how aliens within a 50 light year sphere of us could have picked up Hilter, or I Love Lucy, or whatnot, is just that, talk.
On the other hand, we have already sent out directional pulsed signals that would be detectable over many lightyears. These include radio pulses astronomers use for things like instrument calibration (I could be off on the details here) while doing radio astronomy. They aren’t done for the purpose of contacting alien civilizations and do not carry information, but they are focused beams that are detectable. If an alien civilization sent such a beam in our direction as part of their routine astronomical surveying of their sky, SETI could pick up such a signal from thousands of light years away. But our SETI as it is currently set up would not be able to confirm such a signal as genuine because these kinds of signals don’t always repeat at regular intervals.
Over at Centauri Dreams, they’ve talked about quite a bit of scientific literature speculating on how and why alien civilizations might send directional, detectable beams or messages. The interesting corollary of this speculation is that it indicates that there is sufficient interest within our own civilization, from many quarters, in sending such signals, if and when we obtain the capability for doing so in a manner accessible to smallish privately funded groups (as opposed to huge collective efforts with the attendant political and economic obstacles, which we as a civilization probably already have the technical capacity to do, but not the political will).
PZ has it right. Our radio signals (active for about 100 years) have only reached a tiny fraction of available stars (roughly 15,000), but the strength is ever weakening. So the further away it gets, the more likely it will be confused for noise (if noticeable at all).
So very many problems with SETI. Even if there is a technological civilization within range, their technological path will almost certainly be very different from ours, so they may not even recognize our signals. They may not even recognize us as being particularly intelligent considering how we treat our resources not much differently than a mindless virus treats its host, so not even deem us worthy of contact if they were aware of our existence.
The next reality that SETI doesn’t seem to acknowledge is that we’ve only started figuring out how to listen to basic electro-magnetic signals for about 100 years. The odds that another civilization is within a few thousands years technologically are as astronomical as the existence of a technological civilization even existing within the 15,000 star systems our radio signals have reached. Would they even think to look for extremely rudimentary EM transmissions? Who knows the types of communications channels they actually use. Perhaps they listen in on quantum communications (we don’t think you can see such communications, but we just started down that path) and that is the basic marker of intelligent life to them.
What other things in physics don’t we know about yet? Remember that dark energy is something that we currently have no method of observing. There could be all kinds of ways to manipulate whatever dark energy is into travel, communications, etc.
In the end, humans have a *lot* of growing up to do. Both in really understanding our standing in the universe as well as understanding the true possibilities of what may be out there.
David Brin’s excellent SF novel ‘Existence’ deals with this subject as well, from a refreshingly evolutionary perspective. Certainly one of the best SF novels I’ve read this past decade.
If alien civilizations wanted to contact civilizations at other stars, they might not use radio. Modulated gravity waves or neutrino bursts or something else might be their choice for a communications medium.
Evidence ?
If you want to be heard, you will choose a medium that can be heard most easily. And gravity waves nor neutrinos ain’t.
Intelligent, extraterrestrial life is one of the few things I have faith in. I believe it exists. Yes, the Drake equation is an empty exercise. Yet given the incredible size of the universe I feel it’s virtually certain there are others out there. Call me a believer, but there just has to be. And no, I don’t believe we’ve ever been visited by little green men or “the grays”.
But we’ll almost certainly never make two-way contact, much less in person contact, ever, even if our civilization survives millions of years. The distances are too vast. We will spend our entire existence in this universe alone. We may find evidence that there are others out there. But we will never communicate with them.
Kepler is detecting lots and lots of exoplanets. Both by the Doppler wiggle as well as by eclipsing light curves. When an exoplanet eclipses its parent star there’s the potential for reading an absorption spectrum of the planet’s atmosphere. Imagine if we detected industrial pollution — some components of the atmosphere that could not arise through any sort of natural processes and must have been manufactured. That is really my only real hope for detecting extraterrestrial life. And I hope it happens in my lifetime.
S E N D M O R E C H U C K B E R R Y.
That was when radio communications started, around the beginning of the twentieth century.
10 mld / 40 mil = 250 years. How he does know that our capability to use radio won’t last longer, or that something more durable does not evolve after us ?
When I first saw the headline, I read it as, “The SETI Bondage.”
I think I pulled a muscle doing the double-take.
It has taken hundreds of millions of years for brains to evolve human intelligence, so we cannot expect many planets to have done the same. Even if aliens have human intelligence it does not follow that they would be able to produce radios. If they are aquatic then metal smelting would be impossible, and it is thought that super-Earths would be entirely covered with water. If they are not social then they will never develop a civilisation. And if they don’t have hands then they could never manufacture anything.
We have jumped through a lot of hoops to get to where we are, few other planets can be expected to have done the same.
We just need to start beaming this out to the stars:
If they are not social they will not develop human level intelligence.
tell that to this fellas new caledonian crow
There does seem to be a significant amount of confusion about this. The general perception that a lot of people seem to have (and which the SETI institute doesn’t spend a lot of time dispelling) is that we are looking for “accidental” transmissions.
I had an opportunity to bring this up with Seth Shostak a few years ago (he was doing a presentation at my local astronomy club), and having gone through a rough link budget and failing to get the numbers to work, I asked him about this specifically. He confirmed that yes, they’re assuming highly directional signals.
I don’t get it. This one fact adds so many orders of magnitude to the size of the haystack we’re searching through that I can’t see how it will ever have a meaningful likelyhood of success.
“If they are not social they will not develop human level intelligence.”
Orangs seem to be fairly close.
“tell that to this fellas new caledonian crow”
Get back to me when he has built a radio.
Well, we do know that our planet will only be habitable for another few billion years or so, no matter how wise we are (and no matter what else evolves here if we blow it somehow). That’s for a planet like ours, which is not necessarily a “typical” one harboring life. Some people could set up a small colony on a different planet in this system or another, or they could develop ways to survive for long periods just roaming around in spaceships. (That doesn’t leave much hope for sending out powerful signals for aliens, since energy would be much more limited and would need to be spent on something that, if not critical to survival, would at least be doing something useful.) If people don’t do something like either of those, we’re toast. So your best bet would apparently be dwarf stars, since the stars’ lifetimes (and the planets’?) are much longer, and just because there are more of them. So we may not be typical, but this is all measurable stuff, not a total mystery so that we’re stuck waving our hands and looking for excuses.
The point is, even if some civilizations last for billions or trillions of years (at any arbitrary time, in the past or present or future of the universe), the likelihood of hearing from any one of them (right now, while we happen to be listening for signals which must be very close and pointed straight at us) is still extremely small. It can’t be that much more likely than our planet actually being visited by aliens or getting abducted and anally probed. Sure, it could happen, but if I had money, I wouldn’t put any on it.
How much longer are we talking about? And for how long will we send out extremely powerful signals directly to planets where we think there might be life (since that’s quite different from “our capability to use radio”)? And how long will they check? And when are they supposed to exist? Why assume these civilizations nearby are doing this same kind of stuff at the same time, instead of zillions of years too soon or too late?
Our best hope is that ET is as paranoid about it’s fellow beings as we are. Broadcast signals radiate in all directions which causes their energy to be spread out thin meaning a large radio telescope can detect them out to only about 30-50ly. On the other hand the phased array air defence radars across the North are high power (>1 MW) and focused beams. Such beams are detectable by radio telescopes on the order of the Parkes radio telescope (~63m) at about 1000ly. Of course they have to be pointed in our direction for us to see them (and conversely ours pointed at a prospective alien radio astronomer at the right time as well).
@Amphox #2 – there are only a couple of radio telescopes with the capability to transmit, and those transmissions are used for planetary radar astronomy. The vast majority of radio telescopes have no transmission capability at all and like virtually all astronomical telescopes are passive instruments. Radio telescopes are calibrated using astronomical sources. As I said before our best bet is that any alien civilization is as paranoid as we are and have massive air defence radars which are on 24-7 pumping massive amounts of directional EM radiation into space.
If a civilization actually wants to communicate it has to use strategies to increase it’s chances of being detected as just sending beams of energy in random directions in space is a futile attempt. One such strategy would be to use supernovae. Since supernovae are rare enough and very useful to astronomers, it is a reasonable assumption that any civilization that bothers to do astronomy would study supernovae quite intently. The strategy works like this (lets assume we want to send a signal): We detect a supernovae (usually in a galaxy eternal to ours). We immediately begin transmitting a message 180 degrees from the supernova so that if we are in the line of sight of the supernova from other civilizations, any astronomers on those worlds would see our signal as well as the supernova.
From PZ:
Just out of curiosity a scifi-ish Sunday thought: Is it unreasonable to consider the possibility that we are not necessarily the first intelligent species on Earth? Could it be possible that there could have been a conscious, intelligent dinosaur (or whatever) species that went extinct perhaps 100 million years ago, cataclysmally or otherwise? Even a species with technology, but with no remnants found so far? After all, our human culture is quite young, and will eventually be buried deep under the future sediments. Will there be evidence of our technology after another 100 million years?
Wouldn’t this just be a sort of high-risk high-reward work? Sure, the chances of detecting anything are pretty remote, but if they DID detect something, it would be a fairly groundbreaking discovery. Even if it’s the equivalent of signals archaeology for long dead species, the amount of information you could get from it would be fairly substantial, I’d imagine.
SETI has also developed some technologies that have been used in other fields quite successfully, such as the SETI@Home distributed processing software, and it’s funded entirely by donations (according to their web page) so it isn’t really competing for federal research dollars. Even if it’s pie in the sky work, isn’t it the funders’ money to spend? I mean, they could be funding work to hunt the Loch Ness monster or something with even less basis in reality.
Orangutans are still social… less than the other great apes, but still a lot more than purely solitary animals. And also, they are the least smart of the great apes.
moving the goalposts much ?
We don’t know. you don’t know, I don’t know and PZ does not know either. so it makes no sense to say 250 years ( or any other number ) of attempts at communication max.
People, I am not familiar with all these orders of magnitude and so would like to place a request for comment.
I remember hearing somewhere that George Bush Jr. believed his grandchildren would go out to populate the stars or that if the world gets too polluted, the good guys, you know, the multi-billionaires, could just jettison to space and survive that way (country clubs in deep space).
This irresponsible idea (that many share) seems to me not only repugnant and cowardly but also impractical. As I can’t analyse the probabilities in the magnitudes you all are capable of, the only thing I can think of to show its impracticality is the number of people required here on earth to keep one person in space for a limited amount of time (thousands or more of very highly educated folks, right? That would all need to breathe and drink at very least). Also, how these pioneer space billionaires would spend their time, much of it doing exercises just to keep their muscles from atrophying because of lack of gravity, leaving them little time to repair their space habitat, much less build, invent or learn anything. I imagine the complications of their lives, the fact that they will spend time every day positioning their anuses with respect to a vacuum tube that sucks up their feces. A little more to the left, no, to the right, ready get set….
Yes, that’s unreasonable. They don’t appear to have had brains capable of anything like that. Fish (or, say, bacteria) have been around even longer, yet there’s good reason to think they never made any such technologies either. Claiming it happened but the evidence is now lost isn’t just speculation but requires that you ignore the evidence we already have.
I don’t know. I wouldn’t be surprised at all if there were life elsewhere in the universe, so that by itself doesn’t seem terribly groundbreaking. What kind of information are you expecting?
How’s STI coming along?
If you’re thinking aimed signals, the question becomes “why aim at us?” To be aiming at us, an alien civilization would need either to be so energy-rich that it was transmitting to any planet that showed signs of any form of life—so they could have been sending to Earth for the last billion years, if their own civilization was sufficiently old and patient—or to have detected our radio signals and had time to send a message back, meaning they would have to be within a few dozen light years.
The Drake equation is one equation in six or seven unknowns, but whatever you think the other values are/should be, asking for “within 50 light years of Earth and having a civilization that communicates by radio waves at the same time as we do” makes the chances of finding one much lower than if you ask “anywhere in the universe, any time in its history” or “anywhere within our light cone.”
Gee, read what he said. PZ was talking about progress to date. Nothing about the future.
Isn’t that as big an assumption as SETI is making? After all, the only example we can study shows a 100% likelihood of developing such technology.
The problem as I see it is not just distance but time. The odds of their being a civilization which is advanced enough for us to detect, but not too advanced for us to detect, would seem to be astronomical. It’s not as if all of the stars began their lives at the same time. Civilizations could have risen, flourished and fallen long before humans evolved on this planet, and others would likely rise, flourish and fall long after Earth is gone. The likelihood of two relatively equal civilizations being close enough to communicate seems pretty small.
Still, I see no harm in having a privately funded group listening in for noisy neighbors. Who knows? They might find something worth the money.
then his number is completely irrelevant.
This is the crux of your argument, but it has some problems. First, you are correct about almost all stars in the Universe. Those in other galaxies are too far away for any contact to occur for several reasons. The real question is about stars in our home galaxy. We don’t have enough information about what it takes to create a civilization technologically advanced enough to send a signal or direct a signal toward us. We are, and have been, sending (unaimed) signals into space. We could calculate a radius in which we could detect our own signals and have a much smaller number of stars that potentially have a civilization that can detect each other at interstellar distances with our level of technology. Of course, there is very little reason to think other civilizations have our level of technology. They could be much more advanced, the galaxy has been around for a long time. We need to know more about how likely life is and technological life is to give a reasonable estimate. We don’t know at this point.
Do you have anything constructive to say, instead of irrelevant nitpicking?
As boondoggles go, SETI is pretty cheap. Actually extremely cheap. I’m not sure what the current level of federal funding is (if there is any) and didn’t have any luck finding it in a quick Google search, but this article by Phil Plait, from 2011, indicates the cost of running SETI to be about 2.5 million dollars a year. That’s million with an M, not billion with a B as is usual in the cost of things for the feds.
http://blogs.discovermagazine.com/badastronomy/2011/05/01/the-cost-of-seti-infographic/#.UjXVGdJBT90
If anyone’s got the current level of federal spending on SETI, please let me know.
And yes, I’m sure $2.5M could by PZ a lot of nice zebrafish, or feed quite a few schoolkids. More likely it would just purchase a new Tommahawk missle.
I have to agree with P.Z. here, but as someone who grew up reading Golden Age SF, it makes me very sad to do so.
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This is no nitpick. The ratio of our use of the radio to the total age of our planet is completely irrelevant. Consider for example some PZ’s ancestor computes the ratio 10 seconds after Tesla’s first radio transmission. and then 100 seconds after. See why it is irrelevant ?
The thing that governs the probability of meeting is the total duration of the capability ( and willingness ) to communicate. Not how long ago WE invented radio or started with SETI.
Were you paying attention to the parts where Shostak was claiming we’d find it very soon? (His most conservative estimate was something like hundred or so years). PZ’s claim which you’ve been whining about is relevant to that.
What wouldn’t be relevant? If people (or some other species on Earth) discovered aliens a billion years from now. Because that has fuck-all to do with Shostak’s claims.
Also, his is a better sales pitch, frank. Just let him take care of this.
Shostak has obviously watched “Contact” too often if he thinks he can guarantee it will happen. Making outrageous claims will only embolden anti-science religious extremists and their followers when the predictions turn out to be wrong.
The radio age among humans is barely more than 100 years. Life here is 3.5 billion years old. The universe is 13 billion years old. Even *IF* other planets have intelligent life capable of our technology or better, the chances of that life occuring at the right time and distance to reach us (if in the past) is ridiculously small. And for their signals to actually reach us considering gravity, black holes, direction, etc. is miniscule in an infinite universe. There’s a better chance of randomly picking out a single electron out of all the atoms on the sun than hearing from another world.
And even if we did hear from another planet, it likely won’t be a deliberate signal. It will be random noise, similar to our commercial radio and TV signals, or maybe telephone and radio communications (e.g. airplanes, military, ham radio).
And who says it has to be in the radio or TV frequency? Some animals see infrared and ultraviolet and hear higher (dogs) and lower (whales) frequencies than we can. Life elsewhere might see, hear and transmit in the frequencies they perceive, not ours. Signals might already be coming here and we aren’t listening for it.
are we doing that?
Yeah, actually.
http://en.wikipedia.org/wiki/Arecibo_message
No, not targeted at a nearby likely star. But we’ll soon have several such to choose from.
SETI peeves me because we can’t even have conversations with the other animals on our planet, the animals that we share an evolutionary history with, and yet they assume that some other lifeform with a completely different evolutionary history will be sending off signals in a way that we’ll be able to identify, comprehend, and work with.
We don’t perceive radio waves either. We have technology do it for us (and translate it into visual light and sound).
We’re spending a substantial fraction of the energy of our star to send out messages? I don’t think so.
You haven’t shown the relevancy of your position, especially with sophistry like that. You just keep making noises about the future, when PZ is looking at progress to date, and likely in the next score years.
I run Seti@home, and I don’t expect to see the announcement we have found another civilization in my lifetime.
He’s predicting contact by 2030. Just think about that. He’s either grossly innumerate or he simply doesn’t understand probability.
Why does that gave to be either/or?
Same time as the Singularity. Coincidence? I think not. Conveniently in the distant future, but not distant enough to be discouraging? Definitely.
Maybe our robot super-mind will be the one to find theirs. Or maybe it will invent a time-machine, to go billions of years into the past to seed the alien life, so the aliens would end up creating a new friend for it. There’s no way to know for sure.
Many years ago I taught a course that included discussion of SETI and the Drake equation. For a reasonable set of assumptions about the number of stars with planets, the number of earth-like planets, etc. there was one particular parameter that really played a crucial role. That was the Lifetime (L) of a hi-tech civilization.
It turned out that a critical value of L was ~10,000 years. At that value, the average distance between hi-tech civilizations was about 10,000 light years. This meant that if you received a signal from an extra-terrestrial civilization and sent an answer back, there was a high probability that the civilization would no longer exist by the time our reply got to them.
Since our existence as a hi-tech civilization capable of sending and receiving signals to another civilization is only about 100 years I think the probability of communicating with another civilization is very remote. Yes, perhaps we will last for 10,000 years as a hi-tech civilization, but we certainly have a lot a problems (war, pollution, over-population, climate change) we will have to overcome to last that long.
@coldthinker #20
John Michael Greer shared some relevant speculations recently here which I found rather interesting: http://thearchdruidreport.blogspot.com/2013/09/the-next-ten-billion-years.html
PZ, you make a very valid point about the gigantic (dare I say, astronomical) improbability of ever detecting a signal from an extraterrestrial civilization using the means currently available to us. Heck, I’ll even go one step further and say that it is unlikely that we’ll ever find an extraterrestrial civilization even if we develop physics-defying (at least, to our current understanding) technologies.
But that said, even if dialogue between civilizations takes tens of thousands of years, it would be the saddest kind of tragedy if ET did try to call us and nobody was listening.
ET is out there somewhere, that is almost a certainty. Even if the odds are a million to one that the phone will ever ring, our human desire to learn about the universe outside of ourselves should require us to keep somebody watching the phone.
Eristae wrote @#40:
Extracting complex information from an alien transmission could be exceedingly difficult, especially if it was not designed specifically as a beacon for alien life. On the other hand, determining that such a transmission was not the result of known natural processes would be quite a bit easier. An alien civilization may not be able to decode, display, and make sense of Gilligan’s Island, but they could easily detect the regular narrowband pulse train that corresponds to the vertical blanking intervals in those Gilligan’s Island broadcasts. That would raise curiosity and no doubt motivate further scrutiny towards our part of the sky.
jasonnishiyama wrote @#19:
One can imagine large phased arrays (many miles in diameter) backed up with sufficient processing power being able to scan large swaths of the sky simultaneously at high resolution. That could extend the detection of our terrestrial TV broadcasts out to distances of 1000 ly.
Also, the technology developed for SETI has direct application to Radio Astronomy.
Might be worth looking for artifacts in some of the L4 and L5 Lagrange points in the solar system. Best places for calling cards, or “we were here, where were you?” sticky notes.
@left0ver1under at #38:
SETI searches are done at radio frequencies for a couple of reasons other than we use it for communication.
1) radio penetrates the gas and dust of the ISM better than most other bands of the EM spectrum, letting us listen farther.
2) many SETI searches can be done as parasitic observations on a radio telescope so can be piggy backed on other observations without taking the radio telescope away from other science. This is harder to do at other wavelengths.
@Billy Clyde Tuggle at 50:
I wasn’t arguing against SETI, just at the improbability of picking up alien TV broadcasts. The SKA may have that kind of sensitivity but other, higher priority projects will get to use the instrument. That being said if someone wants to pour through the 1TB/s of data the SKA will produce as a parasitic search, they may get lucky.
So, what yer all saying is, I should give up my hope of being selected as one of the xenolinguists of the first contact team, huh?
Okay.
On to Lifelong Dream #3…(#1 was “being a mom”; already got there).
Funny; I’d have said he was sharing his sense of his own ineffable superiority, which I found rather boring.
@Eristae We would share knowledge of higher mathematics and science with them which is a not insignificant advantage.
I can think of things with a hell of a lot less relevance to humanity that should be cut with priority above SETI.
Drake left out the lifespan of a civilization with nuclear weapons. I estimate it at 300 years, with luck.
Speaking of distance and time, here is a really excellent set of timelines showing exactly how brief we are. I might ask for a few more points (e.g. when personal computers became available) or timelines (e.g. since the Earth’s crust solidified), and I might quibble about some of the dates (I’m pretty sure Homo erectus had fire about 1.8 million years ago) but it is a fascinating look at how deep time really is. I think it deserves a blog post, PZ! Putting Time in Perspective
Or he’s doing what every salesperson does. Make the goal seem personally attainable to customer and get them to work towards it, regardless the realities. Not that this is good human behavior either.
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I don’t have a problem with SETI-the-thing. I do have a problem with talking asshats like Shostak.
Eristae:
Other animals don’t possess a theory of mind, which is a huge hurdle in communication.
I say put the SETI money into straight-ahead exoplanet research.
That’s a field tells you things. Tightens up other parameters on the Drake equation which decades ago when it was written were little better than guesses. Among other things.
I figure on essentially the same reasoning as does PZ that life is likely to be pretty common, life broadcasting radio signals of any kind–let alone any we can detect–a lot less so…
But honestly, the probability even on that former thing is still a lot of induction, not a lot of direct evidence.
But we can practically tighten those probabilities. To do it, we need to improve our detectors, find smaller, cooler planets further from their primaries, get spectral signatures off those reliably, start looking for things like chemical mixtures in atmospheres suggesting the above-mentioned stromatolites or whatever the analogue in a given target system is.
The thing about exoplanet research, again: it finds things out, and it’s got a track record of doing so. Like how many rocks how big there are out there. It’s not this all or nothing you find a signal or you don’t thing. It’s not playing a lottery; it’s investing in the market. Still speculative, in a sense, sure, the way a lot of research is, but way better odds, at least, and you can get something out of it without having to be insanely lucky. SETI, even the so-called ‘negative’ results have pretty limited information content. The absence of a signal means… What? That no one’s beaming anything at us from there? Big whoop. It’s a huge and probably very wrong assumption that anyone out there has much reason to do so.
Exoplanet research, in contrast, quantifies things. Tells us stuff about planetary formation, tells us stuff about how many and how big and where. Work it enough, and we can get what they’re made of, what the atmospheres are. If, in fact, biology like ours is common enough, maybe even the odds of finding atmospheres with suspicious quantities of free oxygen in ’em aren’t so bad. And even if we don’t, it’s an actually meaningful negative results. Tells you how common in the planets you can actually see such things are, at least. Which tells us something about the probability of abiogenesis under such conditions, so on.
Billy Clyde Tuggle #50:
How many dB antenna gain are you assuming with such an array?
Even if it was gigantic, I just don’t see how you could achieve a high enough gain to get an approximately isotropically transmitted signal anywhere close to above the noise floor, assuming that the source signal was intended for local reception (ie not a multi-GW output).
They jury is still out on whether human level or higher intelligence is a successful trait from an evolution standpoint. As for us, we’re so darn good with tools that we’re a species out of control, making our environment uninhabitable for our neighbors and ourselves and I don’t see that changing any time soon. Not to mention our propensity to blow the hell out of each other.
Intelligence, certainly the human kind, may turn out to be just an evolutionary dead end. An interesting trait that pops up from time to time across the cosmos, but quickly extinguishes itself. Given the time and distances involved, it’s unlikely in the extreme that two independently evolved intelligent species would bump into each other. Granted, I’m basing that on humans and our failings, but I’ve no reason to believe other intelligent species would behave any differently.
Life in general is another story. Since the fundamental building blocks are all over the place, it may be relatively common in other star systems. Maybe even those relatively close to us. Simply finding signs of alien life out there would be enough for me. If we’re any guide, an intelligent alien species would be just another group bent on killing us and taking our stuff. We’ve got enough of those in our own species, thank you very much.
Seti@home is run entirely by donations, and has 2.5 FTE people keeping the servers going for the distributed workunits. Scroll down this page to see the servers prior to a recent move. Most of the equipment is donated.
1. How refreshing to see a calm discussion on Pharyngula about an extremely interesting scientific topic. In my opinion the recent focus gender issues, replete with hateful comments from both sides, has seriously detracted from this formerly excellent blog.
2. The odds for success of the SETI project may be higher than we might imagine. Several years ago someone opined that advanced civilizations would probably construct an intra-galactic internet. Robotic probes located all over the Milky Way would act as data repositories, signal repeaters, and beacons. Perhaps not so far-fetched when you consider that we humans created a global computerized internet a mere hundred years after the invention of primitive telephones.
I think it was on a what-if-xkcd that Randall Munroe made an economic argument against finding random, not directed at us, alien radio signals. Any signal that you send out into space, means that you have spent energy transmitting a signal that is not getting to its intended destination.
Thus, as technology improves, so will the ability to direct the majority of your signals power at its intended goal. In other words, as a civilization advances technologically the amount of random signal leakage it emits goes down.
Even though I work at the SETI Institute now, I do get a bit annoyed with Seth (or anyone else, for that matter) says “we will discover ET by [INSERT DATE HERE]”. We simply don’t have the data to make such an assertion – it is impossible to do meaningful statistics on a sample size of 1.
Knowing Seth, I can say that he is neither innumerate nor does he not understand probability. He is, however, making an unjustifiably optimistic assumption.
Also, PZ, the following statement you made is wrong:
Signal strength _does_ fall as the square of distance, but it is still entirely plausible that we’d pick up some broadcast from aliens. The most detectable radio leakage from the Earth is when I’m using Arecibo to bounce a radar beam off an asteroid. Most of the 800 KW or so that we transmit into space misses the rock pile and keeps on going. Alien astronomers with an Arecibo-equivalent could pick up that signal across a large fraction of the galaxy (although not all the way across), if they happened to be inside the narrow cone of the beam. That would be an accidental signal, although perhaps not a terribly informing one beyond knowing “somebody had a transmitter”.
It is also possible to build a beacon that is detectable over the entire galaxy, assuming particular radio telescopes at the receiving end. With our current hardware, we could pick up such a beacon with a transmitting power of a few gigawatts anywhere in the galaxy (however, the current surveys have not covered enough sky to say that no such beacon is currently visible). That is very much less than “a significant fraction” of the energy output of the Sun.
The unknown here is again how common detectable intelligent cultures are in the universe. If it is at least one per 3 x 10^11 stars at any given moment (if such cultures last 100 years on average, then you’d need a least one out of every 10,000 stars to have one near it sometime), then you are looking only over the galaxy – rather than over all of the hundreds of billions of galaxies in the universe. Only if you want to be detected over the entire Hubble volume do you need to be channeling an entire solar luminosity.
With regards to SETI in general, beyond radio surveys:
I’d personally say that since we now know that there are more planets than there are stars, we should start trying to understand what interesting chemistry is happening on them. This will require new hardware, but we’ll learn a bunch even if we don’t find ET anytime soon.
@sciencenotsuperstition:
Your opinion is wrong. It is quite important to discuss the many problems of human society. That PZ wants to talk about some of them here is a good thing. And don’t fall into the Golden Mean fallacy.
On the one hand, PZ is completely right that it’s highly unlikely that there will be contact by 2030, and the person advocating for SETI is playing bad statistical games.
On the other hand, I support SETI in general. It’s a cheap program, only a few hundred thousand a year or so, and if we don’t listen who knows what we’ll miss?
The low cost more than justifies continued deployment of the program.
Correction: that should be “at least one out of every 3,000 stars”. I used the age of the Earth, but what matters here is the lifetime of the stars concerned – many of which are a little bit upwards of 10 billion years old. And, of course, this is _detectable_ intelligent cultures. Earth wasn’t detectable in radio until maybe 100 years ago, and perhaps we will stop being so detectable in the future (although that has not been the case so far – there is a lot more high-bandwidth traffic, which is hard to detect a long ways off, but also more carrier waves, which are easier to see).
@sciencenotsuperstition:
1. Don’t act the tone troll.
And why should we take your tone trolling evidenceless opinion seriously? WHY?
Monitor Note
sciencenotsupersition @ 65:
This thread has a specific topic. If you wish to complain, there are two open threads: The Lounge and Thunderdome. If you wish to go off topic, please do so in one the open threads. Thank you.
Nerd of Redhead @ 71, please take off topic subjects to Thunderdome. Thank you. This goes for everyone else who wishes to argue off topic to this thread.
Haven’t we learned anything from modern pop culture? Alien contact almost never goes well. :p
Why would any intelligent life want to communicate with Earth? It’s the Arkansas of the galaxy.
Even if SETI did get a signal that they could confirm was from an alien civilization, how would they be able to use a signal that likely came from thousands of light years away? The stars we see are so far away they could supernova today and we wouldn’t know it for a long time.
Am I missing something? Because it really seems like we wouldn’t be able to do shit with any signal even if we got one.
Other than confirm we aren’t alone in this section of the universe? You don’t consider that significant?
@MarkM1427 @76:
It depends entirely on what information there is in the signal. If we get the ET equivalent of me pinging an asteroid, all we’d know is “there was somebody out there who had a high-power transmitter” – a pretty big result by itself, to be fair. If we get something that has strong crypto on it, we won’t have any idea what it says. But if we get a deliberate SETI beacon, we might learn quite a bit about whoever set it up – as long as it was designed to be appropriately intelligible.
But you’re quite correct about the long travel time. Thousands of years of time lag means that SETI is like doing archaeology and looking for time capsules.
dantalion @ 75:
We don’t know that, though. Also, there’s no need to tar a whole state. Please avoid comments which contain splash damage. Thanks.
This is what bothered me about Contact. How could we possibly decode an alien transmission? If the Navajo language made the basis for an unbreakable code, how could we even begin to think about ways an alien mind would process information. How would you design an information-laden signal to be “appropriately itelligible” to anything other than another human mind?
Now I’m thinking about Star Trek IV. Y’know, the whales.
Reading “Alone in the Universe” by John Gribbin left me convinced and sad. Earth is likely the only place in the galaxy where humour and empathy can be found. It’s interesting that the book’s title says “universe”, but the arguments within address “galaxy”. But from a practical perspective anything beyond the galaxy is only good for thought experiments. I am now convinced the only good use of the Drake equation is the one Howard used on “the Big Bang Theory”. (He adapted the equation to calculate how many potential mates for Howard existed in the Greater Los Angeles metro area).
SETI is a bit like the lottery; the payoff could be enormous, but the chances of getting it are pretty slim. So it might be worth a few dollars here and there, but I’d prefer we did something more useful with our radio telescopes and transmitters most of the time.
I indulge in shameless self-promotion: http://arxiv.org/abs/0911.3976 .
The basic idea is that any alien who is picking up a signal we sent out, or who transmitted a signal we pick up, will have some common knowledge with us – at least some math, physics, and astronomy. That can then be used to establish a common vocabulary which can then be used to convey more interesting ideas. This is the opposite of cryptography – for a dedicated beacon, there should be a lot of effort into making it intelligible given that common knowledge base.
The code talkers were doing the reverse, be it with Navajo or Cherokee or Choctaw or Cree or Basque. In addition to using an unusual language, there was a layer of alphabetic cipher added – to prevent captured native speakers from being coerced into sending false messages, as well as to account for many of the language concerned not having words for “tank” or “battleship” or “aircraft carrier”. And they deliberately avoided including the context that would have made what they were saying potentially intelligible to someone who didn’t already know the language concerned.
sotonohito #68:
That’s it in a nutshell.
It is a mistake to focus overly much on any particular number you get out of it, but I find that there are two good uses for the Drake equation: public outreach, and as a way of breaking down the components of the problems that SETI has to contend with.
For example:
We want to know how many stars there are in the galaxy and how old they are. We figure the first out with large surveys; the second with helioseismology, stellar modeling, and cosmological data.
Then we want to know how many planets there are out there and what their orbits and sizes are like. We figure that out with radial velocity and transit instruments.
And now we want to know what interesting chemistry may be going on on those planets. We can figure that out with new hardware – coronagraphs and spectrometers on large telescopes, mainly.
Voyager 1 is still out there, operating for 36 years and 10 days as of 15 September 2013, the spacecraft communicates with the Deep Space Network to receive routine commands and return data. At a distance of about 125 AU from the Sun as of August 2013,[3][4] it is the farthest manmade object from Earth.
Anniversaries like this make people a bit wistful, I think. I still remember the excitement of the Voyager launch.
The decades/centuries/millenia lag between responses would make that impractical. You effectively have a single outgoing signal (possibly repeating on a loop, of course) to tell any aliens that might exist about you. How can you say anything more meaningful than “We were here” (You will be long dead by the time any being receives your signal) ?
Again, think of a time capsule and archaeology.
I can understand the criticism as put forth by PZ. I am also under no illusion that the SETI project is going to find anything soon (that is, in my lifetime). But I reckon that listening to and at least trying to analyse stuff from outer space can not hurt. Until we develop better ways to search for E.T., I will still support SETI. And occasionally donate some CPU-time.
Agreed, SETI is a waste of money, little more than a scam. The two main problems with contact with intelligent life is that the distances between even the nearest stars are unimaginably vast and any civilization that persists for very long would be a dead one. It’s the height of arrogance to think that one can imagine what even our own civilization will be like a mere thousand years from now, let alone millions or billions of years older. As a chemist however, I find it unreasonable to think abiogenesis could have occurred on the earth so soon after its formation and cooling, given the complexity of even the most simple microbial life, current extrapolation of which gives an origin point closer to the origin of the universe. The origin of life is a matter of geochemistry, not biochemistry, and likely involves unimaginable concepts of physicochemical mechanisms occurring over deep time, extremely rare combinations of interfacial, organic and nanostructural mineralogy. Life diffuses by impact transfer from “genesis” planets to exponentially more numerous (yet still rare in an absolute sense) “eden” planets, creating diffusion zones of life oriented within a larger spacetime expansion ring from the galactic center. So not only is the distribution of intelligent life a hyper-exponentially smaller subset of life, owing to the necessity of extreme planetary stability over billions of years, but its location in spacetime spans many billions of years in the natural history of the universe. I’m sure if we could see the staggering biological diversity of our planet in its universal context, it would become obvious that projects like SETI are completely beside the point.
No discovery in human history would be more important than discovering a signal from another planet. And no discovery would cause more upheaval to the Abrahamic faiths than a nice solid SETI signal.
Let’s applaud Seth for dreaming a good dream.
Time capsules are basically just saying “We were here”, since there is no way to know who or what will find them.
Archaeology doesn’t count because it’s humans studying humans. Alien “archaeologists” in some nebulous future may well have no clue what humans were about, particularly if they don’t have a complete picture of human society. Hell, archaeologists today are pretty clueless about a lot of past human societies.
But that’s getting off point.
How could you expect to extract meaningful information (beyond “We were here”) from an alien signal even if one was found?
What would “appropriately intelligible” entail?
My first foray into distributed computing was SETI@Home around 2001. After awhile, I began to question the value of it, which was right around the time when Folding@Home first came online.
I have long since stopped looking for E.T.; protein folding is far more beneficial in my eyes.
Eric:
*fistbump* Folding@Home is a good thing.
If it is designed appropriately, a SETI beacon message could say just about anything – just like a time capsule can, if it is properly composed, and just like archaeology can, if the appropriate material is preserved. “there is a bunch of stuff we don’t know” is not the same as “we don’t know anything.
I gave an example of one possible system in the paper I linked above. It started with very simple patterns, which should be familiar to anyone who has the mathematical background necessary to build a narrow-band radio receiver, and worked its way from there through some basic physics and astronomy to describe a bunch of the properties of planets in the solar system. Takes a few tens of kilobytes.
It is true that all such message designs made by humans have only been tested on humans, since Kanzi isn’t well-informed on matters astronomical. And we do not know what any alien SETI beacon would say. But given that in blind tests Caltech undergrads (I used them as a proxy for ET) figured out everything in that test message in about 12 hours, I think there is plenty of grounds for optimism on the potential intelligibility of any alien beacon SETI may find or of any beacon that we may build.
The real problem is detectability – we just don’t know what aliens may be out there, and what signals they may be sending out. Which gets back to why people making claims of “we’ll find ET by [date X]” bothers me.
Yeah, I’m with you there.
I’m still don’t agree that any aliens who’ve developed advanced radio technology will necessarily be able to encode a signal that we could decode, or vice versa. I was taking the detectabilty issue as a given, and considering that even if a signal was detected, I doubt we’d be able to get anything from it other than that it was probably of intelligent origin.
I don’t think SETI is a complete waste of time, but I do feel it should be (as it currently is) relegated to lowest-priority use of radio telescopes. As for distributed computing, if someone want to get involved, sure, why not? I do think some of SETI’s proponents have an over-inflated estimation of it’s importance. I’m looking at you, rickk (#92).
Again: because we have a common set of knowledge to draw from. That we or they are able to encode a signal the other could interpret is a given. If such communication will happen remains to be seen.
Most radio transmissions from Earth are either low-information content (carrier waves) or so encrypted as to appear random to anyone who doesn’t know the keys. Those would be “there was somebody there”. Deliberate beacons are a different matter. And, again, we don’t know if anyone built one or not.
Deliberate beacons are also going to be designed as “We were here” signals, like pulsing the Fibonacci Sequence or something. Actual information (about us as a species, maybe) would be far more difficult to make recoverable. It would be like trying to read Egyptian hieroglyphs without the Rosetta Stone. And that was another human society. I don’t see that just mutually having radio-capability would bridge that gap.
Also:
I take a somewhat different position – this is my personal opinion and is not to speak for any other radio astronomer:
The strategies and hardware used for SETI are wild-field-of-view surveys covering as much sky as possible as sensitively as possible with the best possible resolution in both time and frequency. This is the same as that used for a lot of exciting astronomical research, particularly of variable sources. So SETI can be and is run in parallel with the primary purposes of large astronomical surveys.
They don’t need to be. Again, I refer you to the test message design as an example.
And there is a Rosetta Stone here: The common knowledge of mathematics, physics, and astronomy that is required to build radio transmitters and radio receivers and to identify an artificial signal against the background of natural sources.
That works, too. My point is that is that SETI isn’t a problem as long as it doesn’t draw resources away from other research.
To clarify: there is a potential Rosetta Stone. It could be used. It may or may not be.
Didn’t Hawking say he thought sending out a beacon might be a bad idea, since another civilization might not have our best interests in mind? I think he said something like “That didn’t work out too well for the Indians.”
If the point is to communicate with another planet, given the immense lag between message and reply, at some point it might actually be more efficient to send a messenger which can, after the enormous delay of the journey, exchange enormous amounts of information nearly instantaneously. After all, the bandwidth of a Fedexed hard drive is pretty good.
You keep saying that, but you never explain how it would work. Yes, there will presumably be a level of shared understanding of mathematics, physics, and astronomy. Great. Still, how are you going to communicate anything other than numerical sequences?
Indulging in self-promotion again, see the paper: http://arxiv.org/abs/0911.3976 . That is one possible version of many.
Lots of different information can be communicated by numerical sequences. The test message in the paper defines a functional vocabulary of a few dozen words. It could be extended to describe other types of data: vectors, clocks, maps, arbitrary images, etc.
Brian McConnell’s Beyond Contact: A Guide to SETI and Communicating with Alien Civilizations explores some similar ideas.
Yes, that was Hawking.
That is only an effective strategy if you know exactly where to go.
Can we take on the “we’re ruining Earth’s environment, we’re doomed, so to survive we all need to leave Earth and terraform Mars” dumbness next?
michaelbusch, I’m not sure it’s even an effective strategy when you do know where to go, given our present shortage of interstellar transport, but good point.
re @95 and @96;
I run both SETI@home and Folding@Home on two of my old computers that I did not throw out after upgrading to new systems.
Even if we cannot decode any message we might find, so long as we can recognize that the signal is artificial in origin and not natural, that alone tells us that the intelligent alien civilization existed.
That alone would be monumental.
It isn’t any different, as a scientific discovery, as finding a sequence of DNA from a previously unknown species, and being unable to determine what that organisms’ full genome was.
And I would hesitate to make the assumption that “cannot right now” = “will never”.
Jafafa Hots #110
Yeah. If we can’t “terraform” Earth, how would we manage Mars?
I somehow missed your link previously. You could have just said that you encode a language primer as the initial part of the message. (That’s what I got from your article, anyway) That makes sense. It doesn’t guarantee understanding, but makes it highly probable. Makes for a long message for an effective one-way communication, but that’s another issue.
johnmarley @106:
The artificial language Lincos, and others, supposedly go a lot further than that.
That much is true. But if you’re talking about timescales of many centuries, the bandwidth can be relatively low. The beacon does need to be on for very long time.
SETI probably won’t find anything in the forseeable future but listening is not a bad idea, if only to set a limit to what isn’t there.
The only likely result of SETI is that we hear something that isn’t life but is unpredicted and elsewise informative.
Folding@home and others are a better excuse for unnecessary energy usage.
What do you mean? Drake says that if we multiply enough completely-made-up numbers together then its totally science! On account of the numbers and stuff! You can’t refute numbers; that’s scientastic!
PZ’s criticism may be reasonable in a way, but as a Northern European non-American person, I would say SETI is an excellent way to spend US tax money.
Adventurous things like NASA and SETI are the few remaining reasons for the rest of the world to view the USA in a positive light. And, yeah, some nice movies too, but that’s the private sector. I know it is not in the American nature to care about the feelings of non-Americans, but the US does need some positive PR. I’d say SETI is that with a very cheap price tag.
There is only one relevant number to the question if we will be able to counicate with an alien species.
And that number is the lifetime of our own species.
So. What should we spend our resources on to achieve this?
Agriculture? Peace?
No. That is not at all what Frank says, nor is it what he has said in the past. He came up with the equation not to get a single definite value, which is impossible with the current state of knowledge, but as a way to stimulate discussion at the first SETI meeting in Green Bank fifty years ago.
Nor are the numbers in the equation “completely made up”. We know how old the universe is. We know many stars there are in the galaxy. We now know that there are more planets than there are stars, and quite a bit about their distributions of orbits, sizes, and masses. And instruments designed to investigate the atmospheres of exoplanets for interesting chemistry are currently being designed and constructed.
Again, the purpose of the equation is not to give any particular value. It’s an attempt to break down the different problems that SETI has to address.
@coldthinker @121:
The US government does not currently fund SETI, at least not directly. It’s supported by private donations, taking advantage of existing NSF- and NASA-funded astronomical and computing research programs. For example, SETI@home uses data taken by the Arecibo hydrogen-line survey program. The Allen Telescope Array was funded by private donors (most notably Paul Allen), with much of the operations money coming now from grants to use it for astronomical surveys.
_
More government funding of SETI might be a good thing – I will not pretend to have a sufficiently informed opinion on that. But there is currently none.
After all, our human culture is quite young, and will eventually be buried deep under the future sediments. Will there be evidence of our technology after another 100 million years?
Indirectly.
While one can’t be sure there weren’t intelligent dinosaurs at the stone-age level, we can be fairly confident there have been no prior intelligent civilizations that had similar technology within the last few hundred million years. It comes down to mining.
We’re exploiting, and have exploited, mineral deposits in locations with stable cratons, so there’s been nothing dramatic geologically, going on there for a very, very long time. When you find a small mountain of an iron deposit that’s been pretty much been just sitting there for geological time scales right on the surface, it’s pretty obvious that there was probably no one around who had reason to want large quantities of iron.
Sorry, screwed up the quotation there:
@20:
Caine #87
Oh, totally. I remember skipping some classes in 1979 to watch a flyby of Saturn, and then years later going to a public lecture to see some of the images from Voyager. I remember staring at the image of the rings of Saturn thinking “MUST HAVE MORE!!”
Jafafa Hots, we can do both, we can listen for other civilizations and find out how our own cells work. We have no choice but to take care of Spaceship Earth; we’ll likely be incompetently terraforming our own birthplace before we get around to Mars.
@keithm: And the uranium- and thorium-decay-chain isotope ratios say that there hasn’t been anyone who liked to play with radioactives (although there was that natural fission reactor at Oklo 1.7 billion years ago).
keithm: “Will there be evidence of our technology after another 100 million years?”
Sure. I’ve got a couple of trilobites on my desk, half a billion years old. Conceivably some of our cups and saucers will be around that long. We know how to make durable things; we need to work on ways to make some of the things we use but don’t intend to keep dependably less durable, and gracefully degradable.
It would be progress to find, ten years from now, less evidence of our technology in the form of trash, disposable detritus, mostly packaging, blanketing the landscape and carpeting the oceans.
I was a few months old at the time. Funny to think there’s a space probe heading out of the solar system that’s more or less the same age as me.
Flaunting your ageist privilege, as usual. I was in first grade when humans first launched a satellite into orbit. During my first college summer job, men landed on the moon. I can use a slide rule!
Rob Grigjanis@116,
From your link:
A language for fucking the universe??!!?!
michaelbusch@102
A lot of people here would presumably deny this, given the viewpoint they put forward in this thread on postmodernism, according to which mathematics and science are completely cultural constructs, and so it’s not objectively true that (for example) 17 is a prime number. I’m confident that any technologically capable aliens would indeed readily understand most of our mathematics and science, and share much of the former at least; although since any we contact are likely to be far more knowledgeable than us, they would probably recognize some of our science as crude although useful approximations.
On SETI, yes, Seth Shostak is an irritating numpty, and his “We’ll discover them by 2037” is daft, but I really can’t feel that the small sums spent on it are something to get annoyed about. My own view, which I won’t expound again in detail, is that Fermi’s paradox is good evidence that either there are no other technological cultures within the local group of galaxies, or we’re living on a reservation, possibly being studied using means that are undetectable to us. But I could be wrong, and I don’t think Hawking’s caution makes any sense: if they’re out there, they are almost certainly much more technologically capable than us, and already know we’re here; they just might have been waiting politely for us to begin the conversation.
Hmm the late Stanislaw Lem adresses “Silentium Universii” time and again in his books. And he was VERY pessimistic about establishing a meaningful dialogue if there ever was contact.
“His Master’s Voice” mainly deals with the SETI concept.
— — — — — — —
“Adventurous things like NASA and SETI are the few remaining reasons for the rest of the world to view the USA in a positive light”
Seconded. Space travel and good music.*
*but the music is often made by “those people” Jesse Helms did not like. And if the GOP produce “a hundred like Jesse Helms**” those musicians will be welcome to Scandinavia.
**quote by Ted Cruz
The law of large numbers is convincing, at least to my layman’s mind. There’s almost certainly other life out there, and it’s highly probable that there is other intelligent life. It’s fairly probable that some of that intelligent life has the technology to send and recieve radio signals. And if you don’t look, you won’t find.
SETI’s not particularly expensive, from what I understand, so I like to think of it like the Lottery on a rollover week. If there’s a £10 million payout, it’s worth paying a couple of quid for the ticket. Sure most of the time you won’t win, but if you don’t buy the ticket then you never will.
the only really useful message that we could receive would be directions on how to make an ansible.
and if we ever out how to make one that would be the message we should send.
other than that it will just the answer to the question, is there intelligent life out there in space because there is bugger all done here on earth.
uncle frogy
I never could understand the continuing fascination with ET / SETI. Odds are there is life on some world out there – and the odds are also that it is physically impossible for us to signal them of our existence or the other way around. There are no known habitable planets for many lightyears’ distance and the best of our technology will never be able to send a recoverable signal over any significant portion of our own galaxy much less over any significant fraction of the universe. Anyone who talks about detecting radio waves or whatnot from an intelligent ET civilization doesn’t know anything about the creation and detection of such radiation. Sure we can detect the light of individual stars at incredible distances and we can detect unusually bright high-energy bursts from other galaxies, but unless a civilization can control such light sources (impossible) what hope is there of sending a signal to anyone? Catch a SETI signal within 25 years? Oh come on …
I think a modest allocation of funds to SETI (or a similar program) is worthwhile. The odds of success are very low, but the payoff would be huge. And ideally, like other speculative research, you can finagle it so it has knock-on benefits (e.g. use some of the funding to develop better signal processing algorithms or something).
The 20-30 years timeline? Absurd. Even if it were somehow assured that SETI would last for the next ten thousand years, I’d still put the odds of success at around 50/50 or maybe less.
Ironically, the best criticism of SETI’s chances contains the best hope: The very short duration during which we’ve had the technology to do this. If we are at or near the pinnacle of civilization, and we are at all typical, then SETI is hopeless; the window for success is just far too small. OTOH, if we are at the very beginning of a long-lasting technological civilization, and/or if the typical technological civilization survives and prospers for hundreds of thousands of years, then it’s not unreasonable to hope that during those countless millennia, some of them might aggressively engage in Active SETI-type programs. If there’s civilizations out there doing that (and FWIW I would bet heavily against such a possibility, but I wouldn’t rule it out altogether) then radio contact is quite possible. It’s a long shot, but as I say, the payoff is so huge, some modest expenditure seems justified to me….
Can you explain this example further? Given 17 physical items (whether 17, 0x11,023,…) how can it not be objectively true that they can not be arranged in a rectangle?
I like that. :-)
*eyeroll*
How do you know? Which animals? And how do you know the theory of the theory of mind isn’t hopelessly overrated?
That made me smile. If “hateful comments” distract you from a discussion on “focus gender issues” (whatever that is), you’re hardly capable of discussing any “scientific topic”, because logical fallacies get in your way all the time!
If you’re not outraged, you haven’t been paying attention.
…How might “advanced civilizations” get around the speed of light? And how might they put robotic probes “all over the Milky Way”?
Wow. Congratulations! You managed to bring a completely unrelated old grudge into this thread for no discernible reason! *frenetic applause*
Rickk said (comment 92) “No discovery in human history would be more important than discovering a signal from another planet. And no discovery would cause more upheaval to the Abrahamic faiths than a nice solid SETI signal.”
Rickk you got it exactly right. For many reasons, the discovery of intelligent life on a distant planet would destroy the bronze-age anthropocentric Bible. However, the Vatican, not wanting to repeat the Galileo fiasco, is already preparing to deal with such a Bible-shattering event. Believe it or not, four years ago Holy leaders held their first conference on Astrobiology. Yep, biology on other planets. Catholic theologians are not stupid. They understand that the New Testament is particularly vulnerable since it insists that God sent Jesus to earth save humans (actually only those who believe the myth) from eternal damnation. There is nothing in the Bible about saving unfortunate folks on other worlds. If SETI ever succeeds the Vatican will be instantly ready to respond. Extensive new interpretations of ancient Scripture will be used to save their earth-centered religion.
Oh, I’m not making this up. Here’s a link to a news story about it …
http://www.theguardian.com/world/2009/nov/11/vatican-extra-terrestrials-catholic
Monitor Note: Do not bring arguments from elsewhere into the comment threads. Do not talk about another commenter in the third person; do not call out commenters from other threads. Thank you.
What makes you think they’re likely to be “far more knowledgeable,” and not only that but (later in your comment) that this is “almost certain”? What’s supposed to be so probable about us not being the more advanced ones?
The local group? You realize that includes everything in a radius of several million lightyears, with lots and lots of nothing of any interest whatsoever in the middle. Right? I don’t know why I should expect an encounter from a civilization even on the other side of our own galaxy, much less one that’s come up with bizarre reason to cross intergalactic space. There are billions of stars and planets and so on in between, which they might be interested in checking out first, instead of taking the express route direct to Earth.
Given that any such conversation would take an extremely long time, what would be “polite” about dragging it on even longer than necessary?
David Marjanovic said, “…How might “advanced civilizations” get around the speed of light? And how might they put robotic probes “all over the Milky Way”?”
David, I agree this sounds far-fetched, but think about it for a moment. Humans recently discovered the basic laws of physics and we already have a probe outside of our solar system. Granted, Voyager is moving at a cosmic snail’s pace but we are just getting started in space travel. A probe moving at 1/10 the speed of light would travel ten light years in a single century. And I’m not talking about hypothetical worm holes or warp speeds. There are about 600,000,000 stars within 5,000 light years of earth. Robotic probes could fill this area within a few thousand years. A trivial amount of time on the cosmic time scale.
Is it absurd to think that some civilization may have already done this? Each probe could contain information gathered from several civilizations over vast amounts of time. Given how quickly we humans developed a global internet is it outlandish to envision a galactic internet? This may be just wishful thinking on my part but, unlike the allegedly supernatural claims heard in any church on any Sunday, my dreams do not defy the laws of physics.
Here’s a wonderful map of our local area of the Milky Way Galaxy replete with almost a billion stars…
http://www.atlasoftheuniverse.com/5000lys.html
And how could they already know we’re here, if they’re hundreds or thousands or millions of lightyears away?
sqlrob@139,
Have a look on the thread I linked to.
David Marjanović@140,
It’s not a grudge but a disagreement, and it’s highly relevant, and I consider, an interesting link between two threads. If our mathematics and science are purely cultural constructions, then intelligent aliens, even if capable of interstellar communication, would not be expected to understand us: the prime integers, for example, would have no relevance for them, so sending a sequence of primes, as has been suggested in SETI discussions, would not tell them that the source was artificial. The type of experiment described in the paper michaelbusch linked to @107 would be completely pointless, because we could not expect intelligent aliens capable of interstellar communications to look for regular patterns in radio emissions from elsewhere at all, let alone identify the same patterns human beings from a WEIRD culture would. Surely that’s all obvious?
I am more sanguine about this than PZ and some others. The current SETI Foundation program is privately funded and offers an extremely favorable cost/benefit ratio. We aren’t spending much and if by some chance a signal were detected, it would be one of the most profound events in the history of humanity.
The other angle is that when Projects, Ozma, Orion, and the SETI project (the SETI foundation dates to 1984) were conceived we really had no clue of the extraordinary advances in exoplanet detection and analysis that would, within a generation, put us in position where it is highly likely that we will identify exoplanets conducive to our form of life very very soon. When that happens, allocating resources to a much more focused listening project aimed at a few of these candidates really changes the equation both in terms of search efficiency and, given the ability to devote long periods to single sources, in terms of the ability to distinguish signal from noise.
I’m afraid I see calling SETI a boondoggle puts us at a rhetorical disadvantage when there are SO many other expenditures that are far more worthy of the term.
Bear in mind that they are likely to be considerably more advanced technologically than we are, if they are there at all (if all technological civilizations destroy themselves before they become significantly more technically advanced than we are at present, which I find unpleasantly plausible, then they won’t be there at all). But assuming this is not the case, then:
1) Large enough space-based telescopes. A telescope does not have to be a continuous dish; it can be made up of a number of distant components, held in place relative to each other by careful use of rockets, lasers, andor other technologies. Bear in mind that less than two centuries ago, it was confidently asserted that we would never know the composition of the stars, and as little as twenty years ago, there was scepticism about whether we would be able to detect extra-solar planets. Now there is confident expectation that we will be able to detect earthlike planets and begin to analyze their atmospheres in the next few decades. Earth’s atmosphere already contains components such as CFCs that have no known non-technological source.
2) Von Neumann probes:
Even if this estimate is off by a factor of 1000, there is no known reason technological civilizations could not have developed a billion years ago, if they can do so readily now (that they can do so fairly easily is the assumption underlying SETI). If only one such civilization did so, we’d expect their probes to be here. (Maybe they are.) Only if it can be shown that von Neumann probes are physically impossible does this line of reasoning fail, as far as I can see. I’ve encountered the objection: “But maybe they would decide not to send out such probes.” But that would have to apply to every civilization capable of doing so, since only one needs to have done so to fill the galaxy with them.
You are wrong. I have already explained why, in my first comment on this thread. The problem of SETI is one of if anyone has built a detectably-bright beacon – which we do not know (hence Seth’s assigning a date for finding one is unjustified). It is not that such beacons could not be built.
Also: current exoplanet data says that the nearest Earth-mass exoplanet in the nominal habitable zone of a star is about 7 pc away (Dressing & Charbonneau, 2013, based on the Kepler sample). There are plenty of potentially habitable planets. We just do not yet know if there is life on any of them – that will require considerable new hardware.
I am a professional planetary radio astronomer. Most of my work involves using the planetary radar transmitters at Arecibo and Goldstone, which are the most detectable forms of radio leakage leaving the Earth I like to think I’ve learned something about the creation and detection of radio signals.
consciousness razor@143,
I think my #148 answers most of the questions you raise, except this:
I was admittedly being a little elliptical in using the word “polite”. What I meant was that they may have ethical inhibitions about contacting a “primitive” civilization, and so disrupting its development; they may have found by experience that it is best to wait until such a civilization makes a sustained effort to contact them.
Nick Gotts @150: Maybe we’re too uncouth for them, and they are obeying The Prim Directive.
Not my questions about your near-certainty that, if/when we make contact with an alien civilization, they’ll be scientifically and technologically superior to us. The closest thing to a valid answer is this:
So they’re either advanced and we hear from them, or they’ve killed themselves off with their (perhaps not-so-advanced) technology and we don’t hear from them. Fine. But it doesn’t follow they’ll be more advanced than us, because (by that time) we might be just as advanced or even more advanced than they are. It’d be circular to assume they must get a head start, instead of us.
If we’re factoring in what we think their ethical scruples might be when it comes to the probability of finding (or not finding) evidence for their existence, then surely the same applies to Von Neumann probes, doesn’t it? That’s just a touch disruptive, to the entire galaxy (or maybe the local group, since you don’t seem overly concerned about the logistics), a lot more than simply communicating is.
@myself @149:
There is a typo in what I wrote earlier.
The nearest Earth-sized exoplanet in the nominal habitable zone of a star is less than 5 parcsecs away, to 95% confidence, and has a roughly 50% chance of being within 3 parsecs (i.e. something like 10% of all stars have small planets in their nominal habitable zones). “Earth-sized” in this case means “between 0.5 and 1.5 Earth radii in radius”.
The paper I’m referencing is available here: http://arxiv.org/abs/1302.1647
So the Kepler data actually show that there are even more planets than what I wrote earlier. Again, the question of if any of them have interesting chemistry on them that we might interpret as being due to life remains unanswered.
I came across this site with some interesting ideas about reasons for the Fermi paradox: http://io9.com/11-of-the-weirdest-solutions-to-the-fermi-paradox-456850746
When I’m pessimistic, I’m most worried about #3 — that the reason we don’t hear anybody is that, whenever a species makes too much noise, something shows up in a short amount of time (and a few centuries would be a very short amount of time) to silence them. You wouldn’t need to go yourself — self-replicating machines would take care of the problem nicely.
Why would anyone do such a thing? Religion comes to mind.
One possibility is that any technological civilization will at some point develop the means for an individual or small group to destroy all life on its planet, and once that happens the capability will inevitably be used. Let’s say the average time from the development of radio to extinction is 100,000 years; that’s an eyeblink compared to the existence of the planet. So even if intelligent life did or will develop on another world, what are the odds that its tiny sliver of existence coincides with ours?
I’m a lot more interested in what a society like ours is doing in regards to looking for other like 1000 years further along than us.
3. Little talk from Sean Carroll at TAM 2012 seems relevant here.
Quantum Field Theory in a nutshell? Well, maybe if I type rlly gud.
It wouldn’t need to be that strikingly different actually. It’s really easy to see strong forces that have big effects so everyone is going to know about all of those. It takes a little bit of work to find strong forces that have small effects and weak forces that have big effects but even so that’s still easy enough that we’ve found them all up to a cutoff point where the combined magnitudes are too small to detect. This leaves very little other than extremely weak forces with weak effects.
The actual applications would vary but you’re going to observe the same things (if they’re at all thorough,) and come up with physics to describe them. I guess communication via particles that interact weakly with our everyday material existence might end up being really handy, but there are still only so many of those to utilize.
13. That sounds a lot like Douglas Adams’ puddle to me. How exhaustively have you ruled out other paths that lead to technological societies?
18. Fairly recently we had that entry about the squid utopia scifi book. Nobody seemed concerned about his claim “once humans could free themselves from a gravity well why would they want to go back?” (In this case easy access to the right Uranium isotopes.) There would certainly be a lot more manufacturing involved for any population growth but there’s lots of energy available in space. You could get an awful lot done with 24/7 sunlight on solar panels, without any atmosphere attenuating the light. If you were thinking in the (moderately) long term you would balance the needs of any population center with what energy you could harvest like this.
Start extracting materials off of the various dead rocks in the solar system and you could definitely run some more energy intensive endeavors.
sciencenot superstition said@144
A probe moving at 1/10 the speed of light would travel ten light years in a single century. And I’m not talking about hypothetical worm holes or warp speeds. There are about 600,000,000 stars within 5,000 light years of earth. Robotic probes could fill this area within a few thousand years. A trivial amount of time on the cosmic time scale.
that may be nothing on a cosmic time scale but it is an impossibly long time on a human time scale. Hell we have not even been farming for 20K years yet and people are thinking of making robots that will last for “a few thousands of years?”
it’s a pipe dream like looking for angles which it resembles.
the size of the area of search is just off the scale in space-time in every relevant way for our short life.
there is little to be gained except the knowledge that intelligent life exists some where else
just finding life somewhere else would tend to suggest that given enough time that intelligence that we could understand would arise.
From what little I have learned there is nothing here that does not exist in abundance between here and “there” except life maybe and that may be more abundant, planets turn out to be more common as we develop the means to detect them so who knows.
there is no ansible nor FTL drive
might make as much sense to work on those instead and no one is proposing investing in that as far as I know.
uncle frogy
consciousness razor@152,
The assumption of SETI is that interstellar-communication-capable civilizations (ICCCs) are common enough that we can reasonably expect to detect their signals. Unless we assume they are appearing at an unfeasible rate (since they must be reasonably close), this means they must last a long time, so the probability is high that any we detect will have been ICCCs for much longer than us. Their technology could have plateaued at around our level, but there seems no particular reason why it would have done.
1) I don’t think it at all likely that they are politely waiting for us to begin the conversation: I think it much more likely either that there are no ICCCs within the local group apart from us, or that they are vastly more sophisticated than us and completely ignoring us, or studying us as we study bacteria or flatworms.
2) If I’m right that exploring the local group with space-based telescopes andor von Neumann probes is not that difficult, and wrong in thinking that ICCCs either emerge very seldom andor reliably destroy themselves before reaching von Neumann probe capability, then if those which have already reached that capability are ethically scrupulous about interfering with pre-ICCCs or incipient ICCCs, all they need do is avoid obvious (to a pre-ICCC or incipient ICCC) signs of their presence in any system where a potential ICCC exists.
Rob Grigjanis@151,
:-D
brucegee1962@154,
Yes, I find option 3 at your link disturbingly plausible, but there is ex hypothesi, nothing we can do about it except, possibly, play nice with each other. (Of course, the aliens could be planning to let us survive iff we’re sufficiently nasty to each other to amuse or impress them, but if we have nasty rather than nice aliens watching us, we’re probably toast in the medium term anyway.) I don’t find any of the “everyone stays at home / migrates elsewhere” options plausible, as they have to apply to all ICCCs. I’m sceptical about the simulation one (having designed and run social simulations for a living until recently I’m very aware of how much data empirically-based ones require, and their limitations as scientific or policy development tools).
Finally, on reflection I should have couched #133 in terms of the arguments put forward in the post-modernism thread, not in terms of the people making them, so apologies for that, and thanks to Caine and David.
What makes you think our descendants/successors will have similarly short lifespans?
There is no reason to think that technologically advanced civilizations capable of sending signals that are detectable by us should be limited to habitable zone planets.
Habitable zone planets may be (or maybe not) needed for life to arise and *reach* a technological level, but there is nothing to say that they must be necessary for the entire duration of a civilization’s technological lifespan.
If you can get to the level of power where you can send detectable signals significant distances (a not insignificant fraction of the total energy output of a single star, and the usage of which would be expected to constitute only a small fraction of your total energy budget, because civilizations will have more important things to do than pinging away at potential neighbours), you are very likely talking about a civilization with control of more than one planet, and the ability to establish outposts on otherwise nonhabitable planets.
One thing people who talk about von Neumann probes often miss is that such probes are almost certainly going to be subject to evolution. They are self-replicating, after all, and since no technological process can be made completely perfect, they will be subject to mutation.
How long will the original programming be retained? How long will the original mission parameters be adhered to?
Amphiox@161,
Not a serious problem: at most a few dozen generations would be necessary to send a probe to every star in the galaxy.
@andrewriding #156
If we don’t begin such ventures very soon, in another century or two when Nicholas Georgescu-Roegen’s Fourth Law of Thermodynamics really lays claim on what’s left of industrial civilization, we won’t be making any radio broadcasts at all, let alone doing anything in space. There goes that set of evolutionary pathways for the planet forever.,.
I think if we want to find anything, we’d probably have better results looking for megastructures – large scale structures built in space. Using radio receivers to scan the sky is fine as long as it is the limit of what we can do, but we are getting to the point where we can seriously start looking for (very, very) large scale construction. Over time we’ll be able to look for smaller and smaller objects. Not the same as communication, but it would still be a very important find.
Ah yes, the one he pulled out of his arse. Seriously, we do indeed have very serious problems of resource use and waste production to deal with, but pseudo-science won’t help.
@Nick Gotts #165
Pseudoscience? Out of his arse? Good Sir, you appear to be in possession of hitherto undiscovered knowledge of the means whereby one may recycle a given kilogram of metal for a period of time approximating infinity. Please, by all means, do publish your findings, Mr. Gotts; your Nobel Prize and the eternal gratitude of the future inhabitants of a terrestrial-bound, non-space-faring industrial civilization await you!
lehman scott @166:
A quick first glance says yes.
At the very least, economists (and most other people) should avoid yattering about entropy. As John von Neumann apparently said to Claude Shannon;
@Rob Grigjanis #
Greetings, Mr. Grigjanis. From your link:
The cite (14) is:
Although I am unfamiliar with that paper, I see nothing in the title to lead me to believe it contains a refutation of either my post or NGR’s FLoT . The issue is not whether matter, generically speaking, completely recycles. Of course it does. What is at issue here is the concentration of usable metals available after repeated recycling of an initial given amount of metal. It is not constant. With every current and foreseeable technology slag and other residual waste is always produced (unless you or Mr. Gotts are aware of some magical process that does not). It’s the metals equivalent of EROEI in energy calculations. The amount of energy required to extract those increasingly dispersed metals increases with every recycling cycle (which is why lower entropy metals are always added when they are cheaper than energy). Energy whose EROEI is beginning to drop precipitously. I recommend this article for additional reading on this last point (and Part 2 when Nate posts it later in the week).
When the author returns to NGR it’s just a bunch of handwaving about some cool electricity-producing PV technology. I have two decades of experience working in the metals recycling industry. To convert the types of metal mines, refineries, mills, and foundries required to maintain our current technological level of civilization to run on 100% electricity is going to take enormous amounts of fossil-fueled resources, not to mention the storage and distribution infrastructure. Then there is the construction and ongoing maintenance of the all those PV panels and windmills themselves. What most people do not appreciate is that most “alternative” energy technologies are not really alternative, they are derivative – – derived from fossil fueled resource extraction, refining, and manufacturing operations. Given that these PV and windmill systems now contribute less than 1% of our electrical baseload we are going to be damn lucky if two centuries from now we have an industrial civilization with even a fraction of the energy intensity of what we currently enjoy here in the US.
I believe my original point still stands, Sir. I do agree with you about people yattering on about entropy when they don’t have a clue what they are talking about, however, most especially economists. Nicholas Georgescu-Roegen is among neither of those two groups.
But thanks for your comment, Rob, I enjoy discussing this issue!
lehman scott @168:
Fantastic! Finally, someone with a concrete notion of how entropy can be defined and applied in reference to economics, or civilization, or the biosphere, or whatnot. I eagerly await your summary, or a link. I’m sure no handwaving will be involved.
Rob Grigjanis @169
We were not discussing the definition of entropy, Rob, nor its application in the general areas you listed above. We were discussing its specific application in the area of metals recycling. My last sentence that you quoted is an assertion based on my reading of NGR’s The Entropy Law and the Economic Process. I have encountered nothing in that text or any of his other writings to warrant the labeling of any of his work as pseudoscience. If you have any substantive evidence to the contrary I would be more than willing to examine and discuss it with you. Also, I suggest that if you wish to find information on those former general topics you listed that you speak with someone else, Sir. I am more interested in discussing concrete things that we can do now to help ensure that industrial civilization has the potential for truly long-term sustainability, and I and a number of other folks are advocating extraterrestrial resource utilization as a way to achieve that goal.
lehman scott @170:
I was. If you use it, define it. If you can’t define it, you don’t need it, and using it is bullshit.
Rob Grigjanis @171
I wasn’t, nor do I wish to do so, Sir..
Nor do I respond well to commands, Mr. Grigjanis, with all due respect.
I have difficulty “defining” gravity in anything other than descriptive terms involving metric-tensor mathematics but I still need and make use of it all the time, as you do, too, Sir.
I must say I am rather at a loss trying to understand what point you’re try to make here, Rob.
I am not speculating on things being very different than they are now.
There are no machines that we have built that do not require regular maintenance to function properly past at best a few dozen years. there are no self replicating machines in the real world.
People may be able to live 200 years but none have done it it is rare past 120
No I doubt very seriously that we will ever be living for any 1000 years
we might as well try to build a FTL drive or an ansebile as look for communicating with someone 100,000 years ago!
space is deep time it is not just across the ocean
we can look and spend the money (not much money though) we will not find what we are looking for but we may find what we are not looking for instead
while we are building all these self-replicating space probes that last 10,000 years we could set a side some of the money to fund research on time travel
uncle frogy
lehman scott,
First, do stop being such a pompous ass – “good sir”, “Mr. Gotts”, “with all due respect” etc. – it really doesn’t impress. You are not a nineteenth-century gentleman scientist, and there’s no point in pretending you are.
Second, there are “natural” (i.e.non-technological, undirected) processes which concentrate metals from extremely low initial concentrations – how else do you think rich seams of gold, silver and “rare earths”occur? What undirected nature can do, human ingenuity can potentially do, generally much faster.
Third, Geosgescu-Roegen made the error of confusing closed systems – those having no exchange of matter with their environment, with isolated systems – those having no exchange of matter or energy with their environment. It is the fact that the earth is not an isolated system (although it is to a first approximation a closed one) that has enabled life to flourish for billions of years here. Many life processes, among others, concentrate elements, including metals, from extremely low concentrations. Even if Geosgescu-Roegen’s contention that unlimited energy would not allow indefinite recycling were correct (which it is not), a constraint that has failed to prevent life flourishing for several billion years is hardly one of immediate concern: the sun will make life on earth impossible (unless our distant descendants or successors use a sunshade) in no more than a billion years or so, so perhaps you should turn your attention to that problem.
Geosgescu-Roegen’s errors are exposed in many places on the web, for example, here and here. I quote from the second of these, which deals directly with your point:
as follows:
The point about the waste pile needing to be “big enough” does place limits on the amount of any usable metal available at one time – but that’s simply a refinement of the limit obviously set by the total amount the earth contains.
Good idea. But using pseudo-science to support it won’t impress people who know what they’re talking about.
unclefrogy@173,
But why should anyone be interested in what you doubt unless you can supply some good reason for doubting it?
Since no-one has suggested doing so, your point is obscure.
@Nick Gotts #175
Thanks for the thoughtful reply, Nick. That was a tremendous improvement over your initial off-handed remarks which did nothing to promote having an intelligent discussion on these important issues.
I am familiar with the Ayres paper, I had not seen the redandgreen one, I shall have to read and digest it. I am going to have little time in the next couple of days to offer a substantive response to either one or your remarks, but I shall over the weekend, assuming you wish to continue this discussion.
In regards to the matter of how I address you and others, you may take it as you wish, as I shall continue to do so when I want. I address many, if not most, of my long-time internet friends and family in such a fashion. It’s just an old ingrained habit that I feel no need to break because of your disapproval of it, Sir. But I am sorry for you that it rubs you the wrong way. Your initial response to me certainly had that effect on me, so I know how it feels – – and prompted my usage of “Good Sir”, which I rarely employ except when I am rubbed the wrong way by someone sounding like a know-it-all pompous ass themselves who seemed unable to begin a reasoned discussion with facts and evidence in hand, but rather, preferred name-calling and derogatory remarks.
I shall post my reply this weekend, Nick. I am pleased to see that you are indeed capable of having a civil discussion on this important issue.
Have a pleasant rest of the week, Sir.
Nick Gotts
You must be so proud, Sir.
;)
Forsooth, Sirrah, twas but your tone to which I did object. Let us conduct ourselves like Gentlemen of good standing…
@chigau (違う) #178
Lol… oops, i meant to say *even* address many…. I have the distinct feeling Nick doesn’t like me very much already and probably never will after the poor start we seem to have gotten off to.
@Daz #179
Lol… Well said, Sir, and by all means!
I really do talk this way on a regular basis on the internet, always have and always will. In person is another matter entirely. Always with strangers, though, regardless. It’s just how I was raised. Yes Sir, No Ma’am, please and thank you very much. Civility is an important glue that helps to hold society together, and one that seems to be in rather short supply these days in many quarters, IMHO.
Um, lehman scott, you’re probably not being as polite as you’d like. And by that, I’m being very polite.
Why exactly is it important in your discourse to assign gender to the person with whom you’re, ahem, having intercourse? You say that you always say “Sir” or “Ma’am”, which I take to mean you also do on the phone, and at drive-through windows and such, as well as in person.
With which, you have almost certainly at least once and probably more often, misgendered someone, either someone who is perhaps trans and gets this ALL THE FREAKING TIME, or someone who is cis and gets it all the freaking time but since their gender is supported by society in general it has somewhat less of a cutting edge, or someone who does not identify with either of the traditional binary options.
What greater purpose of politeness, what utility, is there in your arrogating to yourself the right of gendering people you don’t know in the pursuit of sounding like an 18th-C Fleet Street editorial? Is your affectation more important than the people whose day you’ve undoubtedly ruined with this absurdity?
@CaitieCat #181
You raise some interesting questions, CaitieCat. When I’m unsure of a person’s gender I don’t use them at all. On the couple of occasions when I have mis-gender-identified someone I have quickly apologized, but you raise some very good points. I don’t think I’ve ever ruined anyone’s day when I have misspoken, but I very well could have. Perhaps I should reexamine my behavior in this regard and work to break this old habit. Thank you, CatieCat!
Nick Gotts I am making the suggestion that we should be putting at least as much effort into FTL drive and instant across all distances communication (ansible) they may have as much chance of success as SETI does of “talking ” to aliens
or to put it slightly differently the odds are so great against any of it at this point that it makes real difference
this thread was about SETI not about living for centuries, I have heard of no research that would suggest that we will extending live 100’s of years which it would take to have any conversation with anyone a few hundred light years away sorry if I am not so clear but I did not want to write an essay about my thoughts they are not important
SETI is pie in the sky
uncle frogy
@Daz oops, I meant to say Sir/Ma’am. I really should break this habit. I’m off to get ready for meetings now, Ciao, y’all.
sciencenot superstition @144 said,
“A probe moving at 1/10 the speed of light would travel ten light years in a single century. And I’m not talking about hypothetical worm holes or warp speeds. There are about 600,000,000 stars within 5,000 light years of earth. Robotic probes could fill this area within a few thousand years. A trivial amount of time on the cosmic time scale.”
unclefrogy @157 said,
“That may be nothing on a cosmic time scale but it is an impossibly long time on a human time scale. Hell we have not even been farming for 20K years yet and people are thinking of making robots that will last for “a few thousands of years?”
it’s a pipe dream like looking for angles which it resembles.
the size of the area of search is just off the scale in space-time in every relevant way for our short life.”
Unclefrogy, I think you missed my point. I was not suggesting that we build a galactic internet. And I certainly was not suggesting that it could be constructed within a lifetime. I was only pointing out that it was feasible and that advanced civilizations may have already built such a system. The fact that humans have progressed from primitive PCs to a global internet in a mere 30 years is strong evidence for just how quickly technology can advance. True, we can not YET build robots or space probes that function for thousands of years. But 50 years ago we couldn’t build any of the electronic devices we now take for granted. I used a slide rule in college. Electronic calculators did not exist. I now have a tablet PC, a terabyte drive and a scientific calculator on my smart phone. Who would have ever dreamed that technology could advance so quickly?
PSA
<blockquote>paste words here</blockquote>
Thank you.
In case it hasn’t yet been mentioned, there was a great comedy written about that very subject:
Stark
I do recall they even made a very brief TV series out of it.