TSBG, that short story you mentioned is “The Road Not Taken” by Harry Turtledove, and I can’t believe I managed to beat Andy L to posting about this.
The aliens that are the subject of my speculation would be immeasurably farther removed from us than the most advanced technological culture on earth is from our most primitive jungle tribes. Ray Kurzweil suggests that within a hundred years or so we ourselves will be transforming ourselves into bio-cyborg hybrids, an era in which he claims full brain uploading and general purpose AI exceeding human capabilities in broad domains will be commonplace. He may have the timing wrong, but here’s the thing. We tend to get excited about incipient technologies and often over-estimate what is possible in the short term. But at the same time, we tend to overlook and greatly underestimate revolutionary changes that are possible in the long term, because it’s hard to grasp the concept of exponential technological growth and the directions it may take. And here I’m talking about the very, very long term – hundreds of thousands of years. And in an alien context – not that it matters, because humans in that distant future will be just about as alien to us as anything imaginable.
So my speculation is that such hypothetical advanced aliens would have no use for or interest in our biome since they have outgrown any need to have any biome of their own, and have long since mastered such biological trivialities. They themselves would not have had any biological strata in their beings for hundreds of thousands of years. They’re immortal and independent of material substance. Perhaps they’re exploring the wonders of other universes with entirely different physical laws, and have mastered those, too. What would they care about setting up a colony on Planet Earth like 17th century colonial hegemonists?
I overslept this morning!
I like to think that the reason that we are not being visiting by highly advanced civilizations is that interstellar space travel is not feasible. At sub light speeds, travelling to other stars is not a possibility. It would take way too long. And while obtaining the energy to reach practical speeds might be possible, storing the energy to stop where you want to is not.
Why is this idea never mentioned with regard to the Fermi paradox?
Kurzweil has the timing very wrong. We already turned ourselves into bio-cyborg hybrids thousands of years ago. There’s nothing new about “the Singularity”.
Humans have lousy intuition when it comes to very large numbers (where, in practice, “very large” is more than a hundred or so). Fermi’s whole point was that he actually calculated how long it would take to colonize the Galaxy, and he also calculated how long would be “too long”, and it turns out that, in fact, the first number is much, much less than the second one.
Please explain this further.
I think my point still stands. No matter what time frame, the size of spaces make interstellar travel for intelligent life impossible.
On page 150 of the book “If the Universe is Teaming with Alieans, where is Everybody?” contains the statement about two Aricibo telescopes being able to communicate across the galaxy. I’m not sure how that was calculated.
Some possible detection ranges were discussed in this thread: http://boards.straightdope.com/sdmb/showthread.php?p=20364700&posted=1#post20364700
According to one expert in the field, our current technology could detect earth-like TV and radio leakage signals – IOW inadvertent emissions – from an extra-solar planet 1,000 light years away.
If the “alien” signal was intentional, IOW directional and restricted to stars with rocky planets in a habitable zone, the detection distance would be far greater.
That calculation was not assuming current radio telescopes periodically taking a peak at certain stars, but a $6-10 billion directed effort. That’s a fair amount of money but it’s less than the less than the Large Hadron Collider, about 1/2 the cost of the ITER fusion reactor prototype, and about 1/10th the cost of the Apollo project. So it wouldn’t require a “mega-pyramid” scale effort.
However as already discussed we have no idea if non-terrestrial intelligent life (if it existed) would use RF signals at all. Even within our recent memory the earth’s high-power RF emissions are waning due to increased use of fiber optics.
It’s plausible that artificial RF emissions are only a signature of intelligent life during a very brief window of time during its evolution. If so, that’s a very powerful explanation for what we’re NOT seeing.
I think it’s fair to say that what Kurzweil is hypothesizing is a huge quantum leap beyond the development of tools, even advanced technological ones. It’s the literal integration of our own biology with cybernetics, with the ultimate endpoint being the complete elimination of biological dependence from ourselves and from what it means to be human. Today we still get sick and die just as the caveman did, with modern medicine being only the briefest of crutches. If tools and scientific discovery were the first great leap of human development, this would be the second.
It’s never mentioned because it’s not valid. What does “way too long” mean? Too long for who? Under what circumstances?
The second point, about energy, is only an apparent technological limitation with our present capabilities. It isn’t a theoretical limitation like the speed of light, which is in any case only a limitation from an external frame of reference and not from that of the traveler.
As Chronos mentioned, Fermi’s calculations are not in dispute. What I speculate is questionable is whether highly advanced beings would take such a course of action, not whether they could. It’s kind of like a primitive jungle tribe speculating that if they had our advanced modern technologies, they could build really terrific spears and become better hunters. In fact, they wouldn’t do any of those things at all. They would build cities, schools, factories, and farms.
Of the stars within 21ly, I see 15 Ks, 6 Gs, an F, 2 As and a bunch of Ms and low-energy dwarfs and degenerates. Ms, as dwarfs or giants, are unlikely candidates for LAWKI, and the F and the As are too short-lived to support the kind of long track evolution that gave rise to us. That leaves 21 viable candidates, except, the number is a bit smaller because some of those are binary or clustered.
Red dwarf Ms, or possibly some of the other low-energy stars, might give rise to some exotic form of life that would be great to study but not very easy to understand or communicate with. To find something familiar, we would need to look around a G or K, which would have to have a serviceable planetary system (which might be moons of gas giants) and a suitable metallicity – two of these systems show higher than the sun, most of the others a little or a lot lower, the latter being mostly not so promising.
So, in the ~20ly range, there might be 3 or 4 systems of interest for LAWKI. Which does not fill me with optimism, given the numerous other variables the gave us this delightful system. Stray just a little too far from our arrangement and whatever develops, if anything, will not be something we can have a beer with.
The farther out you get, the less likely any kind of signal, much less a decodable one, is. Although, there is quite a lot of farther out that we probably cannot get EM signals from.
Just to throw this into the mix, also…
I don’t remember where I heard this statement: “The universe is 100% malevolent but only 20% effective” but this may have bearing in this discussion. The centers of galaxies, or any place the star densities are high, is quite inhospitable to the evolution of life. Radiation levels and other cosmic catastrophes are just too high for multi-cellular life to develop. It’s only out “in the boonies” – the less populated spiral arms like where we are in our galaxy – that the radiation levels are low enough (and supernovas, pulsars, black holes, and the odd gamma ray bursts infrequent enough) to give life a chance to evolve.
So the number of potential places life could evolve is reduced and the distances between them greater making communication or colonization less practical.
J.
Yup. And he’s not wrong when he says that it’ll happen within thirty years. But the thing is, it’s happened every thirty years, throughout all of history. Ever wonder why old people are often grumpy, especially about newfangled technology and what “kids these days” are doing? It’s because they’ve already lived through two Singularities, and as a result find themselves in a completely incomprehensible world.
As I mentioned in another recent thread, “paradox” here is just a fancy-sounding title for the observation / realization.
Yes there are many possible explanations for why we haven’t seen evidence of ETI yet, but we don’t know which are correct right now, and the whole point of Fermi’s “paradox” is to have that conversation.
…or that they would be interested in exploring, or any other motivation they may have for travelling, or that they would engage in any kind of engineering that we could detect from earth (e.g. Dyson sphere).
Again, the paradox is not making a positive statement, it’s just asking the question.
If no species wish to explore, or do anything we can detect from earth then of course that’s a valid reason why we have not detected any ETI. But at this time we don’t know that that’s the case, and we can debate the likelihood / plausibility versus other hypotheses.