I just finished reading The Three Body Problem and I can't help thinking that we could send signals that would reach these planets in 40 years, we could get a response in 80 and if we could achieve c/10 we could get there in something like 500 years depending on acceleration.
It is extremely unlikely that even if there has ever been an intelligent life there, it's at a similar civilization development stage to ours, today. It took ~4B years to get where we are today on this planet, but the age of our civilization is only about a hundred thousand years. In a few thousand years our civilization will advance so much that it will be completely unrecognizable (or cease to exist), so you're asking for either an overlap in two extremely short historical windows, on planets developing independently for billions of years, or you expect their civilization to be stuck at about our level for many millions of years.
This is why things like SETI (and arecibo for finding ETs) make no sense. I compare it to using a telescope in 1850 to look for https://en.wikipedia.org/wiki/Flag_semaphore in space. The technology we have to send signals today will look completely pathetic to us when we look back on them in 50 years. Why would we expect ETs to use technology that we ourselves will abandon completely in the relative blink of an eye?
Well, for one, the doomed endeavors (if it actually is) are often worthwhile for the following reasons:
-The technology that stems from attempting to answer the problem.
-The unforeseen consequences - i.e. Maybe someday we'll reach technology that can detect signals in a more advanced way than we can currently and, through recording data from the past, have captured a signal years before that technology exists.
-How many people buy into lotteries despite having awful odds? The odds may be bad, but it's non-zero.
There is no reason to think we will be using grossly non-directional broadcast EM waves in 50 years for communication, and certainly not in 100 years. It's far more likely we will have extremely high bandwidth over very low distances, since that allows for far more bandwidth in aggregate (since you aren't interfering with other users on the same spectrum).
Or we might have moved on to laser (highly directional) or something nobody has thought of yet. I promise you we won't be using some kind of nondirectional, multi trillion watt carrier-based radio contraption that we would have to be using to be spotted by something like SETI on alien world.
Receiving a signal would be one of the more chilling things the Earth civilization can ever experience.
Good thing if these guys would be on approximately the same stage as we are, but chances are slim. An answer from someone who knows about radio for 1000 years in much more probable than from someone who knows it for 100 years, as we do.
Meeting the technologically more more advanced European expeditions did change the lives of the natives of the Americas, probably to the better, after a few centuries — if we ignore certain details.
We're pretty close to being capable of launching a Bracewell-von Neumann probe if some billionaire had the urge to do so. But so far as we can tell, the galaxy is not already full of self-replicating interstellar probes. Where are they? The uncomfortable implication is that we are the first/only species to get this far.
I also recently finished The Three Body Problem, we could get there in 500 years with the minor caveat that we are not killed in a dark forest strike sometime before then.
The dark forest strike is an interesting idea but there is no reason to actually believe that is how intelligent life on different planets would behave.
How? Any more advanced technology must still obey the laws of physics, and if we really are that wrong about the laws of physics, we'd have no way to receive such a message.
Well, there's stuff like wormholes, Alcubierre drives, etc. All problematic given our understanding, but a culture having made breakthroughs towards these might just show up on our doorstep one day.
There are ways to receive messages that don't require the recipient to have the tech. An uncontacted tribe in the Amazon can still be reached by megaphone, or plane.
To be fair, in that situation the tribe can be reached because they DO have the tech: ears, eyes, etc. So we're still contacting them via tech they have.
I think we're a bit too late for radio silence. Even if our comms are indistinguishable from noise at that distance, I bet our previously detonated nukes would have sent distinctive pulses across the near cosmos.
I wonder, does SETI look for signs of alien nuclear wars?
Someone else can figure out the math, but I'm pretty sure the energy from all of the nukes that have been detonated, especially if you only count the open-air ones, is minuscule compared to what the sun gives off. That would mask any possible detection. I wouldn't be surprised if just the solar radiation that the earth reflects is enough to mask the nuclear blasts, unless you're viewing them from right inside the solar system.
It is extremely unlikely that superluminal travel exists. It would fundamentally violate so many physical laws (including causality) that our prior for that should be low indeed.
A system that will live for 12 trillion years. A home to seven Earth-sized worlds, rocky planets inside the Goldilocks zone. A hope, at least, for an atmosphere.
Observations have allowed astronomers to put a much higher lower bound on the age of the TRAPPIST dwarf star (~5.4b years) than previously known (~500M years). The rest is primarily conjecture about the atmospheric compositions of its planets and whether life could have evolved on them.
TRAPPIST-1, a system of seven Earth-size worlds orbiting an ultra-cool dwarf star about 40 light-years away. Researchers say in a new study that the TRAPPIST-1 star is quite old: between 5.4 and 9.8 billion years. This is up to twice as old as our own solar system, which formed some 4.5 billion years ago.
Having recently read Eerie Silence, findings like this do underscore the question of just how likely life is. More, given life, is intelligence a given? And if there is intelligence, is scientific expansion style intelligence a given?
I confess these are obvious questions. I had never considered them, though. Is crazy interesting to consider.
I re-read eerie silence every couple of years. Paul Davies is a phenomenal writer. I never even knew about chirality playing a role in looking for life on Mars (basically all Earth DNA from anything has always shown the helix to twist in one direction, but there is no reason why it can't go the other way, so if we find DNA on another planet that twists the other way, it is extremely unlikely to be a contaminant brought on the probe from earth).
Before you can ask these questions, you have to define what "intelligence" is. And it's not at all obvious what the definition would be. And, indeed, whether it's even a quantifiable thing, or a smooth spectrum.
Isn't intelligence just one particular adaptation that helps reproductive success? I'm not sure why it would be more common than flight or warm-bloodedness.
It seems intelligence is more of a 'master key' that unlocks reproductive success in a variety of environments and at large scale. The jury is still out on whether it's a given that intelligence ultimately destroys itself.
The assertion wasn't that it would be more common. Just that it might be inevitable. (Indeed, it seems less common on our earth than either of the things you mentioned, so I don't know why we would think it would be more common.)
And again, I concede that these are somewhat obvious questions. My main assertion at this point is just an affirmation that I find this topic really interesting.
All evidence says it's exceedingly rare. As far as we can tell, it's only emerged once in the entire 3.5 billion year history of life on Earth. On top of that, Earth may be a very rare sample of planets that have intelligent life, among a far larger population of life bearing planets that don't ever give rise to it at all.
Since "intelligence" is ill-defined and "consciousness" can't be measured, some disambiguate with the term "technological". Take what I said to mean that if you prefer. :)
My point: If technological civilizations were common, we'd probably expect to have seen a few pop up in Earth's long history of life. Since it's only us, it's not likely to be more common than "one for every 3.5 billion years of life", and there's no bound how much rarer it could be than that.
