Which would look like this: https://m.youtube.com/watch?v=PrIk6dKcdoU
Not a good example, as Voyager 1 is travelling at 0.006% c (relative to the sun) and wasn’t aimed at anything in particular. Of course it won’t hit anything.
But a ship travelling, say, 10% c, could visit our second-nearest star in 40 years.
Yes, unimaginably far apart. But they’ve also been around an unimaginably long time. When you crunch the numbers, you see a single civilization could have probes orbiting every planet with life in just hundreds of millions of years using sub-lightspeed methods.
Correct me if I’m wrong, but as I understand it we couldn’t detect the radio messages of a clone of our own civilization if it was more than a couple hundred light years away. To detect further out we’d need a ludicrously large receiver or the senders would have to have a much more powerful radio source than we do, aimed right at us.
Cults, alternative lifestyle movements, aliens – always ends up with the old guy wanting to fuck your wife and daughter. That’s convenient.
I agree life will probably arise where conditions allow, but the diversity of life on Earth all has a last universal ancestor, and that went on to evolve and fill all the niches. All we know is Earth life is very adaptable, but it could still require fairly specific conditions to get started. That said, not only did Earth produce all the amino acids and various complex organic molecules we need, but the solar system’s early protoplanetary disc was full of them too, and they rained down on all the planets. So, most of the stuff you need for life seems extremely abundant, in our solar system and others.
I like the idea we could be the elder race. One of the early ones I’d say, not the first. From the dinosaurs to humans took about 500 million years with a few extinction events tossed in, but with the ridiculously large numbers of planets and moons in the galaxy, some other planet must have passed its 500 million year window of opportunity before now, and the question is again, where are they?
Very doubtful that we’re one of the early ones. The sun is either a third generation star or a very late-forming second generation; it is in any case a young star, only 4.6 billion years old in a universe that is 13.8 billion years old. The universe likely had second generation stars with heavy elements very early in its history because the first generation were believed to be massive short-lived stars. There’s even a wacky theory that life could have formed as early as 15 million years after the Big Bang when the whole universe was still warm enough to be an incubator in itself and rocky planets with liquid water and the necessary heavy elements could have formed from early supermassive stars, and been able to incubate life without the aid of a host star at all. Pretty awesome contemplating the possibility of intelligent life as old as the universe itself. I would imagine they’d probably be pretty smart by now! 
But more realistically, there are no doubt many planetary systems in our galaxy much older than ours, and many have probably spawned life.
I’m thinking that if we put the question aside for a few decades and spent money elsewhere there would be no great loss.
I was thinking about the problem of gamma ray bursts. The article mentioned they were more common up to about 5 billion years ago. So, there could have been metal-rich planets much earlier and still been uninhabitable until 5bya. Our star is 4.5 byo, so other planets may have had a mere 500 million year headstart. The GRB theory isn’t widely accepted though, so YMMV.
Why would God create a universe as vast as ours and put 99% of it off-limits, forver? God must not think we’re very special if he has to keep up in a cage.
Why would you think you could conceive God’s motives even if the universe was only 1000 square miles?
I think that should be YLMV.
Your Light-year-age May Vary 
Such statements bother me a lot. How can one say that it’s “statistically absurdly improbable” when we don’t have the slighest clue about the likelihood of intellingent life arising?
It’s like saying “If we throw a die a giganormous number of times, it’s statistically absurdly improbable that no roll will be a 6, regardless of how many sides the die has”.
Yes, there’s an absurdly large number of stars. But intelligent life, or even simply life, might be even more absurdly unlikely. And we have absolutely no clue about this likehood.
No, it demonstrates that life, once established, can spread to many different environments, not that it will arise in any such environment.
Insects and beavers can do this, too. (Emphasis added.)
All of that is incorrect, or if speculation, most likely not correct.
And despite being adaptable, it might get nowhere. Life was pretty happy with staying at the monocellular level for most of the history of Earth, suggesting that the apparition of multicellular life (let alone intelligent life), might be pretty uncommon.
Our home is a pretty unique place. It could be one of a kind. Look at all the things that make life as we know it possible here: Moon/tides, relatively short day/night, seasons, heat/cold distribution, liquid water, protective atmosphere, not too close or far from our sun, some dry and some wet, etc. Take away any one of these things and we may not be here. How many other places could have this perfect combination of events and elements? While there are probably millions of planets like ours, how many are going to have a perfect set-up like ours, with all of those things falling into place just so? Again, for life as we know it.
Yes, it’s time we accept that we are alone for all intents and purposes. Perhaps once this is accepted and we are not going to get help from anywhere else, and we are not getting off of here, we may start to take better care of this place, and ourselves.
Earth was also experiencing extinction events that could have set evolution back. There’s also the idea that Earth is only “marginally” habitable. A “superhabitable” earth might progress faster.
what s your basis for asserting Earth “is a pretty unique place”? All your interstellar travels? And why limit the discussion to “life as we know it”?
I disagree that “we have absolutely no clue”. Just for starters, amino acids and their precursors – the organic chemical building blocks of life – have been found in comets and meteorites, leading to a plausible theory that not only is there abundant life elsewhere in the universe, but in fact even life on earth may actually have originated elsewhere.
Aside from the fact that we therefore know that the most basic elements of life exist elsewhere, there’s also this amazing sort of anthropic center-of-the-universe arrogance about saying that in a galaxy populated by some 300 billion stars, and hundreds of billions of other galaxies in the universe, this one ordinary average-sized star on the backwoods outskirts of one spiral arm of an ordinary small-ish galaxy is the only place in the entire universe that harbors life, because gosh-darn it, we’re special! And saying so without any evidence against the incredible statistical odds that mathematically alone it couldn’t possibly by true. That to me sounds more like religious proselytizing than science, and the center-of-the-universe stuff was pretty much done in by the time of Galileo.
It’s the only place we know of that is not ‘theoretically’ able to support life. And I called out “life as we know it” because some have forwarded the argument that the elements that are part of life here came from space - therefore that line of thought would require those same elements and a similar starting point.
Sure, there could be ‘life as we don’t know it’ out there, there could even be life on the sun for all we know. Why rule anything out?
No, it’s not. There are likely to be “billions and billions” of places like it in the universe.
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Our home is a pretty unique place. It could be one of a kind. Look at all the things that make life as we know it possible here: Moon/tides, relatively short day/night, seasons, heat/cold distribution, liquid water, protective atmosphere, not too close or far from our sun, some dry and some wet, etc. Take away any one of these things and we may not be here. How many other places could have this perfect combination of events and elements? While there are probably millions of planets like ours, how many are going to have a perfect set-up like ours, with all of those things falling into place just so? Again, for life as we know it.
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I think this underscores the issue people have with numbers. It’s difficult to grasp really, really large numbers and what they mean. How many other places in our galaxy could have a perfect combination of events and elements? Let’s say it’s 1 in a billion…that seems reasonable. If it is that remote then there will be hundreds if not thousands of such places that are just like the Earth. And that’s just in our own galaxy. There are 100’s of billions of galaxies (probably a hell of a lot more). And that’s just for life was we know it. There could be a lot of other types of life out there.
Taking better care of what we have has nothing to do with accepting we are all alone. I know you are trying to raise some sort of pull the heart strings point about protecting mother earth and all that, but it has nothing to do with the discussion under way here…and nothing to do with whether we should or shouldn’t protect the earth (we should, regardless).