Why would anyone spend an enormous amount of energy and time to reach us, a miniature rock that has nothing to offer to a space faring race?

I would suggest Peter Watts' "Blindsight" or Liu Cixin's "Three Body Problem" trilogy.

And I really, really tried hard with The Three Body Problem. I get that the English version is a translation, but in the end the flowery language and slow plot just wore me down. Did anyone else have the same experience?

(Off topic, but I find that the problem with fiction based on SETI / first contact is that the subject often ends up being used as a metaphor for the human condition and the difficulty of really communicating with other people. Which is fine, but doesn't make for satisfying SF in my experience.)

(Possible mild spoiler ahead)

[1] Basically: "the forest is full of hunters of unknown strength, so either stay quiet or kill all the hunters." I thought that Greg Bear's Forge of God and Anvil of Stars did a much better job on this aspect of Fermi.

Much of Seveneves was depressing too but it all seemed very plausible. It was in what came next that seemed off.

https://en.wikipedia.org/wiki/The_Killing_Star

And honestly the killing star has aged.. weirdly. Amazing concept, seemingly written by an author with multiple personalities, one of whom just cannot shut up about the Titanic

Has he written about Titanic in his other books too?

This is true for relatively low power omni-directional broadcast signals such as terrestrial TV and radio. The signals proposed by the METI community (and those that have already been sent - e.g. from Arecibo) are broadcast at much higher power using a concentrated beam, and would be detectable over interstellar distances using technology similar to that which we have now.

Yeah but they would need interstellar-type of timescale to reach us anyway even if they moved at a fraction of speed of light, so the risk is close to nil. We are way, way more likely to be hit by an asteroid or to destroy our planet than to be destroyed by a very remote alien civilization.

If you pinpoint its origin to light years away, you know they already had a lot of time to progress past this technology. A good response if you plan on eliminating them would not be a fleet: you'd better setup and direct a huge gamma-ray burst in their general direction.

So the destructive response could come at the speed of light with a little delay at first.

Still this is not a movie where the aliens are on next moon so even if they picked up the signals it would long after the next few generations die off (Light years away - Man they are damn far off). (living in a developing country would give you a whole new perspective on energy scarcity)

In this case, if sending a signal into space takes a lot of energy and if energy is scarce, then it's a waste of energy regardless of if the government provides it or a private donor.

EDIT: I'm not saying this is true in this particular case (I'm also not saying that its not true), I'm merely stating that whether something is a waste doesn't matter on who is doing the wasting. I would gladly listen to a counter argument and maybe a discussion can be had, but I guess its easier to click a down arrow. Oh well. (Yes, yes, I know it'll happen even more due to my mentioning it)

[1] http://io9.gizmodo.com/5784658/so-you-want-to-send-a-message...

[2] http://www.cleanenergyauthority.com/solar-energy-resources/w...

I wasn't taking any sides on this issue, so its not really relevant how much energy it took. I said "if" it is and it was a hypothetical to give a concrete example, not a statement that I thought it was wasteful.

I'll paraphrase:

If <something> is hypothetically wasteful, then <something> is still wasteful regardless of who did it.

I'd think a truly space faring race would probably have very different goals to us and the currency of culture would be much more valuable than natural resources which surely are abundant if space travel is trivial to you. Looking at it that way we'd have a hell of a lot to offer.

I guess that this comment is based on our technologies that we have _now_....

Finally, by the time we'd be able to visit another planet, we'd probably prefer sitting in our Holodecks all day.

Dolphins are pretty smart! Mean like us, too. If we and they didn't inhabit incompatible environments, I suspect we'd have had some complicated history with them, and probably now speak of them in the past tense - or they'd speak so of us.

Fortunately, ravens are smart enough to recognize the combination of repeated food offerings, and a demurral to repeat the initial rudeness, as earnest of good intent - walking out the door with my camera no longer provokes alarm calls and surveillance overflights. Catbirds, not so much - I pissed off one of those back when there was snow on the ground, and I suspect he'd still quite happily rip my lungs out if he could.

ONe intelligent species on Earth? So you are assuming most animals are moving objects without any thought or emotion?

Folks spend lifetimes thinking of philosophy or working on a single science problem. In addition, we are still exploring oceans, depths of volcanos, and we explore space as much as we can without actually travelling to the places ourselves. We research animals and our own bodies. Some folks spend a lifetime making music. Not all of these has a payback outside of satisfying curiosity or enjoyment, at least not upfront.

Considering this, why would it seem odd that a race would explore what there is to explore?

Tipping off a rogue sentient AI that killed off their own creators is what I am more afraid of.

I have heard this line of reasoning often, but it's not clear to me that the logic is correct. I don't think an entity's treatment of itself necessarily implies much about the way it will treat others.

There are many lofty, high minded goals one could consider; exploration, discovery, species/ecosphere survival in the face of an imminent global threat. Finding, enslaving, or eliminating other sentient life forms? I can't see how this could be the goal of any civilization. Maybe the same impulse that could lead to organizing such an incredible, global effort to build the interstellar infrastructure in the first place could also dictate this less savory motives, ie religious zealotry ie Church of Galactic Subjugation.

The above is speaking to a possible interstellar civilization and not much more than our tech level.

Some points I like: - A very advanced lifeform may view us the way that we view plants, so basic that wiping them out for convenience sake is not even something that enters the realm of our ethics - we just do it. I imagine aliens coming to Earth and seeing us humans on it eliciting a response like one of us opening a container in the fridge and going "Eww mould" (ewww Primates) and then washing it all clear with hot water.

- One would think that extra-species aggression would be a trait favorably selected by Darwinian evolution, so super-hostile aliens would survive and propagate. Hopefully that's negated by a post-scarcity advanced alien economy?

- In the universe sentience is relatively rare, so finding another race is something that should be treasured, cherished and nurtured.

- Maybe they'll see us as pets, and shower us with gifts

What other scenarios can you think of? I especially like thinking about what happens when there's large intellectual differentials ...

... unless you consider that all life on this planet began with the same chemicals, and that many different organisms are codependent, the most obvious being plants and animals.

Truly, interstellar existence, once confirmed that we're not alone, may also require teamwork. Perhaps ET is just waiting for us to demonstrate that we don't intend to destroy our planet for the benefit of a few selfish short-lived creatures in Earth's long history.

That kind of AI would be more busy harvesting new worlds than trying to care about an inferior species like ours (and they would likely not even be in the vicinity so no reason to travel up to us either).

Other possibilities:

- The sentient / strong AI may have (developed) FTL travel / signalling capabilities which from our current understanding does not seem to be possible.

- The AI may have sent out scouts millions of years ago into multiple directions. The closest scout only needs to decide to conquer / harvest our planet.

- A combination of the above, for example: FTL signalling and activating scouts where needed.

favorite quote about the possibility concerning all of this Arthur C. Clarke — 'Two possibilities exist: either we are alone in the Universe or we are not. Both are equally terrifying.'

And if the best toys do end up in the hands of those who've never forgotten that life itself is an act of war against intelligent opponents, what does that say about a race whose machines travel between the stars?

- Peter Watts, Blindsight, via http://akkartik.name/post/2012-11-21-07-09-03-soc

My shortlist of hard sci-fi authors that have really interesting ideas about extraterrestrial life: Peter Watts (above) and Greg Egan. Liu Cixin has also become popular recently, but he's not quite as hard sci-fi and also (in my opinion) not as intellectually stimulating. Still a good read though. Ted Chiang has some decent ET stuff (one of his stories was recently adapted to the film Arrival), but I like his biblical fiction and philosophical sci-fi more.

If humans are actually a very clever form of AI crafted by some thing unknown to us, whatever it may be, are we in-fact "artificial?" What if it goes further back: All living things on earth have an origin in an organic artificial intelligence experiment and humans are simply an interesting result?

It may sound far out and perhaps even stupid, but as long as we're talking about AI killing its originator ... it's a legitimate question: Is discerning between Artificial/Natural intelligence even valid outside of planet earth?

Edit: Maybe the word 'program' is what I'm not liking, and your answer is actually legit

Depending on its adaptability that something may outgrow what supports and created it (nature, energy sources, their intelligent / sentient creators etc.).

I mean just consider HUMANS finding an alien civilization first; Do you think the outcome will be the same whether the US gets to them first, or the Russians, or the Chinese, or the Japanese or Indians?

Will every nation on Earth have the same reaction and the same plans for dealing with the alien civilization? No, right?

..I think a civilization capable of interstellar travel will have EVEN MORE factions and subgroups with conflicting interests.

Interstellar travel implies a high likelihood that they have already colonized multiple planets, and it’s very unlikely that the governments of multiple planets would agree with each other on all matters, even if they could communicate fast enough, let alone on how to deal with alien civilizations..