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417 points fuidani | 31 comments | | HN request time: 1.259s | source | bottom
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seanhunter ◴[] No.43714467[source]
Firstly that is completely badass science. The idea that you can use observations to detect the chemical composition of an exoplanet millions of kilometres away is an absolute triumph of the work of thousands of people over hundreds of years. Really amazing and deeply humbling to me.

Secondly, my prior was always that life existed outside of earth. It just seems so unlikely that we are somehow that special. If life developed here I always felt it overwhelmingly likely that it developed elsewhere too given how incredibly unfathomably vast the universe is.

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ta8645 ◴[] No.43714565[source]
If life is very common in the universe, then that is probably bad news for us. It means that civilizations should exist that are millions of years more technologically advanced than us; and should be leaving telltale signatures across the sky that we'd likely have detected by now. And the absence of those signs would be relatively strong evidence that life, while common, isn't long-lived. Suggesting that our demise too, will come before too long.

If, on the other hand, life is relatively rare, or we're the sole example, our future can't be statistically estimated that way.

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Andrew_nenakhov ◴[] No.43714650[source]
It is quite plausible that life is abundant, but sentience is not. If we take Earth, it formed 4.5 billions years ago, conditions became suitable to support life like 4B years ago and first known signs of life are dated 3.7B years ago.

Now, in just .5B years Earth would likely become uninhabitable due to Sun becoming a red giant. In other words, on Earth life spent 90% of its total available time before sentience emerged. So on one side life is constrained simply by time, and on the other, sentience might not be necessary for organisms to thrive: crocodiles are doing just fine without one for hundreds of millions of years. To think of it, it is only needed for those who can't adapt to the environment without it, so humans really might be very special, indeed.

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energy123 ◴[] No.43715071[source]
This is now much less plausible. Intelligence, like eyesight, is believed to be a result of convergent evolution[0].

[0] https://www.quantamagazine.org/intelligence-evolved-at-least...

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1. lupusreal ◴[] No.43715113[source]
Being intelligent doesn't necessarily lead to runaway technological development. Dolphins are smart but they're never going to invent radios to broadcast their existence to other star systems. They're stuck in the water and don't have thumbs. And even orangutans, who have thumbs and live on land, don't seem tracked for technology even if humans weren't around; their ecological niche is small even if we assumed humans weren't wrecking their environment, and they seem comfortable and steady in it.
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2. lordnacho ◴[] No.43715215[source]
We don't even need to look at other species.

Humans have been just as smart as you and me, maybe even smarter according to cranial measurements, without inventing anything that significantly changed their way of life.

There could be loads of planets with prehistoric humans, having a fine time hunting with bows and picking fruit.

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3. energy123 ◴[] No.43715222[source]
Nevertheless, if abiogenesis is common & intelligence is easy for evolution conditional on abiogenesis, the number of explanations for the Fermi Paradox just shrunk by a great deal, increasing the probability of the remaining explanations.
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4. lupusreal ◴[] No.43716651[source]
I doubt there is one single grand answer for the Fermi Paradox. Probably it's lots of smaller blockers which all stack up with each other. The chance of life forming, the chance that it becomes multicellular, the chance that it develops complex nervous systems, intelligence, the physiological hardware for tool use and creation, not stagnating or getting wiped out, having the inclination to look out and broadcast their existence, the chance that they survive long enough while doing this to exist at the same time as another civilization of comparable development, etc. It's easy to come up with these and even if they all have modestly small probabilities each, together they stack up to a plausible answer to the so called paradox.
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5. diggan ◴[] No.43716661[source]
> Dolphins are smart but they're never going to invent radios to broadcast their existence to other star systems.

How could we possibly know this? The only case of "Dolphins" we know of, is on Earth, with the interference of humanity, and we're looking at Dolphins at a really small timescale.

Given N thousands of years without interference from other species, who can really confidently tell exactly how Dolphins would evolve?

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6. Loughla ◴[] No.43716673[source]
I don't think so, though. I think that unless there are limiting factors (no ores or some other necessary component) life would tend toward technology.

Curiosity as an evolutionary trait is quite an advantage, and I would think is necessary for intelligent omnivores. It's what helped us figure out what we could and couldn't eat, and taught us better techniques for living. Curiosity naturally leads to technological developments, I would argue.

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7. lupusreal ◴[] No.43716691[source]
We've had at least two developments of ""dolphins"" that I know of. We also have other intelligent sea life, like squids and octopuses, who've been around for a hell of a long time and are on track to never develop advanced tool creation and use. Living in the water is a massive tech nerf.
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8. diggan ◴[] No.43716757{3}[source]
> Living in the water is a massive tech nerf.

Says land-living animal :)

Again, are you saying that you confidently can predict a hypothetical future where Dolphins, even given millions of years, would never invent the radio? I think it's unlikely too, but so are humans, so who knows what could happen.

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9. andrewflnr ◴[] No.43717431{3}[source]
> life would tend toward technology

Based on what evidence? We only know if it happening once, after a very long delay.

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10. npc_anon ◴[] No.43717695{3}[source]
All humanoids except our species are extinct, and it's not because we killed them.
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11. stnmtn ◴[] No.43717882[source]
We really are pretty lucky that the industrial revolution happened. Thank god for England running out of trees to heat homes with, and abundant surface coal on that island.
12. griffzhowl ◴[] No.43718658{4}[source]
Living underwater puts a dampener (didn't intend this atrocious pun, sry about that) on any technology that depends on fire. So smelting ores seems out of the question, and of course radios are made out of lots of pieces of metal.

I can't think of any plausible ways a water-bound species would be able to harness and use electricity either

13. Scarblac ◴[] No.43718764{4}[source]
It's not? Didn't most of them coexist with us until they didn't?
14. Scarblac ◴[] No.43718806[source]
Dolphins have only lived in the water for 50m years or so, they still breathe air. They could re-adapt to the land in that kind of time frame easily.
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15. ◴[] No.43718865[source]
16. griffzhowl ◴[] No.43718959[source]
I think by the time we get to modern humans it would only be a matter of time for technology to develop to something like the current stage. The main evidence I can think of is the independent development of agriculture in about 4-5 regions, and the independent development of large complex civilizations in the Americas and Eurasia.

Humans are cultural learners, so this allowed cumulative cultural evolution from at least as far back as the transition from Olowan to Acheulean stone technologies with Homo erectus ~2-3 million years ago. By the time we get to Homo sapiens and Neanderthal this capacity for cultural learning seems much increased. Some paleoarchaeologists (e.g. Dietrich Stout) argue that technological development has been exponential as far back as H. erectus, just that the early stages of the exponential curve look flat for a long time.

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17. lupusreal ◴[] No.43718971{4}[source]
Besides the whole fire thing, which is a serious problem for the metallurgy necessary to make radio, to have any chance of it they'd need to get fingers instead of the optimal swimming flippers they have now. They'll never do that as long as they're aquatic. If millions of years of evolution has them climb out of the water and become land animals again then there might be a glimmer of hope for them, but then they'd no longer be recognizable as dolphins. As it stands now, field mice have a more direct path towards becoming radio makers than dolphins do.
18. lupusreal ◴[] No.43719020[source]
They'd still be dolphins in the same way that you are still a fish.

Also, I don't think you're right that they could do this easily. Their hind limbs have almost completely vanished, their pelvis too, and they have no chance of moving on land. To have a chance they would need to redevelop those things which they've lost, and I don't think there's a particularly plausible path where each step helps their survival at that step. In contrast, their four-limbed land adapted ancestors could swim much better than dolphins can walk.

19. lordnacho ◴[] No.43721179{3}[source]
I think it only takes a small tweak for everything to stall.

Suppose say, that people only trust a small group. Extended family and lifelong friends, for instance. People get very violent as soon as they disagree on something, immediately wanting to settle disputes by force.

Nobody can strike a deal to do anything with anyone outside their group, and you certainly can't make agreements with a guy in Seattle to deliver things to London. You can't mine coal hoping to sell it to an as yet unknown person. There's no point in fishing more fish than you and your friends can eat.

What happens in this world? Well, I think people will still be intelligent. They'll still think about social situations, especially when it comes to mating. There will still be stories, and humor.

But we're not advancing tech, and we're not changing economically.

Why do I say it's a small tweak? Well, we've all met people who seem to not be able to work with anyone. It's not unlikely that out in the stars, there's some planet with people who have everything we have, but they can't get things to work.

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20. southernplaces7 ◴[] No.43721240{3}[source]
The paradox would remain valid in my view. Even with all those stacked difficulties and plausibility levels, the galaxy alone is immense and if life of any kind were to be found, i'd argue that we should be able to see signs of sophisticated life somewhere at least, so where is it? It's still a cause for some speculation and maybe even existential worry.
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21. lupusreal ◴[] No.43721637{3}[source]
Humans only started planting grain about 12k years ago. Anatomically modern humans were gathering wild grain, but not planting grain, for about 100k years. Given this very long period of stagnation, I don't think humanities ascension was an inevitability.
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22. lupusreal ◴[] No.43721839{4}[source]
The galaxy isn't really that huge. 10e11 stars. If you stack only a dozen obstacles at 10% odds of overcoming them each, you come up with advanced radio-broadcasting life being an unusual outcome for a galaxy our size. Add a few more and you can bet against another advanced civilization coinciding with us in the entire observable universe.
23. Loughla ◴[] No.43723503{4}[source]
I think it's a natural product of curiosity. And I think that intelligent life would only be so because of curiosity.

You want to figure things out or you're interested in seeing what happens when you fuck around with things.

So I think a technological progression is a natural progression for intelligent life.

Does that make sense? I feel like I'm not explaining myself well.

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24. andrewflnr ◴[] No.43724768{5}[source]
Lots of animals have been curious for hundreds of millions of years, but technology more advanced than breaking bits off rocks and sticks has only been around a couple thousand years. If you say it's a "natural progression", you also have to say there are serious barriers that most species will never pass.
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25. energy123 ◴[] No.43724799{4}[source]
Mutation is random but selection is non-random. Multilevel selection could select against those scenarios you're talking about. Collaboration could be yet another thing that comes from convergent evolution.
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26. griffzhowl ◴[] No.43726375{4}[source]
I know about the Natufan culture gathering and processing grain with grindstones from about 20k years ago, but don't remember anything from 100k years ago. Were they using grindstones to process grain? I'd have thought grass grains wouldn't be a good food source otherwise.

In any case, the seeming stagnation is part of what I meant by the early part of an exponential curve looking flat: broadly it might look like not much is happening, but there are small changes all the time.

Lack of evidence is also a problem when looking that far back: we have little concrete evidence of what these people were doing with wood, fibres, and other perishable materials.

Having said that, archaeologists used to talk about a "cultural revolution" that happened 20-30k years ago. (Maybe they still talk about it, I just haven't looked at the research recently). This was the period of the famous Lascaux cave paintings and what looks like an explosion of greater complexity in tool assemblages. So it's possible there was some rare cognitive leap at that time, or again it could be that we lack the evidence that would show the more gradual progression.

27. Loughla ◴[] No.43728439{6}[source]
Okay?
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28. andrewflnr ◴[] No.43728658{7}[source]
So the notion that "life would tend toward technology", charitably speaking, does not make any useful predictions. Based on all evidence available, including the dearth of extraterrestrial technosignatures, you can't rely on it happening in any particular situation or timeframe. At best it's speculation, more likely it's just false.
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29. fc417fc802 ◴[] No.43731959{5}[source]
Random walks only progress if they don't get trapped in a local minima. GP example is but one entirely contrived scenario. The point is that technological development depends on many factors and it's entirely plausible that some of them aren't strongly selected for.

This seems to be supported if you consider how long it took for humans to emerge and the fact that other fairly intelligent species exist alongside us but didn't follow the same path. If you suppose that technological development has a clear selection path then why isn't there any evidence of space fairing dinosaurs?

30. fc417fc802 ◴[] No.43732015{3}[source]
Notably the latter example has ideal appendages for tool manipulation - likely far superior to primates with thumbs. Yet somehow they're indefinitely stuck without tool use.

I wonder if things would progress if they had the same level of communication that dolphins do.

31. Loughla ◴[] No.43732284{8}[source]
Correct, we disagree in what we think.