“Most promising signs yet” of alien life on a planet beyond our Solar System

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.

The sun has about 5B years more to go before it turns into a red giant, not 0.5B years...

While it has more time to become a red giant, it'll become more luminous over time and life on Earth will be impossible much earlier. I've seen estimates of 0.5B to 1.5B years.

Earth may become uninhabitable in 1By due to increasing brightness of the sun. In 3-4B years it will be too hot for liquid water on the surface.

In 500 million years, hopefully humans (or whatever humans have become at that point) will be able to modify the Earth's atmosphere to deal with the increased luminosity of the Sun.

We'll put a giant sunshade in the Earth-Sun L1 Lagrange point.

We might need to do that by the end of this century.

If we are able to harvest the solar system resources it would take by then.

Trial run for the bigger “solar warming” event.

We might be lucky enough to do that, but it could have easily taken intelligence another 500M years to evolve on another planet. First animal fossils are something like 700M years old, so it took 2-3G years to just any animals.

lol 0.5B to 1.5B is a pretty big difference. Sounds like we really don’t know what we are talking about.

Maybe it'll help if you think of it as 5-6.5 billion years instead.

5B more years and we're here for max 100 years. Cruel joke. Life's too short.

The lower end estimate depends on the specifics of the increase in brightness accelerating the weathering of silicates, leading to more CO2 absorbed out of the atmosphere until C3 photosynthesis isn't possible. Some plants use a different method which will continue to work (C4), but consequences of plant life as we know it dying off would be catastrophic for life on this planet - barring of course, whatever adaptations are made.

But it's certainly the mark of "the beginning of the end" for life on this planet - it's a major milestone that we (the species) do need to leave eventually if we want to continue.

See, it all comes together! ^.^

The fact that sharks have existed for 450 million years fairly unchanged fills me with hope. Our existence might be a huge fluke even if eukaryotic life can happen once and again in the Universe.

why isnt a crocodile sentient?

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...

Sadly it is still only a stop-gap measure. The sun is for all intents and purposes, dying a slow death.

Earth is on course to become uninhabitable for human civilisation its current form within a century, with an associated mass extinction.

Even if all industrial activity stopped tomorrow there's now enough CO2 in the system to guarantee a succession of uncomfortable and expensive droughts, floods, storms, and wildfires for thousands of years.

If it doesn't they will become more and more extreme very quickly.

If ocean acidification and warming destroy the foodchain in the seas, collapse on land will happen very quickly.

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.

Who says they aren't? Of all the reptiles, they seem among the smartest.

Every field of study, subject, or problem, or even business cases, -- all have different ranges.

Why does this one in-particular sound like they don't know what they are talking about? It would be just as accurate for me to say in the range of responses, yours kind of sounds like an anti-science bot. Typical of that type of thinking.

Technically, it is: https://en.wiktionary.org/wiki/sentient (the first two definitions). You mean the science fiction definition though (the third), and it's because it's not self-aware and not very intelligent, because it doesn't need to be to survive and procreate successfully. A slightly smarter crocodile must not have enough of an advantage over its peers to matter for evolutionary purposes.

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.

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.

Sure, but it may keep Earth habitable for an extra billion years.

Birds are not remotely as smart as humans.

Long before death it will expand to or almost to Earth's orbit. I doubt humanity could isolate Earth from that.

Yeah, but if humans exist by the time the sun fails us, they wouldn’t really be the same species as us, and they’d hopefully have progressed to the point that they could escape the Earth.

You may want to update your view that non-human animals lack sentience. [1]

[1] https://pmc.ncbi.nlm.nih.gov/articles/PMC4494450/

If you're referring to technology/civilization-building capabilities, that is a different matter.

The difference between .5B years and 1.5B (BILLION) years is pretty staggering in a conversation basically focused around the last couple thousand years. Definitely room for the comment.

Your anti-science bot comment however, is very anti-science.

Yes but the point is that the window in which we have developed this capability is quite short.

Honestly, I do not think high-intelligence is useful for life. The most successful life forms aren’t the most intelligent, and humans seem to be fixed to self-annihilate.

Sure, and entropy will end us all one way or another

Did you notice that you aren't wrong because you're not really saying anything at all? "in its current form" - so maybe with slightly different distribution of land use but basically fine and not necessarily as different as today is from 50 years ago? "mass extinction" already been happening for ages for many species. "uncomfortable floods/etc?" Already been happening for all of history. "very quickly" is how quicky? "more extreme" is how much more extreme?

Indeed.

Maybe once day, aliens will drop by and discover what remains of humanity. And stories will be told of how, when the time came, our species decided to bury its head in the sand and hope the problem would go away. Or maybe that we attempted to create god to come rescue us.

Life imitates art. We refused to listen to the scientists.

The problem is that there are just so many planets. Sure, another planet could be 500My slower, but with a billion planets, some of them should be 500My faster instead.

It's possible we are absolutely one-in-a-billion uniquely lucky - after all, someone has to be the first and the luckiest. But every year we find indications that our planet is completely typical.

You're saying we wont maintain tradition and our "humanity"?. I like to be a little more optimistic and believe in us as a species transferring values until the end.

Really? With the age of a star, that is too wide a range for you to accept? To pinpoint something like this. What if I were to say, "really it's 1.3435 Billion on a Tuesday".

Of course, calling someone anti-anti-science. The new 'right'. Using science arguments against science. Yes. Your comment is typical, just spam fud. "look at this huge range, see, scientist don't know what they are doing"

Unfortunately it looks like we are more in the track to human inhabitable earth :(

Why do you think aliens will drop by? If aliens were visiting every planet in the universe, don't you think we would have noticed that by now? I mean, why didn't they visit the solar system and colonize it (and everywhere else) aeons ago?

You're assuming we make it out of the industrial age while we backpedal on all of our climate commitments.

I owned quite a number of pets in my life, so I don't need explaining that they do have some kind of relatively high-order intelligence that allows them to do quite a lot of things. Yet, this is clear that no kind of animal on Earth but us exhibits potential to have capabilities to spread themeselves beyond home planet once it becomes uninhabitable. Moreover, signs show that once a type of species finds their niche, their intelligence levels off and does not tend to increase. In other words, modern crocodiles are no smarter than crocs from 10 millions of years ago, because they are doing mostly fine as they are.

According to this Timeline of the Far Future [0], we only have 500-600 million years.

(warning, this is one of the most depressive pages on Wikipedia)

[0]: https://en.wikipedia.org/wiki/Timeline_of_the_far_future

> so maybe with slightly different distribution of land use but basically fine and not necessarily as different as today is from 50 years ago?

No, probably very much more different than that, more like rolling back on industrialisation and globalisation. Closer to 500 years than 50, without the same hope of "progress" that we had back then.

> "mass extinction" already been happening for ages for many species.

Yeah, we all learned about dinosaurs when we were little kids, but if humanity collapses there's no guarantee of anything similar developing after us.

Someone has to be the first.

So, your theory is aliens are abundant, but by extreme coincidence we're first?

Yes, I think GP phrased it badly. This is just about the meaning of words: "sentience" just means sensory or experiential consciousness. It doesn't necessarily imply high intelligence or capacity for using technology

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.

> 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?

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.

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.

> 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.

> life would tend toward technology

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

All humanoids except our species are extinct, and it's not because we killed them.

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.

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

It's not? Didn't most of them coexist with us until they didn't?

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.

Look at all types of mammal that exist, from us to platypuses to bats to whales. Evolved in a few hundred million years. Modern humans have been here for a few hundred thousand.

In 500 million years absolutely anything could happen (if we survive this century).

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.

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.

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.

We'll have colonized the galaxy in 10 million years. In 200 million years, I'd expect that some future historical society could undertake a project to clean out the heavy elements in the Sun to keep it going.

Nothing a bit of stellar lifting would not fix[1]. Or worst case, move to a bunch of habitats orbiting stellified Jupiter[2].

[1] https://en.m.wikipedia.org/wiki/Star_lifting [2] https://www.orionsarm.com/eg-article/4a48d58c84350

That's not the point: if you have capabilities to do stellar lifting, interstellar travel is likely on the table too. Fermi paradox is about the question, why we can't detect any sign of extraterrestrial civilizations out there. One explanation is that while life in general might be relatively abundant, true sentience as in us humans that allows life to spread besides its cradle might be quite unique.

We haven't visited any other planets so we're not the first either.

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.

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.

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.

what do you consider the most successful life forms to be? humans currently inhabit every continent and are unquestionably at the top of the food chain.

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.

> in just .5B years Earth would likely become uninhabitable due to Sun becoming a red giant

The Sun will not become a red giant in 500 million years.

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.

You confused two things. There is the Sun turning into red giant in 5 billion years consuming the Earth, and the Sun getting too bright for Earth to be habitable in 500 million years.

Are we though? Bacteria do better than us. Cockroaches. Rats. Ants. Grasses. Plankton. We aren’t the most numerous. We aren’t the most widespread. We are serious risk of killing off our own species.

If the Earth was about to be hit by a huge asteroid, some people might survive (by fleeing in spaceships) but none of the species you list have a chance unless people choose to save them.

I highly doubt much of the bacteria would care. The amoeba probably wouldn’t either. Also, rodents have already survived such impacts. All mammals alive today are alive because our ancestors didn’t die with dinosaurs.

Suppose the asteroid is much bigger than the one that ended the dinosaurs.

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.

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.

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.

If the Earth is completely destroyed, the humans on space ships wouldn’t survive either. There is no self-sustaining off world colony currently, and there most likely will not be in the lifetime of anyone alive today. At such time that there is, bacteria, rodents, and other life will likely come with humans as humans build the biospheres that we need elsewhere.

Okay?

With a few years to prepare, the humans would have a chance IMHO.

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.

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?

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.

Correct, we disagree in what we think.

What gives you an impression that I am confusing these two things? Becoming a red giant is a long process and increased luminosity and radius are parts of this process.