Life on other planets would likely be brief and become extinct very quickly

http://astronomy.com/news/2016/01/the-aliens-are-silent-because-they-are-extinct

by barce • 11 years ago

59 70 11 years ago

Zikes2• 11 years ago

There sure are a lot of confident yet highly speculative declarations about life in that article, in spite of the fact that we currently only have a sample size of one.

chris_wot2• 11 years ago

Really? Which declaration in particular are you referring to?

Zikes2• 11 years ago

Early life is fragile
The aliens are silent because they are extinct
new life would commonly die out due to runaway heating or cooling on their fledgling planets

I'm not disputing the science or studies the article refers to (I'm far from qualified for that), I believe that models of plausibility are an important part of the process, but as with most science journalism they just can't help turning them into some sort of "absolute" statements.

interdrift2• 11 years ago

There's also the Fermi paradox which makes those speculative declarations somewhat believable..

phreeza• 11 years ago

My personal lesson from the fermi paradox and the drake equation in particular is that we humans are terrible at grasping very small probabilities. Intuition completely fails when we have to decide if something has the probability 10^-5 or 10^-50, which makes sense because for almost all practical purposes both are almost zero in most situations, but for edge cases like the drake equation they make all the difference.

ekianjo2• 11 years ago

Its not just difficult to grasp. Its very difficult to estimate in the first place since have very little data at hand to make any call. For example we may take 1/9 for the probability of life appearing in a given planetary system, but we have no idea if this is representative or not of usual probabilities or if our system is exceptional in any way.

netinstructions• 11 years ago

Is there anything revelatory in this article? I didn't see any links or references to new papers/ideas, but some Googling returned this 2016 PDF[1] titled 'The Case for a Gaian Bottleneck' by Aditya Chopra from ANU.

There's been discussion in the past[2][3] about these 'Great Filters' that prevent life from occurring everywhere in the universe.

[1]http://adi.life/pubs/ChopraLineweaver2016.pdf

[2]http://mason.gmu.edu/~rhanson/greatfilter.html

[3]http://waitbutwhy.com/2014/05/fermi-paradox.html

ekianjo2• 11 years ago

Same impression here, nothing new in this article. Its part of numerous ideas discussed before. And there is no hard evidence to support if this is the main bottle neck or not.

melipone• 11 years ago

What I got was that the rapid emergence of biological feedback was essential for regularizing climate which in turn enabled life on earth to evolve. In a way, life itself enabled life on earth. It's the rarity of this emergence that is important rather than the rarity of intelligent life. Another thing I got is that life itself will destroy life the way climate change is going :-)

civilian3• 11 years ago

I've been reading The Vital Question by Nick Lane, where he puts forth some theories about the origin of eukaryotes, and life in general. It does make it seem that abiogenesis and eukaryote-genesis are much more difficult than we give them credit for.

So in the Drake Equation, I think that F[L] is probably pretty low.

And because eukaroyte genesis is difficult and only happened once (and it took a billion years of bacteria & archea hanging out before we got a eukaryote), and eukaryotes are a prereq for multi-cellular organisms and thus intelligent life, F[i] is also really low.

http://www.amazon.com/The-Vital-Question-Evolution-Origins/d...

monk_e_boy2• 11 years ago

Panspermia is one solution to this.

shawndumas• 11 years ago

All problems [in philosophy] can be solved by another level of indirection...

breckinloggins2• 11 years ago

This gets my vote. My hunch is that intelligent life like the kind we would love to meet happens either on the order of once or twice per galaxy during the galaxy's entire lifetime, or it happens SO rarely that, if the universe is infinite in extent, then any intelligent observer looking out from the "center" of their observable universe will most likely be in the only intelligent civilization in that visible radius.

Depressing, but it seems more plausible than things like "Great Filters of DOOM". It would predict that there is a lot of intelligence in the entire universe, but each cluster of intelligence is profoundly alone.

samstave• 11 years ago

Then why the fuck do we keep killing ourselves?

Seriously, if we taught this level of intelligent-life appreciation to every born soul... the world would be a better place.

Rather than starting with the teachings we do for youngsters; why not just teach them how freaking rare and lucky they are to be a consciousness present to hear that fact and then know that they can then expand the known universe... but do this in a much more deliberate fashion than we are now?

We need to be much much more deterministic from a species if we will survive for eons.

baddox2• 11 years ago

Where do you get the estimate of "once or twice per galaxy"? I can agree that it might be "rare," but I have no idea how you would pin down the rareness to that level of accuracy.

Florin_Andrei4• 11 years ago

One thing to keep in mind is that the time interval of stability for Earth as a life-bearing planet is actually fairly close to the end. We're past the 75% point. The Sun's evolution will "soon" put an end to that (speaking on a cosmic scale).

So it seems like it was a close call. Life needed almost the full extent of that interval of stability to create an (arguably) intelligent species. There can be no reset and start over. This is it, for the solar system. If we fail to survive, this whole star and its planets have failed to produce viable intelligence.

If Earth turns out to somehow be unusually stable as a life-bearing planet, this might explain a large portion of the Fermi paradox. This might be a large chunk of the Great Filter.

PuffinBlue2• 11 years ago

"How long do you say the sun had left?"

"...5 billion years."

"Whew, that's OK, I though you said 5 million!"

orf2• 11 years ago

People always talk about how vast space is, but rarely about how vast time is. We've been looking for life for the last what, 60 years or so? It seems like not only is space so vast which makes finding evidence of life hard, but this is made even harder by the small volume of time we are likely to be around to try and observe in the grand scheme of things. Alien life has to be relatively close in terms of distance as well as time.

What if our closest alien life became discoverable (started emitting radio signals or other signs) a million years from now? Would we be around to see it?

ceejayoz• 11 years ago

Would we be around to see it?

And how long does an average civilization broadcast radio?

On the "life is safe" end of the spectrum, maybe there's much better technology to be discovered. On the "life is dangerous" end, maybe you learn pretty fast not to broadcast your location to the galaxy.

JohnDotAwesome2• 11 years ago

Reminds me of the book, The Three Body problem

orf2• 11 years ago

maybe there's much better technology to be discovered

Obviously we don't have much to draw on, but it seems like our technological growth looks a bit exponential. I'd imagine a civilization that has been around for a million years would have discovered a hell of a lot of technology - but a million years is a blip in 13.82 billion years, the age of the Universe. It's like 0.001% if I've got my maths right.

kposehn2• 11 years ago

Excellent point.

I think that one advantage of interstellar distance is we can effectively look back in time a great distance, so in effect we don't have a visible radius, but a combination of time and distance.

We can see thousands of light years back in time, thousands of light years away. However, we don't have that picture of Tau Ceti at 11 light years away. Perhaps thousands of years ago there was a civilization there that flourished and died - and we'll never know because their signs of life are outside our distance/time perception.

A graph of Time/distance would be Time one axis, distance on the other and a diagonal line stretching up and to the right, showing what we could see at any given time.

Thoughts?

[edit: comment formatting ate my pretty ascii chart]

SEJeff• 11 years ago

Or worse, we do intercept the radio signals, from hundreds of thousands of light years away, from a an alien race long since extinct.

johngalt• 11 years ago

Exactly. 13 billion year old universe. 5 billion year old solar system. Life on earth was effectively pond scum for 3 billion years. Humans went from banging rocks together to transistors and space ships within 500k years. We have been a civilization for a laughably small time on astronomical terms.

Given the timeframes involved it's entirely likely that any 'aliens' are half a billion years ahead or behind us. Our first encounter with life will likely be one of three things.

1. Pond scum millions of years away from being anything else.

2. Aliens who have been extinct for millions of years.

3. Aliens so hopelessly advanced they are deities

Even just a million year gap would be insurmountable. Which is nothing on the universe's timeline.

interdrift2• 11 years ago

Imagine how easily we can also become extict and even our most powerful technology isn't powerful enough to save us. Imagine a big explosion in our galaxy , like that supernova that happend recently. We could die out like ants. We should be progressing faster...

coderdude• 11 years ago

We're already progressing at breakneck speed. The last 10,000 years saw us go from stone tools to the Samsung S6.

JohnDotAwesome2• 11 years ago

And in the last couple of years, from the iPhone 6 to the iPhone 6s!

reasonattlm3• 11 years ago

No answer to the Fermi Paradox works if it requires all aliens to uniformly come to the same end state or satisfy some boundary condition without exception. All it takes is the one exception, one small group in one suitably advanced civilization, and you have self-replicating probes building an expanding wave of computronium, dismantling even the stars themselves as soon as the economics favor a better use for that matter. Such as more computronium.

The Fermi Paradox is more the Wilderness Paradox: why is everything, everywhere we look, wild and unmodified? Why are there still stars, when a simple economic analysis of our future tells us that we will tear them down in favor of more efficient arrangements of matter and energy?

https://www.exratione.com/2015/05/the-cosmological-noocene/

"Per our present understanding of physics and intelligent economic activity, we will turn every part of the great span of the universe into our descendants if not diverted or stopped by some outside influence, stars and all. The cosmological noocene, an ocean of intelligence. That the natural universe remains present to be used by us indicates that something is awry, however, that some vital and important understanding is missing, and as a species we are still just making the first fumbling explorations of the bounds of the possible with regards to what it is that we don't know."

Florin_Andrei4• 11 years ago

dismantling even the stars themselves

It's unclear whether that's actually feasible from an energy balance perspective. You'll need a lot of energy to re-arrange things on that scale. Each star is already sitting at the bottom of its own local energy well.

Maybe the far future will discover radically new ways to produce energy - but until then, this whole thing about the wave of computronium flooding the universe is pure speculation.

reasonattlm3• 11 years ago

Agreed, but stars are very fragile in some ways; surprisingly small disruptions in some of their transitional layers can cause novas. Stellar modeling is entertaining in that way.

So in place of "dismantle star" perhaps "provoke extreme mass loss" would be a more obviously net energy-positive goal for the engineers. Still, one should run the back of the envelope calculations on what you'd have to do with a stellar mass to produce greater energy than it emits in its current form, and whether the difference can be enough to make it a net positive to nova the star. My intuitive belief is that the difference in efficiency of use of materials can be huge, more than enough to justify large investments in stellar engineering at the stage when technologies means molecular nanotechnology plus nucleosynthesis: factories capable of taking in hydrogen and turning out anything.

losteric• 11 years ago

simple economic analysis of our future tells us that we will tear them down in favor of more efficient arrangements of matter and energy?

What tells us this is the case?

How do we know there isn't an upper limit on the amount of computing resources a civilization desires, even if it's an absurdly high limit like "disassemble all the inner planets"? How do we know there is an incentive to build interstellar civilizations, versus independent civilizations? Is computronium even worth spreading?

Analogous to r/K selection, is there more incentive to replicate a particular way of life (eg civilizations uploaded to a particular computronium implementation), or is it more beneficial to simply shotgun probs with very primitive seeds capable of bootstrapping new implementations of life? Is the interstellar competition between civilizations, or is the competition between different fundamental forms of life where civilizations simply mark a system developing to the point it can reproduce?

Given the distances between solar systems, why would a civilization span multiple systems? Wouldn't each system become culturally and economically isolated, evolving independent from the parent civilization? If that's the case, why invest in cloning the parent civilization when they could bootstrap native life from-scratch?

reasonattlm3• 11 years ago

Again, you are looking for bounds on voluntary behavior that every civilization - and all its members - must satisfy. It only takes one to choose self-replicating probes to make the wilderness disappear in very obvious ways, visible in neighboring galaxies.

hyperpallium• 11 years ago

Reminds me of how some animals were domesticated several times, and some only once, because they spread with technology (cats, I think). So, whether alien computronium reaches us before we start our own depends on hsppenstance, of who happened to start first.

PS: Sorry; accidental mobile downvote when trying to upvote :(

nsgoetz• 11 years ago

So life won't always find a way?

givan4• 11 years ago

I wonder why on this subject everyone overlooks two major events witnessed by thousands of people some of which former military pilots and instead focus on science fiction scenarios.

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

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

People try to explain these events in all kind of ways avoiding the most obvious one no matter what.

Is it fear? the lack of recognition by authorities? I never understood why people will talk freely about aliens in the universe but aliens here is always a taboo or a subject of ridicule no matter the evidence.

frozenport• 11 years ago

I think its more likely the government was testing military equipment.

givan4• 11 years ago

Witnesses claim to have observed a huge V-shaped (several football field sized), coherently-moving dark UFO (stars would disappear behind the object and reappear as it passed by), producing no sound, and containing five spherical lights or possibly light-emitting engines

Do you really think the military has this kind of technology?

njharman• 11 years ago

Compared to age of Galaxy, Life on this planet has been brief. Also, aren't something like 99.99% of all species extinct?

vectorjohn3• 11 years ago

Not really, life on Earth has existed for about 26% of the age of the universe (about 3.5 billion years). And we have good reason to expect that life cannot arise before a certain time because we have to go through a cycle or two of supernovas ejecting useful elements into their surroundings.

If you meant intelligent life, then nevermind :)

putlake• 11 years ago

Liu Cixin's The Dark Forest, the second book in his 3-body problem trilogy, posits a similar philosophy: resources are limited so civilizations annihilate other civilizations. So if an alien civilization knew about earthlings, they will destroy earth ASAP if they are capable, lest the earthlings come after their resources.

This is also why some people believe we should not try to make contact with intelligent alien life. They believe broadcasting our location is dangerous.

skybrian• 11 years ago

Except that we have a very big moat. I liked David Brin's take on this in Existence, where anything sent such a long way is likely to resemble a virus.

vectorjohn3• 11 years ago

It just doesn't make any sense. Resources are limited, sure, but they're not scarce. In fact, they might not be limited even. If something can afford to come to Earth, they can afford to get unlimited resources from anywhere. Unless you're positing it's from one of our nearest stars and then just happen to be coming to Earth as a last ditch effort or something.

I mean, scenarios can be imagined where an alien would want to destroy life on Earth, but they seem far fetched.

Animats• 11 years ago

Industrial civilization may not last very long. Industrial civilization on Earth is only about 200 years old. A useful starting point is the first time a railroad train carried paying passengers. There were earlier demos and prototypes, but think of that as the moment the Industrial Revolution got out of beta. Progress up to then was very slow. Progress after that was very fast.

About 75 years ago, progress reached the point that a substantial dent could be made in the planet's resources. Until then, human activity just wasn't large scale enough. Now, we can see the end in sight for many resources. On a scale of centuries, most mineral resources run out.

The high-power, heavy industry phase of life may have an expiration date that's closer in time than the founding of Oxford University.

nickbauman3• 11 years ago

About 75 years ago, progress reached the point that a substantial dent could be made...

Controversial assertion. There's a lot of evidence that we've been able to rank on the level of forces of nature for quite a while now. The disappearance of megafauna, the desertification of Western China and Saharan Africa. There's even evidence that the Amazon rainforest may have been a massive human silviculture project that had been going on for 10,000 years.

givan4• 11 years ago

Our view of life in the universe is subjective, we compare it with the only place we know it exists, earth, probably life exists in many forms not limited to how we know it or how we would expect it to evolve so probably not all life might be brief how earthers might think.

We are amazed how life exists in the most hostile places on earth and how it was able to adapt to very harsh conditions, probably life in universe is also full of surprises.

theboywho• 11 years ago

The problem with this reasoning is that it considers this to be true: if intelligent life exists, we are gonna be able to understand its intelligence.

What if there exist an intelligent life, so intelligent that their level of intelligence compared to ours is like comparing ours with...cats. We all know small genetic mutations can have huge impact. So huge they might just be technically/biologically out of reach.

So maybe an intelligent life exists out there, but they are so ahead of us that we are not even capable of understanding how. Like a little cat watching a car thinking maybe it's an animal.

kposehn2• 11 years ago

So maybe an intelligent life exists out there, but they are so ahead of us that we are not even capable of understanding how. Like a little cat watching a car thinking maybe it's an animal.

So true. We are really bad at looking at things outside the lens of our own experience. Why would life evolve in exactly the same fashion? Would it even have DNA as we know it? There is life that could form in ways we cannot even perceive - intelligence of a type that is so completely alien that neither could every notice or understand the other.

The universe may simply be filled with life, but because it evolves so differently it may simply be impossible to see most of it.

PaybackTony• 11 years ago

A series of unproven theories as a basis for a new theory that further unproven theories can be based on. The cornerstone of modern science.

There really needs to be more documented, observable data before there can be any remotely credible theory about how abundant or desolate our universe is of life. Using such observable data (we know the name) we could only surmise that in 100% of solar systems with a similar sun, bearing a planet at an adequate distance from it's sun, will not only support life, but would have life.

Common sense[?] would dictate that's very unlikely, but there's no scientific basis yet to even theorize otherwise until we can find a way to get that data. To come up with absolutes about planets such distances away is foolish given we don't know half a shit about the planets right next to us.

ZanyProgrammer• 11 years ago

It seems like a lot of SETI/astro biology is more speculation than science, i.e. something that can be disproved or reproduced.

nickbauman3• 11 years ago

The book Rare Earth covers this topic throughly. The conclusion they come to is that complex, multicellular life is likely extremely rare in the universe. But simple, microbial life may be much more common than we think.

http://www.amazon.com/Rare-Earth-Complex-Uncommon-Universe/d...

yongjik2• 11 years ago

I didn't find the book very persuasive. The authors basically take everything that is (or might be) uncommon about the Solar System, and somehow turns them into an argument on why we are so lucky to have them.

E.g., we have big Jupiter. We don't know exactly what it does, but it might have helped the Earth survive its early days. Therefore, it might be the case that the rise of complex life needed Jupiter. Yadda yadda, multiply a dozen of these things, and suddenly life on Earth looks like an incredible stroke of luck.

The problem is, we don't know enough to make that verdict. What if the existence of Jupiter actually postponed the rise of life by sending big comets along our way?

I enjoyed "Life Everywhere" by Darling much more, though it is probably too dated to recommend in 2016. (Astrobiology is a rapidly changing field, I suppose.)

nickbauman3• 11 years ago

That's interesting remember the book explaining Jupiter had a specific influence on earth's ability to develop complex life in that its size and position made it essentially prevent a lot of comets and dangerous asteroids from hitting earth by simply getting in their way.

pklausler• 11 years ago

I am convinced that we're the first/only space-capable species in our galaxy by the simple absence of killer self-replicating interstellar robots. I'm serious. Anything that's remotely possible becomes inevitable on these astronomical scales, and all it takes is one jerk making one self-replicating killer robot and that's it for life for the rest of time in the galaxy.

Life on other planets would likely be brief and become extinct very quickly

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