
Life on other planets would likely be brief and become extinct very quickly - barce
http://astronomy.com/news/2016/01/the-aliens-are-silent-because-they-are-extinct
======
orf
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
> 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.

~~~
orf
> 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.

------
civilian
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...](http://www.amazon.com/The-Vital-Question-Evolution-
Origins/dp/0393088812)

~~~
breckinloggins
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
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.

~~~
civilian
To quote Ender's Game: _" I am not a happy man, Ender. Humanity does not ask
us to be happy. It merely asks us to be brilliant on its behalf. Survival
first, then happiness as we can manage it."_

It doesn't really answer why we commit suicide. But it does give an answer to
why we aren't happy.

------
netinstructions
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](http://adi.life/pubs/ChopraLineweaver2016.pdf)

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

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

~~~
melipone
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 :-)

------
phreeza
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.

~~~
ekianjo
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.

------
theboywho
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.

~~~
kposehn
> 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.

------
Animats
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.

~~~
nickbauman
> 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.

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

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

------
putlake
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.

~~~
vectorjohn
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.

------
reasonattlm
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/](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_Andrei
> _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.

~~~
reasonattlm
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.

------
Zikes
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_wot
Really? Which declaration in particular are you referring to?

~~~
Zikes
> 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.

~~~
chris_wot
Good point, missed those statements (forest for the trees I guess). Those are
quite unfortunate!

------
nickbauman
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...](http://www.amazon.com/Rare-Earth-Complex-Uncommon-
Universe/dp/0387952896)

~~~
yongjik
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.)

~~~
nickbauman
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.

~~~
yongjik
I think I wrote my argument rather poorly. Let me try again:

I could buy that Jupiter in our particular Solar System had the effect of
clearing asteroids in the Earth's orbit. However, that doesn't automatically
mean that Jupiter was essential. What if, say, Jupiter's presence in the early
days of the solar system prevented these asteroids from coalescing further,
resulting in the presence of the asteroids in the first place? Or what if it
didn't matter in the long run anyway?

Okay I just pulled that out of thin air, but what I'm saying is that there's
too many unknowns to declare we needed Jupiter for life. The authors cherry-
picks arguments that support their cause. Also bear in mind that this book was
written in 2003, when we knew less than a dozen extrasolar planets and, IIRC,
basically none looked like our Solar System (because the instruments weren't
good enough to detect such systems). Even now, I don't think we know enough
about planetary systems to confidently say whether Earth-like systems are
common or rare.

------
pklausler
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.

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

------
givan
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.

------
givan
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/Belgian_UFO_wave)

[https://en.wikipedia.org/wiki/Phoenix_Lights](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
I think its more likely the government was testing military equipment.

~~~
givan
> 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?

~~~
leppr
Do you think there used to be dragons roaming the earth?

~~~
givan
Do you still think the earth is flat? This is how it sounds when you try to
ridicule something that you don't know or probably don't want to know for
various reasons, you should read more on the subject with an objective mind.

~~~
leppr
I think the comparison with dragons is appropriate. Religion and talk about
hell and demons was in-vogue at the time so dragons fit in well with that. Why
did aliens wait for us to develop advanced technology before manifesting
themselves, and why did they stop now that smartphones and google-earth are
common-place things?

~~~
jdenning
> Why did aliens wait for us to develop advanced technology before manifesting
> themselves, and why did they stop now that smartphones and google-earth are
> common-place things?

The Prime Directive? :D

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

~~~
vectorjohn
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 :)

------
nsgoetz
So life won't always find a way?

