
The Fermi Paradox Is Not Fermi's, and It Is Not a Paradox - XzetaU8
http://blogs.scientificamerican.com/guest-blog/the-fermi-paradox-is-not-fermi-s-and-it-is-not-a-paradox/
======
careersuicide
What a timely coincidence. I just finished reading Cixin Lui's "The Dark
Forest" (it and the first book in the series "The Three-Body Problem" I cannot
recommend enough). I think the central premise of the book is probably the
worst of the possible reasons we haven't found anyone else out there...

"The universe is a dark forest. Every civilization is an armed hunter stalking
through the trees like a ghost, gently pushing aside branches that block the
path and trying to tread without sound. Even breathing is done with care. The
hunter has to be careful, because everywhere in the forest are stealthy
hunters like him. If he finds other life—another hunter, an angel or a demon,
a delicate infant or a tottering old man, a fairy or a demigod—there’s only
one thing he can do: open fire and eliminate them. In this forest, hell is
other people. An eternal threat that any life that exposes its own existence
will be swiftly wiped out. This is the picture of cosmic civilization. It’s
the explanation for the Fermi Paradox."

~~~
ucaetano
Except that we've been pumping radio waves out of this rock as loud as we can
for decades. We're the loud cousin who can't keep quiet when hunting.

~~~
guelo
And, if one civilization found another it would take massive amounts of
resources and time to launch an interstellar attack. I doubt humanity's first
reaction would be to embark on a giant project to somehow try to destroy the
other civilization. This idea makes no sense.

~~~
TrevorJ
I assume that because in this metaphor we are the baby. Reduce the scenario
to, say two small human villages that just discovered each other, and it's not
so hard to see how our tendency is to overrun and destroy, either by intention
or by mistake. That's certainly something that has played out over and over
again in our history.

------
ramblerman
> and since we don’t see any obvious signs of aliens here, searching for their
> signals is pointless.

That is a huge over simplification. The fermi paradox doesn't really conclude.
It is called a paradox because we need to solve the riddle that combined with
the drake equation it is awfully quiet in our universe, why is that?

If you have 20 minutes: [http://waitbutwhy.com/2014/05/fermi-
paradox.html](http://waitbutwhy.com/2014/05/fermi-paradox.html)

This is probably one of the best long reads on the internet dealing with this
question.

------
exratione
The real issue is not that we haven't been visited (for which read, we exist,
because the matter of the solar system wasn't turned into computronium by some
group billions of years ago), but that everything we see is a wilderness. All
of the observable universe appears natural in every place we can assess
whether or not it is natural. No dyson spheres in evidence, no class 3
civilization in any of the nearest 100,000 galaxies, etc, etc.

This makes no sense given that we exist, and the laws of physics show no
indications that we are a special case, or that transforming the universe into
intelligent matter is impossible. All it takes is one small group in one
species to create the self-replicating probes that dismantle every natural
grouping of matter to create more efficient arrangements to support more
intelligence, and on a small timescale compared to the age of the universe
entire galaxies are turned from wilderness to structure.

[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 that great span 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."

~~~
simonh
There are two main assumptions in those "where are they?" Scenario. One is
that self replicating probes are feasible and the other is that ots practical
for them to travel interstellar distances.

I think the problem of designing and building self replicating probes, capable
of recreating themselves from asteroidal matter, is greatly underestimated. We
currently have little to no idea how to design such a thing, and no real idea
what the lower bound on the mass of such a thing might be.

The next problem is nterstellar travel. The difference un scale between
traveling to the moon and travelling to a nearby star is about the same
difference in scale between throwing a rock down a typical garden and
launching astronauts to the moon. The Daudalus project did down good work on
this and their very modest proble of just a few tons, doing a flyby of a
nearby star, took a large to portion of the mass of Neptune to construct in
terms of fuel. The resources available in a typical planetary system might not
be up to the job.

I don't honk magic future technology hand waves these problems away. Any
future technology will have to work with the same elements on the same
periodic table we have now, manipulating the same physical forces we work with
now. We can't wish magic unobtainable into existence and the limits of what is
achievable with matter and energy are already pretty much computable.

So it really may well be that going sustainably interstellar might be
impractical.

~~~
poopchute
The mass number you through out (large portion of the mass of Neptune) seemed
really off to me so I looked it up and found some comparisons.

For a flyby: Daedalus mass = 5.0 * 10^7 kg (500 kg of scientific equipment)

With a slowdown to stay in the system: Daedalus mass = 10^10 kg

Mass of Neptune: 10^26 kg

So even for an extended stay, the mass of the Daedalus is no where close to a
significant portion of Neptune.

I looked for equivalent mass objects, here is a few:

1.4 * 10^18 = all oceans on earth combined

10^12 kg = 1.4km diameter asteroid (Icarus)

3.5 * 10^10 kg = 0.5 x 0.3 x 0.2 dimension asteroid (Itokawa)

Estimates put the number of asteroids larger than 1km diameter in the belt
between mars and Jupiter at 750,000

These are just straight mass conversions, no idea about the real content of
fuel. If all those asteroids were straight fuel then you could launch upwards
of a million Daedalus class ships that stay in the orbit of their target star.

~~~
simonh
I was thinking of the successor project, Icarus. It's not the mass of the
probe, it's the mass of the gas giant's atmosphere you need to process to
extract the Helium-3.

------
sjclemmy
This is not my understanding of the Fermi Paradox and I've never heard this
interpretation before. The paradox is; given the Drake equation, where is
everyone? That's all it amounts to, hence the paradox. The author of the
article states the paradox differently, that, because we can't see any
evidence, we shouldn't look. That is not the Fermi Paradox.

One of my favourite responses involves cryptography: Given a sufficiently
advanced civilisation, one might imagine that their ability to encrypt
information is perfect, therefore any signal is indistinguishable from noise.

~~~
rumcajz
See Stanislaw Lem: His Master's Voice
[https://en.wikipedia.org/wiki/His_Master%27s_Voice_(novel)](https://en.wikipedia.org/wiki/His_Master%27s_Voice_\(novel\))

~~~
sjclemmy
That's been recommended to me before, but I'd forgotten about it - I shall act
this time. Thanks!

I started to read Solaris, but found the translation stilted and difficult, so
gave up. I've just read that Lem himself didn't like the Rnglish translation!
It's unlikely I'll be learning Polish this lifetime.

------
bladedtoys
Another possibility is: they never feel like it.

It's possible intelligent species inevitably overcome/loose the desire for
infinite self replication.

It's clear other animals will breed to occupy all available habitats. But it
seems humans uniquely are developing the idea of the preserve in which
environments are intentionally left unoccupied. I have even heard a tiny
amount of talk questioning the impact of even a Mars landing. If that question
is already coming up centuries before interstellar travel, one wonders what
attitudes will be prevalent then.

Just a century ago it was quite desirable to intentionally release new species
of bird's into new continents purely for aesthetic reasons. Now such an
attitude would be abhorrent.

I suppose if one could demonstrate that the desire to endlessly replicate
across the universe is somehow beneficial to individuals currently living then
I imagine their values will embrace it. If endless self replication is not
beneficial to the exiting population then they will eventually reason their
way clear of that instinct and that reasoning will be integrated into their
ethical code.

So while I, like most people reading this, am very excited by space
exploration, that attitude may not be a permanent cultural characteristic.

------
cfcef
Fermi:

> ...technological civilization doesn’t last long enough for it to happen.”

Writer:

> Both York and Teller seemed to think Fermi was questioning the feasibility
> of interstellar travel— _nobody thought he was questioning the possible
> existence of extraterrestrial civilizations_

What happens when a technological civilization 'doesn't last long enough'? It
stops existing.

~~~
herbig
That's assuming a technological civilization's natural progression is towards
space travel, which may or may not be true. The Aztecs were way "behind" when
explorers first discovered them, but were doing pretty fine.

~~~
DasIch
Indeed and wouldn't they have been "interrupted" they very well might have
developed further towards space travel or is there anything to suggest that
they wouldn't have progressed further technologically?

------
joesmo
"The other is the so-called Fermi paradox, which claims that we should see
intelligent aliens here if they exist anywhere, because they would inevitably
colonize the Galaxy by star travel—and since we don’t see any obvious signs of
aliens here, searching for their signals is pointless."

Either this is worded wrong or illogical. If this is true, as it's worded now,
then we humans either do not exist or are not intelligent, by its very
definition. Both are ridiculous conclusions. The assumption is "because they
would inevitably colonize the Galaxy by star travel". What if they're not
advanced enough to do so yet? Does that make them not intelligent? If so, that
would make us non-intelligent. Does that prove aliens don't exist? If so, then
we humans are proven to not exist (which is ludicrous).

Finally the stupid conclusion: "since we don’t see any obvious signs of aliens
here, searching for their signals is pointless." So as a corollary, other
aliens searching for us would be pointless since we humans don't exist since
there are no signs of us on other planets.

This is incredibly stupid. No wonder Fermi never wrote it. He would never
write something this dumb.

------
ChuckMcM
I've heard this before, that Fermi was really questioning interstellar travel,
not alien existence. Given all the matter we've found in interstellar space,
from dust clouds to brown dwarfs, it seems pretty clear that travelling near
the speed of light out there would be perilous indeed. Even a small rock,
colliding with your ship travelling at .5c is going to destroy it.

------
pklausler
In a universe that is very old and very large, anything that can occur will
eventually happen somewhere. This includes the launching of interstellar self-
replicating von Neumann probes. All it takes is one civilization somewhere
lobbing one sufficiently automated sublight probe, and in a few million years
the galaxy is full of them for the rest of time. Either the galaxy is full of
interstellar self-replicating probes, or empty of them. Their absence here is
strong evidence that nobody, at least in our galaxy, has evolved a technical
civilization, and that we are the first or only to approach that level.

~~~
Chathamization
Not sure why you wouldn't just manufacture a bunch of probes in one system and
then send them out en masse. You wouldn't need to worry about creating self-
replication units, you'd get to each system more quickly (you wouldn't have to
deal with multiple accelerations/decelerations or manufacturing time), you'd
have more control (wouldn't have to worry about drone swarms and could inspect
each probe before it's sent to its destination), you'd probably have quicker
manufacturing (since it'd be done by specialist machines rather than hybrid
manufacturer/probes), could probably give the probes a boost form the home
system when you send them out, etc. Self replication doesn't seem to add much,
but certainly takes away a lot.

This is also assuming that aliens will want to scout out the universe, and
that probes are the best way for an advanced civilization to do so. We might
be like someone from the past who comes to the present and determines that we
don't have any long distance communication because they don't see any smoke
signals.

~~~
pklausler
You missed the point. I'm not arguing that civilizations would be likely to
launch self-replicating probes. What I am asserting is that the probes will be
out there UNLESS every single actor capable of launching a self-replicating
probe chooses to not do so, and that over billions of years and hundreds of
billions of stellar systems in the Local Group, that probability is
vanishingly small. All it takes is one launch; if it's possible, it'll happen.
And it hasn't. So either there's never been a civilization that launched a
self-replicating probe, or it's not possible, or we're the first or only
civilization to approach that level.

~~~
Chathamization
I don't know about that. Even if we're talking about a large sample size, can
we really say "that probability is vanishingly small"? It's kind of like
saying, "Sure, I don't see any reason why someone would build an underwater
city, but with a couple hundred countries in the world, and 7 billion people,
the probability that no one is going to do that is tiny."

But are we even dealing with a large sample size? Maybe there's "only" been
several dozen large interstellar civilizations out there, and a few hundred
small ones that never really got far beyond a handful of planets. Or maybe
there were a couple of attempts, but they failed horribly. The problem with
the "paradox" is that there seems to be a huge number of possible answers. It
ends up being "how come this one scenario I'm thinking about hasn't happened."

~~~
pklausler
Thinking about this paradox in terms of probabilities:

P(probes) = 1 - (1 - P(a civ can launch a probe)) ^ N(civ)

If we don't see probes, and if we don't think P(can launch) is exactly zero,
then N(civ) just has to be small.

EDIT: HN deleted my Fortran-style exponentiation.

------
acqq
Necessary read for reasonable discussion:

[https://en.wikipedia.org/wiki/Rare_Earth_hypothesis](https://en.wikipedia.org/wiki/Rare_Earth_hypothesis)

"the Rare Earth Hypothesis argues that the origin of life and the evolution of
biological complexity such as sexually reproducing, multicellular organisms on
Earth (and, subsequently, human intelligence) required an improbable
combination of astrophysical and geological events and circumstances. The
hypothesis argues that complex extraterrestrial life is a very improbable
phenomenon and likely to be extremely rare."

~~~
api
Bottom line is we only have one example. We simply do not know. For all we
know the frequency could be less than one per galaxy per billion years, in
which case we are likely alone.

~~~
cdelsolar
There are hundreds of billions? of galaxies though.

~~~
api
Intergalactic travel or communication is exponentially harder than
interstellar.

~~~
acqq
Exactly. As far as I know, except for the Andromeda galaxy, which will collide
with ours, all other galaxies zoom further away.

[https://en.wikipedia.org/wiki/Andromeda%E2%80%93Milky_Way_co...](https://en.wikipedia.org/wiki/Andromeda%E2%80%93Milky_Way_collision)

Far enough in the future, even if we survive, we won't see any other galaxy --
they will zoom out of our observable universe! The expansion of the Universe
accelerates, according to our last estimates.

~~~
skc
Wouldn't this imply that future generations may actually lose this history?

There would be no way to prove that another galaxy ever existed.

~~~
acqq
The universe is still "young enough" for galaxies to be close enough to each
other for a while. But yes, based on the current knowledge of the constants
that drive the universe, in some very distant future we can imagine some
potential civilizations that will be able to learn dramatically less about the
Universe than we already know now, their model will be: What's the Universe?
Only the stars around us, all in the group. What's behind them? Nothing.

In even more distant future, eventually the supply of gas needed for star
formation will be exhausted:

[https://en.wikipedia.org/wiki/Future_of_an_expanding_univers...](https://en.wikipedia.org/wiki/Future_of_an_expanding_universe)

In the exponentially distant future the Universe is going to get always more
and more boring.

~~~
skc
It's actually fascinating.

When future civilizations read "old" science texts it will be virtually
impossible for them to not think of them as crackpot science or fairy tales.
The idea of other galaxies ever having existed will have about as much
verifiable scientific evidence as the tooth fairy

~~~
acqq
The "Big bang" can't be proved anymore then too -- not billions of galaxies
all flying away from us, but just: nothing.

------
ck2
Given the sheer size of the galaxy, forget the universe, C is unfathomably
slow in comparison.

It's no wonder, at least not to my imagination why we haven't found any other
life yet, or visa versa.

~~~
cgriswald
_c_ may be slow relative to distances in space, but the universe is incredibly
old as well. A civilization a million years ahead of us could have colonized
the entire galaxy by now.

And in any case, if there is anyone out there, there should be _some_
evidence. Scientists have looked in various ways for megastructures ( _e.g._
Dyson Spheres) and have found no evidence for their existence, even in the
oldest of galaxies.

The picture in my mind is quite bleak. The evidence seems to point to a very
limited number of scenarios:

1\. We are unique (in existence, in our technology, in our desire to expand,
etc.) 2\. We are first. 3\. Civilizations destroy themselves before they can
expand. 4\. Civilizations do something else we don't yet understand that
doesn't involve gathering more and more energy from surrounding space.

~~~
ck2
Maybe such civilizations instead have value in limited reproduction and
doesn't have the need for colonies all over their galaxy and incredible
resource consumption.

Just because humans breed with no point or purpose and even invent religion to
insist on unmitigated population growth, doesn't mean that's a value shared
with a more intelligent alien race.

If anything, there is proof that more educated humans breed far less than
their counterparts. Extend that further and imagine a planet the size of earth
with only a few million sentient life forms. They might not feel the need to
leave, outside of general exploration, but even then they might just use
probes.

~~~
cgriswald
Which points to either our uniqueness (1) or our not understanding their alien
motivations (4).

A few points I'll make for fun:

1\. Life on Earth propagates as much as possible. It is only external factors
(mostly resources, but also predation and other factors) which keep
populations in check. This is likely a shared trait of all (successful) life
in the universe. This doesn't preclude the possibility of a species moving
beyond this trait* but it does suggest that either the trait fails at some
point prior to stellar engineering or interstellar colonization or that _all_
advanced civilizations move beyond it.

2\. Even if spreading throughout the universe is not a species' goal, whatever
their goals are will require energy. It is likely those goals will require
greater and greater energies as our own goals have and will continue to do for
the foreseeable future. The only way I see around this problem is novel
physics which seem impossible in our current understanding of the universe.

3\. At some point every species must leave their host star or perish.
(However, if they find themselves around a red dwarf, they will have quite a
bit of time - and will not have to have moved since the beginning of the
universe. So it may be we are freaks because we are around a shorter-lived
orange star.)

But this is speculation at best. I'd rather speculate that they all created
their own pocket universes that are ideally suited to their species and left
the rest of us behind. :)

*Although I would suggest that natural selection is an unlikely candidate for the development of such a trait. In my opinion, this would require directly modification of whatever passes for DNA in the species. Even enforced population controls would probably not be enough to contain a species.

~~~
ck2
You're going off the deep-end for fantasy when you start saying "pocket
universes". Even dyson spheres are an exponentially advanced civilization
problem, not just for energy but for material to build it from.

To achieve frequent non-robotic travel beyond a solar system, a species would
have to first master unlimited "free" energy (ie. fusion). This seems to be an
extreme non-trivial problem. Even a civilization tens of thousands of years
ahead of us may not have mastered it on a portable scale, limiting their
travel and making "home" far more comfortable.

And again, with unlimited energy, they still might not even feel the need to
leave their solar system except for basic exploration, they might be
xenophobic.

If the spark of the dna for virtually all life on earth maybe came from
somewhere else, injected into our potent primordial soup, perhaps it happened
when the galaxy, even the universe was closer together so it didn't have to
travel so far. But now the few other "cousins" of life we have in the
galaxy/universe may be too far away simply from the expansion of space itself,
not just big-bang momentum.

------
kordless
A better measure of whether there is other life in our universe might be the
percentage of us which really believe, at our very core, we are the only life
in a vast universe we understand less than the soil we tread on each day.

It can't be a paradox if you know you can change the question.

------
pinkrooftop
I'm skeptical on looking for radio waves. How could interstellar intelligence
use radio waves to communicate anyway, they're traveling at C and are still
too slow

~~~
nine_k
Interstellar intelligence can still travel at time frames much longer than
human life.

It's like complaining that a letter from America to Europe would travel for
many months in 1495. There were still incentives for Europeans to go to
America.

~~~
pinkrooftop
Even our own plans for such a thing included lasers not radio
[https://en.wikipedia.org/wiki/Project_Longshot](https://en.wikipedia.org/wiki/Project_Longshot).
Still not solving communication speed limits

~~~
pavel_lishin
I think the previous commenter was saying that the communication speed limits
may not be a problem that can be, or needs to be, solved.

If the speed of light is the ultimate speed limit, technological civilizations
may just have to accept it and work within that limit. Just because a method
of communication is slow doesn't mean it's not worth using.

~~~
DasIch
If that limit can't be broken, it would massively slow down space travel
though. Our civilization currently consumes more resources than can be
replenished. What if other civilizations have the same problem and can't
travel to other planets before resource starvation comes in?

~~~
krapp
> What if other civilizations have the same problem and can't travel to other
> planets before resource starvation comes in?

They probably die.

~~~
nine_k
Traveling to other _planets_ is relatively easy; in our system it takes just a
few years using the cheapest chemical boosters + ion engines. A nuclear rocket
engine (quite feasible) would probably lower the travel time noticeably.
Communication delays in the range of a few hours maximum are not a significant
problem either.

It's traveling to other _star systems_ what is hard.

OTOH we live in a relatively sparsely populated neck of galactic woods;
thicker clusters of stars exist with much shorter interstellar distances.
Conditions there are usually deadly for us, though.

------
guelo
Our civilization has had radio communication for 100 years but we're well on
our way to environmental collapse within the next thousand years. The milky
way is over 100k light years wide. By the time our signals reach any other
potential civilizations we'll be long gone. If the average civilization
broadcasts for a thousand years but they're tens of thousands of light years
apart, communication is not be possible within a civilization-span.

