
The Big Alien Theory - miralabs
http://www.thebigalientheory.com/
======
TheOtherHobbes
>No matter what degree of variability is chosen, alien planets are very
unlikely to be much larger than the Earth. To be specific, we can say with 95%
confidence that another planet with intelligent life, such as our nearest
neighbour, will have a circumference no more than 20% greater than that of the
Earth.

Huh? I see no justification for this.

I'm firmly in the "We know nothing about aliens and won't until we get some
hard data" camp.

Alien life will, by definition, be alien. We have no basis for assuming it's
even going to be recognisable as life.

Life essentially seems to be a persistent self-reproducing dissipative
structure that responds to evolutionary pressure. There is nothing in the
manual that requires liquid water, gravity, a planetary surface, carbon, or
any of the other ingredients that define life on Earth.

~~~
JoeCoder_
> There is nothing in the manual that requires liquid water, gravity, a
> planetary surface, carbon, or any of the other ingredients that define life
> on Earth.

On carbon, this is from [a recent Astrobiology
textbook]([http://books.google.com/books?id=x83omgI5pGQC&q=%22there%20m...](http://books.google.com/books?id=x83omgI5pGQC&q=%22there%20may%20very%20well%20be%20only%20a%20single%20element%22))
which probably does count as a manual : )

"There are, after all, only a finite number of elements in the periodic table,
and many of these are very poorly suited to support life for any of a fair
list of reasons. Consequently, many of the 90-odd naturally occurring elements
can be ruled out. So many, in fact, that in the end there may very well be
only a single element--carbon, the basis of all life on earth--that is able to
support the complex chemistry presumably required to create any self-
replicating chemical system. The easiest way to appreciate the special,
perhaps even unique, qualities of carbon is to compare it with silicon, its
closest cousin.

Many of the properties that suit carbon so well to its central role in
Terrestrial life are shared or even exceeded by silicon. For example, silicon,
like carbon, is tetravalent--that is each atom forms four bonds, allowing for
the formation of a rich array of complex molecular structures. And, while
silicon-silicon bond is weaker than a carbon bond, the discrepancy is only
about 25%. Consistent with this, both silicon and carbon can form long
molecular chains, For example, compounds of silicon and hydrogen, called
silanes, with up to 28 consecutive silicon-silicon bonds have been reported in
the scientific literature. Likewise, while carbon is the fourth most common
element in the Solar System as a while, silicon is many orders of magnitude
more common on the surface of Earth. Indeed, silicon is second only to Oxygen
in terms of its abundance in the Earth's crust. Nevertheless, silicon simply
cannot support the same rich chemistry as its "upstairs" neighbor in the
periodic table. The problem lies in both the thermodynamics (equilibrium
stabilities) of silicon's interactions with other atoms and the kinetics
(rates) of these reactions...

So carbon wins over silicon. But what of the 90 or so other naturally
occurring elements? They fare even worse than silicon."

~~~
aagha
> "There are, after all, only a finite number of elements in the periodic
> table..."

That's because we've only discovered or figured out how to make a finite
number of them. Is there a reason that other (alien) elements can't exist that
we've never been exposed to?

~~~
Analog24
The structure of elements/atoms is well understood based on their subatomic
constituents. Naively, you might think that can you just keep combining
increasingly larger numbers of electrons, protons, and neutrons to create new
elements. However, the stability of an atom becomes problematic when the size
of the nucleus approaches the interaction length of the strong force (i.e. the
nucleus is too large for the strong force to hold it together). These elements
are unstable and therefor not relevant as far as organic chemistry is
concerned.

Furthermore, the formation of elements in the Universe is also a fairly well
understood process. For elements lighter than Fe it generally occurs through
nuclear fusion in the center of stars. For elements larger than Fe it
generally occurs through the r-process and s-process. With these we can model
nucleosynthesis extremely well and it gives us a very good idea of the
elemental composition of the Universe. That being said, there could be some
crazy unknown element out there but it would contradict almost everything know
about atomic physics.

~~~
nknezek
Good answer, but I think you mean Fe, not Pb.

~~~
Analog24
Good catch! It has been corrected in my comment.

------
zby
So they do something like this: Let's choose a human in random - he is more
probable to be from Pakistan than from Slovakia. (OK) Now let's choose a
country - now an average country like Slovakia is more probable than a country
as big as Pakistan. (OK)

So if you are a human - then it is most probable that you live in a country
that is more populous than the typical country. (OK)

Now they say - ok - so now instead of choosing humans let's do the same thing
with sentient beings. If you are a sentient being it is more probable that you
live on a planet where there are many other sentient beings rather than on a
planet that there are few of them. But if you go to some random planet with
sentient life - then the expected number of sentient beings there would be
average.

Then it goes on that "Physically larger species will on average have lower
population densities." \- so most probably the random alien planet will have
fewer and larger sentient beings than us.

I don't know if I buy that whole argument - but I am too lazy to write the
bayesian equations to nail it down.

~~~
leblancfg
My only gripe is that he's only used vertebrates in his dataset (based on
[http://journals.plos.org/plosone/article?id=10.1371/journal....](http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0078733)).
It's "only human" to include close members on the phylogenetic tree, but I see
it as a flaw.

What if our imaginary aliens are plant-like, squid-like, or something we can't
even begin to fathom, like symbiotic unicellulars? Sentient, self-replicating
machine clusters the size of planets? Take a minute to think about this.

I think his conclusion should then have been worded like: the random alien
planet will have fewer and larger VERTEBRATES than us. And that's a probably
very meaningless conclusion.

I'm not saying his intuition is wrong, though. In fact I quite like it. But in
this scenario, I don't think "whatever remains, however unlikely" lifeforms
can even begin to be imagined by our tiny little human brains.

~~~
wrsh07
The statistics really doesn't care what type of sentient species we are.

If you're confused by the examples given [for the approximate size], that's
understandable, but the examples don't change the analysis. That's like saying
"All of the countries in the example are in the northern hemisphere, so the
analysis is flawed."

~~~
mombul
Well yes the location of the country doesn't matter, but that's not at all
what he said. He said that it's all based on vertebrates which is ridiculous.
We can't begin to imagine what type of life form constitutes an alien, and if
what we'll ever find will constitute a life form as we know it.

We know what a country is. And there's very (very, very, trust me I'm an
engineer) little chance we'll find new countries with characteristics unknown
to us...

~~~
wrsh07
My point is that the initial discussion wasn't limited to anything except
"sentient life." It wasn't limited to vertebrates or mammals or any such
thing.

Thus, the statistics are purely for the discussion of "what should other
sentient life look like?"

Finally, it's ridiculous to complain in a discussion about aliens "that we
can't begin to imagine what type of life form constitutes an alien." You have
to make some fundamental assumptions. For instance, we should be able to
assume that they obey the physical laws of the universe.

Anything else puts you in a totally unscientific world of discussion [your
claims are no longer falsifiable], and that's not one I care to participate
in.

~~~
leblancfg
>[W]e should be able to assume that they obey the physical laws of the
universe

I don't think anyone is assuming otherwise... all I see is statistics and
sampling being argued. You'll have to endure my wall of text, though, sorry
XD.

Let's take the planets again. We don't know the size of every single planet in
the galaxy (i.e. the planet size histogram), so we need to make a guess. So
we've been using Kepler's exoplanet observations, knowledge of planetary
geology, etc. to fit a model, and it's well developed
([http://exoplanetsdigest.com/2014/07/25/exoplanet-
statistics-...](http://exoplanetsdigest.com/2014/07/25/exoplanet-statistics-
and-demographics-update/)). The size distribution is quite well understood,
its bounds and modes are well defined. It's unlikely that our best guess of
what the average size of exoplanets is will change drastically the more we
know about planets. _That_ is why the article's first conclusion is
legitimate.

Now back to (sentient) species, and my original point. The definition of life
in the SETI context has to be VERY wide. It has to encompass any scenario for
a species that we might consider "intelligent" \-- and not just little green
men. It might have (some would say, inevitably) evolved beyond the biological,
and still be considered sentient. After all, life on Earth has only existed
for ~4By, compared to ~13By for the Milky Way. As a base for extrapolation,
just think how different to humans extreme life on Earth is.
([http://www.livescience.com/13377-extremophiles-world-
weirdes...](http://www.livescience.com/13377-extremophiles-world-weirdest-
life.html)) In any case, there are bound to be some weird-as-shit species out
there, whose composition still obeys the laws of physics. In other words,
there is almost certainly many _statistical modes_ of life out there that are,
or can become, sentient.

With that in mind, there's a very good chance that the overall size
distribution of (sentient) species does not match the one the author used
(that of vertebrates only). In statistics-ese: if the distribution is
multimodal, the average of our unimodal sample is not a good guess as to what
the true average really is.

Maybe we can agree upon that?

------
Gravityloss
This is a bit like the sleeping beauty paradox. [1] We have to be careful what
we're sampling.

Is it individuals or civilizations?

An average civilization will be average sized. An average individual will
belong to a larger-than average civilization.

It's also a bit like the problem that in average, your friends have more
friends than you do. (That's easy to understand. It's because they are not a
really random sample of all people. People with more connections are over-
represented in your friends.)

If we assume that observation doesn't depend on civilization size, then we're
sampling civilizations, and on average would find average sized civilizations.

If we assume that we observe individuals and not civilizations, then we're
sampling individuals and are likely to see individuals of a big civilization.

Now, if I look at myself, if I'm a random sample from all individuals in the
galaxy, it's likely that I'm part of a large civilization. That would mean
other civilizations would on average be smaller than mine.

If I look at my civilization, and assume it's a random sample from all the
civilizations in the galaxy, it's likely that it's an average sized
civilization. A random other individual in the galaxy would be likely from a
larger civilization.

I don't think either way of thinking is really justified.

You can extend this to a doomsday argument by the way. Since I am alive now,
it's most likely that most people are alive now. Hence in the past and in the
future, there will be less people alive.

1:
[https://news.ycombinator.com/item?id=10149286](https://news.ycombinator.com/item?id=10149286)

~~~
jstanley
This is good reasoning.

Can you expand on the "waking amnesiac problem"? Google is coming up with
nothing.

~~~
Gravityloss
Edited the original to include the actual name, sleeping beauty paradox.

------
garbage_stain
"Not even wrong". This entire analysis is built on reasonable statistics which
are predicated on dubious and unprovable assumptions, which invalidate the
entire thing.

Consider "the size of alien species". Okay... so we are extrapolating about
the size of beings we know nothing about based on those beings that have come
to existence in our particular situation? Assuming that the distribution of
weight across animals on Earth is the same as the distribution of weight
across beings in the universe is dubious.

This is a wonderful example of Brandolini's law.

~~~
jak1192
That is not an example of Brandolini's law. It took a whole website to spew
the bullshit but only 3 or so sentences for you to refute it.

~~~
klue07
garbage_stain is only refuting a very small part of the entire website.
Imagine the amount of effort to properly refute the entire website addressing
each BS point.

------
bitdeveloper
I'm unclear on why the author posits that we should assume a smaller
population necessarily means the average being will be larger.

For example, if a human did this thought experiment 2000 years ago - a blink
of the eye in the scale we are talking about - we would have perhaps
500,000,000 humans on the planet, or something along those lines. We have 14x
as many humans now.

Yet we have not shrunk in size as the species has grown in population, and if
anything, have grown larger.

If we look at the total biomass on earth, we are a fairly small portion of it.
So shouldn't we assume, as we are assuming our situation is average, that
intelligent aliens are also a fairly small portion of their planet's biomass?
And if so, wouldn't the size of the aliens themselves be something that has
very little to do with the total energy reaching the planet surface?

I get that it's just statistical probability and math, and it's fun, but this
particular thing stuck out for me.

It was a fun read regardless, so thank you for the break from work!

~~~
wrsh07
They actually respond to you in the FAQ:

> "What if people who lived several centuries ago did a calculation on how
> many births there would be?"

> This appears to be one of the most widespread misconceptions on the topic.
> Many scientists have fallen into this trap, such as Lee Smolin's article
> from 2004 . In science there is never absolute certainty, only varying
> degrees of confidence. We should never be 100% sure of anything. When
> stating the degree of confidence in a result, typically 95%, it should be in
> full knowledge that one time out of twenty, we will be wrong. 5% of the time
> we will be misled by statistical chance.

> Now if someone who lived tens of thousands of years ago estimates the total
> number of human births, based on how many there had already been, they will
> underestimate the truth. Because we now know there has been many more. But
> those first 5% of people who ever lived represent the 5% of the time we
> expect to be wrong. This is a basic premise of how science functions, how it
> uses statistics. We must be wrong some of the time. In reality, we are wrong
> much more frequently than statistical chance suggests, because of human
> error or misunderstanding.

~~~
codys
> several centuries ago

> tens of thousands of years ago

This appears to be blatantly moving the goal posts.

> those first 5% of people who ever lived represent the 5% of the time we
> expect to be wrong

This implies that for only 5% of human history the calculation would be wrong,
and the reset of the time it would be 100% correct.

I'm not sure that is how statistics work.

~~~
fergussimpson
That's exactly how statistics works.

You make a statement with some degree of confidence (often 95%) and fully
expect to be wrong 5% the time.

------
gibrown
Interesting use of inference. Kinda feels like it ignores many of the
discussions (or my limited understanding of them) around the Fermi paradox
[http://waitbutwhy.com/2014/05/fermi-
paradox.html](http://waitbutwhy.com/2014/05/fermi-paradox.html)

In summary: "We’re rare, we’re first, or we’re fucked."

The article seems to assume that there are lots of populations just because
there are lots of planets. But the time that those planets have been around
matters too.

~~~
kirykl
That's only if there's a great filter though

~~~
JumpCrisscross
There's no accepted resolution to both Sagan's posited frequency of life and
Fermi's paradox other than filters.

~~~
hodwik2
I would argue that this article posits a new, compelling filter.

If most species are large, and from small planets, they will have much
stricter resource constraints than we did.

As a result, they are unlikely to have industrialized the way we did, as it
would have depleted their resources too quickly. As a result, they are
unlikely to be a silicon-age species.

Drawing from the author's biological/size argument, they're likely to have
longer lifespans than we do, and considerably fewer births.

Given their resource constraints, and longer lifespans, they are likely to
have strong communal systems of resource allocation, and are unlikely to have
moved towards Capitalism.

Given their longer lifespans, they are probably more risk averse than our own
species -- as willingness for an animal to die is strongly related to size and
lifespan. This suggests they may be less war-faring than ourselves, and thus
less likely to have nations.

Given their closer relationship with nature, due to their resource
constraints, they're likely to have developed a Pagan system of thought,
rather than a monotheistic theology.

As a result, they are unlikely to be motivated towards large infrastructural,
imperial or technological projects as a result of: profit motive, national
motive, or religious motive.

I'd argue then, that it is unlikely they have produced a civilization of
significance.

\--

Long story short; local alien species are likely to be tribal, communist, non-
technological, and environmentalist.

If through some strange force a species of this kind managed to become
technologically advanced, they would likely look down on a species such as our
own as a sort of vermin, because of our numbers, hunger and short lives.

~~~
kirykl
interesting view that bypasses a great filter. Advanced without technology.
Highlights that technology really might be an anti-pattern.

But Carl Sagan would probably refute that - "It is perfectly possible to
imagine civilizations of poets or (perhaps) Bronze Age warriors who never
stumble on James Clerk Maxwell’s equations and radio receivers. But they are
removed by natural selection. The Earth is surrounded by a population of
asteroids and comets, such that occasionally the planet is struck by one large
enough to do substantial damage." [http://gencodesignal.info/the-abundance-of-
life-bearing-plan...](http://gencodesignal.info/the-abundance-of-life-bearing-
planets/)

~~~
hodwik
To be clear, I'm not arguing they'd become advanced. I'm arguing they'd never
become advanced.

I think the Drake Equation solution that Sagan proposes puts values that are
orders of magnitude too large for most variables. In this case fi (where he
confuses intelligent life with civilization) and fc.

------
anotheryou
I can't wrap my head around the "we should expect to be in a large group".

We, as a single species, found to the question "is there alien life besides
us?". I'm no individual independent from the culture of our species. I don't
come up with this question randomly, you pointed me to this today.

The other way around: I have to expect to be in the large group only, if the
large group makes it more likely that someone in it has questions about his
group (more members -> more random thoughts -> greater total of thoughts about
which group one is in). This is true for blood types (unless people with weird
blood types commonly get in to issues making them wonder about their blood
type...). But for aliens, probably either more or less all wonder collectively
through cultural exchange, or it wasn't part of a public debate.

Hm, you get the knot in my brain? can you solve it?

~~~
phreeza
I do get the knot. My gut feeling would be that the definition of an
individual in this case is "an entity that is capable of independent thought".
So if all our thoughts as a species were perfectly in sync (borg-style), we
would count as a species of population 1. Because of cultural exchange, one
would probably have to count us as a species of effective size less than that
of the actual population size.

------
pi-err
Great thought experiment.

I would have thought that a planet's life form, shape and variety would be
determined by:

1- the energy output of nearest star

2- the planet's gravity

He barely mentions gravity which is surprising. Earthlings probably wouldn't
be as tall with 1.3x more gravity. Maybe life wouldn't even have made it out
of water, or much more slowly.

Evolution would mean "heavier" eggs would be harder to carry. The entire
evolution process hangs around reproduction so what would that mean?

Same for less gravity - except it would _probably_ be on a smaller planet.
Gravity correlates with planet size in the solar system. Would <0.8G be enough
to retain water, atmosphere, etc?

Somehow I'm not surprised to find out one day that an intelligent alien life
would look a lot like us, on a planet that looks a lot like Earth.

~~~
1812Overture
They'd look a lot like us except they'd all be 1930s gangsters or ancient
Romans.

------
oconnor663
> Within the context of the animal kingdom, our species' position is clear.
> Aside from a disproportionately large brain, we're fairly ordinary mammals.

Oh yeah? :)
[http://prokopetz.tumblr.com/post/57702943181/mikhailvladimir...](http://prokopetz.tumblr.com/post/57702943181/mikhailvladimirovich-
bogleech-its-funny-how)

------
chmike
This analysis is based on many unjustified assumptions. I don't think we can
go reliably very far on this route.

However, I do think that we can scientifically study some aliens today, or
more precisely what we can see from them, through the UFO phenomenon. Yes,
that thing! For me the only paradox in the Fermi paradox is that the UFO
phenomenon is boycotted as a manifestation of Aliens on earth.

The following three articles are a product of such study. They present a new
electromagnetic propulsion system called PEMP inspired by the data of UFO
observations. It also present a totally innovative method to produce the
intense EM fields required by this propulsion system. These are currently only
theories waiting for an experimental validation. The author is a physic
theorist, not an experimentalist.

"Pulsed EM Propulsion of Unconventional Flying
Objects":[http://www.meessen.net/AMeessen/Propulsion.pdf](http://www.meessen.net/AMeessen/Propulsion.pdf)

"Evidence of Very Strong Low Frequency Magnetic Fields":
[http://www.meessen.net/AMeessen/Evidence.pdf](http://www.meessen.net/AMeessen/Evidence.pdf)

"Production of EM Surface Waves by Superconducting Spheres: A New Type of
Harmonic Oscillators":
[http://www.meessen.net/AMeessen/Production.pdf](http://www.meessen.net/AMeessen/Production.pdf)

So there is no need to speculate. Just open your eyes and look at the data we
already have for so many years.

Note that this is the product of an inductive research process. The initial
working hypothesis was that UFO are real and witnesses report real data on
them. Now see if we can derive a valid propulsion system matching the
described artifacts using only conventional physics law.

It was initially a test, an experiment on a pure theoretical ground. The test
is apparently conclusive. We now have a theory we can test in our lab and we
could validate a disruptive discovery.

Objectively, we still don't know if UFOs are real and they are aliens visiting
earth. But we now have an opportunity to indirectly test that possibility with
pure solid ground science and engineering. Thanks to these theories.

~~~
smaddox
Poe's law?

~~~
chmike
I'm very serious.

Is that all you have as "argument" ?

Supposing you referred to my comment on the big alien theory, as a biologist,
I would say that this pure statistical analysis ignores the possible existence
of yet unknown factors that could modulate the probability of existence of
alien civilization of different size, planet size or intelligence.

This is why I concluded that this work is based on a pure speculation that
these unknown factors don't exist. I didn't say this work is false or bad. I
said it won't move us reliably forward on this research topic.

------
marcus_holmes
I don't get the stats here:

\- I am an ordinary sentient being (for the sake of argument... just nod)

\- I am a member of an ordinary species.

according this theory one of these statements is wrong.

~~~
wrsh07
Analogy time:

\- I am an ordinary human

\- I live in an ordinary country

One of these is wrong, and it's the second one.

~~~
marcus_holmes
yeah OK that makes sense.

So what about:

\- Humans are an ordinary species

\- Humans live in an ordinary galaxy

Does that change our relative height?

~~~
wrsh07
I see what you're trying to do, but it doesn't work. Our arguments need to be
like the Doomsday argument, presented here: [https://what-
if.xkcd.com/65/](https://what-if.xkcd.com/65/)

If most species looked at themselves and said "my species is ordinary" the
majority of them would be right; however, it doesn't give you any statistical
reason to think that _humans_ are ordinary.

~~~
marcus_holmes
that was fascinating, thanks :)

The counter-intuitiveness of it all is really intriguing. We really are
evolved to think in small numbers.

------
matheweis
Serious question; why are people willing to seriously entertain the idea of
aliens, but not gods?

~~~
Grishnakh
First, you probably need to define "god". Does a biological being like us but
with extremely advanced technology count? Or do they need to be able to exist
beyond conventional physics and have apparently limitless power in our
universe, like Q? Or do you mean specific gods, namely the ones which various
groups of humans worship?

If it's #1, those are just aliens. If #2, I don't think you can discount the
possibility entirely, but there's no evidence for their existence, but it's
entirely possible. But spending any energy on the question seems a bit
pointless, since no members of the Q Continuum have made their presence known
to us yet. If #3, the problem there is there's no good evidence for their
existence, only ancient stories passed down from oral tradition, and the old
"telephone game" shows how reliable that is, plus the well-known phenomenon of
hallucination, which can happen to people when they eat certain tainted foods.

The question of aliens is worth considering seriously because we do know that
life is possible (look in the mirror), we know under what conditions if can
form (look outside; we have a planet to study that formed life), and now we
know that lots of other planets are out there, and some of them may very well
be similar to our own. If we can evolve here, it's quite possible some other
beings evolved elsewhere under similar conditions. And with many billions of
stars out there (just in our galaxy and nearby ones), the probability of other
planets existing with conditions similar to ours is high. Furthermore, as our
ability to detect exoplanets improves, it's quite possible we may detect signs
of alien life: radio signals, industrial emissions in their atmosphere, weird
starlight patterns indicating a possible Dyson swarm, etc. There's no way to
detect any kind of god (whether it's one from some old book or the Q).

------
catpolice
I think some of the math going on here is interesting and probably has some
interesting consequences for people's expectations about means. But I'm not
sure about that paper...

I want to be generous here and assume I'm misunderstanding, but it does seem a
bit like the argument begs the question a bit.

The intended conclusion is that we should consider non-earth-like (i.e. non-
earth-sized) planets as just as likely to be inhabited as earth-like planets.
Which is to say that we shouldn't expect that population density is strongly
correlated with planet size.

And this is shown starting from a model where "mean population density is
invariant to planet size". Hmm...

------
Touche
Something not mentioned here is the relationship between oxygen levels in the
atmosphere and the size of animals on a planet. During the era of giant
creatures (dinosaurs) the atmosphere was around 35% oxygen, today it is about
21%.

------
Houshalter
This strikes me as very similar to the simulation argument. That is most
beings probably exist in simulations, and therefore you are far more likely to
exist in a simulation than be a living person. Or similar anthropic arguments
could be made about many things. You are more likely to be living in a bigger
country, you are more likely to be living in the period of time where Earth's
population is the largest, etc.

------
GrantS
Interesting analysis, but after reading the FAQ at the bottom, it rests upon
quite a few important hidden assumptions. For example:

>However if there is any hope of finding life on other planets, there must be
a huge number of planets with life in the Universe. Therefore, for the case
we're interested in...

So during the entire analysis, we were limiting ourselves _only to those
universes in which we do make alien contact_ , regardless of how likely _that_
event is.

------
gone35
Reminds me of Joe Polchinski's calculation[1] that the probability of the
multiverse is 94%.

Unbridled Physics-ism (as in [2]) and Bayesianism definitely don't mix well.

[1]
[http://www.math.columbia.edu/~woit/wordpress/?p=8149](http://www.math.columbia.edu/~woit/wordpress/?p=8149)

[2] [https://xkcd.com/793/](https://xkcd.com/793/)

------
tbabb
What is the process by which "samples" are drawn from the population of
intelligent beings? This is a keystone of the article's argument, but it
entirely hand-waved. It is not as if "intelligences" are created in the void
and then assigned with some random distribution (uniform or otherwise) to
bodies on planets-- each intelligent being in the universe is itself with
probability 1.

------
joeyspn
A couple of weeks ago I read a more compelling theory, that also is an
interesting solution for the Fermi Paradox. It said something like this IIRC:

The normal evolution of a civilisation of smart species is to arrive to a
point where they experience an Intelligence Explosion [0]. (or how Elon Musk
puts it: _Chances are we 're the biological boot loader for digital
superintelligence_) [1].

In a cosmic scale, given the fact that the timespan to go from industrial/high
technology civilisation to a SuperAI is like a drop in the ocean (1000 or 2000
years), it'd be impossible to establish contact unless they co-exist at the
same point of evolution, in the same (or near) star system, and in the same
period of time.

Something far from probable...

I think that this is the most plausible solution for the Fermi Paradox, we
haven't been contacted by Aliens for the same reason that we haven't
"contacted" with ant colonies or microbes. We simply can't, we're in a
different state of consciousness.

We are probably living among Aliens, but they're too advanced for our
reasoning and live in a different dimension/cosmic state.

[0]
[https://en.wikipedia.org/wiki/Intelligence_explosion](https://en.wikipedia.org/wiki/Intelligence_explosion)

[1]
[https://twitter.com/elonmusk/status/496012177103663104](https://twitter.com/elonmusk/status/496012177103663104)

------
gmaslov
Couldn't a hypothetical Big Alien make exactly the same argument? There are
plenty of exoplanets larger than Earth.

~~~
wrsh07
Of course they could. And they should! Statistically, if every single sentient
being makes this argument, more sentient beings will be right than wrong.

To quote:

> Given the prevalence of the four different blood groups in the cartoon
> above, the most profitable strategy here would be to bet on "A", as that
> gives you the greatest chance of winning. Another way of looking at it, is
> that if everyone adopted that strategy, the bookmaker would lose the most
> money.

------
ccvannorman
This article strikes me as a man who lives entirely inside a black and white
room insisting that if he thinks hard enough, he can infer what colors in the
world outside are like.

It is true though, that if you spin a black and white patterned disk, you will
see colors.

~~~
mesozoic
It's more like he can say what the colors outside the room are PROBABLY like.

------
aab0
This essay would benefit from making the particular anthropics used like the
Self-Sampling Assumption explicit (and the paradoxical implications of it
which leads to rejection by many) and explaining examples like the Doomsday
Problem.

------
mixedbit
In 'Solaris' by Lem the whole planet is an alien life form.

------
frechtoast
What is less worthwhile for a person to think about than the existence of
aliens? Sure, solve world hunger, figure out inter-space travel, light-years
distant communication mechanisms, prevent cancer, war, poverty.... Last I
checked, aliens weren't threatening the continuation of our species, or even
leaving the lid up after a visit to the john for that matter.

How did this tinfoil-hat ridiculous article even make it into Hacker news!?

~~~
guard-of-terra
If aliens are indeed to be found, this will readily become number one
important event in human history.

~~~
frechtoast
I bet!, And if a meteorite strikes my home and kills me, that will be the most
important event in my life. Nevertheless, I've got more pressing issues than
to debate the statistical likelihood of the size of the rock or it's expected
mineral composition.

~~~
nickcano
Yes, and those more pressing issues are among spending time debating why it's
not worthwhile to spend time debating a topic that is less pressing than the
debate about the time it takes, apparently.

------
JumpCrisscross
Why isn't the conclusion "our population size is the most frequent" versus
"largest"?

~~~
rory
I think he's approaching it from the assumption that a sentient being should
assume itself to be a random individual out of all the sentient beings in
existence, across all sentient species.

~~~
JumpCrisscross
Doesn't that ignore the obvious (and known _a priori_ ) correlation between
sentient beings in a species?

------
srcreigh
The idea of interplanetary species seems to invalidate this website in one
fell swoop.

------
andrewclunn
Wrong. We have no notion if we are more or less populas than other species, so
we should assome that we are one of the many smaller (in number) by virtue of
that being the more common, thus drawing the exact opposite conclusions.

~~~
deciplex
That's what we should expect to see when looking for other _planets_ with
intelligent life. But _you_ , andrewclunn, should expect to live among one of
the more populous species.

~~~
andrewclunn
That's the point, from the individual's perspective the correct prediction is
completely contrary to that from the species' perspective based on this
approach.

~~~
deciplex
Right. So _you_ , the individual reading the article and posting on HN, should
expect to live among one of the more populous species of life in the universe.

e: Maybe you are implicitly assuming that the workflow for "determining" who
you are born as goes: 1. pick a random species 2. pick a random individual in
that species. But it's more like: 1. pick a random individual.

------
tronje
Please, for all our eyes' sake, change the color of the font to something
darker! Light-grey on white is just terrible.

~~~
fergussimpson
Thanks, I've fixed it now!

~~~
tronje
Thank you! I didn't mean to come across as overly critical, but I really think
it is a much nicer reading experience now. Very cool that you considered my
criticism :)

------
frechtoast
I'm of the opinion that life doesn't exist elsewhere. That said, I don't care
enough to even try to support my own bias. I'm not going to spend time trying
to get anyone to believe either way, because we've got bigger issues right
now. Aliens aren't here, starvation is.

How did this ridiculous tinfoil-hat article even make it into Hacker News!?

~~~
drdeca
Is it tinfoil hat? I was not under the impression that it was suggesting any
sort of conspiracy or anything.

Even if the arguments it makes are wrong I'm not under the impression that
they are particularly kooky.

