
Model predicts we're the only advanced civilization in the observable universe - sidcool
https://www.universal-sci.com/headlines/2018/6/22/new-model-predicts-that-were-probably-the-only-advanced-civilization-in-the-observable-universe
======
frisco
So, I read this paper and was pretty unconvinced. I think the premise of using
a Monte Carlo analysis is flawed because _of course_ multiplying together wide
~iid distributions that have big near-zero components asymptotes to zero;
unless I'm misunderstanding something, this is essentially the central limit
theorem. (All of the parameter samples below 1e0 drag the total outcome
towards zero since probabilities are bounded >= 0) Thus, the real information
is still strongly dominated by beliefs about the width and centering of the
distributions, which we still don't know, and as long as enough of the
parameters have high uncertainty with some potentially having near-zero
values, the result will always tend towards zero.

I think what this analysis tell us is that if you don't think it's possible to
get better, more specific values for the parameters, the Drake Equation is
just a bad tool.

Also, the Drake Equation doesn't describe the number of alien civilizations,
it describes the likely number of civilizations. Thus, extremely pessimistic
estimates have to somehow correct for the fact that we know N is not zero,
since we are here. That seems like a highly informative update that is not
addressed in an interesting way.

~~~
bambax
Yes, the Drake equation seems quite pointless because multiplying many
unknowns by one another doesn't reduce uncertainty, it increases it. I don’t
know anything about the history of the Drake equation, but it looks possible
it was devised to demonstrate the unknownability of the result, rather than a
tool to help find it.

Also, the article seems to use "our galaxy" and "the universe" as
interchangeable terms, which of course they are not.

I don’t see how the Fermi paradox is a paradox: given the distances involved
and what we know about the speed of light, an alien civilization would have
had to develop a very long time ago in order to send signals that we would be
able to detect today. Just because, maybe, no civilization was able to do that
a billion years ago doesn’t mean nothing happened since (as you say, at least
we happened).

We just don’t know.

~~~
raducu
Actually Fermi's paradox makes total sense to me:

\- Presume that even with something like travel at 1% o speed of light, the
Milky Way is colonizable in a couple of million years.

\- Presume that we are not special at all and there exist more technological
advanced civilizations that predate us by at least a couple million years

\- Presume such a large scale colonization would be easy to observe

If you accept the 3 presuppositions, the only logical conclusion is that there
are no other technologically advanced species in the Milky Way or that we're
the first(very unlikely).

Or you can choose to attack any of the presuppositions, but that's also very
hard in my humble oppinion.

~~~
TheOtherHobbes
I suspect your second and third points contradictveach other.

We literally have no idea what a >10^6 more advanced civ would look like.

There’s a kind of parochialism about these arguments. They seem to assume that
aliens will be flying around the galaxy communicating by radio in big metal
boxes or giant rocket powered rocks looking for planets to xenoform.

But in the same way that ants can’t see a human city around them, it’s
possible humans will see no evidence of an advanced civ that isn’t doing any
of the things we expect technology to do.

~~~
kulu2002
These can be very stupid questions; but I always ponder over it 1\. Is this
our assumption that extra terrestrial life will have same chemistry/ biology/
consciousness as human beings? 2\. What is definition of Life and Intelligence
for E.T life. The phenomenon what we call life can be completely different for
E.T. being. This is more or less same as que 1 3\. It seems we have also
assumed that our civilisation is advanced. In terms of what? Is our definition
of advancement (and also civilisation) applicable to E.T life? 4\. Consider a
highly advanced civilisation millions of light years away from us finds
Pioneer plaques. Even after finding these plaques they don't (wish to ;-))
communicate with us... does it mean that civilisation is not sufficiently
advanced?

~~~
raducu
Technologically advanced.

Meaning: likes to explore, accumulate knowledge/understanding, harness the
laws of physics for its own betterment/pleasure.

------
sunstone
Possibly, but not the way to bet. Live appeared on Earth very soon after it
started to solidify. That would tend to imply that starting life was pretty
easy or, life arrived by some kind of panspermia mechanism. There is a next to
infinitesimal chance that life started very quickly by some kind of once in
billions of years magical circumstance.

To go from life to beings like humanity it's pretty clear that intelligence
tends to increase as life goes on. For example some birds so exceptional
abilities and they are dinosaurs according to most current understandings.
Octopus can be remarkably clever and their lineage split from the "animals
with backbones" line long before there were animals with backbones. Nerves and
nervous systems seem to have been reinvented by evolution several different
times.

Putting this altogether, it seems there's an excellent chance that primitive
uni-cellular life evolves pretty readily and multi-cellular animals tend
towards increased intelligence soon there after.

There's an assumption that "advanced civilizations" will be communicating with
TV and Radio because that's the best we've got. On average most advanced
civilizations would have had their technology for much more than 150 years and
very likely communicate with methods we are not aware of yet.

So when it's asked "Where are they?" the answer is they are out there, talking
up a storm, they're just not still using electromagnetic "smoke signals" to do
it.

~~~
BjoernKW
The question is: What could they possibly be using instead of some sort of
electromagnetic signals?

There are only a limited number of fundamental forces in the known universe
(unless our current understanding of physics is completely wrong), not all of
which lend themselves to being used for long-range communication.

Gravity possibly could be used as a means of communication but I suppose it’d
be rather slow and have a low bandwidth.

Some sort of quantum entanglement-based form of communication might be
possible though that contradicts our current understanding of how information
can be transmitted in the universe.

So, barring some fundamental shortcut such as Star Trek subspace, there aren’t
too many options for interstellar communication.

~~~
colechristensen
Why not expect new physics we simply don't have the tools to see yet? Maybe
something that only shows itself at very high energy or interacts only with
neutrinos or antimatter or some exotic matter that isn't produced with fusion
or supernovas.

What about beings that operate at very different time scales? What if there is
some encoding scheme that blows our information theory out of the water so
communication just looks like white noise?

What if evolution converges to a single shared consciousness or fierce
independence and communication just stops being interesting after a certain
stage? Or if non-interference is the very well enforced law of our corner of
the galaxy?

I think it's hubris to think that we know the answers to all of the questions
for physics or at least we know what we don't know. My assumption is that
there are questions/problems/phenomena that we don't even have the context yet
to imagine.

~~~
majewsky
> What if there is some encoding scheme that blows our information theory out
> of the water so communication just looks like white noise?

You don't even need a new encoding scheme for that. Compressed data looks like
white noise unless you know the decompression algorithm.

~~~
gus_massa
A signal with compressed data does not look like white noise. It looks like a
sine or cosine wave that is around a well defined frequency, and the
intensity/phase/frequency changes from time to time. The hops may look random,
but the carrier signal is easy to spot.

If they use frequency hoping, the changes in the frequency are even more
regular. It's more difficult to measure the exact signal, but all the hops are
inside an interval.

~~~
sliken
You are describing FM, which does dump quite a bit of power into the carrier
wave.... which is exactly why it's not used if you care about
range/efficiency.

Check out things like "Olivia_MFSK" on wikipedia for something more current.
It can transmit even with 14dB below the noise floor.

Seems like a any sane communication method for any galaxy spanning
civilization would be: * encoded in such an advanced way that we wouldn't see
it, even if using signals within our physics. * be highly directional

Maybe something like 1% of the asteroid belt would be converted into
communication sats that could form a swarm that would over a few ns
significant outshine the sun by focusing a signal on whoever you want to
communicate with.

Of course typically the cloud of sats would be handling within the solar
system communications or nearby stars that didn't require the entire cloud.

I do wonder if you could capture say 0.01% of the solar radiation for 24 hours
and with 50% conversion frequency generate a single for 1 ns on the ideal
frequency... could you outshine the galaxy on that frequency?

Of course the ideal frequency would be minimally blocked by dust and minimally
generated by stars. The "Water hole" as mentioned by Seti (among others) would
be a good start.

------
andbberger
Why is this even still a question... every single time you boil a pot of water
convection rolls form. According to equilibrium thermodynamics it is
vanishingly improbable that Avogrado's numbers worth of molecules will
conspire together to act in a coordinated fashion to form those rolls... yet
it happens every time.

The convection rolls win out over diffusion because they dissipate heat faster
and there is only so much heat. Life is no different. A structured low entropy
process that dissipates energy faster than diffusion - there's no paradox or
anything about emergent complexity.

The fundamental concepts here are pretty simple and any discussion concerning
P(life) need to start by understanding what life is in the first place and how
it can arise.

Point being: life isn't a rare thing or a mystery, anywhere in the universe
you find energy gradients you'll find life.

There just isn't a conversation to have here. If we're alone it's because
we're first. But we are almost certainly not alone. The universe is just
really fucking big.

~~~
em3rgent0rdr
Just because "a structured low entropy process that dissipates energy faster
than diffusion" will win out every-time doesn't answer the question about how
a self-replicating structured low entropy process will form in the first
place. Once life starts then it will explode, but the problem is how to get
life actually started.

~~~
millstone
Perhaps life is easy to start, but is also easily out-competed by non-living
self-replicating organisms.

~~~
kaffeemitsahne
"non-living self-replicating organisms" Sounds like a contradiction to me ;)

~~~
bmc7505
Lots of things are self-replicating that we would not consider "living".
[https://en.wikipedia.org/wiki/Self-
replication](https://en.wikipedia.org/wiki/Self-replication)

------
krob
How would someone living in the dark ages look for intelligent life if they
can't imagine the existence of wireless communications beyond a mythical
transference of thoughts from human to human. Most of this is theoretical, but
all it proves is our lack of understanding is still ever present, and we're
all still just a bunch of ignorant fools trying to make sense of it all. I
think we should just focus our energy into bigger things, and allow the
technological breakthroughs as they will come with time. We just have to put
our focus on bigger better & more interesting pursuits and stop blowing people
up. Stop destroying civilizations, and start to accept civilizations as they
exist. The more we destroy ourselves the harder it becomes for us to overall
advance enough people to create the ever necessary brain trust of the planet
to build these new sophisticated technologies to maybe one day find a way to
decode what was once maybe thought non-existent. Maybe neutrinos are already
used to communicate from light-years away, we just don't have enough advanced
technology to decode it. We're not there yet, maybe we need fusion technology
before other technology makes more sense to us, maybe fusion technology is
what brings us to insane speeds in space that we cannot replicate currently
since we haven't mastered it yet.

Once again, we argue about the unknown, and only create factions of people
hating on others who don't realize they're just ignorant.

~~~
pattisapu
"Stop destroying civilizations, and start to accept civilizations as they
exist."

Civilizations, as they exist and have existed, unfortunately, appear almost
inevitably to involve war.

~~~
erikpukinskis
Do they though?

~~~
pattisapu
Nah.

------
Arubis
While it may be based on what is technically fiction, my views on the Drake
Equation were modified to include a “caution in outbound communication factor”
of fairly low probability after reading Cixin Liu’s “Dark Forest”.

SPOILER ALERT for prior novel: it convincingly argues that, due to the
impossibility of trust across otherwise unrelated civilizations, the rate of
technological progress in any given civilization compared to the speed of
travel between star systems, and the long-term understanding that resources
are limited, and outgoing communication to another intelligent civilization
inevitably results in attack and likely elimination of said civilization.

~~~
peatmoss
Indeed this feels like the most satisfactory explanation for the Fermi
paradox. I’m just starting on the third book, and am starting to think the
eye-popping $1 billion that Amazon is rumored to be paying / have paid to
allow them to make this into a TV series might not be entirely insane.

------
jcims
Shouldn't the title be '..humanity may be the only _detectable_ advanced
civilization..'?

After all, the last two terms of the Drake Equation are all about
detectability, and what are the chances that a civilization outside the Milky
Way would emit a signal that we could possibly detect? Just slapping a couple
of internet calculators together, you'd get about 500dB of loss from Andromeda
(our closest galactic neighbor) to us, requiring a 1x10^41 watt
omnidirectional emission for us to receive a nanowatt signal. This is within a
few orders of magnitude of a supernova. Even if you were to focus the beam,
the transmitting civilization would likely scorch planets within a couple
hundred light years just to say hi.

The paper seemed to inconsistently pepper 'detectable' into the language and I
lost interest before trying to figure out whether or not it included those
terms (fc and L) in the final conclusion.

~~~
em3rgent0rdr
Yeah. Also the successful advanced civilizations might not even be emitting
any signals at all.

~~~
jcims
Exactly. The 'L' term at the end (length of time advanced civilization is
transmitting detectable signals) may be a very small window for most
civilizations.

Energy is precious. If you have the technology to put the signal where you
want it to be, why would you spew it all over the universe?

~~~
pattisapu
Good points--but you might still spew out your signal out all over the
universe if you were still searching for advanced life.

------
rmm
From the article;

>In the end, the team’s conclusions do not mean that humanity is alone in the
Universe, or that the odds of finding evidence of extra-terrestrial
civilizations (both past and present) is unlikely. Instead, _it simply means
that we can say with greater confidence – based on what we know – that
humanity is most likely the only intelligent species in the Milky Way Galaxy
at present_.

~~~
itronitron
>> we can say with greater confidence – based on what we know

if I know nothing, then I can say a lot of things with greater confidence,
especially if I couch the statement with 'based on what we know.'

~~~
woogiewonka
Had exact same thought. "Based on what we know (which is not enough), I can
say with greater confidence" ^^ oh really?

------
tbodt
The paper that this article is based off of was posted on HN a few days ago:
[https://news.ycombinator.com/item?id=17302924](https://news.ycombinator.com/item?id=17302924)

Direct link to paper:
[https://arxiv.org/abs/1806.02404](https://arxiv.org/abs/1806.02404)

------
Sniffnoy
I'm going to repost the same comment I've made on this several times already:

This is quite interesting. It certainly sounds like this does dissolve the
Fermi paradox, as they say. However, I think the key idea in this paper is
actually not what the authors say it is. They say the key idea is taking
account of all our uncertainty rather than using point estimates. I think the
key idea is actually realizing that the Drake equation and the Fermi
observation don't conflict because they're answering different questions.

That is to say: Where does this use of point estimates come from? Well, the
Drake equation gives (under the assumption that certain things are
uncorrelated) the expected number of civilizations we should expect to detect.
Here's the thing -- if we grant the uncorrelatedness assumption (as the
authors do), the use of point estimates is entirely valid for that purpose;
summarizing one's uncertainty into point estimates will not alter the result.

The thing is that the authors here have realized, it seems to me, that the
expected value is fundamentally the wrong calculation for purposes of
considering the Fermi observation. Sure, maybe the expected value is high --
but why would that conflict with our seeing nothing? The right question to
ask, in terms of the Fermi observation, is not, what is the expected number of
civilizations we would see, but rather, what is the probability we would see
any number more than zero?

They then note that -- taking into account all our uncertainty, as they say --
while the expected number may be high, this probability is actually quite low,
and therefore does not conflict with the Fermi observation. But to my mind the
key idea here isn't taking into account all our uncertainty, but asking about
P(N>0) rather than E(N) in the first place, realizing that it's really P(N>0)
and not E(N) that's the relevant question. It's only that switch from E(N) to
P(N>0) that necessitates the taking into account of all our uncertainty, after
all!

[Note afterward: Over on Reddit, hxka points out that that should be P(N>1),
not P(N>0). Or really it should be P(N>1|N>0)...]

~~~
rzimmerman
I think this hits the real point. The expected value of the number of advanced
civilizations may be high, but that could mean a very small probability of
billions of advanced civilizations complemented with a very large probability
of zero, one, or just a few.

------
mbfg
Let's cheat. Let's say that there's another Earth out there with human beings
on it. Let's say they've been producing electrical noise for 200 years like
us. Where would planet Earth #2 have to be in order for us to notice it?

~~~
adamcharnock
I like this approach, but I don't think I like the answer.

If Earth 2 has been producing noise for 200 years, that gives us an upper
bound of 200 light years. However – for general terrestrial traffic – our
detection range is only about 1 light year [1].

There are also no stars within that distance from Earth 1. So, at current
levels of technology, Earth 2 would have to be a sad star-less frozen ball
that just happens to drift into our neighbourhood within the appropriate 1
light year window on its eons-long journey.

Given that, I think we got the best deal here on Earth 1.

[1]
[https://physics.stackexchange.com/a/245562/4602](https://physics.stackexchange.com/a/245562/4602)
(the author does mention interesting caveats regarding directional
transmissions though)

Edit: s/200 window/1 light year window/

~~~
mbfg
Exactly. Now remove the restriction that Earth #2 is active with life at the
same time we are. Instead intelligent life existed 10 billion years ago. Now
we've got a tiny band of space 10 billion light years away where that planet
has to be located where we could have possibly detected it. It doesn't seem
that unlikely that we haven't found intelligent life.

~~~
vkou
The point of the paradox is that if intelligent civilization is only active
for 200 years out of a 10 billion year timespan, there is something seriously
wrong with the survival rates of such civilizations.

~~~
JoeAltmaier
Or, they became something different, not worse. For example, Victorians would
have looked silly to scan the skies for aliens by looking for soot clouds in
their atmospheres, because all 'civilizations' would have steam trains.

We're looking for radio waves. Radio waves! Like a million-year-old
civilization wouldn't be communicating with nano-soliton-pulse masers across
interstellar distances. And to receive one of those, earth's orbit would have
to accidentally cross its path, and then only for an instant. The chances are
trillions to one, and we wouldn't recognize it if it happened.

------
andy_ppp
You can write a model for things you can't measure if you like, but how can
you know the accuracy of it or if it can predict future (impossible)
measurements. It's almost nonsensical to try, unless some alien civilisation
comes along with the data I don't see the point.

~~~
minor3rd
The title is also clickbaity, since the conclusion is really just that "we
can't deduce much of anything... yet".

------
Pxtl
> Claiming long-range settlement or communication are impossible requires
> assuming a surprisingly low technology ceiling. Whatever the answer is, it
> more or less has to be strange.”

Considering the terrifying energies required for launching anything useful
interstellarly, this quote is a bit off.

I'm perfectly capable of believing that there is a tech ceiling preventing
useful interstellar travel.

~~~
adrianN
Roughly a century after discovering powered flight, we are pretty much capable
of building spaceships that can reach Alpha Centauri in roughly 100 years.

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

Single digit percentages of the speed of light are not that hard to achieve,
but would probably be sufficient to launch some von Neumann probes (or
generation ships) and start colonies.

~~~
labster
You are the children of a dead planet, EarthDeirdre, and this death we do not
comprehend. We shall take you in, but may we ask this question--will we too
catch the planetdeath disease?

\-- Lady Deirdre Skye, "Conversations With Planet"

~~~
dirkc
Now I want to play Alpha Centauri all over again!!

------
geebee
It seems like we have an equation with a bunch of variables that are either
extremely close to 1 or extremely close to zero. And really, these variables
seem to group together into two essential variables, which are either almost 1
or almost 0. And we're trying to figure out whether, when you multiply them
together, you get almost 1 or almost 0.

So, what does (almost_1 * almost_0) equal? It requires more knowledge about
"almost" than are able to obtain.

~~~
ambrop7
From a purely mathematical perspective, without respect to the topic, almost_1
* almost_0 is almost_0 (example: 0.999 * 0.001 = 0.000999).

~~~
geebee
You’re absolutely correct, f(almost_1,almost_2) should not be “times” in the
calculation I described. Or alternatively, it should be a massive number times
a tiny number rather than almost 1 and 0.

------
listenallyall
Let's say we absolutely found another advanced civilization, and in fact
somewhat close, reachable in just 500 years. Let's assume we can build a
rather large spaceship, say the size of the Empire State Building, and can
fill it with enough food and fuel for the journey.

My question, what are the ethics of sending humans on such a trip? It would
take 15 to 20 generations of human beings, living their entire lives confined
to a prison, to complete this journey. An absolute nightmare of an existence,
to be entirely disposable except to procreate in order to produce more
prisoners like themselves for a few hundred more years. And when the ship did
arrive, the living passengers would not be Earthlings, in the sense they would
have little idea about the Earth, none would have ever been there or know
anyone who had. We could provide them with every book, movie, etc that ever
existed but they would still have no Earth-bound experiences. And it would
likely depress them greatly, seeing and hearing things they will never
experience. And finally, why would we expect anyone to ever return, to
"complete" the mission? Their choice would be to make the best of life on
their new planet or to once again volunteer for this bleak, suicidal journey
to get back to Earth.

Some may say that future tech, or ultra-advanced VR, or cryogenics, or
"downloading" brains and sending inert bodies, may make such a journey
possible, but no answers sound very convincing, in my opinion.

~~~
summerdown2
> It would take 15 to 20 generations of human beings, living their entire
> lives confined to a prison, to complete this journey.

From a link given by a poster in another comment, earlier, you can do it at 1g
acceleration for just 12 years subjective time:

[http://convertalot.com/relativistic_star_ship_calculator.htm...](http://convertalot.com/relativistic_star_ship_calculator.html)

... so from the look of it, the difficulty isn't having a generation ship,
it's having sufficient fuel to produce the acceleration.

~~~
fhars
The problem with that argument is that a constant acceleration of 1g is an
astronomically huge acceleration (for comparison, it corresponds to the
surface gravity of a stone-and-iron ball with a whopping 12000km in
diameter!). The most extravagant system on
[https://en.wikipedia.org/wiki/Interstellar_travel#Non-
rocket...](https://en.wikipedia.org/wiki/Interstellar_travel#Non-
rocket_concepts) has a maximal acceleration of 0.3g.

------
phront
It may be that an advanced civilization doesnt last long. So it is possible
that we are somewhere on the very big graveyard.

------
ramblerman
For anyone interested in the various competing theories to explain the fermi
paradox, waitbutwhy did a fantastic piece on this:

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

------
SteveNuts
I don't know what's a more terrifying thought; we're alone, or we're not
alone.

~~~
Spartan-S63
Additionally, the thought that we're not alone and we're not the most advanced
species. If that's the case, then why haven't a more advanced species made
contact yet?

~~~
adrianmacneil
The answer to this is very obvious:

For the same reason that humans have not "made contact" with ants.

Why do you assume a higher intelligence would even be capable of making
contact with us on a level we understand? The discussion would be meaningless,
in the same way that an ant would not comprehend our desire to build a freeway
right next to their ant hill.

~~~
pdonis
That just rephrases the question to: Why hasn't a higher intelligence built
their equivalent of a freeway right through our ant hill?

~~~
adrianmacneil
An ant cannot "see" not comprehend the purpose of a freeway, no matter how
hard we might try to explain it. It would walk right over it and not think it
were any different than your average rock.

~~~
pdonis
Sure, but that doesn't change the fact that the ant's ant hill gets destroyed
if the freeway is built over it. Or that the ant itself gets crushed if it
gets run over while walking across the freeway. The ant will notice those
things even if it doesn't understand what caused them.

~~~
adrianmacneil
Exactly. Thus far, all we can say for sure is that we have not yet been
carelessly crushed to make room for some intergalactic freeway we do not
understand.

That doesn't mean there isn't one right in front of our eyes though.

~~~
pdonis
_> That doesn't mean there isn't one right in front of our eyes though._

If there were, I would expect us to be carelessly crushed in a short period of
time.

------
the6threplicant
I love the Drake equation.

It's like the shortest shorthand for "Where is your civilisation at?"

If you go from left to right, each value determines where you are in the
history of galactic civilisations:

R* : you need to understand galaxies and star formation (1930-70s)

fP : you need to have space telescopes (we are here) ne : we'll probably have
this number in the next 10-20 years

fe : might need at least 30 years before we can detect life via atmosphere
spectroscopy

fi : 100 years, maybe?

fc : same as above but with more time since we need more than one other data
point

L : we're at a Star Trek level civilisation - we know of each civilisation's
Shakespeare and Einstein, their history etc. Now we can learn how long
technological civilisations last.

------
everdev
The whole basis seems to be picking a range of values for the variables in the
Drake equation rather than a single value for each variable. As a result, the
variance multiplies significantly meaning that they find a 30% chance we're
alone in the galaxy as the lower end of the deviation (and the higher end
being the common notion that there should be abundant intelligent life
everywhere we look).

I hope they didn't spend too long making this "study" of tossing conservative
estimates into a theoretical equation.

------
ravenstine
On a bit of a tangent from the core content of the article and the discussion
here, I take issue with how easily even the smartest of people will take one
example of a phenomenon and extrapolate the frequency(or replicability) of
said phenomenon. All we really know about life, as we define it, is that it's
_possible_ to occur, because we're here, but we don't have any actual
information about whether we're a fluke or an unknowing part of a greater
community of intergalactic life. Pointing to billions and billions of stars
and saying "there must be life out there" is unfounded at this point because
we still aren't even close to understanding exactly how life came to be on
Earth, as well as why it happened when it did. What the equation of predicting
life is missing is the variable of time; without having at least two examples
of life occurring independently, there's no way that I'm aware of that we can
come up with a useful probability of life occurring anywhere. That is, unless
we can create simulations to test theories outside of real time, which will
probably be a required next step in science for getting a better understanding
of our universe.

------
abakus
It doesn't matter whether we are alone or not. The speed limit is so slow, the
dilation is so quick, we will never be able to contact.

------
specialist
Believe but cannot prove:

Intelligent life on Earth is (effectively) unique. By "intelligent", I mean
capable of purposefully leaving our gravity well.

Residing in the goldilocks zone isn't enough. There needs to be external
forces causing constant adaptation. Otherwise life will reach an equilibrium
and evolve no further.

Our Earth has seasons, plate tectonics, periodic mass extinction events
(asteroid strikes). Other less frequent causes are likely nearby supernovae
and possibly our galactic arm passing thru a gamma radiation beam.

Even with constant evolution forcing habitats, a galaxy faring intelligence
will be rare. As someone else noted, our saurian ancestors didn't stumble upon
a tool building transmissible culture. There's just so many prerequisites.

Compare us to the octopus, likely the next most potent intelligent being on
Earth, and certainly alien (to us). They are frikkin brilliant. But they
unfortunately have no way to transmit, share their knowledge. And their life
spans are probably too brief, birth rate too low.

------
booleandilemma
Does anyone have any book recommendations that are similar to the content in
this comment thread? (speculation on alien life, and such)

~~~
arto
Stephen Baxter's "Manifold" trilogy deals head-on with the Fermi paradox:

[https://en.wikipedia.org/wiki/Time_(Baxter_novel)](https://en.wikipedia.org/wiki/Time_\(Baxter_novel\))

------
kprostyakov
Interstellar 'biomes' would operate on much slower clocks. Human perception
time-scale of ~1s is mandated by fast-paced ecosystem of our gravity well.
Maybe we just not had enough continuous data in ~50 yrs ~ 10e10s to recognise
intersystem channel modulation as such. Economy cycle phase shift across the
civilized area cant be much bigger than cycle duration, so for inter-system
distances of ~1 ly we are looking at 10^6 years (1 a.u. @ 1 year financial
year for humans right now). Any real economy involving Mars will already
showcase the need for much slower finance clocks and longer plans than we have
in current economy. I guess cryptocurrency clocks will split into temporal
tiers according to systems served by that time.

------
makkesk8
Have we seen any proof of life out there? Well, no... So if there's an alien
race out there that's at the same level of technology as we are, could they
prove that we exist? Well no...

Let's think about that for a second, because to me, it's too early to tell
since we don't possess the necessary technology for interstellar travel or any
other technology that could prove it. And no other alien race might not
either. Since we simply don't broadcast our location to half the galaxy that
we exist we can't expect another race to it.

Finding something that might not want to be found has proven to be tricky and
I think drawing the conclusion that there's no other advanced life out there
is arrogant at best.

~~~
ben_w
From what I’ve read, we do have the technology, but not the desire to spend so
much money on what would be a vanity project with no return on investment
possible due to the timescales involved. Especially as we expect our costs to
come down and our early ships to be overtaken.

An alien civilisation with our technology and a million year headstart,
trivial compared to the age of Earth, would have had time to build a K3
civilisation. (Assuming you can call things with that sort if time lag “a
civilisation” rather than “a collection of civilisations the size of a K3”).

------
ianamartin
My pet theory about Fermi’s paradox is that there was only ever a very brief
moment in the history of our civilization where attempted contact was
politically and socially viable.

Think about the Voyager project right now. Assembling a rep sample of all of
human existence onto a single golden record and including the instructions to
decode it in math.

This. Could. Never. Happen. Today.

No one could agree on what to include or exclude or how to execute it. There
was an incredibly brief window of opportunity where we had the technology and
the social capacity to reach out to interstellar neighbors.

There are tons of other civilizations close by us. They just missed that very
tiny window of a chance to say hello.

------
riazrizvi
> Instead, it simply means that we can say with greater confidence – based on
> what we know – that humanity is most likely the only intelligent species in
> the Milky Way Galaxy at present.

The article is light years away from its title.

------
huffmsa
Didn't read it, but that it's taken us ~4 billion years on this rock to git
gud enough to send interstellar transmissions, it's probably taken other civs
that long (because we have no evidence to the contrary).

Given that we're looking at systems thousands to millions and if "visible"
literally billions of light years away, even if they beat us to interstellar
radio, we're still getting messages from them which are hundreds, thousands,
millions and billions of years old.

So they might be there just like us, but the Pony Express can only run so
fast.

------
themagician
Almost all of these models assume that an "advanced civilization" must have
language and radio astronomy and I've always felt that's a rather odd set of
parameters. It's completely possible that we haven't found anyone else because
we are looking for the wrong things.

We are looking for ourselves in the stars and fail to realize that we aren't
"it". We may not even be the most advanced species on Earth.

When all the dolphins rise out of the ocean and into the sky maybe then we'll
realize, but it will be too late.

------
dharma1
We've had EM comms for 100 years. Let's assume life, and civilisations capable
of sending comms beyond their solar system have emerged multiple times during
the history of the universe.

If civilisations have a shelf life (for whatever reason) and don't exist
indefinitely, it's extremely unlikely the timespan of someone transmitting and
us receiving would overlap during those 100 years.

Chances of existence/comms overlap are tiny even for the next 1 or 10 million
years - even if Earth origin civilisation is still around then.

------
rgomez
Yep. The ugly truth: We are kind of alone out there. There's no one, or
there's no one who wants to openly communicate with us, at least not yet. Get
over it.

------
tigerBL00D
The title of this post if completely wrong. The article rather specifically
states that:

 _In the end, the team’s conclusions do not mean that humanity is alone in the
Universe, or that the odds of finding evidence of extra-terrestrial
civilizations (both past and present) is unlikely. Instead, it simply means
that we can say with greater confidence – based on what we know – that
humanity is most likely the only intelligent species in the Milky Way Galaxy
at present._

------
sliken
If we started the colonization of the galaxy in the year 2500 with 10 planets
I suspect we would just wait and see if we came across a society with the
level of technology we have today. After all, why take the risk of meeting a
war like society that lobs nukes at each other?

Just leave a few probes nearby to keep tabs on them and see if they advance to
a level that's interesting.... or scary.

------
turdnagel
I've seen that we search for exoplanets with life by using spectral analysis
to estimate the temperature, atmospheric composition, etc. of these planets,
and seeing whether or not they fall within a range that is similar to Earth's.
I wonder if it would also be instructive to search for planets who exhibit
signs of a man-made apocalypse, like massive nuclear fallout.

------
grigjd3
The Drake equation gets too much attention in the popular press . First, the
selection of factors is an arbitrary choice of basis that may not relate to
what we can measure and second, we don't have good ideas of the values of most
of those factors. It's a mental exercise and useful for showing certain
concepts, but not a prediction based on observable data.

------
woogiewonka
I have always had a sneaking suspicion that the time scale on which we seek
answers is far too narrow for answers to be found. Is it not likely that the
period during which advanced civilizations actually exists is so short that
they never cross each other's paths? I mean, if this were the case, wouldn't
it throw the entire Drake equation out the window?

~~~
caf
That's the "L" term in the Drake equation.

And indeed one of the oft-mooted possibilities is that L is quite small.

Which is a bit of a worry.

------
fipple
Amazing how uncomfortable humans are with ignorance. Are we alone or not in
the universe? Is there life after death? Is existence infinite? _We 'll never
know._ I wish we could be OK with that. "I don't know" is a toxic phrase for
leaders to utter, so they prevaricate and confabulate.

~~~
king_nothing
Spirituality, to the self, is largely a mechanism to sweep dukkha and its
pointlessess, and lack of nuance in messy, real-world, imprecise
interpretations under a rug of happy-clappy self-/mutually-reinforced
delusions, blissful pseudosimplicity and sentimentality.

The big, unanswerable questions include:

1\. Reincarnation: yes/no?

1.5. If yes, are we all one or are there multiple perception entities?

2\. Why are you you and me me? (1. asks “am I and you the same?” implicitly)

3\. Does cognitive dissonance allow “good”-self-image people to live with
their committing unspeakable horrors?

4\. If cancers’ semi-“life” existence can be explained by increasing a host’s
entropy, why don’t most “pathogens” improve a host’s fitness, enable the host
to find, store or expend more energy, reproduce and extend the host’s
lifespan? Since when thr host dies, the cancer dies.

5\. Is there an absolute limit of entropy?

6\. How much neural complexity is needed for self-awareness?

7\. Does global intelligence have a maximum useful upper limit?

8\. If each piece of a person were systematically-replaced with inorganic
parts of close overall function, does the individual retain rights of an
organic person?

8.1. Could they be sued for healing or modifying themselves because of
intellectual property?

8.2. Could they be legally owned, bought, sold, etc.?

------
rvn1045
life forms are just collections of atoms from a few elements. these elements
exist all over the universe, no reason to think they would not have somehow
combined to form life forms else where. I personally don't like the attitude
of thinking we are alone in the universe.

------
VvR-Ox
This is a lie and you all know it!

That's just like in the old days when people used to think that earth would be
the center of the universe.

Prove it or go on with this theory, I don't want to hear it anymore until this
mystery is solved!

------
sidcool
Elon Musk replied to this one:

[https://twitter.com/elonmusk/status/1011083630301536256?s=19](https://twitter.com/elonmusk/status/1011083630301536256?s=19)

------
z3t4
We are currently looking for smoke signals. We need to find a loop-hole in
quantum theory and exploit it to send and listen for signals that wont be
affected by the distance between the sender and receiver.

------
posterboy
Instead, should a model not aim to reach 0.5 probability, because we really do
not know. Fermi Paradox or Drake equation express rather wishful thinking more
than anything else.

------
billforsternz
Being alone in the galaxy and being alone in the universe seem to be casually
equated but are vastly different in every possible way (except perhaps any
practical consequences).

------
lord_ring_111
May be may be not. I wish my teachers would have accepted such answers in my
high school

------
ezioamf
We could just be a pet civilization from an nearby advanced civilization that
blocks all signals coming to us.

------
interfixus
The author seems possessed of a fairly creative unwillingness to spell the
name _Sandberg_ correctly.

------
didibus
Curious what a similar model would show if applied to earth pre the discovery
of the other continents.

------
viach
After reading the "The Three-Body Problem", I think it might be not that bad
news after all.

------
089723645897236
Not enough data to make this conclusion in any actionable way.

------
semasad
Elon Musk is not sure about this:
[https://twitter.com/elonmusk/status/1011082171170242560?s=21](https://twitter.com/elonmusk/status/1011082171170242560?s=21)

------
daodedickinson
What do you even mean by "we"?

------
cvaidya1986
What a comically arrogant species.

------
jlebrech
observable by us

------
oooooof
That means that Trump is the most powerful person in the universe.

