

Why Astronomers and Journalists should pay heed to Biologists about ET - roberthahn
http://praxtime.com/2013/11/25/sagan-syndrome-pay-heed-to-biologists-about-et/

======
Glyptodon
The Milky Way is around 100000 light years wide. Humans have had the
capability to look for ETs (as we expect them to sound) for what, 40-ish
years?

Considering the time and space scales involved, it's hard for me to believe we
have enough data for a conclusion either way, particularly without assuming
faster than light travel and also given the 'youth' of the universe. Even if
we did assume faster than light travel, it seems like you'd have to have
insane levels of population growth to make it all that far from home without
going very very slowly. And if you do start moving out, would it really be
worth trying to signal home if it would take 1000 years or 100 years to reach
'home?'

Another issue I have is what I'd term anthropological environmental
constraints as applied to aliens, namely it's quite conceivable that some home
worlds would not offer the resources needed to make it into space, or would
contain them in an inaccessible way. If a race of Einstein-like aliens is
stuck on the a planetary equivalent of a desert island we'll never hear from
them.

As far as the self replicating robots go, I see two issues: first, it should
still be pretty slow without light speed travel, and second, if these robots
don't have a realistic chance of reporting back to their source civilization,
why would the civilization even bother? (We can barely understand the ancient
Maya. When a robot returns after 30 million years, this problem seems like
it'd only be exacerbated. Likewise, the time horizon is so far out it'd be
unlikely a particular group would see an ROI argument to attempt it other than
as a hobby.)

So I really feel like it's a bit premature to draw conclusions about the
'Fermi Paradox.'

~~~
svachalek
If you could travel at only 1% of c you could cross from one side to the other
in only 10 million years. At evolutionary time scales you could have been
there and back three times since the dinosaurs disappeared. It's not hard to
imagine that within a couple of centuries we could start a self-replicating
robot project that would explore the entire galaxy in that time frame. We'd
have the complete results within a mere 100,000 years of completion.

If you assume that aliens with the intelligence and drive to achieve star
travel are common, it becomes pretty laughable to think that NONE of them had
the curiosity to explore or meet other species or eradicate the competition.
If you're arguing that we're the 5th such species in the galaxy then... maybe.

~~~
mcguire
If you are limited to travel at 1% of c, communications at c, and self
replicating probes, you'll have to wait many times 10 million years before you
get more than a tiny sampling of responses from your probes.

How long is your curiosity willing to wait?

------
roberthahn
One paragraph stands out for me:

”In his article Dobzhanksy turned Sagan’s argument on its head. Dobzhansky
cited the fact that of the more than two million species living on Earth only
one had evolved language, extragenetically transmitted culture, and awareness
of self and death, as proof that it is “fatuous” to hold “the opinion that if
life exists anywhere else it must eventually give rise to rational beings.”“

I find this interesting because some scientists are open to the fact that
dolphins[1] and elephants[2] may be significantly more intelligent than we
previously supposed, and possibly as intelligent as humans. The difficulty
lies in defining exactly what intelligence is - and how we measure it in other
animals.

That in turn leads to more questions. Suppose that there is, in fact, at least
3 human-level sentient species on our own planet. Observe: only one of them
have developed tools to the extent that space travel is a problem that we're
trying to solve. Perhaps the reality is that there _are_ as many intelligent
species as astronomers posit - maybe multiple species per planet! - but almost
all of them have no interest in exploring and settling on other planets.

[1][http://www.dolphins-world.com/dolphin-intelligence/](http://www.dolphins-
world.com/dolphin-intelligence/)
[2][http://en.wikipedia.org/wiki/Elephant_cognition](http://en.wikipedia.org/wiki/Elephant_cognition)

~~~
Roboprog
Other animals also make simple food gathering tools or construct simple
dwellings.

However, humans seem to have had a qualitative impact on the planet due to the
quantity of things that they imagine and build. Perhaps the capacity for
written language gives us the ability to recursively combine our tool building
in layers? (not that reading and writing is required, but simply using that as
a indicator that the species in general is capable of such permutation of
ideas)

~~~
undersuit
Without reading and writing I think the whole 'Standing on the shoulders of
giants' thing falls apart because you must be directly associated with the
'giant'. How do you transmit the ideas of an Einstein between generations of
normals?

~~~
scrumper
Agreed, but it's possible, up to a point: oral history, apprenticeship,
observation all serve. It is much less efficient, much less reliable, and
probably impractical for higher-order things (such as theories of relativity)
but it does work as a bootstrap. Human culture did well enough for a long time
before writing.

I think a bigger reason that intelligent animals haven't progressed as far as
us (qualify 'progress' however you like) is more to do with evolutionary
pressure from humans changing the environment faster than they can adapt to
it. That extends to populations of humans at different stages of societal
evolution as well: cultures are snuffed out very quickly when more advanced
groups make their presence felt.

------
mcguire
* Snarky comment numero uno: If I understand the author and the Less Wrong, Bayesian, weirdish probability thought process, I suspect that the correct conclusion to this article is that humanity doesn't actually exist.

* Snarky comment numero dos: The Drake equation includes a term:

"L = the length of time for which such civilizations release detectable
signals into space"

(I originally heard that as the length of time before or probability of a
civilization destroying itself. Yay, collapse of the Soviet Union! Progress!)

Anyway, I believe that humanity is no longer trying to outshine stars with our
radio broadcasts, or at least that we are not getting any brighter. So here's
a question or two for the author's model:

What is the probability that a civilization will release self-replicating
probes? (Granted, that anything that _can_ be done _will_ be done, _must_ be
done by someone, sometime.) What is the probability that you will be able to
detect such probes if one was standing next to you right now? I'll just note
that in a comment on another article, the author writes, "But if 1000 years
from now we start sending probes out to explore and replicate across
millions/billions of stars. We’d have detectable radio traffic and other signs
that SETI would pick up."

Snarky comment numero tres: So, evolutionary biologists believe that Darwinian
evolution, if it leads to intelligent life, further _inevitably_ leads to
self-replicating robotic space probes?

I suspect the only reasonably hard conclusion that biology lends to the goofy
debate is that life, not necessarily intelligent life, is _everywhere_ , given
that our one anecdote here indicates that life developed incredibly quickly on
the scale of planetary existence.

------
heydenberk
I think this piece makes a very good point and makes it very well.

One thing I wonder about, vis-a-vis SETI-style projects, is the idea the
humans could identify extraterrestrial communication even after receiving it.
I'm fine with assuming that extraterrestrial life is attempting to communicate
with us and is using technologies we'd be familiar with (eg., electromagnetic
radiation transmitting binary data) — until we ourselves develop some other
technology, this is our safest assumption. But we should also assume that a
sufficiently-advanced lifeform would transmit data near the information
theoretical maximum efficiency, and of course, maximally-efficient data will
appear entirely random to an observer who has no means to make sense of it.

------
coke12
When approaching the Fermi paradox astrobiologists usually use the principle
of convergent evolution [1], where multiple types of life will evolve similar
features because of similar environmental pressures. (the application is the
development of intelligence.) I'm a big fan of this, because it affirms my
hope that life exists elsewhere. But unfortunately we don't really know what
"life" and "intelligence" is -- an intelligent dolphin might never think or
desire to leave the ocean, and an intelligent four-legged creature might never
think to look up at the sky and wonder, the way that humans have always done.

[http://en.wikipedia.org/wiki/Convergent_evolution](http://en.wikipedia.org/wiki/Convergent_evolution)

------
molbioguy
So why is it inevitable that any civilization that can evolve to the point of
space travel will necessarily have the desire and capability to continue to
expand before extinction? We've only been around a relatively short time and
there is no certainty that we will be around long enough to be able to spread
across the galaxy. If someone had told me in 1969 that 45 years later we would
have lost the capability (or desire) to colonize the moon, I would have
thought it highly unlikely. But here we are.

~~~
joshdick
Our history is filled with explorers and frontiersmen. We've grown to fill the
world. We climb mountains and explore valleys. We cross oceans and fly around
the world as soon as we know how.

Why would you expect space to be any different?

~~~
bluesnowmonkey
Because it's a one way trip. Terrestrial explorers tend to be looking for
resources to take home. You can't bring anything back from another star.

~~~
MadManE
That's not exactly true. . . isn't there a company that was created recently
dedicated to mining asteroids and bringing the precious metals back home?

------
roberthahn
A few people in different threads here talk about self-replicating robots or
probes. The way they write, it seems as though we already have the technology
to make them - which comes as a surprise to me.

So: for those of you who have talked about self-replicating machinery - where
exactly are we at with that technology? And why are so many people sure it's
more attainable than, say, faster-than-light travel?

~~~
Glyptodon
I think it just seems superficially attainable given things like 3-D printers
and continuing improvements in AI, forget questions like how it fuels itself.

~~~
bashinator
Yeah, we're talking about fully-automated, fully self-repairing facilities
that encompass the entire vertical industrial production infrastructure -
mining, refinement, raw material production, all the way to assembly of
finished good and _installation of those goods into the infrastructure_.

We're not remotely close to having that on Earth, let alone as self-contained
spacecraft.

------
heygrady
Taking a cynical view of the paradox, saying that not having already detected
ET means that ET couldn't exists, opens a new paradox. What if every
intelligent civilization looked at the same problem and reached the cynical
point of view: why bother looking?

And what's to say we're not aliens ourselves? That Prometheus movie hinted at
the possibility, so did Star Trek. Both point to an original creator that uses
simple biology and knowledge of evolution to seed planets with life and let it
grow. Modern astrobiology, as documented in the recent Cosmos reboot, thinks
that life has already been traversing the galaxy on space rocks; crashing into
planets in an ice ball and taking hold where it can. While not intelligent by
human standards, it still spreads ET life. With the time scales involved, it
seems like space rocks with simple life on them might be spreading ET fairly
evenly through our galaxy and beyond.

As smart as we are, we have only recently been able to hurtle some space junk
out of our solar system and into deep space. The distances involved and the
limitations of our current understanding of physics make it seem likely that
we wouldn't be in direct contact already. It's taken 2 generations for Voyager
1 to travel that far.

Using ourselves as the perfect example, our own broadcasts haven't reached
very far into our own galaxy. If we are typical and our understanding of
physics is reasonably accurate, there could be numerous human-like
civilizations broadcasting and sending out probes constantly and we just
haven't waited long enough -- the distances are too vast for us to have heard
them. Or worse, we're not intelligent enough yet to listen to the broadcasts
that are being sent to us already.

I say we build these magical self-replicating probes and send them out and
hope we don't accidentally create the Borg. The only way to beat the paradox
is to play along. And if we don't find anything, then we'd better get to
colonizing!

------
jcfrei
Nathan Taylor introduces the (in my eyes) most comfortable explanation for the
Fermi paradox. While I think it's a perfectly reasonable explanation, I also
wanted to add my own from a while back: [http://jcfrei.com/my-take-on-the-
fermi-paradox](http://jcfrei.com/my-take-on-the-fermi-paradox)

------
msane
I take a Kurzwielian view. There is probably a significant transition in the
physical bodies of an intelligent lifeform past a certain point of evolution.
and a dramatic increase in cognitive ability.

Fermi's Paradox makes more sense when you theorize that ET transforms its
biology into a computational substrate prior to gaining the ability to travel
between stars, as will likely happen with us. When it does this it turns into
something we won't even recognize, something likely a million times smaller
than us due to miniaturization, and a trillion times smarter. Even if they are
around they probably don't have the patience to interact with us, dumb as we
are and with minds that travel 10^5 or so slower.

~~~
rational-future
That view doesn't strike me as very Kurzwielian. IMHO that would be more like:

1\. A singularity happened in a human civilization, that was 1st to evolve in
it's galaxy.

2\. That civilization turned all the energy and matter in that galaxy into
computronium.

3\. They run a 10^70 simulations and we are inside one of those.

~~~
msane
It is actually, he says roughly the same thing about miniaturization; that any
post-biological extraterrestrial life is possibly microscopic and not
something we would easily recognize.

I don't think post-biological ET necessarily turns all the energy and matter
in its galaxy to computronium either. It's possible that an amount of matter
on the order of a planet or less is more than enough to satisfy. The same
postulation can function as an attempt to explain the absence of Dyson spheres
or anything of the like.

When we think of theoretical star-faring advanced ETs we anthropomorphize.
We're imagining them on the same temporal and spatial scales which we occupy,
but they are possibly many orders of magnitude smaller and faster. So this is
a Kurzwielian view in that it extrapolates from the patterns that he
identifies.

------
Scottn1
I've read two books on this and my current favored solution to the Paradox is
Supernovae and/or Gamma Ray Bursts. Particularly GRB as they have to ability
to sterilize whole galaxies. There is a possibility even Earth has already
faced one 440m years ago.

[http://www.youtube.com/watch?v=7HIokbQMHB8](http://www.youtube.com/watch?v=7HIokbQMHB8)

------
3rd3
In summary: The universe is very young and we might be one of the first type
>= 0 civilizations.

~~~
dnautics
According to contemporary cosmological estimates, the earth has been around
for the latter 1/3 of the universe's age. Even given that life-bearing planets
must be at least second generation stars, and conservatively saying that it
should take about as long as earth is around for the first generation to go
(not true) the universe is already fairly old.

Interestingly, life evolved on earth in the first billion years. That's
incredibly fast. Arguably, life is inevitable whereas intelligent life might
not be so. Multicellularity didn't come about till the most recent billion...

------
rational-future
A friend of mine is professor in genetics in Columbia university. He spent
many years experimenting around the RNA world hypothesis and his opinion is
that the origin of Earth life was a very unlikely event. Once in a Universe
unlikely.

~~~
hitchhiker999
That's an extremely humorous notion.

~~~
rational-future
Why?

~~~
hitchhiker999
You're dealing with the infinite, and returning with a high probability of the
value 1.

If that turns out to be correct - I'll eat my own brain.

------
InclinedPlane
The Fermi Paradox is nothing of the sort. It is simply an expression of how
thoroughly ignorant we are about the nature of advanced technological and
interstellar life, no more. It might mean that we are ignorant of the short
lifespan or extreme rarity of technological civilizations, but we have
insufficient data to support conclusions along those lines. It is more likely
that our surmises about the nature of colonizing interstellar civilizations
are just fundamentally in error in some way we cannot even really understand
today in the same way that someone in the year 1500 BC would not truly
understand the internet or antibiotics or electricity produced by way of
nuclear fission and so wouldn't understand their impact on our way of life.

~~~
Scottn1
It is not really the same because any of your examples would not supposedly
coincide with a 1500 BC civ. So none of it would be observable. You would only
be talking about stuff in the way distant future that did not exist at the
time and only a time traveler would be able to describe.

The Fermi Paradox is a discussion based on that there currently SHOULD be
advanced tech and colonized civs at the SAME time we are and have been looking
for them. So where are they?

Even ruling out a Earth or even Solar System visit, they should have evidence
out there that can be seen. Some sort of energy signature, a space station,
satellite, giant mothership as it checks out life detected as us. SOMETHING.
The Fermi Paradox says, by now, there should have been at least one Type III
civ in our galaxy given how old it is and they would eventually tip their hat
to their existence, unless they purposely try and are able to hide themselves.

