
A New Constraint on the Drake Equation - growlix
http://online.liebertpub.com/doi/full/10.1089/ast.2015.1418
======
ChuckMcM
Personally, I find these miss one of the key points.

Today, we can kill everyone off with an exchange of the already existing
nuclear weapon inventory. But that requires a reasonably large number of
people to make mistakes or take action.

We're in the process of killing everyone off by screwing up the natural
climate process which requires a large number of people to commit to inaction.

Within this century we will have the means and the understanding for a single
individual to craft a DNA based pathogen that can infect and kill nearly
everyone on the planet.

These are the three tests for graduation into the club of "long lived
intelligent species." Fail any one of them and you don't make it. I call them:

    
    
       * Action of the group
       * Inaction of the group
       * Action of the individual
    

We apparently passed test 1, we're not doing so well on test 2, and we'll have
to be a lot better at eradicating hate in individuals if we want to have a
hope of passing test #3.

~~~
arcticfox
It's beside the point, but IMO the human species is at almost zero risk of
extinction from climate change. Maybe you could find a better example. The
worst case would certainly be a calamity, but it would require an _immense_
amount of additional failure for humanity to actually go extinct from it.

~~~
danieltillett
If we had loss of technological knowledge (say due to climate change induced
conflict), it might not be possible in the future for the surviving humans to
re-bootstrap back up to our our current technological level.

We have exhausted all the easily accessible minerals and fossil fuels (i.e.
those resources that can be extracted using stone age tools). Any break in our
current technological systems might make it impossible to recover for 10s of
millions of years.

~~~
epicureanideal
Like the article posted last week titled "this is not a place of honor" about
making obvious markers on nuclear waste to last 10,000 years...

We may also want to invest in creating some "breadcrumbs" for a future
civilization to build up from. Say, a reserve of easily accessible fossil fuel
and other raw materials, and some long-lasting guideposts that indicate where
to find them.

~~~
danieltillett
It is a good question of how much breadcrumbs you would need to jump from the
stone age to using whatever accessible resources are left after us.

A lack of accessible fossil fuels is likely to be the major factor as it would
be really difficult to get an industrial revolution going without access to
the easy energy provided by fossil fuels. We could easily find a rebooted
society gets stuck in a pre-industrial state with no way of breaking out.

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keithwarren
Michael Crichton tears up the Drake Equation (and SETI) pretty thoroughly in
his speech entitled Aliens Cause Global Warming.

[http://stephenschneider.stanford.edu/Publications/PDF_Papers...](http://stephenschneider.stanford.edu/Publications/PDF_Papers/Crichton2003.pdf)

"...the Drake equation can have any value from “billions and billions” to
zero. An expression that can mean anything means nothing. Speaking precisely,
the Drake equation is literally meaningless, and has nothing to do with
science. I take the hard view that science involves the creation of testable
hypotheses. The Drake equation cannot be tested..."

-Crichton

~~~
drewrv
The fact that the Drake equation can have any value from “billions and
billions” to zero is precisely the point. There is a "right" answer and we can
get closer and closer to it if we choose what to study properly.

We know a lot more about exoplanets now than we did in 2003. We're moving on
to find out how many are in the Goldilocks zone, or how many contain water.
Our idea of what to plug in is slowly getting better.

Pointing out that the Drake equation is technically not science since it
doesn't involve testable hypotheses is pointless pedantry. Call it statistics
then. Or metaphysics. Or a thought experiment.

~~~
jerf
"We know a lot more about exoplanets now than we did in 2003. We're moving on
to find out how many are in the Goldilocks zone, or how many contain water.
Our idea of what to plug in is slowly getting better."

"Unfortunately", that's nailing down the one parameter that nobody has ever
particularly questioned. There's some lines of thought that our solar system
might be unusual in relevant ways, but nobody has ever seriously argued that
the only planets in the galaxy are in our system, or anything related to that
that would make that parameter small.

It's all the rest of the parameters where the mystery is.

------
imh
One in 10^24 seems like really easy odds to beat. Basically anything should
happen more often than that, right? But if we choose a random 17 letters of
the alphabet, the odds that they spell "probabilistically" is less than that.
If we gave 17 letters to each of the 10^24 planets, we expect the word to
happen on only one star (actually less than one). It's not too hard to argue
that life is more difficult to get by random chance than the word
"probabilistically."

So before taking this article to mean that life is actually pretty likely,
consider that an event having to occur at least one in 10^24 odds is actually
extremely difficult for complex probabilistic phenomena. Who knows how likely
life is, but we can't just assume it's higher than one in 10^24.

~~~
guelo
You're obviously coming down on the pessimistic side of the line but what's
cool about this paper is that we now have a line in the sand to argue about!

~~~
imh
I deliberately tried not to come off as pessimistic. I'd just seen a pop
science article on this paper that went along the lines of "OMG, 10^-24?
That's so small! Aliens are basically guaranteed!" It was totally exploiting
people's lack of intution about numbers. I just felt the need to point out
that 10^-24 is much more run-of-the-mill than it seems. The crazy thing is
that probabilistic things are multiplicative, so it's all exponential. The
difference between 10^-3 and 10^-4 is a single extra flip of a 10-sided die.
The odds of life on a habitable planet might be 10^-10, it might be 10^-100,
but you can be damned sure our uncertainty spans many orders of magnitude
above and below 10^-24.

(edit: I just looked up the pop article I was complaining about. It was in the
new york times and the title was literally "Yes, There Have Been Aliens."
Hence my crankiness.)

------
amelius
> We find that as long as the probability that a habitable zone planet
> develops a technological species is larger than ∼10^−24, humanity is not the
> only time technological intelligence has evolved.

I wonder how they turn a statement based on a probability into a statement
that is an absolute truth (no probabilities involved).

------
jessaustin
TFA has the same problem the Drake equation has in general. We lack the
insight to judge whether -24 is a reasonable exponent. Why shouldn't it be
-35, or any other number?

~~~
cortesoft
I don't think the paper is arguing whether it is a reasonable exponent or not.
They are just saying IF the exponent is -24 or smaller, then there is more
than one technologically advanced species. It makes no claim about how close
to reality that exponent is.

~~~
jessaustin
Right, TFA is at least as pointless as the Drake equation itself.

------
hoodoof
The universe is a really inconceivably big place. In fact they (the smart
people) are not entirely sure that it isn't infinite.

Drake equation or not, seems such a big place that it seems hard to imagine
that this tiny little spot is in some way unique.

~~~
millstone
You can use this same argument to conclude that there's an alien race that
speaks French. Of course we know they don't: as big as the universe is, the
possibility space of possible languages is much bigger. French is only spoken
on Earth, not because French is unique, but because it's not unique.

But maybe, if everyone only spoke French, it wouldn't occur to us that other
languages were even possible. We'd be trying to estimate how many French
speaking aliens were out there.

Deoxyribonucleic acid is our French. Because it's all we know, we think it's
special. But the possibility space is much bigger.

~~~
adrianN
People have been thinking about non-carbon based life, so not everyone is
thinking only about French, at least not all the time.

------
4e1a
What about ancient Vimana and places like ankor wat? Wouldn't that suggest
that technological species happened at least twice on the same star?

~~~
hugh4
Angkor Wat was built in the twelfth century AD, and is well within the known
technological capabilities of the Khmer empire at the time.

A vimana, which from googling appears to be some kind of flying temple in
Sanskrit myths, does not appear to have actually existed.

~~~
4e1a
Vimana are not unique to India and there are references from all over the
world and include the Egyptian Saqqara Bird, the pre-Columbian golden airplane
models, the Greek Icarus legend, the Chariot of Ezekiel, the Nazca runways
(lines), The Abydos carvings, The Tassili rock paintings from Algeria and the
Chinese references to Lu Ban’s wooden aircraft that flew great distances.
Naturally, these references are often dismissed by modern historians as simply
impossible but there can be no doubt that humanity has a collective memory of
have once been able to fly in ancient times.

~~~
srtjstjsj
correctio:

> a collective memory of having once DESIRED to fly in ancient times

~~~
simonh
Or even just to have worshiped flying beings. Modern fiction is full of
fantastical and impossible things. Are we to believe that people in the
ancient world were incapable of flights of fancy and everything they wrote and
made must be taken absolutely literally?

