jv@... [spacesettlers] wrote:

> Once a multitude of free flying colonies in space are utilizing the
> available Gold, Platinum, Nickle, and Stainless Steel Iron ore stocks,
> won't that make the people remaining on earth an inferior civilization?
> That is to say, will the earth side economy be capable of expanding at
> the same rate as the space economy? Will the various societies in space
> even NEED the earth's economy?

Well, I think it's clear that eventually the Earth's economy will be a
minor part of the overall economy of the solar system.

However, I also think that's going to take a very long time -- the Earth
will probably be the economic and cultural center of human civilization
for centuries (or more).

- Joe

That is to say, will the earth side economy be capable of expanding at the same rate as the space economy?

The Earth economy will certainly bump up against limits to growth sooner than the space economy. Were not as close to those limits as the people who alarmed ONeill had argued. But the Earth is inarguably finite.

Will the various societies in space even NEED the earth's economy?
They will certainly need the Earth economy for many decades to come. But in the extreme long run, into an era where most space habitats might orbit closer to the Asteroid Belt? Certainly Earth will become a diminishing fraction of the overall economy.
Regards,
Mike Combs

How quickly the space economy will dominate is the question. Some years ago,
I did a growth study to determine how much asteroid ores would be needed in
what timeframe.

I assumed the early space economy economy was driven by the construction of
space solar power satellites (need several thousand workers to build one per
year, and we'll need a lot of them).

There are nearly unlimited resources in the asteroids - but they aren't
conviently located, and acquiring sufficient resources and moving them where
they're needed is the first huge challenge.

If we could ramp up to 10,000 Earth-launched colonists/workers over ten
years, keep up the 10k colonists per year and let them start having
children, then:

(assume population growth rates somewhat slower than the Earth currently
experiences, resulting in a population doubling time of 50 years,
characteristic of expansionists societies on Earth. Note that 4.2 children
per couple results in population doubling every 25 years.)

In 20 years more children are born in space than immigrate to space.

In 33 years the space-born outnumber the immigrants.

In 40 years we reach 1 million people living in space (half of which are
children under 20).

In 53 years we reach 2M in space; by this time, the growth of the space
economy is for itself - but exports are still important.

In 70 years we reach 4M - 2/3rd of which are natives.

Assuming for the moment that we start this late enough that we reach 2M in
space by the year 2100...

In 2700 the space population will equal the current terrestrial population -
and I think it's safe to say the space economy will be larger.

But assuming we keep growing (there is lots of room and resouces)...

About 2800 space will have 3 times Earth's population (assuming terrestrial
limits to growth stagnate it near the current level).

Around the year 3000 space will have 52 times Earth's population. The Earth
economy is insignificant - and possibly dominated by space-born tourists
visiting humanity's home.

And that ratio of space population to Earth population goes up by a factor
of four every hundred years.

Sometime in the 3700's the asteroid civilization could outnumber the
Earth-bound by a factor of a million.

Easily less than 2,000 years from now. Whew!

Actually, in the early decades the first challenge is in retrieving and
processing hundreds of tonnes of asteroid ores PER DAY. Which kind of
implies that early growth is resource limited - including the resource of
orbital settlements for those first workers (the bootstrap problem).

But soon after that is achieved, the next challenge is in finding enough
teachers to educate the rapidly growing population of children born in
space. Yes, we don't have to worry about elementary school for the first 6
years or so, but even assuming only one child per couple per five years (a
very slow rate for young couples!), and zero children immigrants (unlikely),
that first grade first year might be 50 kids, then 200 the next year, 500
the third year, 1100 the fourth year, 2200 the fifth year, and so on. No
school system has ever grown that fast. At least we won't need all grades at
once - but these kids will be smart (considering their parents), and are
likely to stay in school well past college! The growth rate of schools
worries me, as does having large enough communities to support a college or
university. By the year we award the first 1,000 Ph.D's in space, we'll have
100,000 first graders

How quickly the space economy will dominate is the question. Some years ago, I did a growth study to determine how much asteroid ores would be needed in what timeframe.

I assumed the early space economy economy was driven by the construction of space solar power satellites (need several thousand workers to build one per year, and we'll need a lot of them).

There are nearly unlimited resources in the asteroids - but they aren't conviently located, and acquiring sufficient resources and moving them where they're needed is the first huge challenge.

If we could ramp up to 10,000 Earth-launched colonists/workers over ten years, keep up the 10k colonists per year and let them start having children, then:
(assume population growth rates somewhat slower than the Earth currently experiences, resulting in a population doubling time of 50 years, characteristic of expansionists societies on Earth. Note that 4.2 children per couple results in population doubling every 25 years.)

In 20 years more children are born in space than immigrate to space.
In 33 years the space-born outnumber the immigrants.
In 40 years we reach 1 million people living in space (half of which are children under 20).
In 53 years we reach 2M in space; by this time, the growth of the space economy is for itself - but exports are still important.
In 70 years we reach 4M - 2/3
rd
of which are natives.
Assuming for the moment that we start this late enough that we reach 2M in space by the year 2100...
In 2700 the space population will equal the current terrestrial population - and I think it's safe to say the space economy will be larger.
But assuming we keep growing (there is lots of room and resouces)...
About 2800 space will have 3 times Earth's population (assuming terrestrial limits to growth stagnate it near the current level).
Around the year 3000 space will have 52 times Earth's population. The Earth economy is insignificant - and possibly dominated by space-born tourists visiting humanity's home.
And that ratio of space population to Earth population goes up by a factor of four every hundred years.
Sometime in the 3700's the asteroid civilization could outnumber the Earth-bound by a factor of a million.
Easily less than 2,000 years from now. Whew!

Actually, in the early decades the first challenge is in retrieving and processing hundreds of tonnes of asteroid ores PER DAY. Which kind of implies that early growth is resource limited - including the resource of orbital settlements for those first workers (the bootstrap problem).

But soon after that is achieved, the next challenge is in finding enough teachers to educate the rapidly growing population of children born in space. Yes, we don't have to worry about elementary school for the first 6 years or so, but even assuming only one child per couple per five years (a very slow rate for young couples!), and zero children immigrants (unlikely), that first grade first year might be 50 kids, then 200 the next year, 500 the third year, 1100 the fourth year, 2200 the fifth year, and so on. No school system has ever grown that fast. At least we won't need all grades at once - but these kids will be smart (considering their parents), and are likely to stay in school well past college! The growth rate of schools worries me, as does having large enough communities to support a college or university. By the year we award the first 1,000 Ph.D's in space, we'll have 100,000 first graders

Sometime in the 3700s the asteroid civilization could outnumber the Earth-bound by a factor of a million.
Now think about this: Imagine that belter civilization with million times the population of the Earth.
Now imagine their cell-phones ringing.
Marshall Savage put this best. The SETI astronomers are cupping a hand to their ear, struggling to catch a whisper. When an advanced technical civilization (by this estimate less than 2 millennia past our own) would be a deafening hurricane of radio noise.

Regards,
Mike Combs

Sure. I once wrote an article which included,
Perhaps when we turn on the world's first tachyon receiver, it will hum with ten trillion conversations.

But

Even a highly advanced civilization which doesnt use the EM spectrum for communication would probably still be noisy in the EM spectrum.

Regards,
Mike Combs

From:
spacesettlers@yahoogroups.com [mailto:spacesettlers@yahoogroups.com]
Sent:
Friday, May 15, 2015 7:14 PM
To:
spacesettlers@yahoogroups.com
Subject:
[spacesettlers] Re: Inferior Civilization?

This assumes that they use radio. They could use lasers or neutrinos or something. That's not considering some new discovery in physics which allows communications we can't detect at all (neutrinos just fall into this). Quantum pairs, Alcuberrie warps, something nobody's thought of at all.
Which still means SETI isn't going to find much with their radio searches. Ah well.

harlockacadia@... [spacesettlers] wrote:

> I see several comments about the EM noise generated by advanced
> civilizations, why can't we hear them. It has been computed that any
> broadcast that we can make becomes noise at 1.96LY. I computed that
> tracking a signal from earth would pass LS at 1.94LY. Both of these
> calculations preclude hearing EM "Signals" at greater than 2LY. If you
> want to be heard further than that the broadcast would need to be
> pointed at a target and equal to the combined output of the entire
> planet. These are the reasons that EM communications are unlikely over
> interstellar distances.

That's all true, but not relevant to Fermi's paradox (which I assume is
the context in which you saw these comments).

The point is that within a few hundred million years of the evolution of
the first civilization, they should colonize the ENTIRE GALAXY. Every
star, every hunk of matter should be settled. This follows very
directly from evolutionary forces (which select for growth) and
exponential growth (which applies until you run into resource limits,
i.e., fill up the galaxy).

Our solar system is one of those in the galaxy, yet after decades of
searching, we see no sign whatsoever that aliens have settled here.

There are only a few possible classes of explanation for this:

1. Civilization is astronomically unlikely, and we happen to be the first.
2. Every civilization disappears for some reason before it settles the
whole galaxy.
3. The galaxy is indeed settled, but our solar system is inside some
sort of nature preserve, and the aliens are hiding from us.

Which of these is the truth is one of the great mysteries of our time,
but one day we will know the answer. However, listening for EM signals
is very unlikely to help. In cases 1 and 2, there is nobody out there
to hear; we are alone in the galaxy. In case 3, ET is out there and
watching us, but chooses not to say hello; their communications would
not be so wasteful (or careless) that we could eavesdrop just by
pointing a radio dish in the right direction. And when they do choose
to say hello, it will be unmistakable; they'll probably just fly over
from their nearest observation outpost.

Personally, until we have evidence otherwise, I'll subscribe to
explanation 1, which is by far the simplest that fits the data. Occam's
Razor and all that.

Oh, and while Francis Drake may have many other fine qualities, his
famous equation is utter bunk. Anybody who quotes it with a straight
face hasn't thought about it very deeply.

'Combs, Mike' mikecombs@... [spacesettlers] wrote:

> Youre quite right about the Fermi Paradox. I think one reason why its
> not widely appreciated why the Fermi Paradox is so inescapably blatant
> is because we persist in the idea that intelligent life will limit
> itself to inhabiting planets. A galactic civilization which is planetary
> will be a far cry from the kind of galactic civilization one anticipates
> when viewing this from the High Frontier perspective:
>
> http://www.nss.org/settlement/MikeCombs/alone.htm

Yes, and this is a very well-written essay which anyone interested in
the topic should read.

I also think that years of Star Trek and Star Wars have inculcated our
culture in the notion that there could be many other civilizations out
there at basically the same technology level (give or take a couple
hundred years) as us. I love those stories, but scientifically, that's
ridiculous. Given that it's taken us 4.5 GY to reach this level on
Earth, and there's a whole lot of random factors at play there, we
should expect any other civilization we meet to be many millions (or
small number of billions) of years ahead or behind us.

> I think number 2 [every civilization disappears]
> can apply to civilizations up to the point that they
> establish their first self-sufficient settlement beyond their homeworld.
> Once theyve done that, I think they become unkillable.

Probably, but there's always the chance there is some danger or
opportunity we're not even aware of. Perhaps physicists inevitably do
some experiment that goes awry and swallows up their whole solar system
in a ravenous black hole. Or perhaps they discover how to create new,
custom universes, and leave our universe for greener pastures.

These all seem unlikely to me, but since we know our understanding of
physics is incomplete, it's hard to rule this sort of thing out.

> The question 3 [nature preserve] should provoke is, So what about
> outlaws/dissidents/poachers?. For us to still see no signs of galactic
> civilizations is dependent on an infallible law-enforcement mechanism.
> Nothings ever perfect.

Yep, good point.

> And so we should be more open-minded to 1 [we're alone].

Agreed. It's a terrifying and somewhat depressing possibility, but that
doesn't make it any less likely.

> But I think you might be a bit unfair to Drake. I think, properly
> understood (which its probably not in many cases), the Drake Equation
> has only one utility: It allows us to see the numerical outcomes of our
> assumptions. But I take your point; it tells us nothing about whats out
> there. But I dont think a proper understanding of it should expect it to.

No, you didn't get my point because I failed to make it. The problem is
the assumption built into the very form of the equation: that the
universe is static, and nothing is growing within it. It's a
steady-state equation.

In reality, in a universe where interstellar colonization is possible,
you would need to use the entirely different equations of population
dynamics (https://en.wikipedia.org/wiki/Population_dynamics). Just try
describing the number of bacteria in a petri dish with something like
Drake's equation; you can't, no matter WHAT values you plug in for the
numbers. To attempt it is pure nonsense (until the petri dish is full
and has reached a steady state, of course).

This is what I mean when I say Drake's equation is bunk. Show it to any
ecologist, and he will laugh at you and give you an "F" on your
undergraduate homework for completely failing to understand even the
simplest basics of population growth.

And since, as far as we can tell, we DO live in a universe where
interstellar colonization is possible -- just keep building space
colonies until you're so far out in the Oort cloud, that the next Oort
cloud over is no longer a stretch -- then a static equation does not apply.

However, this does point out another group of people who don't see the
importance of Fermi's paradox: those who simply believe that
interstellar travel/colonization is impossible. I think this is fairly
prevalent among the SETI crowd, though they rarely say so explicitly.
If it's really true that no civilization, no matter how old or advanced,
ever manages to spread from its home star system to the next one over,
then it's easy to imagine the galaxy filled with millions of trapped
civilizations, each one desperately crying out for contact with their
neighboring prisoners. (And in only such a case, Drake's equation would
apply.)

However, I find that far less plausible than any of the three classes of
explanations we've just discussed. Here we are, barely out of our
industrial revolution, and we can already see how to spread to the stars
in fairly clear detail. I don't see how civilizations thousands or
millions of years ahead of us could fail to find a way.

Best,
- Joe

The comment about the petri dish sparked a thought ... Does this equation take into consideration the continuing biological evolution of the species under the microscope? Many programs such as Star Trek, Stargate, Babylon 5, offer quandries relative to species evolving beyond the "civilization" we have grown accustomed to.
Would it not be true that as a species evolves, their needs relative to the available resources changes ... putting in question the foundation of the equation?

Would it not be true that as a species evolves, their needs relative to the available resources changes ... putting in question the foundation of the equation?

Donald Jacques djmitzlplick@... [spacesettlers] wrote:

> The comment about the petri dish sparked a thought ... Does this
> equation take into consideration the continuing biological evolution of
> the species under the microscope? Many programs such as Star Trek,
> Stargate, Babylon 5, offer quandries relative to species evolving beyond
> the "civilization" we have grown accustomed to.
>
> Would it not be true that as a species evolves, their needs relative to
> the available resources changes ... putting in question the foundation
> of the equation?

The equations of population dynamics still apply; what changes is the
resource limits. As a species becomes able to make use of new
resources, it will expand into the new niches that makes available.

For example, we're almost (but not quite) able to make use of off-planet
resources, so we should be soon expanding into space.

Once those niches are available, it's hard to see why life would ever
disappear from them... you don't find warm sunny ponds on Earth that
aren't teeming with life at some level. And this is a good analogy:
every star system in the Galaxy is like a warm sunny pond on Earth, so
if spacefaring life is common, why isn't this star system (or any other
one, as far as we've been able to tell) teeming with life?

Best,
- Joe

> On Oct 15, 2015, at 7:30 AM, Joe Strout joe@... [spacesettlers] wrote:
>
> For example, we're almost (but not quite) able to make use of off-planet
> resources, so we should be soon expanding into space.

There are around 1,300 operational satellites today almost all of which use off-planet energy. I.e., they are powered by solar panels converting sunlight to electricity.

Human use of in-situ resources in space is ubiquitous to the point people forget the obvious.

It should also be noted that although material resources can be recycled, energy cannot. This has important implications for space settlements. Namely, access to in-situ energy is more important than access to in-situ materials (although both are important).
joe@strout.net
[spacesettlers] <
spacesettlers@yahoogroups.com
> wrote:
For example, we're almost (but not quite) able to make use of off-planet

resources, so we should be soon expanding into space.
There are around 1,300 operational satellites today almost all of which use off-planet energy. I.e., they are powered by solar panels converting sunlight to electricity.
Human use of in-situ resources in space is ubiquitous to the point people forget the obvious.
It should also be noted that although material resources can be recycled, energy cannot. This has important implications for space settlements. Namely, access to in-situ energy is more important than access to in-situ materials (although both are important).

wlm_efn@... [spacesettlers] wrote:

> > Oh, and while Francis Drake may have many other fine qualities, his
> > famous equation is utter bunk. Anybody who quotes it with a straight
> > face hasn't thought about it very deeply.
>
> Frank Drake, not (Sir) Francis, the 16th century explorer.

Whoops! Absolutely right.

> I've come to think that while not plain wrong, the Drake equation,
> instead of the 8 factors it now has, should have at least 30.

No matter how many static factors you multiply in, it will still be a
static equation, and therefore fundamentally wrong (unless interstellar
colonization is forever impossible).

> This connects to the Rare Earth Hypothesis. For whatever reason
> science shies away from this theory or paradigm. And the only
> people who are willing to advocate it are religious Christians!

That's not entirely true. I'm traveling now, but I have a book at home,
written by real scientists, on this very topic... it's been a few years
since I looked at it, but I think this is the one:
http://smile.amazon.com/Rare-Earth-Complex-Uncommon-Universe/dp/0387952896/

Best,
- Joe

Thanks Joe, for your response. Though I was thinking in a skewed direction.
Let's say we settle the moon with it's lighter gravity ... and the process of evolution being what it is, those who live there begin to change over time, adapting to the gravity difference.
Then we settle Mars, and like the moon, they change there as well.

Now we potentially have three variants of humans. As we reach outward, I suspect that these three variants will each develop additional contributions to the spacefaring qualities of the species overall, further propelling us outward.
Assuming a slow, yet continuing evolution, one might consider the varying evolutionary directions we could go - including (cyborg, uploaded, and even frozen heads) - is it possible that over multiple millenia of such evolutionary branches, and the full access to resources in the galaxy, that a species might evolve ... or to use Stargate's idea, transcend beyond what we consider civilization? Do the equations, and the Paradox address these posibilities?
I question that a civilization can survive through thousands of years, much less millions of years without the very fabric of that civilization changing. The very assumption (ref: the "classes" of civilizations) that a civilizations general appearance over such time frames will still bear any resemblance to what we share now seems ... arrogant.
Human history is replete with "civilizations" breaking up over a few thousands of years. Rome, Persia, the Maya and Aztec - even China has suffered, is suffering similar growing pains. I grant that the example is "human civilization", but I wonder if our limited experience has limited our view of where other civilizations might evolve ... as well as develop technologically. Technology isn't everything. It helps, but isn't the solution .. it is how those civilizations use knowledge and experience.
In other words, have the equations considered civilizations who learn and evolve beyond technological tools?

Let's say we settle the moon with it's lighter gravity ... and the process of evolution being what it is, those who live there begin to change over time, adapting to the gravity difference.
Then we settle Mars, and like the moon, they change there as well.
Now we potentially have three variants of humans. As we reach outward, I suspect that these three variants will each develop additional contributions to the spacefaring qualities of the species overall, further propelling us outward.
Assuming a slow, yet continuing evolution, one might consider the varying evolutionary directions we could go - including (cyborg, uploaded, and even frozen heads) - is it possible that over multiple millenia of such evolutionary branches, and the full access to resources in the galaxy, that a species might evolve ... or to use Stargate's idea, transcend beyond what we consider civilization? Do the equations, and the Paradox address these posibilities?
I question that a civilization can survive through thousands of years, much less millions of years without the very fabric of that civilization changing. The very assumption (ref: the "classes" of civilizations) that a civilizations general appearance over such time frames will still bear any resemblance to what we share now seems ... arrogant.
Human history is replete with "civilizations" breaking up over a few thousands of years. Rome, Persia, the Maya and Aztec - even China has suffered, is suffering similar growing pains. I grant that the example is "human civilization", but I wonder if our limited experience has limited our view of where other civilizations might evolve ... as well as develop technologically. Technology isn't everything. It helps, but isn't the solution .. it is how those civilizations use knowledge and experience.
In other words, have the equations considered civilizations who learn and evolve beyond technological tools?

This connects to the Rare Earth Hypothesis. For whatever reason
science shies away from this theory or paradigm.

And I think the reason why is obvious. Wed far rather consider a universe filled with neighbors than contemplate being alone in the cosmos. The former fills us with a quasi-religious sense of awe. The latter only makes us feel lonely.

Regards,
Mike Combs

wlm_efn@... [spacesettlers] wrote:

> sailor.barsoom wrote:
> > To put it bluntly, we are all of us disgustingly ignorant on what it
> takes for a
> > planet to give rise to one or more intelligent beings. We make our
> decision
> > with our hearts because our heads don't know jack.
>
> An oasis of wisdom, in a desert of assumptions, presumptions and unproven
> ideas.

Well, OK, I agree with the basic point, but I think it's overstated.

There are things we DO know. We have a grasp of mathematics. We know
how big and how old the galaxy is (and what other galaxies are nearby,
or not). We know how heavy elements form from lighter ones, how long it
took our planet to form, and how long it took civilization to arise on
this planet. We understand evolution. We know the central limit theorem.

So, clearly it's not true that we don't know anything.

OK, sure, it could be that everything we think we know is false; maybe
the whole universe was created five subjective seconds ago, with all of
us in our current chairs and with entirely false memories planted by
some kid in a different universe as part of his science fair project.

But it's quite reasonable to doubt that. We must assume that the
evidence we have accurately reflects the universe we live in, until
contradicted by other evidence.

So, given all that stuff we know, there ARE reasonable conclusions that
can be drawn. And, there are entirely unreasonable conclusions that can
be drawn by ignoring some or all of the stuff we know.

Everybody's entitled to their own opinion, but some opinions are more
sensible than others.

wlm_efn@... [spacesettlers] wrote:

> Joe wrote:
> > No matter how many static factors you multiply in, it will still be a
> > static equation, and therefore fundamentally wrong (unless interstellar
> > colonization is forever impossible).
>
> Not if it comes out to <= 1 civilization per galaxy.
>
> It could also be right if interstellar travel is not impossible but
> just difficult, and there are only a few industrial civilizations per
> galaxy.

Even then it's only right for the time period before the first
civilization starts spreading to the stars. After that, you need a
dynamic equation rather than a static one.

But I think I see your point: if it turns out that we are exceedingly
rare, and given that we haven't yet started colonizing the stars, then
the Drake equation may be an adequate description of the galaxy today.

> >> This connects to the Rare Earth Hypothesis. For whatever reason
> >> science shies away from this theory or paradigm...
> >
> > That's not entirely true. ...
>
> Yes I know all about this book. I guess I could have prefaced it by saying
> with the exception of Ward and Brownlee, the two "official" inventors of
> the Rare Earth theory.

Ah yes, now I see.

Well, for what it's worth, I'm with those guys. I think when we get out
into the galaxy, we'll find plenty of planets with single-celled life,
but no other civilizations. I don't WANT it to be that way, but that's
what the evidence seems to suggest.

Best,
- Joe

sailorbarsoom@... [spacesettlers] wrote:

> Not only does anybody guessing that they are or are not there have a
> 50/50 chance of being right, but a much better chance of never finding out.

True story about chances.

A friend of mine is on a county volunteer Search & Rescue team in
Colorado. Once a year they have a meeting/training with the local
rescue helicopter pilot. This guy says -- quote -- "Every time this
helicopter takes off, there is a 50/50 chance it's going to crash."

My friend says he looked at his buddies, wondering if the guy was
kidding. But he wasn't. He argues that either it will crash or it
won't crash, so it's a 50/50 chance.

This is, of course, ridiculous. Now and then somebody tries to explain
probability to him, but he won't listen. It's funny and sad at the same
time.

Anyway... let's not be like this guy. :) We can estimate probabilities
based on measured statistics, or theory, or some combination of both.
It can be hard to know how good our estimate is... but I'm pretty sure
we can do better than 50/50.

> But since we can all speculate, I'd like to suggest a Great Filter of my
> own.
> Eucaryotic life is weird, in its very existence. A germ ate another germ,
> but instead of digesting it they lived happily ever after and gave rise
> to all multi-cellular life, and a decent chunk of unicellular life as
> well. How likely is that? How many planets have great conditions for
> life, and life arose, but that particular bit of
> predation-turned-marriage never happened?

Possible. It looks like eukaryotic cells first appeared about 1.5
billion years ago. That was after more than 2 billion years of
prokaryotes swimming around.

So, yeah, I could see that. Maybe when we finally get out there, we'll
find planet after planet of prokaryotes, but nowhere else that made that
leap.

Or, more likely, a few scattered planets here and there that made that
leap, but didn't make the next one.

If we wanted something Drake equation-ish, this is what we should be
focusing on: what is the average (and standard deviation) time to cross
each of these filters? Then we can add those up to get an estimate for
the distribution of time to colonize the galaxy, and from that, figure
out how likely it is that that hasn't happened yet.

Estimating those values is hard, of course, because we have only a
sample size of one... but it's no harder than estimating the silly terms
in the Drake equation, and far more useful.

> But like everybody else I don't really know. The Universe could be
> crawling with eucaryotes or something equivalent. As far as that goes,
> who knows how many "something equivalent" there could be?

True. But it's a hypothesis (which we could frame more concretely as
something like: going from prokaryotic life to eukaryotic life takes an
average of ten billion years, with a standard deviation of 5 billion or
so) that is falsifiable. We just have to get out there and start
gathering statistics on other pockets of life!

Best,
- Joe