
Two potentially life-friendly planets found orbiting a nearby star - TuringTest
https://www.nationalgeographic.com/science/2019/06/two-potentially-life-friendly-planets-found-12-light-years-away-teegardens-star/
======
mabbo
Being that close also offers us a better ability to examine it. The nearer the
star, the more arc-seconds (or tiny fractions thereof) the star will appear in
telescopes. 12ly is ridiculously close!

It also tells us something interesting. If we presume there's nothing special
about our little corner of the universe, then the distance to the nearest
potentially habitable planets gives us an estimate of how many habitable
planets are out there. Only 12ly away and that one has maybe two habitable
planets? That tells me the universe is teaming with potential homes for life.

~~~
joshuahedlund
Yes 12 ly is amazingly close!

> If we presume there's nothing special about our little corner of the
> universe, then the distance to the nearest potentially habitable planets
> gives us an estimate of how many habitable planets are out there

I would put a slight caveat to this - I would argue we _do_ know there's
something "special" about our little corner of the _galaxy_ , at least - we
are in the continuously habitable zone - for example, there are billions of
stars at higher densities closer to the core whose planets are _likely_
uninhabitable due to toxic levels of radiation, GRBs, etc. So I actually might
expect other planets near us to be more habitable on average than at least
some other places in our galaxy.

But I also think it's too soon to know how potentially habitable these planets
are, until we have a chance to check a bunch of other things on the checklist,
like the long-term stability of the sun's output and the planet's orbits, the
frequency of destructive solar flares, the frequency of asteroid bombardments
(if there are no Jupiters to absorb them), etc.

Regardless the close distance should make it much easier to answer these sorts
of questions than it would be far planets much farther away, and I'm excited
to see what we can learn in the coming years.

~~~
soulofmischief
Wouldn't each system's star do a decent job of pushing back extra-solar
radiation? Up to a point, obviously, but it would seem that planetary
background radiation levels aren't a direct function of solar density.

~~~
akiselev
It's not the density of the star but the density of stars. Dense clusters like
those found in the center of our galaxy create a lot of secondary effects like
bigger stars pulling matter away from smaller stars (creating lots of
background radiation and matter floating around) and then stars plow through
those interstellar clouds, creating deadly bursts capable of cooking entire
planets, stripping away their atmospheres, etc. In the center of the galaxy,
these events happen so frequently that it's extremely unlikely life on any of
the planets would survive long enough to evolve beyond simple single celled
organisms.

~~~
soulofmischief
I'm talking about the local solar density, not an individual star's density.
Obviously that has little effect on the habitable zone of a planet.

My question was about the ability of a system's star's own radiation to ward
off extra-solar radiation and what kind of limitations we are aware of.

~~~
snowwrestler
Electromagnetic radiation from one star does not repel electromagnetic
radiation from other stars. If it did, we wouldn’t be able to see stars at
night from the Earth.

~~~
xelxebar
> If it did, we wouldn’t be able to see stars at night from the Earth.

Ha! I love straighforward sanity checks like this. My initial reaction was to
ask myself about photon-photon collisions which are im fact possible, but your
comment gives a nice Fermi bound on how rare such events actually are. Cool!

~~~
Robotbeat
Photon-photon collisions are still technically possible... I remember a
professor mentioning this as one question he got in grad school... draw out
the Feynman diagram and you see a vanishingly small probability of photon-
photon interaction.

But yeah. Ionized particles like Galactic Cosmic Rays can be repelled by the
local stellar magnetic field, but mostly the lower energy rays are deflected.
Higher energy -to-charge-ratio GCRs can punch right through the weak stellar
magnetic field, just like do for our Sun’s interplanetary magnetic field.

~~~
soulofmischief
Thank you for understanding my question before reaching for dismissal :)

I knew low-energy waves are partially deflected, I just wasn't sure about
high-energy waves. Makes sense!

------
XorNot
The note that it's an old star makes me worry though. If they're older then
us, and habitable, were they inhabited?

Our current era is a few hundred years of real, directed technological
development. A few thousands years either side of that and who knows what we'd
be looking at, but you imagine that - hopefully - the general progression of
technology is forward.

So if they were inhabited, what happened to them? Are they _exactly_ at our
level of development? Earlier? Hopefully. Because later poses some real big
questions - does technology top out about where we are now - no FTL travel, no
really big radio transmitters or stellar engineering? No probes to nearby star
systems? Did they even make it past the nuclear age, or avoid wrecking their
climate?

One thing's for sure - if there's really 2 habitable planets, with liquid
water, then we've got a hell of a target to point James Webb at when it
launches - an infrared spectrum star should mean any plant life is well
optimized to towards the redder end of the spectrum - we should see some type
of chlorophyll.

~~~
caymanjim
> So if they were inhabited, what happened to them? Are they exactly at our
> level of development? Earlier? Hopefully. Because later poses some real big
> questions - does technology top out about where we are now - no FTL travel,
> no really big radio transmitters or stellar engineering? No probes to nearby
> star systems? Did they even make it past the nuclear age, or avoid wrecking
> their climate?

You get more than one chance. While finding intelligent life would be great,
finding any life is nearly as great. We might not catch them at a comparable
technological moment, but over 8 billion years, intelligent life could have
come and gone many times. All we need are some biosignatures to confirm that
something's out there, and exploration will kick into overdrive.

~~~
rdm_blackhole
> _While finding intelligent life would be great, finding any life is nearly
> as great._

That would actually be worrisome. If we found and detected microorganisms on
nearby planet e.g 12 light years away from earth, then that means we are
probably headed for extinction.

The reason is the theory of the Great Filter. Given that we have not been able
to observe any kind of activity outside of our solar system, it means that
either life is rarer than we think or that entire civilisations go extinct
pretty quickly.

If we find microorganism on a nearby planet, the logical conclusion is that
life is not as rare as we think but evolved civilisation such as ours simply
go extinct in a relatively short amount of time.

The Great Filter may be ahead of us.

~~~
thfuran
Have we done anything that we'd be able to detect from 12 ly?

~~~
xenadu02
The window for detection at different power levels is probably quite small.

Very early radio would be somewhat weak. The middle phase of analog
transmission probably has some higher power levels. The digital phase would
coincide with rapid decreases in detectability.

That assumes every planet capable of supporting life a) has life and b)
develops intelligent life. If only 1% of planets capable of supporting life
develops life and only 1% of those develop intelligent life then it is
extremely unlikely these two nearby planets would have any life at all. Even
if you bump the odds to 10% or even 33% the odds are still against it.

For sake of argument assume we (or they?) won the lottery and intelligent life
exists. Make an even larger stretch and assume that life is technologically
capable, has been for 10,000 years, and didn't destroy themselves (achieving a
stable population size and reasonable resource usage). Even then the odds are
against us detecting any kind of radio transmissions.

------
petercooper
_" just 12 light-years away"_

I love the "just". I know it's nearby on galactic scales but it's practically
about 450,000 Earth years away with current technology :-)

~~~
lmm
> I know it's nearby on galactic scales but it's practically about 450,000
> Earth years away with current technology :-)

If we had the political will, the Orion design could get people there in,
what, 200 years, and that's with '70s technology.

~~~
tictoc
Imagine being the child born on the ship on a crash course to this new planet.

~~~
onemoresoop
And imagine you're the first ship to arrive only to find out

a) that the planet is not habitable and there were some wrong assumptions
about it

b) that the planet is already occupied by a different form of life and there's
no warm welcome to us

~~~
corodra
This is also assuming

A) Human engineering can create something that can last 200+ years of space
travel. We don't even build houses anymore that can feasibly last 100 years.

2) People don't go mad and kill each other or do a mutiny

III) Any number of stray objects from asteroids to rogue planets that just
slams into the ship and causes major malfunctions

d) Food and life support sustainability

I mean... there are SOOOOOOOO many more problems than actual politics. This is
where, and it hurts me to say this, the politicians are right to say "are you
insane?".

~~~
svd4anything
> d) Food and life support sustainability

Could we just send frozen embryos of humans and then have the ship auto thaw
and gestate them 16 years to arrival?

With another 2-300 years of technological progress this doesn’t seem
outlandish mission at all.

~~~
8note
that sounds highly unethical. none of those people agreed to go on the trip

~~~
svd4anything
did any of us agree to go on our current trip? I do see your point but I think
eventually humans might do it.

------
cptaj
And to think that there is likely an Easy Mode system out there.

A habitable planet on the low end of the mass spectrum needed for a stable
atmosphere with other habitable planets in-system. And all that close to
another star with habitable planets, possibly in the sub-lightyear range.

Basically everything ripe for a spacefaring civilization to grow without too
much trouble and with plenty of motivation.

The Earth is hard to leave and everything else in our system is dead rocks
with hellish environments as far as we know with the nearest alternative at
least dozens of lightyears away

~~~
MRD85
Imagine an easy mode planet in a system with multiple habitable planets. Now
that I've typed that I'm also considering how Mars would look from 12 light
years away.

Is establishing a colony 12 light years away easier than transforming mars
into a habitable planet?

~~~
jl6
Harder, I think. We have the technology to live on Mars (not to terraform it,
just to survive on it). We have some ideas from physics about how to get to a
planet 12 ly away, but not the technology. Nor, I would argue, do we have the
social and political setup required for such a project, which would most
likely take hundreds of years to get to a basic colony.

~~~
blotter_paper
> We have the technology to live on Mars (not to terraform it, just to survive
> on it).

I'm not convinced this is true intergenerationally without a maternity ward in
a centrifuge; the low gravity mouse embryo experiments don't look promising.
Maybe 1/3rd earth gravity is enough, but I'm doubtful. If we're granting
centrifugal habitats as something doable with current technology, an
Orion/Daedalus style nuke-propelled spacecraft seems in the same ballpark.
It's been sketched out and tested with models, it's clearly possible, but
nobody has really made one yet and it's a hell of an engineering problem
still.

~~~
kevin_thibedeau
We should be colonizing the moon first, then Phobos or Deimos. Then, once
established, we can conquer the martian gravity well with local resources.

~~~
blotter_paper
I like Musk's plan of using Mars as a fuel-planet, I just don't expect a self-
sufficient colony for some time. Mars is like an oil rig or a mineshaft; no
place for children.

~~~
jacobush
In fact it's cold as hell.

And there's no one there to raise them if you did.

------
dheera
"Habitable" in also relative to our Earthly form of life. There may be other
architectures that prefer different temperatures and pressures, perhaps.

~~~
derekp7
Also, from 12 ly away, I'm sure that Sol would appear to have at least 3
habitable planets (Venus, Earth, Mars).

~~~
TheOtherHobbes
Sol does have three habitable planets. Plus some moons, at a push.

Habitability isn't a Boolean. It's hugely dependent on history, context, and
resources.

The more Boolean distinction doesn't have a name - but if it did, it would be
something like Stable Evolutionary Potential.

Mars and Venus both fail on that. The moons fail on it now, but may pass when
the Sun turns into a red giant.

The Earth has offered it for long time, with some uncertainty about the near
future.

There's no reliable way to distinguish SEP at a distance. But noting that a
star has planets in its habitable zone and making some estimate of how many
planets in stable systems are likely to offer SEP is a decent start.

~~~
hueving
>The Earth has offered it for long time, with some uncertainty about the near
future.

What uncertainty is that? Nuclear winter won't even wipe life off the planet.

------
skribbj
How common are "life-friendly" planets (Let's say: on a ratio of Life-Friendly
Planet:Non Life-Friendly Planet)? And is there any way to check if life-
friendly planets contain life without actually going there?

~~~
maxxxxx
There are plans for doing spectrography on the atmospheres of these planets.
This would allow us to get a pretty good picture of the chemical composition.
Biological life as we know it should leave a different footprint than a
lifeless planet but in the end we can only extrapolate what we already know
about life.

~~~
civilian
Yep! And more specifically, if we found a planet that had an atmosphere with
O2 in it, that would be highly indicative of life. Although it's not the only
option, O2 is pretty reactive, and you need a constant O2-producing force to
maintain it. An O2-producing force would be something like plants or some life
that is creating hydrocarbons from CO2 and H2O.

------
CWuestefeld
I saw a study recently, unfortunately I can't locate it now.

It discussed the possibility of there having been past civilizations on Earth,
hundreds of millions or even billions of years ago. The conclusion was that
this can't be entirely ruled out. It noted how few actual fossil remains we
have for what we know of dinosaurs, and that there's a _lot_ of space left in
those gaps for all the evidence to have been destroyed.

~~~
hesk
Maybe it was this?

Gavin A. Schmidt, Adam Frank: The Silurian Hypothesis: Would it be possible to
detect an industrial civilization in the geological record?,
[https://arxiv.org/abs/1804.03748](https://arxiv.org/abs/1804.03748)

I found it through an article in The Atlantic that may or may not have been
linked on HN recently.

[https://www.theatlantic.com/science/archive/2018/04/are-
we-e...](https://www.theatlantic.com/science/archive/2018/04/are-we-earths-
only-civilization/557180/)

~~~
lioeters
Indeed, there was a discussion about this article, about a year ago. As a fan
(and amateur writer) of science fiction, I greatly enjoyed learning about this
hypothesis.

Was there a civilization on Earth before humans?

[https://news.ycombinator.com/item?id=16837120](https://news.ycombinator.com/item?id=16837120)

------
westoque
Waiting for the moment where we actually find a habitable planet with
intelligent life. Next thing you know, we'll be developing ways in order to
communicate with them, not just observing them.

------
vkaku
Stop teasing me, Universe - and show me the aliens already!

~~~
krisroadruck
Check out the Dyson Dilemma for a well-reasoned theory as to why it is a high
probability that there is no space-faring intelligent life anywhere in our
galaxy or even perhaps our super-cluster.

[https://www.youtube.com/watch?v=QfuK8la0y6s](https://www.youtube.com/watch?v=QfuK8la0y6s)

~~~
sulam
There are holes wide enough to fit a solar system through that argument.
Reductio ad absurdum.

Here, I'll construct an argument in a similar form. People don't like
mosquitos, for various reasons including that they transfer deadly diseases.
Therefore the presence of mosquitos says there's a high probability that the
planet isn't actually inhabited by us, because we would have killed them by
now. After all, we have the technology.

Maybe, by the time we get around to wanting to construct a Dyson Sphere, we
will have found a better alternative. Maybe they aren't a good idea for any
number of reasons (if you need one, read the Cixin Liu "Dark Forest" series).

Any argument of the form "X is inevitable but hasn't occurred, therefore Y"
first needs very strong proof of the inevitability of X.

~~~
fastball
To be honest, I've never really understood how a Dyson sphere would be
superior to many nuclear fusion reactors that you can move around / turn off
and on / build more of / etc

~~~
michaelmrose
The sun is 99.9% of the mass in the solar system. Most of the rest of the mass
is in Jupiter.

If you are ultimately bounded by energy requirements then solar is where most
of the available energy is even if you literally cannibalize the gas giants.

------
Tepix
There was a paper recently that argued that the habitable zone is smaller than
anticipated because either the concentration of carbon dioxide will be too
high (and thus toxic at least to life on Earth) or - for small stars like this
- there will be (toxic) carbon monoxide in the atmosphere.

[https://phys.org/news/2019-03-complex-life-require-narrow-
ha...](https://phys.org/news/2019-03-complex-life-require-narrow-
habitable.html) (good article with link to the paper)

~~~
nine_k
Life on Earth lived in CO2-dominated atmosphere for 1.5B years. If anything,
CO2-rich world which is not overrun by SO2 and chlorine and phosphoric
anhydride and scorching heat, like Venus, is as "potentially life-supporting"
as it gets, save for a world with actual oxygen-producing life like ours.

------
TwoNineA
I was under the impression that planets to be life-friendly have to be close
to their red dwarf star to a point they'll be tidally locked (one side always
light other night), meaning their atmosphere would freeze on the dark side and
planet would end up without an atmostphere.

~~~
sushibowl
This was indeed the prevailing wisdom for some time. However, more recent
research is somewhat more optimistic. Even an atmosphere 10% as dense as that
of earth can circulate heat to the dark side efficiently enough, given the
right composition. The night side temperature could be within the parameters
required to sustain some form of life.

Furthermore, tidal locking is dependent on oceans and atmosphere, and can take
many billions of years to occur, or even never. Mercury has plenty of time to
tidally lock but is in a 3:2 resonance with the sun. There are even other
options; for example, moons of gas giants within the habitable zone would be
tidally locked to their primary and thus have a day-night cycle.

~~~
jerf
"However, more recent research is somewhat more optimistic."

I am deeply skeptical of that "recent research", which AFAIK is "computer
models, where we have zero capability to verify the computer models against
even a single data point".

The incentives to keep kicking the computer model until it provides something
publishable, with no countervailing force provided by real data to be
explained by the model, are just too strong for me to take that too seriously.

~~~
abdullahkhalids
Physics models are often checked against other models (which might have had
some confirmation) in simple cases, and there are a lot of other sanity checks
you can make on them to ensure they are providing reasonable results.

Obviously, one shouldn't blindly accept them without experimental
confirmation, but one shouldn't also be wildly pessimistic in believing
calculations grounded in three centuries worth of validated equations.

~~~
jerf
Yes, I'm sure the simulations don't have results like making these atmospheres
suddenly collapse into black holes due to errors in the simulation or
something. They'd notice.

But these atmospheres have to stable across cosmological scales in a highly
iterative, chaotic environment. There is a mathematical lower bound on the
rate such simulations _must_ leak bits as a result of those things. I don't
think we have enough bits of real information to make up for that, as it would
take rather a lot.

Against the mathematical argument, I set the human argument that, like I said,
there's all sorts of incentives to report the one simulation that produced the
result that there may be an atmosphere and maybe it could even sustain life!
That's a lot of high-profile articles and probably a promotion for getting my
department some public attention. Even if hundreds of other simulations all
result in "Yeah, the atmosphere freezes out".

Between the math saying we can't really expect this sort of simulation to
contain meaningful information and the human factors involved, I can't put a
lot of confidence in a model which can't be validated against real data.

I do find it amazing how people who probably think they're really in favor of
science and support it will jump up to defend a methodology that literally
runs off of _zero data_. Can someone explain the scientific process to me
clearly that involves having no data at any point?

------
_Kristijan_
Feels like we're playing the first round in "Master of Orion" when you start
scanning the stars around you ;)

~~~
jzawodn
I still love that game.

~~~
WhompingWindows
I remember around 2003, making huge battleships in that game and squaring up
against the AI's armada. The AI made about 500 tiny ships with weapons
incapable of breaching my shields, and with their own shields incapable of
surviving my dreadnought blasts. I would kill 5 with my big ships, take no
damage from 495 shots, rinse and repeat. The battles took hours! I had to skip
tactical battles, couldn't stand that much time, just had the AI simulate it.

------
clarkmoody
> The team calculates that one of the planets, called Teegarden’s star b,
> completed an orbit in a mere 4.9 Earth-days; the other world, Teegarden’s
> star c, has an orbit of just 11.4 days.

I wonder how our understanding of orbital mechanics would have evolved
differently had our planet orbited the Sun this fast?

If the planets have long days, then they could potentially see in one night
what it takes us a full year to see!

~~~
vkreso
Just imagine the astrology columns in the local newspapers

------
sambeau
_" Seen here in an illustration"_

This half-hearted attempt to say that the impressive-looking image of _The
Nearby Star_ was in fact an artist's impression of what a Red Dwarf might look
like, made me laugh. Is it seen here? Or is it an illustration? I suspect
someone changed the copy just before publishing

~~~
hughes
If you see a picture of the surface of a star that's not our sun, it's
certainly an illustration. No such image exists of any other star.

------
umeshunni
Wouldn't planets orbiting this close to the star be tidally locked to it? If
they are tidally locked to the star, they are also likely to have extreme
temperature variations between the two sides. This could rule out life.

~~~
vikasnair
If that’s true, as it is true for planets in the TRAPPIST system, then at
least there is a potential for life to develop around the thin longitudinal
slices located more centrally, where climate may be more temperate.

Also see this comment below, something I wasn’t aware of:
[https://news.ycombinator.com/reply?id=20212953&goto=item%3Fi...](https://news.ycombinator.com/reply?id=20212953&goto=item%3Fid%3D20212374%2320212953)

I’m curious- at the end of the article, one of the scientists remarks that the
stars might be “zipping around” their host star faster than measurements
predict, which could rule out potential for life. Is this referring to your
suspicion re: proximity => tidal locking => extreme temperatures? Or is there
some way that speed of orbit can affect potential for life?

------
gattr
As for interesting consequences of a vastly different planetary age: in one SF
novel (could be Peter F. Hamilton's, I can't remember right now) humans
colonized an Earth-like planet only some 2 billion years old or so. Its
uranium ores had so high U235 content (as opposed to Earth's 0.72%, which
requires costly enrichment), that you could simply smelt it and put straight
in a reactor (cheap nuclear-powered locomotives anyone?).

------
wppick
By the time our technology reaches the point that we could feasibly travel to
and inhabit another distant planet, and with all the challenges with that
(space travel, terraforming, radiation protection), couldn't we feasibly
create or move a planet or gigantic space station built from materials of
another planet into whatever orbit we want?

~~~
radium3d
Yes, possibly, but my curiosity about the natural life on those other planets
outweighs that thought.

------
m3kw9
For those that wants to live on another planet, you will unlikely like how
things look under another suns sunlight. It is hard to have a planet that will
have day light like our sun and be habitable. Think of a yellow-reddish, or a
light that is cold blue when you walk out. Human eyes evolved with earths
lighting conditions.

~~~
rossdavidh
You assume that any of us ever go outside to see the light on Earth, anyway.

------
totaldude87
If there is a Life friendly planet, which is much older than where we live,
shouldn't there be life forms?

Shouldn't those be searching for other life supporting planets, vigorously
than us since they would be much mature and advanced?

why no one found us?

WHAT IS THE PROBABILITY OF US FINDING AN ALIEN VS AN ADVANCED RACE FINDING US
AS ALIEN?

~~~
nine_k
"We can be either alone in the Universe, or not alone. Both possibilities are
terrifying" (quoting from memory).

------
hirundo
> Teegarden’s star is a stellar runt that’s barely 9 percent of the sun’s
> mass. It’s known as an ultra-cool M dwarf

Is it too late to change the name to Tyrion Lannister?

~~~
wibble10
Tyrion Lannistar _

------
pault
What are the consequences of a star that mostly radiates infrared light for
habitability? Would it restrict what kind of life could evolve there?

------
m3kw9
What I’m interested in is if somehow there is a planet almost exactly like
earth, if so would they have evolved humans similar to us.

~~~
hakanito
I too like this thought experiment! Checkout the movie Kpax with Kevin Spacey
if you haven’t already, it touches on the subject — ”Why is a soap bubble
round? It’s the most efficient form”

------
monomyth
Assuming we have technology to reach a new planet 12 ly away, is going to a
red dwarf star a good investment strategy?

~~~
cududa
If you have the money and technology to go, you’ll just hop to the next solar
system

------
EGreg
Perhaps habitable planets will be necessary for human migration and
colonization, rather than finding aliens.

------
kristianp
Is it possible to determine the atmospheric composition of these planets? How
much water for example?

------
m3kw9
Why aren’t we discovered? Probably because an advanced civilization but barely
reach for the first time would be wise not to fly in risk getting detected and
captured. So they wait till they have overpowering cloaking ability before re
attempting a sighting. Maybe by that time, we are no longer interesting
because of their own advances

~~~
m3kw9
Also there is probably a super small probability where both civilizations are
in similar advances that they can brave a encounter without worrying. If one
is way more advanced, either one may not be interested, or the less advanced
one chickens out/ gets destroyed because they want to hide their location.

------
known
I don't think there is redundancy in Universe

------
guru88
Do these planets have their own moons?

~~~
sampo
Moon-size objects are probably not detectable with current technology.

------
iamgopal
How do we check about life that far?

------
kingkawn
Only 70 trillion miles away...

------
thepangolino
Calling than A and B

------
siruncledrew
"nearby"

------
dboreham
Telephone Sanitizers and Hairdressers back your bags!

------
cjbprime
The trilogy _Three Body Problem_ is a good read, and has something to say
about this. :)

~~~
psychometry
I had high hopes, but TBP is a terrible novel. It certainly has some
fascinating ideas, but just as many ludicrous ones that are equally central to
the plot. Not to mention Liu is absolutely terrible at anything relating to
characters: dialogue, character development, etc.

~~~
CWuestefeld
Over in the s-f subreddits, this novel gets so much love. So I feel left out
that I - like you few here - really hated it.

My big thing was that the science is just _wrong_.

Most fundamentally, it's not a three-body problem, there are (at least) four
bodies: the three suns and the planet.

And the real world isn't going to follow any theoretical solution to TBP
anyway. There is atmospheric drag, microscopic gravitational perturbations
from the rest of the universe, decreasing solar masses as the stars age, and
so forth.

In a system as chaotic as was described, any of these things make the problem
intractable.

That said, I did enjoy the description of a digital computer implemented with
"people" acting as the logic gates.

~~~
losvedir
I don't understand your opposition to the name. The three body problem is so
named precisely _because_ it's intractable. In physics with two bodies you can
perfectly model the evolution of a system, but as soon as you add a third it
becomes chaotic and requires numerical simulation to approximate solutions.

~~~
CWuestefeld
_I don 't understand your opposition to the name. The three body problem is so
named_

Look at my first objection, that the problem described in the book has (at
least) _FOUR_ bodies. Yet the idea that it's a three-body problem is pervasive
throughout the book.

Surely that in itself is enough to justify some aggravation.

------
reneberlin
How long will it take until the next planet is overpopulated and resources are
consumed?

I mean: birth control? Socialism? Rules to obey?

If it is a competitive race it will end up pretty much the same. The question
is then only: how long will it take?

Over to the next one ...

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JaggerFoo
You got me. I'm from one of those planets.

A group of us decided to move to earth for the warmer weather. It's also why
most of us live in California and Florida.

Tan Mom is our leader.

