Grizzly Bears from Outer Space

A region of space barely a thousandth of a square degree on the sky contains a whopping 5,500 galaxies. Making the probability that there exists at least one planet that could support life pretty tantalizing. What might that life form look like? Robert and Joe discuss cosmologist Fergus Simpson's statistical argument that an extraterrestrial could weigh in at 660 pounds. My friend, can your heart stand the shocking facts of grizzly bears from outer space?

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Episode Transcript

Speaker 1 (00:03):
Welcome to Stuff to Blow your Mind from how Stuff
Works dot com. Hey, welcome to stuff to Blow your Mind.
My name is Robert Lamb and I'm Joe McCormick. So Robert, Yes,
I want you to do a little experiment with me.
All right, let's do it. Put yourself in the shoes

(00:23):
of a paranormal phenomenon investigator. Okay, okay, somebody with some judgments,
some authority. You're not necessarily a skeptic or true believer,
maybe somewhere between Molder and Scully and you old scolding
older sculder exactly. You are Sculder, and you have just
been caught by security guards while raiding the file cabinets

(00:47):
of a secret evidence room chock full of alien conspiracy documentation,
and before you can get a good look at all
these autopsy reports and heavily redacted witness Affidavid. You've pulled
the security guards who caught you. They lead you down
the hall, this long dark hall, to the office of
a bald man with a goatee and a green Paisley

(01:10):
bow tie, obviously a major player in the shadow government. Yes,
that's what the bow tie signifies. So Paisley bow Tie
stares you down, and he says, Okay, hot shot, you
think you know a lot about aliens. Well, I've got
a test for you, and if you pass the test,
I'll let you in on the whole conspiracy and you

(01:30):
can know everything. But if you fail, you're going to
spend the rest of your career at a weather station
in the Arctic Circle. Okay, so the stakes are pretty
high here, right, So he pushes a short stack of
staple documents across the desk towards you and gestures for
you to peruse them at your leisure. And here's what
he says. One of these five accounts is true. The

(01:53):
other four are lies. Pick the right one and you pass.
So you flip through the documents. They tell this first
person account of a young woman who was abducted by
aliens while hiking on the Appalachian Trail, And in all
five accounts, the abductee is lifted off the ground in
this beam of strobing violet light and sucked into the

(02:13):
interior of an alien spacecraft, where she meets a group
of aliens. They take a blood sample, They check our
blood pressure, maybe do a cheek swab cotton swab on
the inside of the mouth, very on the level. Everything
is very professional, yes, uh, and then the next morning
she wakes up in the forest with vague memories. Now,
the only difference in the five accounts is how the

(02:35):
aliens are described physically. So, in one account they're tall,
about seven to eight feet tall, beautiful humanoids with smooth
skin and pure white eyes. In another one, they are short,
stout humanoids about three to four feet tall, covered in
thick black body hair from head to toe, with curling

(02:58):
tusks extending for the lower jaw. Okay, so so far
we have elves and we have dwarves to choose from. Gotcha? Yeah,
pretty much? Okay. Then you've got eight legged, crab like
animals with a brittle exoskeleton, two pairs of grasping claws,
one larger pair and one smaller pair of claws, and
compound eyes. The whole creature is approximately the size of

(03:20):
a cargo van. Giant crab. Gotcha. Then you've got small
blobs about one meter cubed of thick beige putty that
seemed to move as though guided by intelligence, and they
interact with onboard machinery and communicate psychically with the abductee.
Each one moves about on the spacecraft on four long
stilts on the underside of the putty, and occasionally they

(03:43):
excrete small puddles of sludge resembling muddy snow onto the
floor of the cabin, and these puddles are promptly removed
by room by like robots that emerge from the vents
whenever needed. And then in the fifth account there are predators.
They just straight out predators from the dreadlocks, the wrist blades,
the mask predators. Okay, so which one is the true account?

(04:05):
M Now this is an interesting quandary to deal with
because on one level, like just knowing what I know
and what I actually believe about encounters with aliens, and
in any kind of paranormal experience, I would I would say,
I would want to pick the thing that could that
that that matches up with our expectations more in our

(04:28):
popular minds that concerning aliens. So in that regard, I
would tend to either go with predators or or perhaps
the the eleven creatures, because they're kind of matches there
the grays right. Okay, so you're saying you're more likely
to see these show up in fiction, So so that
this seems like if one were to have a paranormal experience,
if one were to have an hallucinatory experience, um, your

(04:52):
mind would would be more likely to pick from those
two buckets of alien content. However, wait, hold on, so
wait are you assuming the abduct team made this whole
thing up? Yeah? That my My first response to this
would be, all right, this, this individual has had a
paranormal experience that feels very real to them, but is
ultimately uh, but is ultimately not supernatural. It's ultimately is

(05:17):
all about their mind uh making sense of some sort
of um, you know, abnormal experience. But so she actually
just kind of like got dizzy from walking too much
one day, passed out and dream you know, she's or
she's been awake for an extended period of time. However,
if i'm if, I'm going to get outside of that
mindset and get in the mindset if someone's actually act

(05:40):
actively assuming as same one actually happened, assume one of
these is actually legit. I would probably go with the blobs,
because the blob idea, as as you laid it out here,
feels weird enough, unique enough, inhuman enough, and departed enough
from our more mainstream ideas of what alien life who

(06:01):
consists of so I would think that one sounds out
there enough to actually be out there. You know, I
wondered myself because I was trying to decide after I
wrote these which one is more plausible. And I also
felt like the blobs. But maybe that's just because I
used the deceiver's tactic of adding interesting details like the
stilts and the and the sledge pooping on the floor

(06:23):
that seemed to make things more believable. If you add
weird little details, yeah, you you embellished it enough to
where I I got a sense that there was actually
some sort of, h you know, a culture going on here.
If you were to subtract to those details, I wonder
if I might not drift towards the crab. You know,
I I love predators, but I might have to go
for the crab because the crab has two things going

(06:45):
for it. It's both weird enough and different enough from
humans to be sort of conceivable as as outside the
realm of normal standard abductee imagination. But it's also familiar
enough that I can see biology creating that. I'm not
quite sure that the chemicals available in the universe would

(07:09):
create sentient blobs. Maybe that would, but I'm not sure.
I know that the chemicals in the universe can create
things like crabs, yes, And I guess my reluctance to
go with the crab is that it's essentially a giant crab,
that it's essentially just something very terrestrial that it's just
been u spaced out a little bit, you know. But

(07:30):
there's one feature of the giant crab that might actually
be a selling point, depending on how much credence you
give to a recent paper that came out that's sort
of like the inspiration for this episode, which is that
the crab is the size of a cargo van. Uh.
And this is a paper we're gonna get to in
a little bit, but it actually did some statistical calculations

(07:51):
to try to determine one particular aspect of what alien
bodies are going to look like in that aspect's size,
because obviously there are countless additional questions regarding the possibility
of life elsewhere in the universe, but this particular study
that we'll look at deals exclusively with just the size

(08:12):
of the organism. Yeah, and well in the numbers you
would expect and what their planets look like. But the
one takeaway about the alien bodies themselves is the size.
But I thought that was an interesting thing to address
because actually, in fiction we've seen a vast sort of
range of imagination in how large aliens can be expected

(08:32):
to be. Obviously, the most common are your human sized aliens,
because they are there are human actors playing them. That's right,
I mean, that's always the concern, right if you're and
and it is understandable if you're dealing with you want
to get a really cool sci fi idea out there,
and you want to discuss it, and you want to
shoot it in a way that actually, uh comes under budgets.
Under budget, It's far easier to just put somebody in

(08:55):
a guerrilla suit than put a microwave on their head
and call it an alien robot. Yeah, the what was
his name? I think I have it in my Roman
Roman Extension x J two. Yeah, folks at home, if
you haven't seen Robot Monster, it's a classic. It's pretty fun.
I mean I like to think of it as um,
you know, kind of like a biospace suit worn by

(09:17):
some other organism that just happens to look like a
gorilla costume with a like a TV set on its head.
Oh that's interesting, but yeah, we have countless examples, like
Star Wars and Star Treker are particularly just loaded with
humanoid roughly human size alien species, the track being the
most scandalous in its way because it's because we you know,

(09:38):
it's just like a ripple on the forehead makes this
species and this entire you know, this entire strain of
evolution different from this one, or sometimes just give them
different clothes. That's enough. And then, of course there is,
in my opinion, the greatest and most scientifically plausible vision
of alien life ever created, which is Cone Heads. Yes

(09:58):
you are now are you yourst referring only to the
original Saturday in Life skits or the Oh no, I'm
including the films. Yeah, the film includes lots of relevant details. Yeah,
we we learned about their mating practices and so well.
I don't know. Those might have been the sketches too,
I haven't seen all of them. I remember they had
a great stop motion creature in the film. It actually,

(10:19):
yeah they did. I think it was claymation. It was
this Ray Harry Housing kind of thing. I don't know
who actually created it, but it was pretty awesome. There's
a monster towards the end. I can forgive just about
any film if it has a cool stop motion creature
in it, I am right there with you. You ever
made it to the end of Howard the God, I
was just thinking about Howard the Duck, like that's literally

(10:39):
the only thing that I remember about it is that
at the end um the dude of the mustache turns
into this awesome, like weird technically creature and and it's
it's glorious the dark overlord of the universe. Yeah. But
then of course we've also got aliens that have been
imagined to run rather to the small side, which I

(11:00):
think is kind of interesting. Often if you hear the
actual abductee stories, so you go back to that scenario
we had at the beginning, I think most likely you're
going to hear that people were abducted by the gray aliens, right,
which you're typically pretty small, right, Yeah, generally got two
to four feet tall, and you're in varying accounts. Yeah,
this is this is sort of the alien mythos that

(11:22):
has sees the popular consciousness, and so they're these short, smooth,
gray things with large black eyes, big heads. Yeah. So
it's since it's the idea that's in the popular consciousness.
People have these paranormal experiences and they tend to draw
from that that bucket of content, if you will. Um
outside of the grays though, the average ewalk stands about

(11:44):
three ft tall a little over depending on the you
know they ran. You have your your wickets, but then
you also have those bigger, sort of chunkier monkeys. You know.
I do wonder exactly how small and actually intelligent organism
could run. Indeed, I mean in our science fick and
you see, uh, such creatures as the virus, the flood

(12:05):
from Doctor Who, or the thing from John Carpenter's two Masterpiece,
where every cell of the shape shifting organism is itself
an individual organism with its own survival instake. And that's
how they end up discovering who has been replaced by
the thing sticking the hot wire and the blood and
seeing if the blood tries to escape. Yeah, yeah, they

(12:26):
take a blood sample from each one, and if your
blood tries to defend itself, that's not a good sign. Yeah,
And that's uh, that's if not a space faring species,
at least a species intelligent enough to steal the space
faring technology from another species. Yeah, so it could perhaps
co opt the intelligence of a host species, if even
if it's not particularly intelligent or conscious itself. But certainly

(12:50):
when we look at terrestrial models, and we'll be coming
back to this again and again, um, it's it's hard
to find any examples of a particularly small all life
where you can say, oh, well, there you go, that
that could be a space faring species on its own. Yeah.
But of course this paper we're about to talk about
in a minute doesn't say that aliens run small. It's
ays that they run large. And we've got no shortage

(13:14):
of large aliens. You could run all the way up
to probably some Kaiju monsters, right, Oh yeah, yeah, the
let's see. Uh I was looking around and there are
a lot of Kaiju monsters to consider, Um, how many
of them are actually aliens though? Yeah, because yeah, a
number of them have more terrestrial origins. I found one,
in particular, a hundred and thirty foot tall millenniums from

(13:37):
god Zilla two thousand UM millennium which came out and
uh I, it seems like various other Tohoe properties in kaiju,
and certainly when you get into um like power rangers
and whatnot, right. I mean, they're always battling some sort
of giant creature. And but doesn't that take a magic
wand to make the monster grow? Well? Yes, but if

(13:59):
you look at them, magic wand is some form of technology.
I don't know, it gets kind of complicate. But but
even then you have other examples of really huge alien
life and sci fi. Um. You know, Old Cathulu stood
hundreds of meters tall, and he, of course was an
extraterrestrial creature. What about the native inhabitants of Arakushea, the sandworms, Uh,

(14:21):
they are They at least had been measured up to
four d fiftys long, but there were speculations that in
the polar regions of Iraqis they might reach seven hundred
or even a thousand meters. So that's uh, upwards of
three thousand, hundred and eighty feet long. That's pretty big.
I'm not sure why, but intuitively I find it more
plausible that a giant land dwelling animal would be worm

(14:45):
like and sort of horizontal, rather than like a upright
two legged kaiju monster. Yeah, I think that. Yeah. The
larger to get when you start looking at the limits
of morphology, um, Like the human model is just gonna
fall upon part if you just try and wave the
magic wand at it right. And then then of course
you've got your aliens that are just basically huge humans, right,

(15:08):
the engineers of Prometheus, they're about seven ft tall. Um,
there are the oh did you ever see Fantastic Planet?
Actually haven't? Oh yeah, nineteen three wonderful animated film, and
you have these these enormous blue humanoid drugs uh stand
about three nine ft tall, and they keep little human
homes as pets. So they are these little naked humanoids

(15:29):
that they they kind of dress up in like weird
kind of cute, kind of sexy doll costumes and just
keep them as pets. It's a creepy, fabulous film. But
but they had another extra large critter there. Um, there's
a tin foot tall species and E. N. M. Banks
culture series uh known as the Darians. And they're also

(15:51):
a three legged uh species, which is interesting. I think
that's interesting because fun fact, did you know that there's
no such thing as a three legged animal anywhere on Earth? Um,
not a single side of the dogs you see, but right, well,
and naturally occurring three legged animals. So there are some
things that sort of actual like a tripod by using
back legs and balance with a tail or something. So yeah,

(16:12):
some things like a kangaroo or something might sort of
use a tail sort of like a leg, But there's
no such thing as a three legged animal. That's kind
of a strange fact about the way life emerges on Earth.
If you go millions of years back, you see certain
particular body plans emerge, and one of those body plans
is the four legged body plan that informs all reptiles

(16:35):
and mammals. But you didn't have an ancestral three legged
body plan to grow into animals that survived today. Yeah,
the the sort of stand the standard models become set
in stone evolutionarily, and uh and and yeah. So if
you go back far enough, I feel I feel like
there there is an example or two of like three

(16:55):
eyes and very small creature. Really, I think one in particular. Um, yeah,
animals with odd numbers of features. That's weird, Yeah, but
it is rare. Generally you see the typical two legged,
four legged, two eyes. Yeah. Alright, so we've hinted that
this paper we're gonna talk about says aliens are going
to be rather large. What's the deal with this actual paper. Well,

(17:18):
in March, the cosmologist Fergus Simpson of the University of
Barcelona published this paper pre published on archive called the
Nature of Inhabited Planets and their Inhabitants, which is a
great name for a scientific paper. And so what was
his reasoning? How did he come up with the idea
that aliens are going to be on balance rather big?

(17:40):
Well for starters, he uh largely employs Bayesian statistics, which
is a model based on Bay's theorem. So the way
of calculating probability of things, like if anyone out there
is familiar with what a Nate Silver, right, Yeah, who's
who's made a name from self predicting things like presidential elections,
Like he used his Bayesian logic and in crunching the

(18:02):
numbers on the statistical possibilities of varying outcomes, and that's
scarily good at predicting the future. Yeah, yeah, And it's
this is the same model that that Simpson employees here.
So as we as we mentioned, his work concerns the
statistical probabilities of inhabited planets, how many aliens would be
on those planets, and then the size of those uh,

(18:24):
those aliens, what would be the sort of standard model
and uh and in determining the number of individuals UM
that would most likely live in a given civilization, he
came up with fifty million or fewer individuals. While any
given alien in our universe would likely be from a
high population world in the same way that most people
on Earth are going to be just statistically Chinese, Indian,

(18:47):
or American, um, very few worlds would host either a
small number or or a large number of individuals. Right.
So the idea is that if you randomly select a
human from anywhere Earth, it's more likely they'll live in
China or the United States, one of the most populated countries.
But if you randomly select the population of a country,
you're more likely to select a country that's near the

(19:09):
Median somewhere in the middle. That's you know, like Canada
or some you know, not particularly huge, not particularly small. Yeah,
it's kind of like imagine all the nations of the Earth,
and each nation is its own planet, some large, some small,
and then the larger ones have higher populations. Yeah, okay.
So he also argues that a planet supporting extrastraustrial life

(19:30):
is likely to be smaller than Earth closer to the
size of Mars. Yeah, and he assumes that about fifty
percent of Earth's diameter is there, you know, in the
lower limits. Smaller than that, and it becomes difficult for
the gravity of the planet to hold onto the atmosphere
in water, right, So you see, Mars is pretty much
at the limit it's about of Earth. And Mars actually
already has that problem because Mars has almost no atmosphere.

(19:54):
Asphere is like one percent of the thickness of Earth's,
so that's another factor to take into account. He also
says that each individual alien would be more likely to
live on a big planet, as those worlds can clearly
support more individuals. Kind of again, it sounds like an
overstatement of the obvious, but it's an important one to
get out there. So his basic prediction when you boil

(20:15):
all this down again to figuring out trying to figure
out how many worlds are gonna be um inhabited, and
then how many uh individuals are gonna live in those worlds,
and he says that most of these creatures are going
to be big. Nearly seven hundred pounds three ms, the
size of a terrestrial bear. Um the exact number that

(20:36):
he ends up spouting in the piece is six pounds
or three ms um. So we're talking half the creatures
in the universe are going to weigh more than the bear.
Half are gonna weigh less, but the bear sized extraterrestrial
is going to be the standard model. It's if if
outsiders from another universe peered into ours, according to this paper,

(20:58):
they would say, hey, this is that uni verse where
bear sized creatures with well bear sized creatures do live,
you know. Yeah, And then that's the thing. It is
something that matches up with why, yeah, why isn't the
bear the dominant species on Earth already? Well, perhaps it is,
and we're just kind of being selfish, but well, uh,

(21:19):
you know, there are a number of you know, you
get into arguments and just discussions about why humans evolved
to the point where we have all of this, you know,
this great intelligence and then on top of that intelligence,
technologies and culture, right, and a lot of it comes
down to our need to use our brains to uh,
to score our next meal, to use our our our

(21:41):
intellect because we don't have clause. We don't have we
don't have if we had bear strength, we'd be dumb
because we wouldn't need to be smart. Yeah. I think
the thing is that the bear is just The bear
doesn't need to be super intelligent, because the bear can
do things like like hibernate through the winter. The bear
can care things part with its clause, it can it

(22:02):
can stand up for itself against pretty much anything on
Earth except for the technology assisted human. Yeah. So I
thought this paper was interesting. I gotta admit I read
it twice and I still don't fully understand the statistical
argument that's being made. I've read some commentary on the
paper where some experts consultant said that they agree with
the math of what he's doing, saying that the statistical

(22:23):
calculation is is pretty much sound, but he might be
not taking into account lots of factors that could change
things dramatically, such as just physical conditions that give rise
to life on planets, things like gravity, or some of
just the basic facts we observe about how certain life
forms make their living in different environments on Earth. And

(22:46):
this leads into one of the criticisms we read from
the seat researchers Seth show Stack. Yeah, and particularly he
was I was thinking about the likelihood of of of
large creatures actually, uh, you evolving too, where they would
have advanced intellects and also technology. He pointed out that
larger creatures are likely to reside in the water, where

(23:07):
the advent of technology just might not happen. Um, because
you're a large creature, you're gonna you know, all this mass.
The buoyance of water helps you to stabilize it, right,
And think of a blue whale. You wouldn't have a
blue whale on on land. Right. And then if you
are a very large animal, lika blue whale, like an elephant. Whatever, Um,
are you going to need to advance like humans develop

(23:30):
these technologies? Develop this an advanced intelect to win food?
Probably not because you're big, You're content, You're you're station
in life is achieved. You're you're a You're you're this
blue whale just grazing through the ocean. You're an elephant
pushing over anything you need to eat and just consuming it.
You don't need technology if you're a filter feeder. Right,
So you have to ask yourself this and this organism

(23:52):
that we're trying to imagine, why does it need to
start externalizing its abilities and and dipping into tool use
and dipping into more complicated systems. Yeah, and of course
that could lead to the broader question of how are
we characterizing intelligence, Like is intelligence necessarily technological intelligence for

(24:13):
some purposes? That is what we're talking about, because sometimes
when people talk about encountering alien species, they're talking about
the kind that would send radio signals where you could detect,
or the kind that would visit Earth in spacecraft, in
which case you're not going to be dealing with aliens
that might be intelligent in some kind of strange social way,
but that don't build machines. Yeah, we kind of get

(24:34):
into this this anthropomorphic bias here, and almost kind of
a Captain Kurt kind of bias where it's like, it's
only alien life if it's like us, um, can I
kiss it? I? Can I kiss it? Can I seduce it? Right?
Because you know, an alien visitor Earth might would look
at something like a dolphin or even something arguably like
an octopus and say, well, this is a highly intelligent creature.

(24:56):
Do they do these either of these species? Do they
build things? Do they have a language? Do they have
culture as humans think of it? Well? No, uh, I
mean for starters there in the water, which, to show
sticks point unlikely that technology is going to emerge. It's
hard to build an integrated circuit underwater, right, and uh, yeah,

(25:17):
intelligence doesn't necessarily mean the advent of technology. Well, I
think we should take what we've looked at so far
and see if we can draw some broader conclusions about
what alien life is actually more likely to look like.
Is there anything we can actually say on this subject
or is it all just speculation? Is there anything we

(25:38):
can base our assumptions on? You know, I'm currently reading
Ian M. Banks culture novel Accession, which has a fabulous
extraterrestrial creature and it called the the Affront. An extraterrestrial
species called the Affront and their space faring. They're kind
of like a a gas world um cephalopod creature, but

(26:01):
they're also really sadistic and awful in their own way.
So they the culture in this novel, which is like
a far future post singularity um humanoid culture for the
most part. Uh, they spent a lot of time like
trying to figure out the Affront like they want to.
They want to push the Affront, encourage them to be

(26:21):
less awful and uh and and get along better with
their neighbors instead of just constantly enslaving or wiping out
other species, and so they have to ask themselves, well,
you know, why are the affront warlike? And they look
to their evolution in uh, you know it advanced hunting
practices where they work together as a group to to
to hunt their prey, and they say, well, if they

(26:42):
hadn't done that, if that hadn't been a part of
their evolutionary is since, then perhaps they'd be more peaceful.
But then on the other end of the that argument
is if they hadn't had that that hunting nature and
that warlike aspect of themselves, they might not have evolved
to this level. And either So now one thing I'm
orious about you said, you said that they're sadistic. Did

(27:03):
you actually mean that they're sadistic as in terms of
taking pleasure in the pain of others or is it
just that they're kind of like numb to our concerns
and desires. Oh no, No, they're they're awful like they're
they're they have this big hunting spirit. They'll have these
dinners where they'll they'll all be eating a particular type
of animal and then they'll be a fighting pit in
the middle of the table where that same type of

(27:25):
animal is alive. Fighting each other and they're betting on it.
And then they also have a little miniature harpoons that
they throw across the table at other dinner guests to
try and snag some of their food and drag it
over to their play. Okay, so they're kind of like predators. Yeah, yeah,
they're they're kind of like a more humorous predator because
there they strike me. They have kind of like an

(27:47):
Oliver read quality to them, like they're they're kind of
like big drunken louts that also developed uh, space faring
technology and occasionally sing yes, yeah, yeah, I can I
can definitely imagine in building out. Well, yeah, I think
that brings up an interesting point, which is that, of
course our evolution informs what type of creature we are,

(28:09):
and we can probably safely assume that that's going to
be true no matter where you go in the universe,
Like you can go to other planets, you can probably
even go to other galaxies, and while lots of local
conditions might be different, there are a couple of things
you can depend on when looking at alien life. One
of them is that the physics of the universe are

(28:30):
going to be the same, So all the same basic
physical laws, and the presence of the same basic chemicals
might be in different quantities, but still the palate, the
color palate is the same. Yeah. And then the other
thing is evolution. We can probably safely assume that whatever
life forms are out there, they come about and gain
complexity through the process of evolution. By one would have

(28:54):
to assume by something like mutation, something that encourages change
with replication, and then something like nat real selection some
form of evolution at least until they reached the point
where they have advanced technology and then are either creating
their own life or creating mechanical life that then recreates
organic life. Sure. And then of course there's the argument,

(29:14):
which I probably support, that we're much more likely to
encounter alien technology than we are to encounter aliens themselves.
Like when we meet aliens, we're not going to meet them,
We're going to meet their robots scouts. And that that
lines up very much with with Banks's vision of the culture.
Is that really you keep referencing these books. I've got
to read them. They're they're pretty great. I I strongly

(29:34):
recommend them. Anytime anybody writes into us and says, hey,
what's some good you know, thought provoking and fun sci
fi banks. This stuff is great, except I'm currently like
two percent into Dune for the first time. I've got
to finish that first. Oh yes, well, that's a that's
a that's that's indeed a great book. Well, I think
we should look at some of the principles of Earth
life and ask the question of can we assume, based

(29:57):
on the things we've already stated, that the physics going
to be probably equivalent and life comes about through evolution.
Can we assume that these principles are going to be
present in the aliens we observe coming from other solar systems,
other planets, and maybe even other galaxies in the far future.
And one of the things that I think is interesting
is how many animals in nature exhibit some form of symmetry. Now,

(30:22):
whether that's bilateral symmetry like us, if you folded us
in half, we would be roughly equivalent. Then the other
thing would be radial symmetry, and that's something like an
apple pie. Basically it extends out along the radius. And
you can think about a jellyfish like it's symmetrical looking
from the top down, like if you saw it a

(30:42):
person in half, you could counted the rings if you will.
If you will, there would be radial symmetry. Yeah, and
symmetry is approximate. Of course, the sides rarely match each
other exactly, but they roughly match each other. And it's,
in my opinion, pretty easy to see why evolution might
tend towards symmetry because it's easier. I mean, it's easier

(31:02):
to make half of a person and then just copy
that half than it is to come up with different
halves of body plans for the same individual. Yeah. I mean,
one thing you have to always keep in mind with
evolution is that evolution is essentially lazy. Evolution is it's
the path of least resistem exactly, Like even just thinking
about the brain, Like one of the analogies I love

(31:23):
is the idea that the human brain is like a
a double scoop ice cream cone, so that we didn't
when it's our brains evolved like just another scoop was
added on top of the existing scoop. It wasn't like
a complete overhaul of the system. Yeah. Yeah, And you
can see that in the brain actually, the different levels
the brain stem, the cerebellum, cerebrum kind of like extending
up towards Godhood. I guess, you know, to where eventually

(31:48):
we get we get the angel brains that have the
ethereal particles floating above the skull, or just the cone
head brain. The cone head brain would be a wonderful example.
So observing this principle on Earth very naturally leads us
to assume that, Okay, if we see other aliens out there,
they might be totally weird. They might have claws, they

(32:08):
might be like crabs, they might be slimy lizard like organisms.
They might have you know, weird you know, twenty ft
long legs and huge pyramid heads. Who knows what they're
going to look like. But almost all visions include basic
bilateral symmetry. If you fold the alien in half, the
sides match. But is that a safe assumption. There are

(32:31):
animals on Earth that actually don't display external symmetry. They're
they're asymmetrical on the outside. And one of the examples
would be sponges. You've seen pictures of sponges. I mean,
sponges are animals, yet they don't necessarily match when you
fold them in half. They can have weird little nodules
coming out on the side. So that, you know, they

(32:52):
look more like a plant of some kind. Indeed, so
if we were if we were trying to imagine a
sponge based alien species, they might not have symmetry. Yeah.
Then again, sponges don't possess intelligence, and I guess we
don't know if it's possible for something like a sponge
to possess intelligence. We're back to the question of, well, well,

(33:13):
the only creatures on Earth that have anything like intelligence
are basically symmetrical. You can fold them in half. Uh,
And so should we assume the same is true for
the rest of the universe. Yeah, this is where we
get into that interesting discussion of On one hand, life
on Earth is our only model we can We only
have terrestrial life when it comes to trying to extrapolate

(33:35):
what life elsewhere in the universe would consist of. So
we we have to base it on this model. And
we see symmetry here and we have to imagine it
that way elsewhere we see uh, we see the importance
of water and the evolution of life here, we have
to assume that elsewhere, and and that's really the best
course of action. On the other hand, Uh, there's this
little thing called the Copernican principle, which states that there's

(33:57):
nothing special or privileged about Earth or hu manity, which
is sort of the um you know, sort of the
Fox News fair and balanced approach to cosmology, like in
trying to when thinking about the universe, try not to
have too big of a head about the importance of
Earth and the human species. Right. Of course, the Copernican
principle originally comes from like astronomy and cosmology, the idea that, hey,

(34:21):
you don't necessarily have to start with the assumption that
the Earth is the center of the universe. But it
has been extended to a much more general principle beyond
just saying we don't start with the assumption Earth is
the center of the universe. Two, we don't start with
the assumption that whatever our position is as an observer
is privileged. Yeah, it's we don't necessarily assume that we're

(34:43):
looking from a unique vantage point. Yeah. It seems to
me that the safe course of action, I think this
is the one that most cosmologist tint to to lean towards,
is use the Earth model of what life is like
when thinking about other worlds, but then also have the
Copernic and principle. In the back mind, it's kind of
like if you interact with people in your daily life,
treat other people like you would like to be treated,

(35:06):
but then adjust accordingly as new information becomes available, bearing
in mind that everybody is not going to have the
same case and preferences as you yourself. Yeah yeah. Another
way of looking at this would be calling it something
like the mediocrity principle. This has been invoked in speculating
about alien life before, and it's a sort of statistical argument.

(35:26):
The idea is, if you're drawing a random sample from
a pool of objects, and you don't have information to
the contrary, the safest assumption is that the sample you
select is typical or average, and in this case, the
sample would be Earth. So that's our one sample. We've randomly,
not by choice, but by necessity, randomly selected Earth from

(35:47):
the pool of possible inhabitable planets. Is one ping pong
ball in the powerball and yeah, and so we've selected
this and it's Earth. Now we're looking at it. What
can we assume about its relationship to all the other
balls in the in the powerball thing? Well, the safest
assumption is that it's pretty normal it's average. And of

(36:09):
course this becomes uh, this becomes kind of heartbreaking I
guess at times for a top modelist as we continue
to get new information about various excep planets and and
how few of those ex planets are really earthlike in nature.
But there's another interesting way of applying the sort of
averageness principle or the typicalness principle towards the universe, and

(36:32):
some people have gone a lot farther with it, saying
that basically Star Trek got it right. Yeah, that essentially
the the universe is likely filled with other humanoid species
if it's filled with animals, because if it has anything
at all, then they're likely going to be humanoids. They're
gonna be I mean, it kind of gets into the

(36:52):
whole territory that Stephen Hawking uh dipped into talking about, Well,
if there are other alien species out there, they're probably
awful like us, right. Yeah. That that's the pessimistic way
of pointing it. But there could be the colder, more
anatomical way of looking at it, which would mainly come
back to this one guy whose name I kept seeing

(37:13):
when this theory came up. It's the Cambridge paleontologists Simon
Conway Morris, and he has argued that aliens are likely
to be a whole lot like us, so that intelligent
aliens are gonna be a whole lot like humans, and
that aliens in general are going to be a whole
lot like animals on Earth. And so in a two
thousand five edition of the Journal Astronomy and Geophysics, Conway

(37:36):
Morris begins with this interesting question. He starts by looking
at this three hundred and twenty million year old fossil
from you know, carboniferous strata in Montana, and it's some
kind of weird water dwelling animal that made its living
in a giant lagoon millions of years ago. And he
describes it as quote vaguely fish like, but neither fish

(37:58):
nor like any other group of known animals. And so
it's the strange thing that we just have nothing like
it on Earth today. And he actually imagines a scenario.
So three million years ago, this disgruntled alien bureaucrat is
visiting Earth and he's angry. He's kicking around on a
beach in ancient Montana, and in frustration, he releases some

(38:23):
of his alien pets into Earth's ecosystems. Against all regulations,
the alien pet fish die, become fossilized, and millions of
years later human paleontologists dig up these weird fossils. This
raises some interesting questions. One of them is, if there's
intelligent life all over the galaxy, how come there's no

(38:43):
evidence that it has ever visited or colonized Earth in
the past. How come we don't have obvious fossils of
dead aliens in the fossil record. And then two, if
we were to encounter aliens in the fossil record, how
would we recognize them? M Well, I mean, one obvious
point that comes up is that it's it's fairly difficult

(39:04):
for a creature to enter the fossil record, particularly a
small number of of of visitors happened to drop by, right,
they could be their fossils could be out there right now,
and we might find them. We might never find them.
We might build a mall on top of their location. Yeah,
they might have died in some arid climate that's not

(39:25):
conducive to fossilization. They didn't necessarily position they're dead right on, Like,
what are those the muddy banks that are Yeah, yeah,
that's place the number of fossils have to be met
for for fossilization to take place, and you're far It
kind of gets down to the mediocrity principle, right, Yeah,
you're you're far more likely to find fossils of particular
types of creatures, particular populations of creatures that live in

(39:46):
the right environment, or apex predator fossils are fewer and
farther between. Sure, we have lots more fossils of like
sort of bottom dwelling ocean animals. I mean we have
tons of those, because of course there were tons of
so Conway Morris's point is sort of that we might
not be able to tell if some aliens had landed

(40:09):
on Earth and become fossilized, because he argues that alien
life is going to be striking lee similar to Earth life.
One of the arguments he makes is that all life
is likely to be carbon based, like like life on Earth.
He says it's basically a quote strong hunch among molecular
biologists that any life in the universe is gonna have
a chemical basis that's really similar to terrestrial life to

(40:32):
life on Earth. One of the things he points out
is that he says the fundamental operations such as primary
metabolic cycles, possibly photosyn synthesis, and maybe d N A
and the replication of DNA just really don't have any
chemical alternatives that we can come up with. You you
can't mimic processes like this without a system that's pretty

(40:54):
much the same as what we already have. Uh. And
then he he sort of goes on deposit that there
are general rules to evolution. He says that they're independent
of the quirks of your local ecosystem and the accidents
that would arise through you know, just random trial and
error throughout history. He points out convergent evolution. What do

(41:15):
you know about converge and evolution? Oh, this, of course
is uh, for instance, the model to say, all right,
you have birds that can fly, you have bats that
can fly. Yeah, these both of these, Uh, these lineages
evolved flight separately. Yeah, they didn't get it from a
common flying ancestry. And so yeah, that's the ideas that
organisms arrive at these very similar biological solutions through completely

(41:41):
different routes or from different starting points. Uh. Two people
start on opposite sides of the globe, somehow they end
up in the same place. One great example of this.
In addition to wings would be eyes, So not all
eyes evolved from the same line. A squid has a
camera IE, and you have a camera I, But you
and squid did not both evolve from a common ancestor

(42:02):
with the primeval camera I. The humans and the squid
do evolve from a common ancestor, but they've got their
eyes in different ways. We know. The cephalopod was a
great It's a great point because it reminds me of
some information I've read before on arguments for octopy consciousness,
which is actually a reason I don't I do not
eat octopi anymore, just because if you if you look

(42:24):
at the octopus and you try to judge its consciousness
based on human models, it doesn't pass the test, the
test that we have that even the test that we
can give you know, a primate or even a dolphin
are not going to apply to the octopus. But if
you if you look at the octopus brain, which has uh,
you know, evolved separately from these other models of what

(42:47):
we think of is highly intelligent animals, uh, it itself
has a very advanced brain and could arguably could be conscious. Yeah,
I've had the same thought. If you ever watch octopuses
is like play with toys. This is the thing they do.
It's very strange and it's somewhat unsettling. You see a
weird kind of intelligence in them that you don't quite recognize.

(43:12):
It's like hard to empathize with it, almost because it's
so alien to human intelligence. Yet it's so different from
what we think of as like fish, you know, this
ocean dwelling kind of dull creature. Yeah, they play, they explore,
they they utilized tools in some cases we're going to
of course, you ask yourself when they steal things from divers,
steel things from divers. But but then you also have

(43:35):
to ask, could a creature like the octopus ever evolved
to the point where it would develop technology, where it
developed some sort of culture in the way that we
think about it? And it is that even a fair question,
because it again comes down to us taking this very
anthromomorphic sense of the universe and applying it to a
creature that that emerged rather differently differently than we did. Yeah,

(43:59):
totally so, Conway Morris. He basically has two main arguments
for thinking that convergence, like convergent evolution, is a universal
of evolution, it's not just that we're witnessing convergence between
different species on Earth made of terrestrial biological building blocks,
but that we should expect to see convergence no matter
what planet you're looking at. Right. But it's basically the

(44:21):
argument is the basic shape of the evolution of life. Yeah,
and so he says, one thing in this in favor
of this is the pervasiveness of convergence. It's all over
the natural world. You know, tons and tons of examples
of it. It's at every level of resolution. So if
you zoom way into the tiny little gears and parts

(44:41):
that make bodies work, you can see it there. And
he points out the enzyme carbonic anhydrace. He says that
accelerates the hydration of carbon dioxide by more than a
million times, and he this is a quote. He says
on Earth it plays a key role in processes as
desparate as photosynthesis, respiration, and by mineralization. And then of

(45:02):
course you see convergence at the larger level with things
like cameras and wings. And then of course he also
says that it's the degree of similarity in complex, highly
integrated systems. So it's not just small individual components but
large systems that have different things working together still seem
to converge on pretty similar working models. An example of

(45:24):
this might be, for example, the brains of primates and corvids.
You ever noticed that, Huh? It's kind of weird that
human brains and crow brains can both come up with
tool using technologies that seem to arise by pretty similar
patterns of evolution and adaptation, yet their brain structures are

(45:47):
radically different. I mean, one's bird and one's a primate. Indeed,
I think that's the pretty convincing argument, espect as long
as I try to disregard any star trek now in
there and rippled foreheads. But yeah, if you imagine any
any war, you have this, uh, this this complex system
of evolution taking place, varied models of life emerging. There's

(46:07):
going to be some model of life that it doesn't
have these extra bells and whistles anatomically to deal with
acquiring food, protecting itself, carrying out its basic genetic mission
of species that has to depend more on ingenuity, um
and tool use, and it's probably probably going to look

(46:28):
something like us. It's going to be vaguely humanoid in
form at least. Yeah, that's another sort of final position
he arrives at that it's not just that our bodies
are gonna look similar to alien bodies, but that he
believes intelligence is pretty much a an inevitable consequence of
life in the universe, that all things evolved towards some

(46:49):
kind of human like intelligence. And in fact, there's the
I mean, the further argument is that any complicated system
moves towards intelligence, right, the emergence of intelligence? Right, Well,
what what do you mean by that? Like? What other
than life? What do you mean? Um, I've heard this
argument in terms of of of artificial systems, but that

(47:10):
even even systems, And this is where he gets, you know,
kind of out there outside of biological life, that that
the universe itself is a complicated is a complex system,
and an intelligence must emerge from that system. Okay, so
that if you have like a wave action acting on
a bunch of different rocks, creating vortexes of current at
the shoreline, eventually that start God exactly, I like that. Yeah,

(47:36):
I'm partially convinced. I'm not quite sure what I think
about Conway Morris. He's obviously a smart and well respected scientist,
but I think a lot of people disagree with him
quite strongly on this argument. He makes one more thing
I wanted to end on I thought was interesting. Earlier
we mentioned the Ceti researchers Seth show Stack, and in
two thousand eleven he gave an interview to Popular Science

(47:57):
where he said some things about alien body plant that
actually some of them I found pretty interesting. One of
them was referring back to this thing about size that
inspired this episode. He was talking about the maximum size
of aliens, and he was sort of arguing against these
gigantic world size aliens or even probably maybe even against

(48:18):
the sandworm due definitely planet from Marvel would be right out. Yeah, yeah, no, no, no,
Because he says, if you keep making an animal larger,
its strength increases as a square of its size, but
its weight increases as a cube of its size. So
as you keep scaling up, weight becomes too much for
even a strong animal. And according to him, this is

(48:40):
unlikely to be a problem specific to Earth. This is
a problem in physics and engineering that you would encounter
on any planet. Yeah, and it's one of the reasons
why you start, if you start throwing a lot of
science at King Kong. It falls apart. I mean literally,
the monkey falls apart, right, it is not strong enough
to lift its bones. Furthermore, I don't know if do

(49:01):
you think the buildings that climbs would be strong enough
to support it? You know, I've never seen anyone crunch
that data. You know that we tend to focus more
on the structural engineering project. Yeah, are there what? What
buildings out there are essentially rampage proof? Another one, this
is a direct quote. Heads are a good deal. Yeah,

(49:23):
he's a show stack. He thinks that heads are a
common feature that you'd find on alien land animals. And
I think his argument is really interesting. It would sort
of be the cup holder of the animal body plan,
you know, like it's a car. You can't sell a
car without a cup holder. You can't have an you
can't have an alien without a head. Yeah, I mean
this is basically the sensory array of any organism. And

(49:44):
uh yeah, I've actually looked into this before. Um in
uh doing various monster monster the weak monster science stuff
for the for the website. You know, you'll see like
a two headed monster in fit in fiction, or you'll
see a no headed mind stern fiction, and you ask yourself,
was this possible. Is there anything in the natural world
that conforms uh to this model and uh and generally

(50:08):
that there isn't you get into like two headache organisms?
Why would it have two heads? And that seems counterproductive? Yeah,
the best you could really get into is you don't
want to debate about what your body is gonna do, right, Like,
the best you can get into is, essentially you could
have an organism with some of its sensory material on
one stalk and other sensory material on another stalk. But

(50:31):
other than that, there's just no evolutionary reason for two
heads or for a species to be conjoined by its
very nature. Well, show Stack makes a good argument actually
against even the sensory stalks because he he says that
basically is a head. We're talking about a consolidated housing
unit for the primary sense organs, which in our case
would be things like eyes and ears, though that wouldn't

(50:52):
have to be sensing. The visible spectrum on any planet
would be whatever organs this alien uses to take an
in formation about its environment. And why why would the
primary sense organs need to be on the head. Well,
it might seem kind of arbitrary at first, but I
like his reasoning, He says that heads put the input
devices right next to the central processing unit for rapid response,

(51:14):
and he categorizes this in terms of response time, like
it's important to your survival that you be able to
respond immediately to what you see. But I actually thought
of another thing about this. It seems like less likely
that you can have your vision impaired by damaging the
pathways of information exchange. So if you imagine the dude

(51:34):
from Pan's Labyrinth, what's that guy called has the eyes
in his hands? Oh, I don't know, it's like that
the paleman or something like that, and that might be it.
So he's so this monster has got eyes in his
palms and he's walking around looking around with his hands.
On one hand, that seems kind of cool, like you
can peek around a corner with your hand. But on
the other hand, you could probably blind this guy by

(51:57):
injuring his arms. That's not something you'd want. Yeah, Also,
like how does he cut up peppers for dinner? You know?
I mean there's just a number of problems that stem
from that. Yeah. Yeah, So you wouldn't want this long, exposed,
kind of vulnerable path of information exchange from your primary
sense organs to the thing that needs to receive them. Yeah,

(52:19):
plus the transfer of of those neural signals from from
touch from pain uh four different uh accent pathways. When
you say stub your toe, uh, it takes time for
that for that signal to reach the brain. Now, it's
a very small amount of time. Um, and it varies
depending on the type of sense data. But but there

(52:40):
there is a delay. And in the evolutionary scheme of things, Um,
you know, the body is going to again, it's gonna
be lazy, it's gonna go with the path of least resistance.
So it's easier just to to cut down that that
delay time as much as possible. Yeah. I think he
makes that point pretty convincingly. The the other thing he says,
I think this is into thing too. Despite the fact

(53:01):
that he's very pro head, he characterizes the number of
limbs we have is pretty much happenstance of evolution, Like
that's just a fluke. We have four limbs because we
evolved from four lobed fish, but we could have had
any other number of limbs. Though somehow, I don't know,
four limbs seems economically primed to me, Like if you

(53:22):
have an animal with less than four limbs. It seems
like you couldn't evolve an intelligent animal with two limbs,
because they wouldn't have tool manipulating uh you know, like
grabby grabby things whatever those be. Well, it instantly makes
me think though about giraffes and elephants, um, because of
course the elephant has a highly tactile trunk, uh, and

(53:46):
then the giraffe has a pretense prehensile a tongue. So
I could I could imagine alien species who say, I
only have two legs and they walk on them, but
then when it comes to using their computers or what
have you, they rely on their trunk, they rely on
their their their draft like tongue. In fact, in one
of the culture books in Banks has an elephant type

(54:07):
creature that has two trunks I remember correctly, and those
are its primary manipulation uh limbs. Man. That's fascinating. Yeah,
it just highlights actually how poor our imagination is, because
I was thinking, yeah, yeah, you need hands, but you
could I don't know, you could have a tail, and
then you could have a tail that over time grew
a fork in it and it had prehensile forks, and

(54:30):
then you could basically have tentacles on land. Let's not
count out ear lobes. You know, we take them for granted,
But there could be a species out there on a
artist in alien world and those are its primary you know,
tactile instruments. I have a question, do you think it's
really all that advantageous to have like four arms? Like,

(54:51):
would would Goro have a real advantage as an organism
outside of the sacred rights of Mortal Kombat? Yeah? Why
would Goro? What? What was he? A showcan? Is that
his species? I don't recall? Um? Yeah, why why is
this model evolved? Um? Well mhmm, yeah, he certainly has

(55:11):
an advantage against humanoids, and maybe he had if I
if I remember correctly, his his species sort of ancestral
enemy is essentially a centaur right of a big Oh
is that right? Yeah? The one in the third Mortal
Kombat film Motaro. Okay, so if they're fighting there was
a third film? No, no, well, Motaro might be in

(55:31):
the films too, But in the third game of Taro's
like a coo role of being like the sub boss.
So I was about to leave work and go watch
the third Mortal Kombat film. I think he shows up
in it, you would probably not be surprised. But so
maybe there is an evolutionary advantage to having a second
pair of arms if you're having to grapple with uh. Yeah,

(55:52):
another species that has six limbs, six limb creatures, maybe
that's ultimately the model of life uh on the go homeworld.
You know, I have to come down with one sad
prediction of my own, which is that if we encounter
alien species, I don't think they will biologically emit rays.

(56:15):
This is a thing that's often imagined, right, I can
see them having laser guns, but I don't think from
their bodies they will emit rays. It just seems like
the energy requirements are implausible. Yeah, that's probably a safe bet.
You're probably not going to be vaporized by their their
heat vision, right, you see them, So Kryptonians are out.

(56:35):
And plus if a creature has like a natural heat
vision ability, again, they why are they Why are they
developing the kind of advanced intellect that would enable them
to travel. They're just setting there blasting whatever they want
to eat, and if anything messes with they blast the predators.
So no problem and no reason to venture out into

(56:57):
the void. Well, I always enjoy talking about aliens, but
this has been particularly fun. Robert, Yeah, yeah, I mean it's, uh,
it's one of those things that, like, oftentimes I find
myself just sort of thinking at night, and I tend
to more and more and more pessimistic about the idea
of intelligent life in a sci fi sense existing out there.

(57:18):
But I'll often think, well, there's probably somewhere, just so
far away, there's an ocean that I can scarcely imagine,
and there's some sort of like slug like creature just
doing it's very basic thing, and it's it's incapable of
knowing me, incapable of imagining me. But it's out there somewhere. Well,
not to open a whole other can of sandworms, but

(57:40):
there are I mean, their their whole environments we haven't
even really discussed in this. I mean we're talking about
sort of like surface dwelling creatures that might be in
the water, or they might be walking around on some
kind of hard, rocky surface of a planet. There's also
the idea that's pretty common is that well, what if
gas planet it could be inhabited but basically floating or

(58:02):
flying aerostatic types of creatures that that move up and
down in the thick, dense, fluid like atmosphere of gas
and a gas planet. Essentially Jovian jellyfish. Yeah. I can
see something like that too, though with those I also
don't know, if you know, would technology evolve, would would
something like that create tools if they don't have hard,

(58:23):
rocky materials to make tools out of. Yeah, what would
their technology consists of? Perhaps it would be entirely organic
or yeah. It just it just blows the mind to
try and think about it. But that's why we keep
coming back around to it. One. We we keep envisioning
all these different fantastic aliens. You know, essentially giant and
small aliens are not any different than the giants and

(58:44):
dwarves that inhabit our mythologies and folklores. But as we
look into the future with them, we take we take
more and more of our scientific quandaries and apply them
to the creation. Yeah, all right, So there you have it. UH,
Space Faring Bears considerations UH on the size of aliens

(59:06):
and the populations of of aliens elsewhere in the universe.
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Mind dot com. That's the mothership and that's where you
will find all of it. In the Landing Patriot. This

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episode will include some links out to the materials we
discussed here, and if you've ever been abducted by an alien,
seen an alien, or just have any relevant thoughts about
what aliens might look like, how big their bodies are,
what their brains are like, you can email us at
blow the Mind at how stuff works dot com and
tell us all of your crazy fantasies. For more on

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this and thousands of other topics, is it how stuff
works dot com