July 24, 2023 • 38 mins
How would we know if we were living in a simulation? What if you were a butterfly having a dream it was a human? What does any of this have to do with John Lennon, or Renee Descartes, or freezing yourself in a vat of liquid nitrogen? How will we eventually solve the problem that human bodies can’t do space travel? Join Eagleman for a wild ride into the strange possibility of making brains immortal.
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Speaker 1 (00:05):
How would we know if we're living in a simulation,
And what does that have to do with having a
dream that you're a butterfly or John Lennon or Renee
des Cartes or freezing yourself in a vat of liquid nitrogen?
And how will we solve the problem that human bodies
can't do space travel? Welcome to Inner Cosmos with me,
(00:31):
David Eagleman. I'm a neuroscientist and an author at Stanford University,
and I've spent my career studying the intersection between how
the brain works and how we experience life. And what
I'm going to talk about today is the possibility of
living forever. What does that have to do with the brain?
Would we want to live forever? And how could we
(00:52):
get there? Humans have been obsessed with the idea of
immortality for ages. As far back as documented history goes,
there are stories of humans trying everything to unlock the
secret to eternal life. In Arthurian literature, the Holy Grail
(01:14):
was said to have miraculous healing powers and it would
grant anyone who drank from it eternal youthfulness, and the
ancient Egyptians they would painstakingly prepare the physical body for
the journey to the afterlife, and they believed you were
reborn again and again. And China's first emperor launched an
(01:35):
obsessive search for the elixir of life, and that obsession
continues and cultures all over the world today. While leaving
a legacy is the only thing close to immortality by
today's standards, Woodie Allen wanted the real thing. He said,
I don't want to achieve immortality through my work. I
want to achieve immortality through not dying. He said, I
(01:59):
don't want to live on in the hearts of my countrymen.
I want to live on in my apartment. So what
are our options for achieving eternal life? Well, the first
option has to do with medical innovations, such that we
keep repairing things that go wrong with the body. And
in fact, it's rumored that life insurance companies assume in
(02:22):
their actuarial tables that children born now are going to
live to one hundred and fourteen years old. And this
is based just on extrapolating medical innovation curves. In other words,
you take the pace of medical progress and you guess
what things are going to look like in a century
from now. But the fact is there are barriers to
(02:45):
physical immortality, like aging and disease, and then of course
there are accidents that can happen, like you fall off
a cliff, where you get in a car accident, or
a tornado gets you, or a volcano explodes, and on
and on. So although we can continue to make improvements
in medical science to expand the average lifespan, there's no
(03:09):
real guarantee that your lifespan is going to be any
better now. There's a second approach that some people have taken,
and that's about making a throw to the future, when
people will know things like.
Speaker 2 (03:22):
How to repair bodies.
Speaker 1 (03:24):
The issue is that we just don't know how to
cure lots of problems now, but it's not impossible that
two hundred years from now a lot of this stuff
will be obvious. In two hundred years, we'll look back
at our textbooks and we'll think, my gosh, how did
we not know that? How did we not know that
we can just reach in and tweak some things on
the telomeres and cure cancer easily with a few zapps
(03:47):
and essentially make ourselves live much longer, maybe forever. The
problem is that this is in the future and not
right now. And therefore we don't get any of the
benefits of that. So the idea is, perhaps you could
by pausing yourself now and rebooting yourself in that future.
(04:08):
And that's the approach of a company called Alcore. Alcore
is based in Arizona, and they have these giant silver
tanks called doers that are filled with liquid nitrogen and
they're kept at a temperature of negative one hundred and
ninety six degrees celsius. So when you're expiring on your
hospital bed, this company gets contacted either by your family
(04:32):
or because you're wearing a special bracelet, and as soon
as your heart stops, a team from Alcore rushes to
your bedside and starts the deep freezing process. Then they
transport your body to Arizona where they put it in
the giant vat with the liquid nitrogen. And you actually
have two choices here. You can freeze your entire body,
(04:54):
or if you can't afford that, you can just have
your head removed and just have your head frozen. Because
while it's great to have your whole body, the real
representation of who you are is theoretically just kept in
the brain. Or suffice it to say, that's the densest
representation of who you are.
Speaker 2 (05:12):
You just need the head.
Speaker 1 (05:14):
Now, as a side note, you might wonder how much
this costs. Well, you don't actually have to pay anything upfront. Instead,
you can modify your life insurance payment to make its
payout to the company. So this allows you the possibility
of living a second chapter. Now, if you're unfamiliar with
this slice of the world, it will blow your mind.
(05:35):
I visited al Core and met the then CEO, Max
More for my television show The Brain, and I got
to tour around the facility and it's quite striking. There
are these giant silver vats of liquid nitrogen and they
currently have two hundred and eight people stored in there,
and the company has over fourteen hundred people who are
(05:56):
signed up for the service, but they haven't died yet
and they will eventually end up in these vats. Now,
although scientists don't currently know how to unfreeze and revivify
a body, the idea is that some generation in the
future will figure that out. Maybe that's a century from now,
or maybe that's a millennium. And then the idea is
(06:18):
that the frozen person will awaken into a new world.
So people who sign up for the service operate on hope.
They're making a deep football throw into the future, hoping
someone will be there to catch it, and some people
choose to cryo preserve their pets. Also, the idea is
(06:40):
that if you awaken to a completely new reality, that's
likely to be disorienting, and if you have a familiar,
fuzzy face by your side, that could be really nice
and reassuring. Also, it turns out that Alcore allows you
to have a small memory box to go along with
your frozen body. And the reason I mentioned this is
(07:01):
because sometimes people ask me to inscribe one of my
books to them. But I recently got a really interesting
request from a man who had just signed up for Alcore.
He said he'd been moved by my book to the
Brain and wanted to keep that in his memory box
that goes along with the frozen body, so he'd have
it in his new world when he gets rebooted. So
(07:24):
he asked me to sign my book for his revivification
in a century or two. In other words, I would
sign the book to him for his re entry into
the world sometime in the future. Now I've had a
lot of cool requests to sign books for special occasions,
but signing for someone who is possibly coming back in
(07:45):
a couple of centuries. That was a new one for me.
So here's what I wrote, Dear Steve, welcome back. I'm
so curious what secrets the world has divulged now. Presumably
the text books have been thoroughly rewritten, and the current
understanding of science would intimidate and thrill a twenty first
(08:07):
century mind. Presumably I am long gone and all that
remains of me are fading echoes of my genetic code.
But this book remains. It memorializes what we knew in
the early part of the millennium. Like all snapshots of science,
some notions will stale, while others will prove more durable.
(08:31):
Whatever the case, these pages form a bridge. They allow
me to talk with you as though we still live contemporaneously.
They allow two brains to span an unknowably wide chasm
of time.
Speaker 2 (08:47):
Enjoy the future, David.
Speaker 1 (08:51):
So that's the method of freezing yourself until biology is
better understood. It's a hail Mary throw, and you don't
know for sure that anyone's going to catch the ball.
For all you know, society will have collapsed, and maybe
your body is going to get cannibalized, or legislatively, something
might happen in the future where all these frozen bodies
(09:13):
don't get unfrozen, or we are long blown up in
a nuclear war and there's nobody there to unfreeze you.
But people who sign up for this figure that at
least they have a non zero chance of something happening here,
of getting to live a second chapter, and that's better
than having one hundred percent certainty that you're going to die.
(09:35):
But fundamentally, there's a problem that's probably intractable, which is
that we are made of biological pieces and parts, and
those things are going to wear down. Even if we're
able to successfully unfreeze people, the ticking clock of aging
will keep ticking, and we're always going to be racing
(09:55):
against entropy. As the poet William Butler Yeates said, things
fall apart, the center cannot hold, and this is what
aging and death is. And that brings us to a
question of how we might solve this for the long term,
forever by just extracting the part of us that matters
(10:15):
our consciousness. So could it be possible someday to upload
our consciousness out of our brains and onto a different
substrate like silicon and run it, and would that still
be you.
Speaker 2 (10:31):
So here's the idea.
Speaker 1 (10:32):
Maybe the hardware of the brain, all these cells, that's
not the important part. But instead it's the software of
the brain that matters. In other words, the algorithms that
are running. Maybe that's what makes a mind. Maybe it's
the patterns by which these spikes, these zeros and ones
are running.
Speaker 2 (10:51):
And if we could extract those.
Speaker 1 (10:53):
Massive patterns and reproduce them on something different, maybe that
would be you.
Speaker 2 (11:00):
This idea is called computational equivalents.
Speaker 1 (11:04):
The idea is that the eighty six billion cells of
the brain are just running algorithms that have been sussed
out by mother nature over billions of years. But fundamentally,
it's just code that's being run. And so the idea
of computational equivalents is that it doesn't matter if you
reproduce this system out of legos or tinker toys or
(11:28):
ball bearings or silicon. If the system runs the same program,
you will get the same consciousness.
Speaker 2 (11:35):
You will get you.
Speaker 1 (11:38):
Now, we don't know if the theory of computational equivalents
is correct, but if it is, it implies that we
could shift ourselves off the degrading biological substrate of our bodies,
and with powerful enough computers simulating all these neural interactions,
we could upload our consciousness and exist digitally, circumventing the
(12:02):
inevitability of demise. That would be the single biggest leap
in the history of our species, launching us into an
era of transhumanism. Just imagine what it could look like
to leave your body behind and wake up in a
simulated world. Your simulated existence could look like anything you wanted.
Speaker 2 (12:24):
Programmers could make any virtual world for you. If you've
ever wanted to fly.
Speaker 1 (12:30):
Or breathe underwater, or inhabit an alien planet, you just
sign a contract for it, You pay, and that becomes
your new existence. It's your simulation and your reality is
up to you. And as a side note, we could
in theory run virtual brains as fast or slow as
we wanted, so in seconds of computing time, you could
(12:54):
have thousands of years of experience. In fact, even if
the cosmos were coming to an end tomorrow, the programmers
could simulate a billion more years for you.
Speaker 2 (13:04):
In that time.
Speaker 1 (13:07):
So all that sounds great, but there are some technical
and theoretical hurdles. The first one is the enormous difficulty
of figuring out the secrets of the brain. And this
is a problem that can't be underestimated.
Speaker 2 (13:23):
As much as.
Speaker 1 (13:24):
We've discovered about how the brain works, we are a
long way off from understanding the big picture. It's a
very tough problem. You've heard me mentioned before on this
(13:47):
podcast that the brain is the most complex device we
have ever discovered. It has almost one hundred billion neurons.
Each of those is as complicated as the city of
New York, and you've got detailed connections between them that
number in the hundreds of trillions. So figuring out the
algorithms running in the system, or even just scratching the
(14:09):
surface of those is something that still, for the most.
Speaker 2 (14:13):
Part, has completely eluded us.
Speaker 1 (14:16):
Consider this experiment that a couple of my colleagues did
in twenty seventeen. They asked, what would happen if we
used our best neuroscience approaches to understand a simple microprocessor,
just a computer chip. So if the brain is really
like a giant, complex computer chip, let's see how far
we can get by analyzing this very simple one. So
(14:38):
they picked an Atari microprocessor from nineteen eighty one that
ran donkey Kong. And it turns out that after measuring
all the input and output signals from the chip and
applying the type of analyses that we have in neuroscience,
they couldn't say much of anything about the function of
the chip. I mean, note that they all already knew
(15:00):
what the chip accomplished, and they know how chips work.
But when you're looking at a ton of zeros and
ones streaming in and streaming out, it's really difficult to say, Okay,
here's the algorithms that the chip is implementing. As the
researchers put it in that paper quote. In the case
of the processor, we know its function and structure, and
(15:22):
our results stayed well short of what we would call
a satisfying understanding. So figuring out what the brain is
implementing may turn out to be really hard.
Speaker 2 (15:33):
So can we copy the brain?
Speaker 1 (15:35):
Well, we're nowhere close to copying the human brain because
the detailed structure of it is so enormous. It's probably
a zetabyte of data, which is maybe around a tenth
of the computational capacity of our planet right now. But
this is fundamentally just a technology challenge, and the way
(15:55):
that things are going we will probably get there at
some point. It may not happen in our lifetime, but
it's essentially guaranteed to happen in the future as our
computational power increases.
Speaker 2 (16:07):
Okay, but this brings us.
Speaker 1 (16:09):
To a tougher hurdle, which might be a theoretical one,
which is, there may be physics happening in the brain
that don't make it as easy as copy pasting a
giant document.
Speaker 2 (16:22):
For example, the.
Speaker 1 (16:24):
Brain might be exploiting quantum mechanical effects, and if so,
that means we can't pretend the brain is just a
big clockwork machine. Quantum mechanics is the science of the
very small. It explains the behavior of subatomic particles and
how they interact with each other and with light. The
thing is that it's extraordinarily counterintuitive, and it's not really
(16:46):
anything like classical physics, and we have no idea how
to build a.
Speaker 2 (16:51):
Quantum system the size of the brain.
Speaker 1 (16:54):
Now I'll just mention there are many scientists like Roger Penrose,
who recently won the Nobel Prize, who suggest that there
might be quantum mechanical effects in the brain, And there
are many more scientists on the other side of the
debate who say they think there aren't quantum mechanics in
the brain, but I just want to note that we.
Speaker 2 (17:12):
Don't actually know.
Speaker 1 (17:14):
Some people make fun of the quantum mechanics approach and
they say something like, well, quantum mechanics is mysterious and
the brain is mysterious, so maybe they're the same thing.
Speaker 2 (17:23):
Ha ha, Okay.
Speaker 1 (17:24):
Skepticism is always warranted until something is demonstrated to be true.
But science doesn't rule things in er out in advance
of having enough data, So when it comes to quantum mechanics,
we don't actually know yet. Part of the problem that
people have excepting quantum mechanics is that it's poorly understood
and it's relatively new for us humans. But remember that
(17:46):
for mother Nature, quantum mechanics has been around from the beginning.
And one thing that's clear is that if there's something
mother Nature can take advantage of, she will. So maybe
quantum mechanics has nothing at all to do with the
brain or everything to do with the brain, but we
can't rule it out yet. And if it turns out
that the brain is not so straightforward but requires quantum
(18:08):
effects or whatever we discover next century like super hyper
quantum x effects, then this path of learning how to
reproduce the.
Speaker 2 (18:16):
Brain might take much longer.
Speaker 1 (18:19):
Maybe we'll need quantum computers or something we haven't even
thought of yet. And I want to mention a third
technical hurdle to successfully uploading our consciousness, which is that
the simulated brain has to be able to modify its
own structure. This is what's known as brain plasticity. In
some of my other episodes have been about this. The
(18:40):
activity that runs through a brain modifies the brain.
Speaker 2 (18:45):
It changes the brain.
Speaker 1 (18:46):
That's why you have memory, for example, because everything you
experience is actually changing the physical structure of your brain,
so that activity runs through it differently. Next time, when
you learn that the name of this part podcast is
inner cosmos, that physically changes the structure of your brain
so that when someone asks you, hey, what was the
(19:07):
name of that podcast, your brain can retrieve that information.
So we need to simulate not only the detailed structure
of the brain to run the software, but we also
need to understand the physics of the ongoing interactions and
how it changes. For example, in the brain, you have
the activity of transcription factors that travel to the nucleus
(19:30):
and change gene expression. You have dynamic changes in the
location and strength of the synapses, the connections between neurons,
and so on. And unless your simulated experiences change the
structure of your simulated brain, you could inform new memories.
You'd have no sense of the passage of time. Your
(19:52):
consciousness would be frozen at whatever point it was uploaded
into the simulation. Under those circums stances, would there be
any point to immortality? Okay, So let's imagine that two
hundred years go by and we managed to surmount all
those technical hurdles.
Speaker 2 (20:10):
We have enough storage.
Speaker 1 (20:11):
Capacity, we figure out any quantum effects, We make it
so that the simulation self modifies based on its experience.
So great, we're there, and in this future world, uploading
our consciousness would be possible. Now what would that mean
for the human species? Well, among other things, it would
open up the possibility of getting to other solar systems.
(20:35):
There are at least one hundred billion other galaxies in
our cosmos, each of which contain one hundred billion stars.
We've already spotted thousands of exoplanets orbiting those stars. There
are planets that are like Earth in some way, and
some of those have conditions quite.
Speaker 2 (20:52):
Like the Earth.
Speaker 1 (20:53):
But The impossibility lies in the fact that our current
fleshy bodies will ever get to those exoplanets, because there's
just no real way that we're going to be able
to travel those kind of distances in space and in time.
Speaker 2 (21:09):
But uploading would allow us.
Speaker 1 (21:12):
To transfer our minds into bodies that are built for
space travel, and that way we could travel between stars
in between galaxies with a human mind and a titanium body. Also,
note that with a simulated mind, you could pause the simulation,
you could shoot it out into space and reboot it
(21:35):
a thousand years later when it arrives at a planet,
So it would seem to your consciousness that you were
on Earth, you had a launch, and then you instantly
found yourself on a new planet. In other words, if
you could upload your brain into silicon, this would be
equivalent to the physics dream of finding a wormhole that
(21:56):
lets you get from one part of the universe to
another in a subjective instant. Okay, so we've established that
if the algorithms are the important part of what makes
you who you are, rather than the biological physical stuff,
then it's a possibility will someday be able to copy
(22:17):
our brains and upload them onto Silica and run them there.
But there's an important question here, is it really you?
I was thinking about this the other day because Paul
McCartney announced an upcoming song with vocals by John Lennon
thanks to AI that brings Lennon's voice back to life.
(22:38):
But even though John Lennon is out there singing new
songs now and everyone's talking about his immortality, he doesn't
get to enjoy it. John Lennon doesn't know that he's
been brought back. It's just zeros and ones running on
a computer. John Lennon doesn't get anything out of that.
Speaker 2 (22:58):
So even if there's.
Speaker 1 (22:59):
A suit for a complete simulation of you, is it
really you? Or is it just zeros and ones? Well,
I think this could be argued either way. For example,
every night when you go to sleep, it's like you
are turning off, and then the consciousness that awakens on
your pillow in the morning inherits all of your memories
(23:22):
and we say, yeah, I'm the same person who climbed
into this bed last night. I turned off, and then
I turn on again and it's me and I'm getting
back to business. So maybe the process of transferring from
your physical body to a computer is just like that
where you open your eyes in the simulated world and
you think, cool, here I am.
Speaker 2 (23:44):
Let's get back to business.
Speaker 1 (23:45):
But there's another way to look at this too, which
is that possibly when some company scans your brain and
then uploads you into the computer, that's not you at all.
That's just a computer program that's running. That program happens
to feel confident that it's you. It has all your
(24:06):
memories and beliefs, and thinks that it was just there
standing outside the computer in your body, but its existence
inside the computer doesn't help you at all. Let's imagine
you just paid a million bucks to this immortality company
and they tell you, hey, it worked. You see this
little coordinate moving around on the screen. That's you. You're
(24:27):
living forever now. And then you leave the immortality company
and you drive home and sit on the couch and
your life is no different.
Speaker 2 (24:36):
You are still heading towards death.
Speaker 1 (24:39):
It's just that you know you've paid all this money
so that some computer simulation has a good afterlife.
Speaker 2 (24:44):
But is that really you?
Speaker 1 (24:45):
Did you gain anything out of paying this one million dollars?
The actual situation is that there are now two of you.
It's not like your consciousness is split or something, because
you immediately move off on different trajectories. With each new experience,
your brain and the computer simulation's brain are becoming different,
so it really is like two separate beings. Now, interestingly,
(25:09):
there's a philosophical question here about the timing. If the
company uploads a copy of your brain to the computer
and you go home, then it definitely seems like you
have not achieved immortality.
Speaker 2 (25:22):
But if the.
Speaker 1 (25:23):
Company kills you and turns on the computer one second later,
then it's like a transfer. You've gone from being inside
your body to being inside the virtual world. It's like
waking up on your pillow. Now you may well say, yeah,
but I'm not actually sure that's me inside the virtual world.
Speaker 2 (25:43):
It's like a recreation of me.
Speaker 1 (25:46):
But I'm dead. I just got killed by the company.
But again, this is the situation when we turn off
at nighttime and wake up again in the morning. And
you can ask the same question about Captain Kirk beaming
himself up in Star Trek. One moment he's standing on
the surface of the planet, and then he gets completely disintegrated,
(26:06):
and then he gets reconstituted inside the ship.
Speaker 2 (26:10):
But is that really him now?
Speaker 1 (26:12):
Inside the ship, or was he actually killed on the
surface of the planet, torn apart into his constituent atoms
and some identical version of his structure gets rebuilt, But
it's a new creature, it's not really him. These are
all thorny questions that philosophers and neuroscientists wrestle with. And
(26:33):
there are versions of these questions, like does it matter
if you capture just the structure of the atoms that
make up Captain Kirk and reproduce that structure with new
atoms in the spaceship or whether you take his actual
atoms and push those through space and rebuild him from
his original atoms? Does it make any difference? Did he
(26:55):
die in either case and it's just a rebuild of him.
And by the way, returning to this question of timing,
if the company kills you one second before turning on
your simulation, they can call that a transfer. But if
they kill you one second after turning on your simulation,
then it's murder because you have an independent existence from
(27:18):
that computer program and they have just taken that away
from you.
Speaker 2 (27:21):
So the timing matters.
Speaker 1 (27:23):
And what you can see is that these are all
tough philosophical problems. Now we've been conjecturing over whether you
(27:43):
could reproduce consciousness. But it's of course a possibility that
all of this conjecture is not conjecture at all.
Speaker 2 (27:52):
Maybe we have had.
Speaker 1 (27:53):
These conversations a thousand years ago and already figured out
the key to successfully transfer our consciousness into a simulation,
and the idea is that our reality is actually already
a simulation. Now thinking about these issues, this is not
a new idea. Two three hundred years ago, the Chinese
(28:15):
philosopher Tuang Tu wrote that he once quote dreamt, I
was a butterfly, fluttering hither and thither to all intents
and purposes. A butterfly. I was conscious only of following
my fancies as a butterfly, and was unconscious of my
(28:35):
individuality as a man. Suddenly I awoke, and there I
lay myself again. Now I do not know whether I
was then a man dreaming I was a butterfly, or
whether I am now a butterfly dreaming that I am
a man. And what this illustrates is the difficulty of
(28:58):
knowing precisely what reality we're in. The French philosopher Ney
Descartes wrestled with a different version of the same problem.
He wondered, how could we ever know if what we
experience is the real reality. So he proposed a thought experiment.
He asked, how do I know that I'm not a
(29:19):
brain in a vat? Maybe some scientists are stimulating that
brain in just the right way to make me believe
that I'm here and that I'm eating this delicious food
and seeing these stunning colors, and I'm listening to this podcast.
And Descartes concluded there might not be any way to know.
But he also realized something else. There's some me at
(29:43):
the center trying to figure all this out. So whether
or not I'm a brain in a simulation, I'm pondering
the problem. I'm thinking about this, and therefore there is
some I that exists. Japons don't suis. I think therefore
I am irrespective of whether I understand precisely what that
(30:05):
I is. Now, the modern version of the brain in
a vat question is how do I.
Speaker 2 (30:12):
Know if I'm living in a computer simulation?
Speaker 1 (30:15):
And in fact, some philosophers like Nick Bostrom have suggested
that in fact, it is more likely that we are
in a simulation than not. His argument is that once
it becomes possible to create a computer simulation of reality,
then it's likely that many such simulations would be created,
(30:36):
and in this scenario, it is more probable that we
are living in one of these simulations rather than the
real reality. And in fact, there are several philosophical arguments
that have been put forward to support this idea. One
argument is that the universe appears to be exquisitely finely
tuned for life, with the laws of physics being very specific,
(31:00):
which suggests they might have been designed by an intelligent being.
And while some people use this as an argument for
religious creationism, some philosophers use this argument that we are
perhaps the creation of a very convincing virtual reality, of
a simulation.
Speaker 2 (31:19):
The question of whether we are.
Speaker 1 (31:20):
Living in a simulation seems impossible, at least at the moment,
to know how to address scientifically, but it certainly seems
like a possibility. I mean, we already know how easily
we can get fooled into accepting our reality. Every night
we fall asleep and we have these bizarre dreams, and
(31:42):
while we're there, we believe in those worlds entirely, and
then we wake up and we think, oh, that wasn't
actually the real world.
Speaker 2 (31:49):
Now I'm in the real world. So we know that
we are completely capable of.
Speaker 1 (31:53):
Being in simulations and believing them entirely. In other words,
the mere existence of dreams may be sufficient evidence that
it is possible we are living in a simulation. Now,
if we are living in a simulation, could we escape
from it like they do in the matrix? Or are
we trapped in it? Would we have any power to
(32:16):
change the simulation? What's the purpose of the simulation? Who
exactly created the simulation? Okay, so those are tough questions
and we really have no way of tackling them, But
I want to pile on one more.
Speaker 2 (32:28):
I think there's an open.
Speaker 1 (32:29):
Question for us about the usefulness of immortality. Would you
actually want to live forever? And let's say, with your
uploaded brain on a new substrate, you don't even require sleep.
So for four hundred years you're looking for ways to
occupy yourself.
Speaker 2 (32:48):
Time can be painful.
Speaker 1 (32:50):
Imagine for hundreds of years you're looking for entertainment like
the best new series on whatever the streamers are at
that point, or you're scrolling through your social media with
infinite scroll and it really is close to infinite. Maybe
you actually reach the end of the Internet. Is there
a time when you say, Okay, it's been four hundred
(33:12):
and seventy years, I am ready to wrap this up now.
So I'll give you a sense of this from a
short story that I wrote my book sum So in
this story, you become a famous medical visionary, and here's
how it goes. You argue that there's no such thing
as a natural death, and you raise millions to fund
your research. You program computers to calculate all possible mutations
(33:36):
of viruses before they happen, and you design prophylactic treatments
against them. You compute the exact effects of every medication
on the normal cycles of the body. Your aggressive anti
death program is a success. After the final breath of
an incurably ill elderly woman, you are able to announce
(33:57):
that hers represented the last natural death. Great celebrations ensue.
People begin to live forever, healing just as they would
when they were young, free at last from the overhanging
cloud of mortality. You are greatly admired, but eventually your
success begins to lose its shine. People come to discover
(34:20):
that the end of death is the end of motivation.
Too much life, It turns out is the opiate of
the masses. There's a noticeable decline in accomplishment. People take
more naps, there's no great rush. In an attempt to
salvage their once dynamic lives, people begin to set suicide
dates for themselves. It is a welcome echo of the
(34:43):
old days of finite life spans, but superior because of
the opportunity to say goodbye and complete your estate planning.
That works well for a while, rekindling the incentive to
live strongly, but eventually people begin to take the system
with less than the appropriate seriousness, and if some large
new development occurs, such as a new relationship, they simply
(35:06):
postpone the suicide date. Whole cadres of procrastinators grow. When
they reschedule a new date, others ridicule them by calling
it a death threat. There develops enormous social pressure to
follow through with the suicides at long last. After many
abuses of the system, it is legislated that there's no
(35:27):
changing a preset death date, But eventually it comes to
be appreciated that not just the finitude of life, but
also the surprise timing of death is critical to motivation,
So people begin to set ranges for their death dates.
In this new framework, their friends throw surprise parties for
(35:48):
them like birthday parties, except they jump out from behind
the couch and kill them. Since you never know when
your friends are going to schedule your party, it reinstills
the carpae dm attitude of former years. Unfortunately, people begin
to abuse the surprise party system to extinguish their enemies
under the protection of necro legislation. In the end, great
(36:11):
masses of rioters break into your medical complex, kick the
plugs out of the computers, and once again have a
great celebration to mark the end of the last unnatural life. So,
although there's been a millennia long reach for immortality, I
think it's worth exploring this question of would it be
(36:31):
worth it?
Speaker 2 (36:32):
So let's wrap this up for today.
Speaker 1 (36:34):
In the coming years, we are going to discover more
about the human brain than we can describe with our
current theories and frameworks. And at the moment we are
surrounded with mysteries, many that we recognize and many we
haven't even yet registered as a field. We have vast
uncharted waters ahead of us. As always in science, the
(36:55):
important thing is to run the experiments and assess the results.
Some of the approaches are going to be blind alleys
and others are going to move us farther down the
road of understanding the blueprints of our own minds and consciousness.
Speaker 2 (37:09):
But one thing is certain, which.
Speaker 1 (37:10):
Is that our species is just at the beginning of
something and we don't fully know what it is and
where it's going. We are at an unprecedented moment in history,
one in which brain, science and technology are co evolving,
and what happens at this intersection is poised to change
(37:32):
who we are and how we think about life and immortality.
For thousands of generations, humans have lived the same life
cycle over and over. We're born, we control a fragile body,
we enjoy a small strip of sensory reality, and then
we die. And science might give us the tools to
transcend that evolutionary story, because we can now hack our
(37:56):
own hardware, and as a result, our brains don't need
to remain as we have inherited them. If we are
able to upload our consciousness, eventually we're gonna be able
to shed our physical forms altogether. So our species is
just now discovering the tools to shape our own destiny,
(38:18):
and who we become is yet to be Imagined. To
find out more and to share your thoughts, head over
to eagleman dot com slash podcasts and send me an
email at podcast at eagleman dot com with questions or discussions,
and I'll be making an episode soon in which I
(38:39):
address those. Until next time, I'm David Eagleman, and this
is Inner Cosmos
How would we know if we're living in a simulation,
And what does that have to do with having a
dream that you're a butterfly or John Lennon or Renee
des Cartes or freezing yourself in a vat of liquid nitrogen?
And how will we solve the problem that human bodies
can't do space travel? Welcome to Inner Cosmos with me,
(00:31):
David Eagleman. I'm a neuroscientist and an author at Stanford University,
and I've spent my career studying the intersection between how
the brain works and how we experience life. And what
I'm going to talk about today is the possibility of
living forever. What does that have to do with the brain?
Would we want to live forever? And how could we
(00:52):
get there? Humans have been obsessed with the idea of
immortality for ages. As far back as documented history goes,
there are stories of humans trying everything to unlock the
secret to eternal life. In Arthurian literature, the Holy Grail
(01:14):
was said to have miraculous healing powers and it would
grant anyone who drank from it eternal youthfulness, and the
ancient Egyptians they would painstakingly prepare the physical body for
the journey to the afterlife, and they believed you were
reborn again and again. And China's first emperor launched an
(01:35):
obsessive search for the elixir of life, and that obsession
continues and cultures all over the world today. While leaving
a legacy is the only thing close to immortality by
today's standards, Woodie Allen wanted the real thing. He said,
I don't want to achieve immortality through my work. I
want to achieve immortality through not dying. He said, I
(01:59):
don't want to live on in the hearts of my countrymen.
I want to live on in my apartment. So what
are our options for achieving eternal life? Well, the first
option has to do with medical innovations, such that we
keep repairing things that go wrong with the body. And
in fact, it's rumored that life insurance companies assume in
(02:22):
their actuarial tables that children born now are going to
live to one hundred and fourteen years old. And this
is based just on extrapolating medical innovation curves. In other words,
you take the pace of medical progress and you guess
what things are going to look like in a century
from now. But the fact is there are barriers to
(02:45):
physical immortality, like aging and disease, and then of course
there are accidents that can happen, like you fall off
a cliff, where you get in a car accident, or
a tornado gets you, or a volcano explodes, and on
and on. So although we can continue to make improvements
in medical science to expand the average lifespan, there's no
(03:09):
real guarantee that your lifespan is going to be any
better now. There's a second approach that some people have taken,
and that's about making a throw to the future, when
people will know things like.
Speaker 2 (03:22):
How to repair bodies.
Speaker 1 (03:24):
The issue is that we just don't know how to
cure lots of problems now, but it's not impossible that
two hundred years from now a lot of this stuff
will be obvious. In two hundred years, we'll look back
at our textbooks and we'll think, my gosh, how did
we not know that? How did we not know that
we can just reach in and tweak some things on
the telomeres and cure cancer easily with a few zapps
(03:47):
and essentially make ourselves live much longer, maybe forever. The
problem is that this is in the future and not
right now. And therefore we don't get any of the
benefits of that. So the idea is, perhaps you could
by pausing yourself now and rebooting yourself in that future.
(04:08):
And that's the approach of a company called Alcore. Alcore
is based in Arizona, and they have these giant silver
tanks called doers that are filled with liquid nitrogen and
they're kept at a temperature of negative one hundred and
ninety six degrees celsius. So when you're expiring on your
hospital bed, this company gets contacted either by your family
(04:32):
or because you're wearing a special bracelet, and as soon
as your heart stops, a team from Alcore rushes to
your bedside and starts the deep freezing process. Then they
transport your body to Arizona where they put it in
the giant vat with the liquid nitrogen. And you actually
have two choices here. You can freeze your entire body,
(04:54):
or if you can't afford that, you can just have
your head removed and just have your head frozen. Because
while it's great to have your whole body, the real
representation of who you are is theoretically just kept in
the brain. Or suffice it to say, that's the densest
representation of who you are.
Speaker 2 (05:12):
You just need the head.
Speaker 1 (05:14):
Now, as a side note, you might wonder how much
this costs. Well, you don't actually have to pay anything upfront. Instead,
you can modify your life insurance payment to make its
payout to the company. So this allows you the possibility
of living a second chapter. Now, if you're unfamiliar with
this slice of the world, it will blow your mind.
(05:35):
I visited al Core and met the then CEO, Max
More for my television show The Brain, and I got
to tour around the facility and it's quite striking. There
are these giant silver vats of liquid nitrogen and they
currently have two hundred and eight people stored in there,
and the company has over fourteen hundred people who are
(05:56):
signed up for the service, but they haven't died yet
and they will eventually end up in these vats. Now,
although scientists don't currently know how to unfreeze and revivify
a body, the idea is that some generation in the
future will figure that out. Maybe that's a century from now,
or maybe that's a millennium. And then the idea is
(06:18):
that the frozen person will awaken into a new world.
So people who sign up for the service operate on hope.
They're making a deep football throw into the future, hoping
someone will be there to catch it, and some people
choose to cryo preserve their pets. Also, the idea is
(06:40):
that if you awaken to a completely new reality, that's
likely to be disorienting, and if you have a familiar,
fuzzy face by your side, that could be really nice
and reassuring. Also, it turns out that Alcore allows you
to have a small memory box to go along with
your frozen body. And the reason I mentioned this is
(07:01):
because sometimes people ask me to inscribe one of my
books to them. But I recently got a really interesting
request from a man who had just signed up for Alcore.
He said he'd been moved by my book to the
Brain and wanted to keep that in his memory box
that goes along with the frozen body, so he'd have
it in his new world when he gets rebooted. So
(07:24):
he asked me to sign my book for his revivification
in a century or two. In other words, I would
sign the book to him for his re entry into
the world sometime in the future. Now I've had a
lot of cool requests to sign books for special occasions,
but signing for someone who is possibly coming back in
(07:45):
a couple of centuries. That was a new one for me.
So here's what I wrote, Dear Steve, welcome back. I'm
so curious what secrets the world has divulged now. Presumably
the text books have been thoroughly rewritten, and the current
understanding of science would intimidate and thrill a twenty first
(08:07):
century mind. Presumably I am long gone and all that
remains of me are fading echoes of my genetic code.
But this book remains. It memorializes what we knew in
the early part of the millennium. Like all snapshots of science,
some notions will stale, while others will prove more durable.
(08:31):
Whatever the case, these pages form a bridge. They allow
me to talk with you as though we still live contemporaneously.
They allow two brains to span an unknowably wide chasm
of time.
Speaker 2 (08:47):
Enjoy the future, David.
Speaker 1 (08:51):
So that's the method of freezing yourself until biology is
better understood. It's a hail Mary throw, and you don't
know for sure that anyone's going to catch the ball.
For all you know, society will have collapsed, and maybe
your body is going to get cannibalized, or legislatively, something
might happen in the future where all these frozen bodies
(09:13):
don't get unfrozen, or we are long blown up in
a nuclear war and there's nobody there to unfreeze you.
But people who sign up for this figure that at
least they have a non zero chance of something happening here,
of getting to live a second chapter, and that's better
than having one hundred percent certainty that you're going to die.
(09:35):
But fundamentally, there's a problem that's probably intractable, which is
that we are made of biological pieces and parts, and
those things are going to wear down. Even if we're
able to successfully unfreeze people, the ticking clock of aging
will keep ticking, and we're always going to be racing
(09:55):
against entropy. As the poet William Butler Yeates said, things
fall apart, the center cannot hold, and this is what
aging and death is. And that brings us to a
question of how we might solve this for the long term,
forever by just extracting the part of us that matters
(10:15):
our consciousness. So could it be possible someday to upload
our consciousness out of our brains and onto a different
substrate like silicon and run it, and would that still
be you.
Speaker 2 (10:31):
So here's the idea.
Speaker 1 (10:32):
Maybe the hardware of the brain, all these cells, that's
not the important part. But instead it's the software of
the brain that matters. In other words, the algorithms that
are running. Maybe that's what makes a mind. Maybe it's
the patterns by which these spikes, these zeros and ones
are running.
Speaker 2 (10:51):
And if we could extract those.
Speaker 1 (10:53):
Massive patterns and reproduce them on something different, maybe that
would be you.
Speaker 2 (11:00):
This idea is called computational equivalents.
Speaker 1 (11:04):
The idea is that the eighty six billion cells of
the brain are just running algorithms that have been sussed
out by mother nature over billions of years. But fundamentally,
it's just code that's being run. And so the idea
of computational equivalents is that it doesn't matter if you
reproduce this system out of legos or tinker toys or
(11:28):
ball bearings or silicon. If the system runs the same program,
you will get the same consciousness.
Speaker 2 (11:35):
You will get you.
Speaker 1 (11:38):
Now, we don't know if the theory of computational equivalents
is correct, but if it is, it implies that we
could shift ourselves off the degrading biological substrate of our bodies,
and with powerful enough computers simulating all these neural interactions,
we could upload our consciousness and exist digitally, circumventing the
(12:02):
inevitability of demise. That would be the single biggest leap
in the history of our species, launching us into an
era of transhumanism. Just imagine what it could look like
to leave your body behind and wake up in a
simulated world. Your simulated existence could look like anything you wanted.
Speaker 2 (12:24):
Programmers could make any virtual world for you. If you've
ever wanted to fly.
Speaker 1 (12:30):
Or breathe underwater, or inhabit an alien planet, you just
sign a contract for it, You pay, and that becomes
your new existence. It's your simulation and your reality is
up to you. And as a side note, we could
in theory run virtual brains as fast or slow as
we wanted, so in seconds of computing time, you could
(12:54):
have thousands of years of experience. In fact, even if
the cosmos were coming to an end tomorrow, the programmers
could simulate a billion more years for you.
Speaker 2 (13:04):
In that time.
Speaker 1 (13:07):
So all that sounds great, but there are some technical
and theoretical hurdles. The first one is the enormous difficulty
of figuring out the secrets of the brain. And this
is a problem that can't be underestimated.
Speaker 2 (13:23):
As much as.
Speaker 1 (13:24):
We've discovered about how the brain works, we are a
long way off from understanding the big picture. It's a
very tough problem. You've heard me mentioned before on this
(13:47):
podcast that the brain is the most complex device we
have ever discovered. It has almost one hundred billion neurons.
Each of those is as complicated as the city of
New York, and you've got detailed connections between them that
number in the hundreds of trillions. So figuring out the
algorithms running in the system, or even just scratching the
(14:09):
surface of those is something that still, for the most.
Speaker 2 (14:13):
Part, has completely eluded us.
Speaker 1 (14:16):
Consider this experiment that a couple of my colleagues did
in twenty seventeen. They asked, what would happen if we
used our best neuroscience approaches to understand a simple microprocessor,
just a computer chip. So if the brain is really
like a giant, complex computer chip, let's see how far
we can get by analyzing this very simple one. So
(14:38):
they picked an Atari microprocessor from nineteen eighty one that
ran donkey Kong. And it turns out that after measuring
all the input and output signals from the chip and
applying the type of analyses that we have in neuroscience,
they couldn't say much of anything about the function of
the chip. I mean, note that they all already knew
(15:00):
what the chip accomplished, and they know how chips work.
But when you're looking at a ton of zeros and
ones streaming in and streaming out, it's really difficult to say, Okay,
here's the algorithms that the chip is implementing. As the
researchers put it in that paper quote. In the case
of the processor, we know its function and structure, and
(15:22):
our results stayed well short of what we would call
a satisfying understanding. So figuring out what the brain is
implementing may turn out to be really hard.
Speaker 2 (15:33):
So can we copy the brain?
Speaker 1 (15:35):
Well, we're nowhere close to copying the human brain because
the detailed structure of it is so enormous. It's probably
a zetabyte of data, which is maybe around a tenth
of the computational capacity of our planet right now. But
this is fundamentally just a technology challenge, and the way
(15:55):
that things are going we will probably get there at
some point. It may not happen in our lifetime, but
it's essentially guaranteed to happen in the future as our
computational power increases.
Speaker 2 (16:07):
Okay, but this brings us.
Speaker 1 (16:09):
To a tougher hurdle, which might be a theoretical one,
which is, there may be physics happening in the brain
that don't make it as easy as copy pasting a
giant document.
Speaker 2 (16:22):
For example, the.
Speaker 1 (16:24):
Brain might be exploiting quantum mechanical effects, and if so,
that means we can't pretend the brain is just a
big clockwork machine. Quantum mechanics is the science of the
very small. It explains the behavior of subatomic particles and
how they interact with each other and with light. The
thing is that it's extraordinarily counterintuitive, and it's not really
(16:46):
anything like classical physics, and we have no idea how
to build a.
Speaker 2 (16:51):
Quantum system the size of the brain.
Speaker 1 (16:54):
Now I'll just mention there are many scientists like Roger Penrose,
who recently won the Nobel Prize, who suggest that there
might be quantum mechanical effects in the brain, And there
are many more scientists on the other side of the
debate who say they think there aren't quantum mechanics in
the brain, but I just want to note that we.
Speaker 2 (17:12):
Don't actually know.
Speaker 1 (17:14):
Some people make fun of the quantum mechanics approach and
they say something like, well, quantum mechanics is mysterious and
the brain is mysterious, so maybe they're the same thing.
Speaker 2 (17:23):
Ha ha, Okay.
Speaker 1 (17:24):
Skepticism is always warranted until something is demonstrated to be true.
But science doesn't rule things in er out in advance
of having enough data, So when it comes to quantum mechanics,
we don't actually know yet. Part of the problem that
people have excepting quantum mechanics is that it's poorly understood
and it's relatively new for us humans. But remember that
(17:46):
for mother Nature, quantum mechanics has been around from the beginning.
And one thing that's clear is that if there's something
mother Nature can take advantage of, she will. So maybe
quantum mechanics has nothing at all to do with the
brain or everything to do with the brain, but we
can't rule it out yet. And if it turns out
that the brain is not so straightforward but requires quantum
(18:08):
effects or whatever we discover next century like super hyper
quantum x effects, then this path of learning how to
reproduce the.
Speaker 2 (18:16):
Brain might take much longer.
Speaker 1 (18:19):
Maybe we'll need quantum computers or something we haven't even
thought of yet. And I want to mention a third
technical hurdle to successfully uploading our consciousness, which is that
the simulated brain has to be able to modify its
own structure. This is what's known as brain plasticity. In
some of my other episodes have been about this. The
(18:40):
activity that runs through a brain modifies the brain.
Speaker 2 (18:45):
It changes the brain.
Speaker 1 (18:46):
That's why you have memory, for example, because everything you
experience is actually changing the physical structure of your brain,
so that activity runs through it differently. Next time, when
you learn that the name of this part podcast is
inner cosmos, that physically changes the structure of your brain
so that when someone asks you, hey, what was the
(19:07):
name of that podcast, your brain can retrieve that information.
So we need to simulate not only the detailed structure
of the brain to run the software, but we also
need to understand the physics of the ongoing interactions and
how it changes. For example, in the brain, you have
the activity of transcription factors that travel to the nucleus
(19:30):
and change gene expression. You have dynamic changes in the
location and strength of the synapses, the connections between neurons,
and so on. And unless your simulated experiences change the
structure of your simulated brain, you could inform new memories.
You'd have no sense of the passage of time. Your
(19:52):
consciousness would be frozen at whatever point it was uploaded
into the simulation. Under those circums stances, would there be
any point to immortality? Okay, So let's imagine that two
hundred years go by and we managed to surmount all
those technical hurdles.
Speaker 2 (20:10):
We have enough storage.
Speaker 1 (20:11):
Capacity, we figure out any quantum effects, We make it
so that the simulation self modifies based on its experience.
So great, we're there, and in this future world, uploading
our consciousness would be possible. Now what would that mean
for the human species? Well, among other things, it would
open up the possibility of getting to other solar systems.
(20:35):
There are at least one hundred billion other galaxies in
our cosmos, each of which contain one hundred billion stars.
We've already spotted thousands of exoplanets orbiting those stars. There
are planets that are like Earth in some way, and
some of those have conditions quite.
Speaker 2 (20:52):
Like the Earth.
Speaker 1 (20:53):
But The impossibility lies in the fact that our current
fleshy bodies will ever get to those exoplanets, because there's
just no real way that we're going to be able
to travel those kind of distances in space and in time.
Speaker 2 (21:09):
But uploading would allow us.
Speaker 1 (21:12):
To transfer our minds into bodies that are built for
space travel, and that way we could travel between stars
in between galaxies with a human mind and a titanium body. Also,
note that with a simulated mind, you could pause the simulation,
you could shoot it out into space and reboot it
(21:35):
a thousand years later when it arrives at a planet,
So it would seem to your consciousness that you were
on Earth, you had a launch, and then you instantly
found yourself on a new planet. In other words, if
you could upload your brain into silicon, this would be
equivalent to the physics dream of finding a wormhole that
(21:56):
lets you get from one part of the universe to
another in a subjective instant. Okay, so we've established that
if the algorithms are the important part of what makes
you who you are, rather than the biological physical stuff,
then it's a possibility will someday be able to copy
(22:17):
our brains and upload them onto Silica and run them there.
But there's an important question here, is it really you?
I was thinking about this the other day because Paul
McCartney announced an upcoming song with vocals by John Lennon
thanks to AI that brings Lennon's voice back to life.
(22:38):
But even though John Lennon is out there singing new
songs now and everyone's talking about his immortality, he doesn't
get to enjoy it. John Lennon doesn't know that he's
been brought back. It's just zeros and ones running on
a computer. John Lennon doesn't get anything out of that.
Speaker 2 (22:58):
So even if there's.
Speaker 1 (22:59):
A suit for a complete simulation of you, is it
really you? Or is it just zeros and ones? Well,
I think this could be argued either way. For example,
every night when you go to sleep, it's like you
are turning off, and then the consciousness that awakens on
your pillow in the morning inherits all of your memories
(23:22):
and we say, yeah, I'm the same person who climbed
into this bed last night. I turned off, and then
I turn on again and it's me and I'm getting
back to business. So maybe the process of transferring from
your physical body to a computer is just like that
where you open your eyes in the simulated world and
you think, cool, here I am.
Speaker 2 (23:44):
Let's get back to business.
Speaker 1 (23:45):
But there's another way to look at this too, which
is that possibly when some company scans your brain and
then uploads you into the computer, that's not you at all.
That's just a computer program that's running. That program happens
to feel confident that it's you. It has all your
(24:06):
memories and beliefs, and thinks that it was just there
standing outside the computer in your body, but its existence
inside the computer doesn't help you at all. Let's imagine
you just paid a million bucks to this immortality company
and they tell you, hey, it worked. You see this
little coordinate moving around on the screen. That's you. You're
(24:27):
living forever now. And then you leave the immortality company
and you drive home and sit on the couch and
your life is no different.
Speaker 2 (24:36):
You are still heading towards death.
Speaker 1 (24:39):
It's just that you know you've paid all this money
so that some computer simulation has a good afterlife.
Speaker 2 (24:44):
But is that really you?
Speaker 1 (24:45):
Did you gain anything out of paying this one million dollars?
The actual situation is that there are now two of you.
It's not like your consciousness is split or something, because
you immediately move off on different trajectories. With each new experience,
your brain and the computer simulation's brain are becoming different,
so it really is like two separate beings. Now, interestingly,
(25:09):
there's a philosophical question here about the timing. If the
company uploads a copy of your brain to the computer
and you go home, then it definitely seems like you
have not achieved immortality.
Speaker 2 (25:22):
But if the.
Speaker 1 (25:23):
Company kills you and turns on the computer one second later,
then it's like a transfer. You've gone from being inside
your body to being inside the virtual world. It's like
waking up on your pillow. Now you may well say, yeah,
but I'm not actually sure that's me inside the virtual world.
Speaker 2 (25:43):
It's like a recreation of me.
Speaker 1 (25:46):
But I'm dead. I just got killed by the company.
But again, this is the situation when we turn off
at nighttime and wake up again in the morning. And
you can ask the same question about Captain Kirk beaming
himself up in Star Trek. One moment he's standing on
the surface of the planet, and then he gets completely disintegrated,
(26:06):
and then he gets reconstituted inside the ship.
Speaker 2 (26:10):
But is that really him now?
Speaker 1 (26:12):
Inside the ship, or was he actually killed on the
surface of the planet, torn apart into his constituent atoms
and some identical version of his structure gets rebuilt, But
it's a new creature, it's not really him. These are
all thorny questions that philosophers and neuroscientists wrestle with. And
(26:33):
there are versions of these questions, like does it matter
if you capture just the structure of the atoms that
make up Captain Kirk and reproduce that structure with new
atoms in the spaceship or whether you take his actual
atoms and push those through space and rebuild him from
his original atoms? Does it make any difference? Did he
(26:55):
die in either case and it's just a rebuild of him.
And by the way, returning to this question of timing,
if the company kills you one second before turning on
your simulation, they can call that a transfer. But if
they kill you one second after turning on your simulation,
then it's murder because you have an independent existence from
(27:18):
that computer program and they have just taken that away
from you.
Speaker 2 (27:21):
So the timing matters.
Speaker 1 (27:23):
And what you can see is that these are all
tough philosophical problems. Now we've been conjecturing over whether you
(27:43):
could reproduce consciousness. But it's of course a possibility that
all of this conjecture is not conjecture at all.
Speaker 2 (27:52):
Maybe we have had.
Speaker 1 (27:53):
These conversations a thousand years ago and already figured out
the key to successfully transfer our consciousness into a simulation,
and the idea is that our reality is actually already
a simulation. Now thinking about these issues, this is not
a new idea. Two three hundred years ago, the Chinese
(28:15):
philosopher Tuang Tu wrote that he once quote dreamt, I
was a butterfly, fluttering hither and thither to all intents
and purposes. A butterfly. I was conscious only of following
my fancies as a butterfly, and was unconscious of my
(28:35):
individuality as a man. Suddenly I awoke, and there I
lay myself again. Now I do not know whether I
was then a man dreaming I was a butterfly, or
whether I am now a butterfly dreaming that I am
a man. And what this illustrates is the difficulty of
(28:58):
knowing precisely what reality we're in. The French philosopher Ney
Descartes wrestled with a different version of the same problem.
He wondered, how could we ever know if what we
experience is the real reality. So he proposed a thought experiment.
He asked, how do I know that I'm not a
(29:19):
brain in a vat? Maybe some scientists are stimulating that
brain in just the right way to make me believe
that I'm here and that I'm eating this delicious food
and seeing these stunning colors, and I'm listening to this podcast.
And Descartes concluded there might not be any way to know.
But he also realized something else. There's some me at
(29:43):
the center trying to figure all this out. So whether
or not I'm a brain in a simulation, I'm pondering
the problem. I'm thinking about this, and therefore there is
some I that exists. Japons don't suis. I think therefore
I am irrespective of whether I understand precisely what that
(30:05):
I is. Now, the modern version of the brain in
a vat question is how do I.
Speaker 2 (30:12):
Know if I'm living in a computer simulation?
Speaker 1 (30:15):
And in fact, some philosophers like Nick Bostrom have suggested
that in fact, it is more likely that we are
in a simulation than not. His argument is that once
it becomes possible to create a computer simulation of reality,
then it's likely that many such simulations would be created,
(30:36):
and in this scenario, it is more probable that we
are living in one of these simulations rather than the
real reality. And in fact, there are several philosophical arguments
that have been put forward to support this idea. One
argument is that the universe appears to be exquisitely finely
tuned for life, with the laws of physics being very specific,
(31:00):
which suggests they might have been designed by an intelligent being.
And while some people use this as an argument for
religious creationism, some philosophers use this argument that we are
perhaps the creation of a very convincing virtual reality, of
a simulation.
Speaker 2 (31:19):
The question of whether we are.
Speaker 1 (31:20):
Living in a simulation seems impossible, at least at the moment,
to know how to address scientifically, but it certainly seems
like a possibility. I mean, we already know how easily
we can get fooled into accepting our reality. Every night
we fall asleep and we have these bizarre dreams, and
(31:42):
while we're there, we believe in those worlds entirely, and
then we wake up and we think, oh, that wasn't
actually the real world.
Speaker 2 (31:49):
Now I'm in the real world. So we know that
we are completely capable of.
Speaker 1 (31:53):
Being in simulations and believing them entirely. In other words,
the mere existence of dreams may be sufficient evidence that
it is possible we are living in a simulation. Now,
if we are living in a simulation, could we escape
from it like they do in the matrix? Or are
we trapped in it? Would we have any power to
(32:16):
change the simulation? What's the purpose of the simulation? Who
exactly created the simulation? Okay, so those are tough questions
and we really have no way of tackling them, But
I want to pile on one more.
Speaker 2 (32:28):
I think there's an open.
Speaker 1 (32:29):
Question for us about the usefulness of immortality. Would you
actually want to live forever? And let's say, with your
uploaded brain on a new substrate, you don't even require sleep.
So for four hundred years you're looking for ways to
occupy yourself.
Speaker 2 (32:48):
Time can be painful.
Speaker 1 (32:50):
Imagine for hundreds of years you're looking for entertainment like
the best new series on whatever the streamers are at
that point, or you're scrolling through your social media with
infinite scroll and it really is close to infinite. Maybe
you actually reach the end of the Internet. Is there
a time when you say, Okay, it's been four hundred
(33:12):
and seventy years, I am ready to wrap this up now.
So I'll give you a sense of this from a
short story that I wrote my book sum So in
this story, you become a famous medical visionary, and here's
how it goes. You argue that there's no such thing
as a natural death, and you raise millions to fund
your research. You program computers to calculate all possible mutations
(33:36):
of viruses before they happen, and you design prophylactic treatments
against them. You compute the exact effects of every medication
on the normal cycles of the body. Your aggressive anti
death program is a success. After the final breath of
an incurably ill elderly woman, you are able to announce
(33:57):
that hers represented the last natural death. Great celebrations ensue.
People begin to live forever, healing just as they would
when they were young, free at last from the overhanging
cloud of mortality. You are greatly admired, but eventually your
success begins to lose its shine. People come to discover
(34:20):
that the end of death is the end of motivation.
Too much life, It turns out is the opiate of
the masses. There's a noticeable decline in accomplishment. People take
more naps, there's no great rush. In an attempt to
salvage their once dynamic lives, people begin to set suicide
dates for themselves. It is a welcome echo of the
(34:43):
old days of finite life spans, but superior because of
the opportunity to say goodbye and complete your estate planning.
That works well for a while, rekindling the incentive to
live strongly, but eventually people begin to take the system
with less than the appropriate seriousness, and if some large
new development occurs, such as a new relationship, they simply
(35:06):
postpone the suicide date. Whole cadres of procrastinators grow. When
they reschedule a new date, others ridicule them by calling
it a death threat. There develops enormous social pressure to
follow through with the suicides at long last. After many
abuses of the system, it is legislated that there's no
(35:27):
changing a preset death date, But eventually it comes to
be appreciated that not just the finitude of life, but
also the surprise timing of death is critical to motivation,
So people begin to set ranges for their death dates.
In this new framework, their friends throw surprise parties for
(35:48):
them like birthday parties, except they jump out from behind
the couch and kill them. Since you never know when
your friends are going to schedule your party, it reinstills
the carpae dm attitude of former years. Unfortunately, people begin
to abuse the surprise party system to extinguish their enemies
under the protection of necro legislation. In the end, great
(36:11):
masses of rioters break into your medical complex, kick the
plugs out of the computers, and once again have a
great celebration to mark the end of the last unnatural life. So,
although there's been a millennia long reach for immortality, I
think it's worth exploring this question of would it be
(36:31):
worth it?
Speaker 2 (36:32):
So let's wrap this up for today.
Speaker 1 (36:34):
In the coming years, we are going to discover more
about the human brain than we can describe with our
current theories and frameworks. And at the moment we are
surrounded with mysteries, many that we recognize and many we
haven't even yet registered as a field. We have vast
uncharted waters ahead of us. As always in science, the
(36:55):
important thing is to run the experiments and assess the results.
Some of the approaches are going to be blind alleys
and others are going to move us farther down the
road of understanding the blueprints of our own minds and consciousness.
Speaker 2 (37:09):
But one thing is certain, which.
Speaker 1 (37:10):
Is that our species is just at the beginning of
something and we don't fully know what it is and
where it's going. We are at an unprecedented moment in history,
one in which brain, science and technology are co evolving,
and what happens at this intersection is poised to change
(37:32):
who we are and how we think about life and immortality.
For thousands of generations, humans have lived the same life
cycle over and over. We're born, we control a fragile body,
we enjoy a small strip of sensory reality, and then
we die. And science might give us the tools to
transcend that evolutionary story, because we can now hack our
(37:56):
own hardware, and as a result, our brains don't need
to remain as we have inherited them. If we are
able to upload our consciousness, eventually we're gonna be able
to shed our physical forms altogether. So our species is
just now discovering the tools to shape our own destiny,
(38:18):
and who we become is yet to be Imagined. To
find out more and to share your thoughts, head over
to eagleman dot com slash podcasts and send me an
email at podcast at eagleman dot com with questions or discussions,
and I'll be making an episode soon in which I
(38:39):
address those. Until next time, I'm David Eagleman, and this
is Inner Cosmos
Host
David Eagleman
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