Speaker 1: Okay, stop what you're doing for a moment and just
consider this. Right now, this very second, the universe might be.
Speaker 2: Splitting, and not just splitting once.
Speaker 1: No, splitting into just countless parallel universes. And I don't
mean that in some metaphorical way like a story.
Speaker 2: I mean literally, right physically, real separate universes are branching
off from our own moment by moment.
Speaker 1: And in every single one of those new realities, there's
a new version of you, a distinct you, living a
completely different, non overlapping life.
Speaker 2: It's a concept that sounds so much like science fiction.
It's so big, so profoundly counterintuitive, that you'd be forgiven
for just dismissing it.
Speaker 1: You would. But here's the thing you can't, because this
isn't fantasy. It's a direct consequence of the mathematics of
quantum mechanics, the.
Speaker 2: Very same physics that you know powers your phone, your computer,
the Wi Fi are probably using to listen to this.
The math works, we know it works, and this is where.
Speaker 1: It leads, and this is where it gets really really interesting.
We are doing ad dive today into something called the
many world's interpretation of quantum mechanics, or MWI for sure.
Speaker 2: It's an attempt to solve one of the deepest, most
stubborn problems in all of physics, and it leads directly
to I think the most radical idea.
Speaker 1: Imaginable quantum immortality.
Speaker 2: Quantum immortality the idea that from your own subjective point
of view, you might just live forever.
Speaker 1: So our mission for this deep dive is it was
pretty demanding. We've gone through a mountain of research on
the history, the actual mechanics, and the wild implications of
this theory.
Speaker 2: And we're going to distill it all down. Our goal
is that by the end of this you will understand
the fundamental conflicts in quantum physics better than almost anyone.
You know.
Speaker 1: It's a journey that will, I promise, probably redefine how
you think about reality itself and maybe just maybe your
own existence.
Speaker 2: And to really get the solution, you have to start
with the problem exactly.
Speaker 1: So let's go back. Our story begins over a century ago,
early nineteen hundreds. You've got this incredible ferment of intellectual
activity in physics.
Speaker 2: Oh, the Titans, Einstein, mex Plank, Bore, Shrewdinger, all of them.
Speaker 1: And they were all wrestling with these new phenomena, things
like black body radiation, the photoelectric effect, that the old
physics that classical Newtonian physics just couldn't explain at all.
Speaker 2: Classical physics was beautiful. It was deterministic. It described a
world like a giant clockwork mechanism. If you knew the
position and momentum of every particle at the start, you could,
in theory, calculate the entire future of the universe, perfect prediction.
Speaker 1: But when they started looking at the sub atomic world,
at electrons and photons, they realized those classical rules just
completely fell apart.
Speaker 2: They failed spectacularly. So they had to develop a new theory,
quantum mechanics, which was I mean, unbelievably successful at making predictions.
It explained that energy comes in these little discrete packets or.
Speaker 1: Quanta, but that success came with a really high price.
The map was telling them that things like light and
matter had this bizizar are dual nature. So as it
acts like a particle, you know, tiny little.
Speaker 2: Ball, and sometimes it acts like a diffuse wave spread
out over space. And worse, it introduced probability and pure
chance right into the very fabric of reality.
Speaker 1: And that underlying weirdness was a bitter pill to swallow,
even for the people who invented the theory.
Speaker 2: So to really get why something as wild as a
many World's interpretation was even necessary, we have to hammer
home this fundamental split between the old world and the
new quantum world.
Speaker 1: Right think about the world we live in. The macroscopic
world classical physics. Everything is exact, it's definite.
Speaker 2: We can measure the trajectory of a baseball. We can
calculate the orbit of a planet down to the millimeter.
If you ask me where's the Earth right now, I
can give you a single precise set of coordinates.
Speaker 1: Determinism is king. Everything has a definite value, whether we're
looking at it or not.
Speaker 2: But the second you shrink down to the world of
atoms and electrons, all of that comforting certainty just evaporates.
It completely disintegrates.
Speaker 1: You go from exact numbers to probability probabilities.
Speaker 2: That's it. You can't say anymore the electron is right
here at position X with this exact speed. You can
only talk about the likelihood of finding it in a
certain place or a certain state, and.
Speaker 1: The tool they use to figure out those likelihoods. That's
the core of this whole thing, isn't it the wave function?
Speaker 2: The wave function yes, usually written with the Greek letter sigh,
and it's crucial to understand what it is and what
it isn't. It's a purely mathematical.
Speaker 1: Object, so it's not describing something we can like see
or touch, not directly.
Speaker 2: It's a recipe. It's a tool physicists used to calculate
the probability of all the possible outcomes for a quantum system.
The key is it doesn't describe where a particle is.
It describes all the places it could be, all at once.
Speaker 1: And that's such a critical distinction because it's not just
that we're ignorant, right. It's not like me saying I
don't know where my keys are, but there's a fifty
percent chance through on the kitchen ca exactly.
Speaker 2: That's a perfect analogy with your keys. They are in
one definite place, you just don't know where. The wave
function says that before you look, the particle doesn't have
a single definite location. It physically exists in a kind
of blurry haze of all possibilities at the same time.
That's superposition, a superposition of all possibilities defined by that
wave function.
Speaker 1: Simultaneously, Let's drill down on that idea of superposition, because
that's where all the weirdness really comes from.
Speaker 2: Okay, good idea. Let's take an electron spin You can
think of it like a tiny spinning top. In our world,
a top is either spinning clockwise or counterclockwise, spin up
or spin.
Speaker 1: Down right one or the other.
Speaker 2: But in quantum mechanics, before you measure it, the electron
is in a superposition of both. It is literally spin
up an a spin down at the same time.
Speaker 1: Not flipping back and forth really fast.
Speaker 2: No, it's existing as a combination of both states. The
wave function might tell us there's a fifty percent probability
of finding it spin up and a fifty percent probability
of finding it spin down, But until we look it's
a literal physical blend of the two.
Speaker 1: And this is what just drove the founders of the
theory crazy. How does this system, which is this lurry
haze of probabilities, suddenly decide to be just one thing
in one place the instant we look at it.
Speaker 2: That is the question, That is the measurement problem. If
the wave function is a complete description of reality, and
we know the math works, because again, all our modern
tech is based on it. What is the physical mechanism
that forces that superposition to resolve into the single definite
reality we actually experience.
Speaker 1: And trying to answer that question basically started a civil
war among physicists that lasted for decades. So the first
major attempt to answer the measurement problem and the one
that was dominant for what fifty sixty years?
Speaker 2: Oh, easily, it was the only game in town for
a long time. It was the Copenhagen interpretation.
Speaker 1: Name for where it's main champion Neil's Boorr worked. He
and vererneror Heisenberg developed it in the nineteen twenties.
Speaker 2: Right, and they introduced a new extra rule into quantum mechanics,
a concept they called the collapse. Postulate the collapse the collapse.
It's a simple but very strange assertion. It says that
the wave function, with all its possibilities, evolved perfectly fine
on its own, but it instantly and randomly collapses down
to just one of those possibilities the moment it's measured
by an observer.
Speaker 1: So if we go back to our electron, that's fifty
percent spin up and fifty percent spin down.
Speaker 2: As soon as you bring a detector, a magnet, anything
to measure it, that wave function just snaps instantly. It
becomes either one hundred percent spin up or one hundred
percent spin down.
Speaker 1: And the other possibility, the one that didn't happen gone.
Speaker 2: According to Copenhagen, it just vanishes from reality. It never existed.
Speaker 1: That is so deeply weird. I mean, why, why does
the act of looking the active measurement have this almost
magical power to force reality to make a choice.
Speaker 2: That was the problem. It introduced this strange dualism. You
had the quantum world, which was governed by this smooth
wave function, and then you had the classical world of
observers and measuring devices, which followed different rules and could
somehow reach in and break the quantum rules.
Speaker 1: It seems so arbitrary, and a lot of the big
thinkers at the time were really not happy.
Speaker 2: With it, not at all. It felt like a philosophical cheat.
It suggested that reality was fundamentally fuzzy and undecided until
a conscious being or at least a big, clunky machine
got involved. It took objectivity out of physics, and.
Speaker 1: The person who hated the most was Albert Einstein.
Speaker 2: Oh, he despised it. He was a realist through and through.
He believed in an objective reality that exists independent of us.
He just couldn't accept that the universe's fundamental nature was
based on chance.
Speaker 1: That's where his famous line comes from, Right, God does
not play dice with the universe exactly.
Speaker 2: He was convinced the theory was incomplete. He believed there
must be some hidden variables, some deeper layer of reality
we just hadn't discovered yet that would restore determinism and
explain away all the randomness and to home just.
Speaker 1: How absurd this whole observer causes collapse. Idea was another
founder of the theory, or when Schrodinger came up with
what has to be the most famous and maybe darkest
thought experiment in all of science.
Speaker 2: Schrodinger's cat. And it's so important to remember, as you said,
he wasn't proposing this was real. He was making a
reductio ad absurdum argument. He was trying to show the
ridiculous logical conclusion of the Copenhagen interpretation.
Speaker 1: So let's walk through the setup, because the details really matter.
You take a cat, poor cat, You put it in
a sealed steel box, and in that box with the cat,
you have this diabolical device.
Speaker 2: It's a tiny amount of radioactive material, so small that
in the course of one hour there's a perfect fifty
to fifty chance that just one atom will decay.
Speaker 1: And if it does decay, it triggers a guy your counter.
Speaker 2: Which is connected to a relay that releases a hammer.
Speaker 1: Which then smashes a little flask of hydrocyanic acid, a
deadly poison which would kill a cat insecse.
Speaker 2: Very grim rube gold machine.
Speaker 1: It is. So the key is that the fate of
the cat is now inextricably linked, entangled with the state
of that single quantum particle.
Speaker 2: Precisely, the atom is the quantum system. It's in a
superposition fifty percent decayd and fifty percent not decayed. And
since the cat's life is now tied to it, the
whole system atom hammer poison cat has to be described
by one single wave function.
Speaker 1: So, according to the Copenhagen interpretation, until an observer opens
the box to make a measurement, what state is the cat.
Speaker 2: In the cat is literally and mathematically in a superposition
of being fifty percent alive andy fifty percent dead.
Speaker 1: At the same time, maybe alive, maybe dead, both both.
Speaker 2: It's only when you open the box that the system
wide wave function collapses and the cat resolves into being
either definitely alive or sadly definitely dead.
Speaker 1: And Schrodinger's point was just that's insane. No one actually
believes a cat is a sort of zombie ghost hybrid
until we look at it. There has to be something
wrong with an interpretation that leads to such a Bonker's conclusion.
Speaker 2: The problem was the boundary, where does the quantum world
stop and the classical world begin. Copenhagen was just totally
vague on that point.
Speaker 1: And yet, despite Einstein's objections, despite Schrodinger's brilliance at hire,
the Copenhagen math just it worked.
Speaker 2: It worked flawlessly, it was predictive, it was accurate. It's
the foundation of the entire technological revolution of the twentieth century.
So for decades the attitude of most physicists was just
shut up and calculate except the weirdness. Don't ask what
it means, just use the equations. But that discomfort, it
never really went away, that special role for the observer.
It just felt wrong, It felt I don't know, almost supernatural.
Why should the laws of physics suddenly change just because
a person decides to look at something right.
Speaker 1: It's a huge philosophical leap, and that tension, that dissatisfaction,
is really what set the stage for a completely different.
Speaker 2: Approach, a truly radical one.
Speaker 1: It comes in nineteen fifty seven a twenty seven year
old PhD student at Princeton named Hugh Everett the Third's
Right Now thesis, and he looks at this whole measurement problem,
this collapse postulate, and he asks this incredibly simple but
profound question, what if the.
Speaker 2: Wave function never collapses at all?
Speaker 1: What if the weird part is in the wave function?
What if the weird part is this extra rule we
added on the collapse exactly?
Speaker 2: What if the math is telling us the truth all along?
What if the probabilities in the wave function aren't just
describing potential outcomes, but are actually describing all outcomes, all
of which are real.
Speaker 1: And that is the birth of the many World's interpretation MWI.
Speaker 2: Everett's insight was just so elegant. He said, look, you
don't need to add any new rules. You just have
to take the existing rule, the Schrodinger equation that governs
the wave function and take it seriously. Assume it applies
to everything all the time, with no exceptions.
Speaker 1: So let's get into the mechanics of it, the branching,
because this is where it really diverges from Copenhagen. Let's
go back to our electron with two choices. It can
go left or go right.
Speaker 2: Okay, So in the Copenhagen view, electron is in a superposition.
It's a wave of left plus right, and observation happens,
and bang, the wave collapses. Let's say it collapses to left.
Speaker 1: And the possibility of it going right is just gone,
wiped from.
Speaker 2: Existence, annihilated. It never became real in our universe. But
in everetts mwiview the process is totally different. The electron
is in the superposition of left plus right, a measurement
or really any irreversible interaction happens, and instead of collapsing in.
Speaker 1: The universe itself splits, the entire.
Speaker 2: Universe splits into two separate, equally real physical universes.
Speaker 1: So in one universe the electron went left, and in
another completely separate universe it went right.
Speaker 2: Yes, And this process is what physicists call branching and
it's not just the electron that splits. The measuring device splits,
the air in the room splits you, the observer, You
split too.
Speaker 1: So there's a version of me in universe A that
sees the electron go lest and another completely real version
of me in universe B that sees it go left right.
Speaker 2: And once that's split happens those two universes, those two
branches of reality can never interact or communicate with each
other ever. Again, they are causally disconnected.
Speaker 1: Okay, now we have to scale this up because it's
not just one electron every now and.
Speaker 2: Then, O, my god, think about the sheer number of
quantum events happen constantly every fraction of a nanosecond all
over the universe. Every photon of light hitting your retina,
every radioactive atom decaying in the Earth's crust, every molecule
bouncing off another in the air.
Speaker 1: Each one is a decision point.
Speaker 2: Each one forces a split, which means the universe is
branching at an almost infinitely fast rate. It's creating this
unimaginably vast, ever growing tree of parallel realities.
Speaker 1: My consciousness. Yeah, it's not just one thing. It's like
a passenger on a train that's constantly arriving at a
station where the tracks split in a million different directions.
Speaker 2: That's a great way to put it. You are riding
along one single path through this infinite multiverse, but at
every single quantum juncture, an alternate version of you, just
as real as you you are, continues on a different path.
Speaker 1: So, yeah, this morning, I hesitated between having coffee or tea,
and the quantum processes in my brain that led to
that decision they branched. So there's a version of me
out there right now who is having a very different
day because he.
Speaker 2: Chose tea, absolutely, and he's just as real as you are.
He just exists on a different, inaccessible branch of the
universal wave function.
Speaker 1: The universal wave function that was Everett's big idea, right,
one equation for everything.
Speaker 2: That was the philosophical cleanup. Instead of having one set
of rules for quantum stuff and another for big stuff,
Everett said, there's just one thing, the universal wave function.
It describes the state of the entire multiverse, and it
always evolves smoothly according to one equation. The collapse is
just our subjective experience of getting locked into one of
these branches after a split it's so much cleaner.
Speaker 1: So much more elegant. You'd think people would have jumped
on it, you.
Speaker 2: Would think, But the reception was huh, cold, glacial. Everett
was only twenty seven. He takes his theory to Copenhagen
to present it to the great Nils bore the father
of the established interpretation, and Borr just completely dismissed it.
Found it way too extravagant, too ridiculous.
Speaker 1: Ookham's razor, right. Why invent an infinite number of unseeable
universes just to get rid of one little rule about collapse?
Speaker 2: That was the argument. The scientific community just wasn't ready
for it. They stuck with what worked, what was practical,
and Everett w well, he was pretty as heartened by
the whole thing.
Speaker 1: Yeah. Our sources say he left academia right after getting
his PhD, never published another physics paper.
Speaker 2: Which is such a tragedy. He went on to have
a brilliant career in military research and computing, but his idea,
the many World's interpretation just kind of sat dormant for
almost two decades. It needed another piece of the puzzle
to become truly viable.
Speaker 1: Okay, so let's get into the big problem that MWI
had for all those years, the one that made people
like Borr dismiss it out of hand, right.
Speaker 2: The elephant in the room. If the universe is constantly
splitting into all these different branches, why do we only
ever see.
Speaker 1: One outcome exactly? If Schrodinger's cat is genuinely in a
superposition of alive and dead, why when we open the
box do we never see some sort of blurry half dead,
half alive monstrosity.
Speaker 2: Why don't we feel ourselves splitting? Why does every single
experiment we've ever run look exactly like the wave function
is collapsing to a single result.
Speaker 1: This was the major hurdle. It's a great theory, but
it seems to contradict observation. If the other worlds are real,
where are they? Why can't we see them?
Speaker 2: And the answer? The mechanism that rescued MWI from being
just a philosophical curiosity didn't really come into focus until
the nineteen seventies and eighties, and the key word is decoherence.
Speaker 1: Decoherence, let's break that down. We probably have to start
with coherence, then.
Speaker 2: Good idea. A quantum system is coherent when all its
different possible states like our electrons spin up and spin
down states are all in a neat orderly relationship with
each other. They maintain what's called a stable phase relationship.
Speaker 1: It's like they're all marching instead.
Speaker 2: Perfect analogy. But that coherence can only be maintained if
the system is in perfect total isolation from the rest
of the universe.
Speaker 1: And in the real world, perfect.
Speaker 2: Isolation is impossible. It's absolutely impossible. And that's where decoherence
comes in. The instant that quantum system interacts with its environment,
and I mean anything, a single photon of light bouncing
off it, a stray air molecule, a tiny vibration, it
becomes entangled with that environment.
Speaker 1: Entanglement, so its fate is now tied to the fate
of all these other particles.
Speaker 2: Inextricably, the states of that one little electron are now
linked to the states of the trillions upon trillions of
particles in the surrounding environment. So if the electron goes left,
all the air molecules around it are jostled in a
way that reflects the.
Speaker 1: Left path, and if it goes right, they're all jostled
in a slightly different way that reflects the right path.
Speaker 2: Precisely and because the environment is so unimaginably huge and complex,
the simple neat wave function of the electron gets smeared
out and lost in the staggeringly complex wave function of
the environment. That nice orderly marching in step relationship between
the spin up and spin down states is destroyed almost instantly.
Speaker 1: That loss of order, that's decoherence.
Speaker 2: That's decoherence. And what's so brilliant about it is that
it provides a purely physical mechanical explanation for why the
branches of the multiverse become separate.
Speaker 1: So the left world where the electron and all the
air molecules went one way, and the right world, where
they all went another.
Speaker 2: Way, they are now so vastly different. Their wave functions
are so completely orthogonal to each other that they can't interfere.
They can no longer interact or communicate. The information that
will let them see each other has been diluted into
the vastness of the environment.
Speaker 1: So decoherence is the mechanism that prunes the branches of
the tree and make sure they can't grow back into
each other.
Speaker 2: That's it exactly. So an MWI proponent looks at the
results of an experiment and says, see, decoherence has rapidly
and permanently separated the alternative outcomes into distinct, isolated realities.
Speaker 1: While the Copenhagen believer looks at the exact same result
and just says the wave function collapsed.
Speaker 2: But the MWY explanation doesn't require a magic collapse rule.
It just uses the standard known physics of entanglement and
environmental interaction. It explains how the fuzzy quantum world can
appear to become the definite classical world without needing any
special role for a conscious observer.
Speaker 1: And that's what made it a serious theory against It
was everything.
Speaker 2: It took away the biggest objection. It was no longer
just a philosophical preference. Decoherence provided a concrete physical mechanism.
It showed how MWI could be consistent with all our observations,
retain all the predictive power of Copenhagen, and get rid
of the part that Einstein and Schrodinger hated the most,
the observer. The observer, it's removed from its special privileged position.
The universe just does its thing, splitting and evolving according
to one consistent law. So once decoherence was understood, MWI
wasn't this fringe idea anymore. It became a respectable, viable
contender for what's actually happening at the fundamental level of reality, and.
Speaker 1: In the twenty first century it's really gained a lot
of ground.
Speaker 2: It has when you pull physicists today on which interpretation
they favor. Copenhagen and its modern variations are still in
the lead, but MWI is a strong second. Somewhere around
twenty percent of the community.
Speaker 1: Endorses it, and its popularity seems to be rising, especially
with people in certain fields right like cosmologists and quantum
information scientists.
Speaker 2: Yes, people who have to deal with the universe as
a whole quantum system, or who work directly with things
like entanglement and superposition all day. For them, MWI is
often the most straightforward way to think about it.
Speaker 1: And as our sources point out, things have really heated
up recently because of a very practical, real.
Speaker 2: World development quantum computer.
Speaker 1: It's quantum computers. This is where the theory might actually
be moving from the abstract to something we can see
the effects of potentially.
Speaker 2: Yes, to get it, we need a quick refresher on
how computer's work. Your laptop or phone uses classical bits.
They're like little switches. They can be either a zero
or a one.
Speaker 1: On or off. Simple all calculations are done one after
another sequentially.
Speaker 2: But a quantum computer uses quibits, and because of superposition,
a quibit can be both a zero and a one
at the same time, that blurry state against exactly. And
if you have two quibits, they can be in a
superposition of all four possible states zero, zero, zero, one, ten,
and eleven simultaneously. This is where the exponential power comes from.
Instead of doing one calculation at a time, a quantum
computer can explore a huge number of possible calculation paths,
all in parallel.
Speaker 1: And David Deutsch, who's a huge modern proponent of MWI,
I mean, it's a fascinating argument about this. He basically
says quantum computers are indirect physical evidence of the multiverse.
Speaker 2: It's a really provocative claim. Let's use his example. Suppose
you build a quantum computer with three hundred qubits that
are all entangled. That system is now in a superposition
of two to the power of three hundred classical.
Speaker 1: States and two to the three hundred. I mean, that
number is just it's beyond astronomical it's.
Speaker 2: A number that is vastly larger than the total number
of atoms in the entire observable universe. It's incomprehensibly huge.
Speaker 1: Okay, so you have this machine in a state of
two the three hundred possibilities and you run a quantum
algorithm on it. Where is that computation actually happening?
Speaker 2: That's Deutsche's killer question. If that computation is exploring all
those possibilities in parallel to find the answer, and say
a few minutes, where did the physical resources to do
that come from? Our one single universe doesn't have enough
matter to write down the problem, let alone solve it
that fast.
Speaker 1: So his answer is.
Speaker 2: His answer is that those two to the three hundred
parallel computations are literally being performed in two to the
three hundred parallel universes. The quantum computer is, in a
very real sense, harnessing the processing power of the multiverse.
Speaker 1: That is just a staggering thought. Yeah, that the reason
these machines are so powerful is that they are borrowing
resources from other realities.
Speaker 2: It provides a simple, if mind boggling, physical explanation for
where the power comes from. If you don't accept MWI,
you have to come up with some other, often much
more convoluted, explanation for how all that parallel processing is
happening within our single universe.
Speaker 1: Well, hold on, I have to play Devil's advocate here
for a second. Isn't this still just a matter of interpretation?
It sounds great, but doesn't this sheer extravagance of it
the infinite universes just violate Okham's razor. M isn't it
simpler to just believe in the collapse even if it's weird?
Speaker 2: That is the number one philosophical argument against MWI, and
it's a very fair one. Critics say it's not a
real scientific theory because it's non falsifiable. We can never
visit these other branches to prove they exist. Right, But
proponents like George flip Oham's razor right back at them.
They argue that MWI is actually the simpler theory from
a physics perspective, because it doesn't add any new laws.
Copenhagen adds a whole new arbitrary rule, the collapse posti,
that says the known laws of physics stop working when
a measurement happens. MWI just takes the one known law,
the Schroderer equation, and says the sit this is the
only rule, and it applies to everything, everywhere, all the time.
Speaker 1: So MWI has fewer rules, even if it leads to
a much bigger reality.
Speaker 2: Exactly, it's the simplest law, even if it produces the
most complex cosmos. And that's the reframing. It's not a
complex theory. It's the simplest interpretation of the mac we
already know is correct.
Speaker 1: And if we're going to accept that, if we accept
this new definition of reality with infinite, constantly generated parallel worlds,
well we have to talk about the ultimate consequence for us,
for the observer.
Speaker 2: So if we take the many world's interpretation as a given,
just for the sake of argument, if reality really is
this constantly branching tree of possibilities, and.
Speaker 1: What does that mean for us, for human consciousness? And
this is where we get to the most speculative but
also the most profound implication.
Speaker 2: Of all quantum immortality.
Speaker 1: It's a direct, if contra virtial, logical consequence of the theory.
The core idea is all about the subjective continuity of
your experience from your own point of view. Do you
ever actually witness your own death.
Speaker 2: Let's run a thought experiment, a pretty grim one, as
laid out in the research. Imagine you're in a situation
that is almost certain to be fatal, a game of
Russian Roulette, but with a quantum trigger instead of a
spinning chamber.
Speaker 1: Okay, so there's a gun pointed at your head and
it's set up to fire based on the spin of
an electron. The electron is measured to spin down, it fires.
If it's pin up, it just clicks, and the odds
are fifty to fifty.
Speaker 2: You pull the trigger, the quantum measurement is made, the
universe splits. In one massive branch, fifty percent of the
wave function, the electron will spin down, the gun fires,
and you die instantly.
Speaker 1: End of story for that version of may end of story.
Speaker 2: But in the other branch, the other fifty percent, the
electron will spin up, the gun clicks, and you're still alive,
heart pounding thinking, who I got lucky.
Speaker 1: The theory of quantum immortality says that your subjective consciousness,
the thing you experience as you, can only continue in
the branch where you survive.
Speaker 2: Because consciousness, by definition requires a functioning brain. The stream
of your awareness is terminated in the death branch. So
from your perspective, you will always find yourself in the
branch where the gun clicked.
Speaker 1: So I pulled the trigger again. The universe splits again. Again,
My consciousness follows the survival path.
Speaker 2: And again and again. From your subjective point of view,
you play ten rounds, one hundred rounds, one thousand rounds,
and the gun just clicks every single time. You would
feel like the luckiest person who ever lived.
Speaker 1: You would seem immortal, while in the vast majority of universes,
countless versions of me are dead.
Speaker 2: Exactly, death becomes something that only ever happens to the
other guys who just happen to also be you. For
the continuous stream of consciousness that you identify as yourself,
you only ever experience survival.
Speaker 1: And this isn't just some fringe idea attacked on Hugh
Everett himself, the guy who came up with MWI.
Speaker 2: He believed this, he did now. He was very careful.
He never wrote about quantum immortality in his formal physics papers.
It was too speculative, But his colleagues, his friends, even
his family have all said in secondhand accounts that he
privately believed his theory guaranteed his own immortality.
Speaker 1: He genuinely believed that his consciousness would just follow whichever
branch didn't lead to his death.
Speaker 2: It's a pretty powerful belief to hold. Imagine living your
life with that conviction. You might see a series of
what looked like miracles. You survive a car crash that
should have been fatal, You recover from a disease that
was supposed to be terminal to you. It feels like
a one in a billion streak of luck.
Speaker 1: But in the MWI view, it's just you following the
one in a billion survival branch that was always there
in the wave function.
Speaker 2: And this connects in a really fascinating way to near
death experiences.
Speaker 1: Oh wow, think about it.
Speaker 2: Someone has a terrible accident, their heart stops, and they
report this experience of seeing a light a tunnel a
life review. If that subjective flash isn't just brain chemistry,
what if that's the moment the multiverse branch violently.
Speaker 1: And the person reporting the experience is the one whose
consciousness made it through to an incredibly improbable survival branch.
Speaker 2: While trillions of other versions of them simply died and
couldn't report anything. We only ever hear from the survivors.
So what we call a near death experience might just
be what it feels like to land on a low
probability branch of the wave function where you didn't die.
Speaker 1: The implication is just staggering. It means every single fatal event,
no matter how certain, has some astronomically tiny, non zero
probability of survival hidden in the math.
Speaker 2: A quantum tunnel effect in your cells that stops a bullet,
a freak gust of wind that saves you from a fall,
and your consciousness will always experience that improbable outcome.
Speaker 1: So from my own frame of reference, death is an illusion.
It's something that is constantly happening to my duplicates, but
never to me.
Speaker 2: But that raises a huge question about identity, doesn't it.
If I am the version of me that survives ten
rounds of quantum roulette, am I still the same person
as the one who started after experiencing a series of
impossible escapes? My life would be so radically different from
the statistical average.
Speaker 1: At what point do I become a completely different person
defined only by my improbable survival?
Speaker 2: That's the ultimate existential fallout of the theory. The physics
might guarantee your subjective continuity, but it shatters our concept
of a single, unified self.
Speaker 1: Wow. Okay, that has been a deep, deep dive. We
started in the safe, deterministic.
Speaker 2: Classical world, and we plunged right into the strange, probabilistic
quantum realm, all governed by the enigmatic wave function.
Speaker 1: We saw the first big attempt to make sense of
it all, the Copenhagen interpretation, the idea that an observer's
measurement forces the wave function.
Speaker 2: To collapse, a position that led to the wonderful absurdity
of Schrodinger's cat being both alive and dead and prompted
Einstein's famous protest that God doesn't play dice.
Speaker 1: And then the radical alternative from Hugh Everett, the Many
World's interpretation. The wave function never collapses, it just branches.
Every possible outcome becomes real in its own parallel universe.
Speaker 2: We saw how that wild idea was made physically plausible
by the discovery of decoherence, the way a quantum system's
interaction with the environment naturally isolates these branches, giving us
the illusion of a collapse.
Speaker 1: And finally we saw how This framework isn't just philosophy.
It has connections to the real world, offering a potential
explanation for the incredible power of quantum computers.
Speaker 2: And leading us down the rabbit hole to the ultimate
thought experiment, quantum immortality, where your consciousness might just be
a passenger that always, against all odds, finds itself on
the path of survival.
Speaker 1: So we always end with a final provocative thought for
you to take away.
Speaker 2: Right and here it is. If your subjective reality is
in fact guaranteed to follow the survival path through every
single fatal quantum decision, what does that really mean for
your sense of self? Think about it this way. If
eighty percent of all possible future branches of your life
and in a tragic car accident tomorrow, but your consciousness
is guaranteed to follow the remaining twenty percent, the improbable
branch where you swerve at the last second, what price
do all those other versions of you pay for your
subjective immortality.
Speaker 1: They are just as real, Their experience was just as
valid up until the moment it was extinguished.
Speaker 2: Does your singular, continuous experience come at the cost of
the termination of millions of your other selves? If reality
is an infinite tree, but your awareness only ever follows
one increasingly unlikely golden path. It forces us to ask
what self and time and luck even mean. And a
cosmos that is perpetually splitting.
Speaker 1: Was that near miss you had on the highway last
week just a lucky break? Or did a very real
alternate version of you in a universe that just split
off from ours make the ultimate sacrifice so that your
conscious journey could continue.
Speaker 2: The deep dive is complete.
Speaker 1: We'll see next time.