Speaker 1: Welcome to the quark Side. Quantum Physics podcast, an exploration
Speaker 1: of the fundamental structure of reality, where quantum laws govern matter, energy,
Speaker 1: and information. Here, uncertainty is a feature, not a flaw,
Speaker 1: and understanding begins at the smallest scales.
Speaker 2: Okay, I have a request. It's a small one, but
Speaker 2: I need you to just commit to it for a moment.
Speaker 2: I'm okay to stop whatever you're doing just for a second.
Speaker 3: Tune everything else out exactly.
Speaker 2: Don't look at your phone. If you're driving, well, okay,
Speaker 2: please keep your eyes on the road, but just shift
Speaker 2: your mental focus. Try to really look at the.
Speaker 3: Now, the present moment.
Speaker 2: Right, you can watch the second hand on a clock,
Speaker 2: or just you know, feel your own heartbeat, don't. Don't
Speaker 2: that sensation right there, that feeling of flow.
Speaker 3: It's the most fundamental thing we experienced.
Speaker 2: We're obsessed with it. We live our entire lives in
Speaker 2: this tiny, razor thin slice of reality. We mourn the
Speaker 2: past because it's gone, it's buried in memory, and we
Speaker 2: stress about the future because it hasn't happened yet.
Speaker 3: Right, it is the universal human condition. We treat the
Speaker 3: past as a fixed record. It's done, it's written, and
Speaker 3: the future, Well, the future is a void. It's a
Speaker 3: blank canvas waiting for paint.
Speaker 2: That is the common sense view. I mean, that's how
Speaker 2: I live my life. Next Tuesday is a ghost. It
Speaker 2: doesn't actually exist, it's it's waiting for me to create it.
Speaker 2: But and this is why we're here today. We have
Speaker 2: a stack of research sitting right here on the desk
Speaker 2: that says, my common sense is what's lying to me.
Speaker 3: Lying is a polite way to put it. I mean,
Speaker 3: if we take the sources we're analyzing today, and they
Speaker 3: range from Einstein's relativity to the absolute latest papers on
Speaker 3: quantum gravity, that void of next Tuesday might be just
Speaker 3: as solid, just as real, and just as already there
Speaker 3: as the chair you're sitting.
Speaker 2: In right now, which is frankly a terrifying thought.
Speaker 3: It's deeply unsettling.
Speaker 2: It implies the script is already written. It implies that
Speaker 2: while I feel like I'm improvising my life, you know,
Speaker 2: make some choices. Yeah, I might just be reciting lines
Speaker 2: that were stamped into the fabric of the universe thirteen
Speaker 2: billion years ago.
Speaker 3: It does, and the more you dig into the physics
Speaker 3: of it, the harder it gets to hold onto that
Speaker 3: simple idea that time flows at all. We might be
Speaker 3: dealing with a universe that is at its most fundamental
Speaker 3: level static frozen, frozen, a block of ice where we
Speaker 3: are just well trapped in the middle thinking we're swimming.
Speaker 2: Okay, so the mission for this whole exploration today is
Speaker 2: to see if we can break that block of ice,
Speaker 2: or at least understand it. We're going to start with
Speaker 2: it intuitive feeling the arrow of time, crash it head
Speaker 2: on into general.
Speaker 3: Relative, get completely confused by quantum mechanics.
Speaker 2: And see if something like free will can even survive
Speaker 2: the laws of physics as we understand them.
Speaker 3: It is going to be a messy investigation. We are
Speaker 3: going to have to dismantle your intuition piece by piece.
Speaker 2: Good. I like messy. So let's start with the most
Speaker 2: obvious thing, the arrow me This is the most tangible,
Speaker 2: undeniable proof that time exists and that it moves in
Speaker 2: one direction. Okay, I drop a coffee mug, It falls,
Speaker 2: it hits the floor, and it shatters into a thousand pieces.
Speaker 2: I have never not once in my entire life see
Speaker 2: a pile of ceramic shards on the floor suddenly jump
Speaker 2: up and assemble themselves back into a perfect mug.
Speaker 3: Right, you are describing the macroscopic world, the world of
Speaker 3: big things, mugs, cars, people, omelets, And in that world
Speaker 3: the arrow is absolutely undeniable. Events flow from order to disorder.
Speaker 3: We see effects follow their causes.
Speaker 2: But the sources we're looking at highlight this massive contradiction
Speaker 2: right out of the gate. They claim the fundamental laws
Speaker 2: of physics they don't care about that arrow at.
Speaker 3: All, And that is the reversibility paradox. This is really
Speaker 3: the first major hurdle we have to clear in this
Speaker 3: whole discussion. If you zoom in, and I mean way
Speaker 3: way into the atoms that are making up that coffee mug.
Speaker 3: Let's say you could film two of those out I'm colliding.
Speaker 2: Okay, just two particles bouncing off each other.
Speaker 3: They bounce off each other. Now play that film backward.
Speaker 2: It would look exactly the same. They'd just be coming
Speaker 2: from different directions and bounce off each other again.
Speaker 3: Precisely, the laws of physics don't care. Newtonian physics, Maxwell's
Speaker 3: equations for electromagnetism, even the Schrodinger equation in quantum mechanics, essentially,
Speaker 3: all the foundational equations we use to describe reality. They
Speaker 3: are time symmetric. They work just as well with a
Speaker 3: positive T moving forward or a negative T moving backward.
Speaker 2: Waitait, are you actually saying that if I could somehow
Speaker 2: reverse the velocity of every single particle in the universe
Speaker 2: right now, the mug would unshatter.
Speaker 3: In theory, yes, the math allows for it. There is
Speaker 3: absolutely nothing in the fundamental laws of motion that forbids
Speaker 3: those shards from gathering all their thermal energy, leaping up
Speaker 3: and fusing back into a perfect mug. The energy transfer,
Speaker 3: the momentum, it all works perfectly in reverse.
Speaker 2: That sounds completely insane. I mean, it feels wrong on
Speaker 2: a gut level. The the math says the mug can unshatter.
Speaker 2: Why doesn't it ever? Is physics just lazy? Why do
Speaker 2: we never ever see this happen.
Speaker 3: It's not laziness, it's statistics. It's just probability on an
Speaker 3: unimaginable scale. And this is where we have to talk
Speaker 3: about the physicist Ludwig Boltzmann and his concept of entropy.
Speaker 2: The universe tends toward disorder. Yeah, the messy room analogy.
Speaker 3: Exactly, But we need to go deeper than just saying
Speaker 3: things get messy to really get it. We need to
Speaker 3: talk about the difference between micro states and macro states.
Speaker 2: Okay, lay that out for us. I've heard the messi
Speaker 2: room analogy a thousand times, but give me the technical version.
Speaker 2: What's the real engine behind this?
Speaker 3: Okay, So think of your coffee mug again. The macro
Speaker 3: state is the description whole mug. It looks like a mug.
Speaker 3: You can drink from it.
Speaker 2: It's a mug, simple enough.
Speaker 3: But to achieve that specific shape, that whole mug macro state,
Speaker 3: the trillions and trillions of atoms inside it have to
Speaker 3: be arranged in a very very specific way. They have
Speaker 3: to be bonded here, not there. The handle atoms have
Speaker 3: to be with the handle atoms.
Speaker 2: So there are very few ways for all those atoms
Speaker 2: to be arranged and still be called a mug.
Speaker 3: Correct. A relatively low number of posttle micro states correspond
Speaker 3: to the macro state. Whole mug. Now, think of the
Speaker 3: pile of shards on the floor. That is the macro state,
Speaker 3: broken mug, chaos, a mess. But think about the atoms. Now,
Speaker 3: you can rearrange those shards in a billion different patterns
Speaker 3: on the floor and it still just looks like a
Speaker 3: pile of shards. You can move the atoms around within
Speaker 3: the shods, you can twist them, scatter them across the
Speaker 3: entire room. It's still just a broken mug.
Speaker 2: I see where you're going with this. There are vastly
Speaker 2: more ways for something to be broken than for.
Speaker 3: It to be whole, trillions upon trillions upon trillions more ways.
Speaker 3: It's not even close. So as the system evolves over time,
Speaker 3: as particles jiggle and move around purely by chance, it
Speaker 3: is just overwhelmingly, staggeringly likely to move toward the state
Speaker 3: that has more possibilities, more available micro states.
Speaker 2: So the arrow of time isn't a force. It's not
Speaker 2: some cosmic river pushing us forward.
Speaker 3: No, that's the big takeaway. It's just the law of
Speaker 3: large numbers playing out. We are drifting from the incredibly
Speaker 3: unlikely state, which we call order, to the ridiculously likely stay,
Speaker 3: which we call disorder. We perceived the statistical drift as
Speaker 3: time flowing, but really it's just things shuffling into more
Speaker 3: probable configurations.
Speaker 2: That is slightly depressing. So our entire experience of past, present,
Speaker 2: and future is just us losing a statistical game against
Speaker 2: the universe.
Speaker 3: Essentially, Yes, but this realization leads to the biggest, most
Speaker 3: profound problem in all of cosmology. If time is just
Speaker 3: a one way slide toward disorder, that implies we must
Speaker 3: have started at the very top of the slide, the
Speaker 3: Big Bang, the Big Bank. The sources call this the
Speaker 3: past hypothesis. For the arrow of time to even exist today,
Speaker 3: for mugs to break, and for us to remember yesterday,
Speaker 3: the universe at the moment of the Big Bang must
Speaker 3: have had an entropye so low, so incredibly ordered, that
Speaker 3: the odds of it happening by chance are well astronomical
Speaker 3: doesn't even begin to cover it.
Speaker 2: I saw a number in the notes attributed to the
Speaker 2: physicist Roger Penrose. Honestly thought it was a typo.
Speaker 3: It wasn't a typo. Pennos calculated the probability of our
Speaker 3: universe starting in such a low entropy state by random chance.
Speaker 3: The number is one in ten to the power of
Speaker 3: ten to the power of one hundred and twenty three.
Speaker 2: Can you even visualize a number like that? Is there
Speaker 2: an analogy for it?
Speaker 3: No, there are not enough particles in the entire known
Speaker 3: universe to write the zeros of that number on them.
Speaker 3: It is the working definition of a statistical miracle. It
Speaker 3: suggests that the beginning was special. It was highly tuned,
Speaker 3: incredibly specific.
Speaker 2: So the only reason I can remember yesterday, and the
Speaker 2: only reason eggs break and never unbreak, is because the
Speaker 2: Big Bang was, for some unknown reason, weirdly tidy.
Speaker 3: That is what some call the cosmological brute fact. We
Speaker 3: are surfing the wave of that initial, unexplained order. But
Speaker 3: here's the crucial catch. Entropy explains the direction of time,
Speaker 3: why we go from past to future, but it doesn't
Speaker 3: explain the existence of time.
Speaker 2: Right Okay, just because my room is getting messier doesn't
Speaker 2: prove that next Tuesday is already built and waiting for me.
Speaker 2: It just means that if I get to next Tuesday,
Speaker 2: my room will probably be messier than it is today exactly.
Speaker 3: Entropy is a signpost pointing the way, but it isn't
Speaker 3: the road itself. To understand the road. To really grapple
Speaker 3: with whether the future actually exists right now, we have
Speaker 3: to leave thermodynamics behind and bring in the heavy hitter.
Speaker 3: We have to bring in Albert Einstein.
Speaker 2: The presentism Killer.
Speaker 3: A very fitting nickname. Before Einstein, pretty much everyone, including
Speaker 3: Isaac Newton, thought time was this absolute universal clock TikTok TikTok,
Speaker 3: everywhere in the universe at the same time.
Speaker 2: A universal now God's wristwatch. So if it's twelve pointy
Speaker 2: zero pm here on Earth, it's twelve point zero pm
Speaker 2: on Mars, and it's twelve point zero zero pm in
Speaker 2: the Andromeda Galaxy, all at the exact same instant.
Speaker 3: Right, That feels deeply intuitive, it feels correct. But special
Speaker 3: relativity took that universal wristwatch and just smashed it on
Speaker 3: the floor. Einstein showed that now is relative. It actually
Speaker 3: depends on how fast you're moving.
Speaker 2: I always struggle to visualize this part. I get the
Speaker 2: time dilation thing. I travel near the speed of light
Speaker 2: in a spaceship. I age slower than someone on Earth.
Speaker 2: But this is different. This is about simultaneity that was
Speaker 2: happening now it is.
Speaker 3: It's a much weirder concept. And the best analogy on
Speaker 3: the sources we looked at rely on heavily, is to
Speaker 3: think of the universe as a loaf of bread.
Speaker 2: Okay, I'm listening, I like bread. How does a bakery
Speaker 2: item explain the nature of reality?
Speaker 3: Imagine the entire universe, all of space and all of time,
Speaker 3: is one giant loaf of sour dough. You have length
Speaker 3: with height, and the long way from crust to crust
Speaker 3: is time. One end of the loaf is the big Bang.
Speaker 3: At the other end is the eventual heat death of
Speaker 3: the universe.
Speaker 2: Okay, so everything that ever was or ever will be
Speaker 2: is already baked into this loaf. My birth, this conversation,
Speaker 2: the sun exploding. It's all in there.
Speaker 3: It's all in there now. If you and I are
Speaker 3: standing still relative to each other, our concept of now
Speaker 3: is like taking a knife and making a perfectly straight
Speaker 3: slice down through the loaf. Everything contained and that one
Speaker 3: thin slice is happening at the same time for us.
Speaker 2: Cut it's a single snapshot of the entire universe at
Speaker 2: one instant.
Speaker 3: But here's where Einstein's math comes in. He showed that
Speaker 3: if you start moving, even just walking across the room,
Speaker 3: your knife angles. You start to cut the loaf at
Speaker 3: a slant.
Speaker 2: A slant.
Speaker 3: What do you mean, Yes, you're slice of now tilts
Speaker 3: in the direction you're moving. Your slice tilts into what
Speaker 3: for me is the future part of the loaf, and
Speaker 3: behind you it tilts into my past.
Speaker 2: But if I'm just walking, the tilt must be I
Speaker 2: mean infinitesimally small. I walk it maybe three miles an hour.
Speaker 2: That can't make a real difference.
Speaker 3: It's microscopically immeasurably tiny. On human scales here on Earth,
Speaker 3: you would never ever notice. But and this is the
Speaker 3: absolute mind blower. Basic geometry tells us that a tiny,
Speaker 3: tiny angle, when extended over a massive distance, creates a huge,
Speaker 3: huge gap.
Speaker 2: Right the liver effect. If I'm holding a laser pointer
Speaker 2: and I tilt my wrist just a millimeter, the dot
Speaker 2: on the wall across the room might move ten.
Speaker 3: Feet exactly that. Now, replace the wall with a galaxy.
Speaker 3: This brings us to a thought experiment called the Andromeda paradox.
Speaker 3: The Andromeda galaxy is about two point five million light
Speaker 3: years away from us.
Speaker 2: It's very far down the loaf of breath.
Speaker 3: Very far down the loaf. Now, imagine there's an alien
Speaker 3: invasion fleet in Andromeda right now, in my slice of now,
Speaker 3: me standing still on Earth. Those aliens are in a
Speaker 3: council meeting debating whether or not to launch their attack
Speaker 3: on Earth. They haven't decided yet.
Speaker 2: Okay, So for you, the fleet is grounded, the war
Speaker 2: hasn't started. The future is open.
Speaker 3: Now you stand up, and start walking, just a slow
Speaker 3: stroll in the direction of the Andromeda galaxy. Because of
Speaker 3: that vast two point five million light year distance, your
Speaker 3: slice of reality tilts dramatically by the time it reaches
Speaker 3: that galaxy.
Speaker 2: How much of a difference does just walking make over
Speaker 2: that kind of distance.
Speaker 3: It can make a difference of days, maybe even weeks.
Speaker 3: So in your now, purely because of your slow walking motion,
Speaker 3: your slice cuts through the Andromeda part of the loaf
Speaker 3: days after their council meeting. For you, the fleet has
Speaker 3: already launched. The decision has been made. It is a
Speaker 3: historical fact.
Speaker 2: Wait. Stop, this is the part that always breaks my brain.
Speaker 2: We are standing right next to each other. I take
Speaker 2: one step forward, and for me an alien invasion has
Speaker 2: already begun. But for you, who's standing still, yeah, there's
Speaker 2: still peace.
Speaker 3: Correct. And to make it even weirder, if you were
Speaker 3: to turn around and walk away from Andromeda, your slice
Speaker 3: would tilt the other way into their past. For you,
Speaker 3: the council meeting hasn't even been proposed yet, the idea
Speaker 3: of invading Earth doesn't exist.
Speaker 2: So in this one spot right here, we have three
Speaker 2: completely contradictory realities, all existing at the same time the
Speaker 2: fleet is launching, the fleet is grounded, and the fleet
Speaker 2: isn't even a thought yet. How can that be right?
Speaker 3: And that's the trap, that's the part that kills presentism.
Speaker 3: If the invasion is a real historical event for you
Speaker 3: and we inhabit the same physical universe, it implies that
Speaker 3: event is sitting there in space time. It has a coordinate.
Speaker 3: You're just viewing it from a different angle. You can
Speaker 3: no longer say only the present exists, because your present
Speaker 3: is my future and someone else's past.
Speaker 2: It's like a statue. I'm looking at the front, you're
Speaker 2: looking at the side, but the whole statue is solid,
Speaker 2: it's already fully carved.
Speaker 3: That is the block universe in a nutshell. If you
Speaker 3: accept the core tenets of special relativity, you are almost
Speaker 3: forced logically to accept that the future is just as
Speaker 3: real and fixed as the past. It's all just geometry.
Speaker 2: That makes me feel incredibly claustrophobic. It implies the future
Speaker 2: is just a city down the road. We haven't driven
Speaker 2: there yet, but the buildings are already built, the stop
Speaker 2: lights are already timed, everything is in place precisely.
Speaker 3: This philosophical view is called eternalism. The past, the present,
Speaker 3: and the future are all equally real, all coexisting in
Speaker 3: this four dimensional block. Our feeling of now is just
Speaker 3: an illusion of consciousness, like a spotlight moving across the
Speaker 3: stage that's already been built and set.
Speaker 2: But hold on. If that's true, then my choice to
Speaker 2: interrupt you just now wasn't really a choice. It was
Speaker 2: It was just a pre written line in the block.
Speaker 3: Under a strict intern interpretation of general relativity. Yes, it
Speaker 3: was a fixed point in forty space time that was
Speaker 3: always going to happen.
Speaker 2: Iest I refuse to accept that there has to be
Speaker 2: an escape patch. We are just creatures of relativity. We
Speaker 2: have quantum mechanics, and quantum mechanics is famous for being
Speaker 2: fundamentally weird and random. Doesn't that randomness save us from
Speaker 2: the block?
Speaker 3: Ah? And this is the quantum wrench in the gears
Speaker 3: of the whole machine. Just when relativity convinces us that
Speaker 3: the future is fixed and deterministic, quantum mechanics enters the
Speaker 3: chat and makes everything fuzzy and uncertain.
Speaker 2: Again, because in the quantum world, things aren't fixed until
Speaker 2: you look at them, right, That's the basic idea.
Speaker 3: Broadly speaking, Yes, on one side, we have the Schrodinger equation,
Speaker 3: which describes how a quantum system like an electron in
Speaker 3: a cloud of possibility, evolves over time, and interestingly, the
Speaker 3: equation itself, the evolution of that wave of possibility is
Speaker 3: perfectly deterministic. It's predictable until measurement. The famous collapse of
Speaker 3: the wave function when you interact with the system. When
Speaker 3: you measure the electron to see where it is, the
Speaker 3: entire wave function collapses from a clide of possibilities into
Speaker 3: a single, definite state, and this collapse appears to be
Speaker 3: completely random, an irreversible.
Speaker 2: Okay, So if the fundamental building blocks of reality are
Speaker 2: essentially slipping coins every time they interact, how can the
Speaker 2: future possibly be fixed? Let's say I have a choice
Speaker 2: to eat a burger or a salad for lunch. That
Speaker 2: choice ultimately depends on some neuron firing in my brain,
Speaker 2: and that neuron firing depends on some quantum event. Isn't
Speaker 2: the future genuinely open?
Speaker 3: Then that is the great hope for those who want
Speaker 3: to save free will in an open future. But and
Speaker 3: I hate to be the bearer of bad news again,
Speaker 3: it depends entirely on which side of the quantum wars
Speaker 3: you're on the interpretation of what quantum mechanics is actually
Speaker 3: telling us about reality matters immensely here.
Speaker 2: Okay, let's break down the camps, who are the main
Speaker 2: combatants in these wars.
Speaker 3: Well, first, you have the oldest, and you know, the
Speaker 3: standard textbook view. It's called the Cockenhagen interpretation from Bore
Speaker 3: and his colleagues. It basically says, the wave function isn't
Speaker 3: real reality, it's just a mathematical tool we use for
Speaker 3: making predictions. Reality is created in the act of measurement.
Speaker 3: So in this view, the future is genuinely open because
Speaker 3: nothing is decided until the moment of collapse. The electron
Speaker 3: wasn't anywhere until we looked.
Speaker 2: Okay, so that's a point for Team free Will. The
Speaker 2: bloc universe is cracked, the future is unwritten perhaps.
Speaker 3: But then you have the second camp, the hidden variables interpretation,
Speaker 3: which was famously championed by physicists like David Boehm. They
Speaker 3: looked at that random electron and essentially said Einsteinstein's line,
Speaker 3: God does not play.
Speaker 2: Dice, meaning that the randomness is just an illusion. It's
Speaker 2: fake exactly.
Speaker 3: This view says that the particle always had a definite
Speaker 3: position and a definite path. We just didn't know the
Speaker 3: hidden variables that were guiding it. It's like a complex
Speaker 3: magic trick. It looks like magic to the audience because
Speaker 3: they can't see that the hidden wires and mirrors, but
Speaker 3: the magician knows exactly where the card is going to
Speaker 3: end up.
Speaker 2: So if the hidden variables interpretation is correct, and all
Speaker 2: that quantum weirdness is just a sign of our ignorance,
Speaker 2: and we're back to a fully deterministic universe, we are.
Speaker 3: Right back in the block universe. The future is fixed
Speaker 3: and determined. We just can't predict it because we don't
Speaker 3: have access to all the data.
Speaker 2: That's deeply disappointing. What about the third one, the one
Speaker 2: that science fiction absolutely.
Speaker 3: Loves, ah the Many World's interpretation. This one is utterly
Speaker 3: fascinating when you think about it in terms of time.
Speaker 3: It was proposed by Hugh Everett, and it takes the
Speaker 3: Schrodinger equation at its word, as the wave function never collapses.
Speaker 2: It keeps going. What happens at the measurement, then it branches.
Speaker 3: The entire universe splits. Every single possible outcome of a
Speaker 3: quantum measurement actually happens. So in your lunch decision, the
Speaker 3: universe splits in two. You eat the burger in one branch,
Speaker 3: and an identical copy of you eats the salad in
Speaker 3: another branch.
Speaker 2: So the universe is constantly infinitely splitting into this massive
Speaker 2: fractal of different realities and.
Speaker 3: Ever growing branching tree of timeline.
Speaker 2: Wait a minute, If the universe splits, then the future
Speaker 2: isn't a single line anymore. Correct, So does the future
Speaker 2: exist in the mini world's view or is it being created?
Speaker 3: All of them exist objectively from a god's eye view
Speaker 3: of this multiverse. The entire branching structure is a fixed,
Speaker 3: deterministic object Subjectively to you, the future feels open because
Speaker 3: you don't know which branch of the tree your consciousness
Speaker 3: is going to travel down.
Speaker 2: But the whole tree is already there. All the branches
Speaker 2: are already mapped out.
Speaker 3: The structure is rigid. It's a giant branching crystal that.
Speaker 2: Is somehow even worse than the block universe, and that
Speaker 2: one at least my choices are singular. This makes my
Speaker 2: choice feel meaningless because I end up making every choice anyway.
Speaker 3: In a sense, Yes, in the block universe, you play
Speaker 3: one pre written role in many worlds, you play every
Speaker 3: possible role in every possible play, But in neither interpretation
Speaker 3: do you actually get to write the script yourself.
Speaker 2: So quantum mechanics, which I thought was our great hope
Speaker 2: for freedom, might just be a cage made of infinite mirrors.
Speaker 3: It's certainly looking that way. Relativity says it's a block.
Speaker 3: Many world says it's a branching block. Hidden variables says
Speaker 3: it's a secret deterministic block. The open future of the
Speaker 3: Copenhagen interpretation is starting to look like the outlier.
Speaker 2: Is there any theory that just gets rid of the
Speaker 2: problem entirely, like just kills time itself?
Speaker 3: Ironically? Yes, And this is where things get even stranger.
Speaker 3: If we try to go to the absolute deepest, most
Speaker 3: fundamental level of reality that we can currently probe, which
Speaker 3: is trying to combine gravity or general relativity with quantum mechanics,
Speaker 3: we get an equation. It's called the Wheeler DeWitt equation.
Speaker 2: And this is supposed to be the master equation for
Speaker 2: the whole universe, a theory of everything.
Speaker 3: It's an attempt at it. Yes, It tries to describe
Speaker 3: the quantum state of the entire universe as a single object.
Speaker 3: But there is something profoundly strange about this equation. Something
Speaker 3: is missing. What's missing the variable for time?
Speaker 2: What do you mean it's missing?
Speaker 3: I mean the letter T. It just drops out of
Speaker 3: the map entirely the equation. It has variables for the
Speaker 3: geometry of space, for the matter fields within it, but
Speaker 3: there's no variable that corresponds to a clock. The equation
Speaker 3: describes the universe as frozen static, a single timeless now
Speaker 3: hold on.
Speaker 2: So at the most fundamental level of reality we can
Speaker 2: describe mathematically, time doesn't exist at all.
Speaker 3: That is one very powerful, very influential interpretation. It suggests
Speaker 3: that the universe as a whole quantum system just is.
Speaker 3: There is no when it's a vast collection of static configurations,
Speaker 3: all existing timelessly.
Speaker 2: Then why are we having this conversation? Why do things change?
Speaker 2: I'm definitely getting older, My coffee is getting colder. I
Speaker 2: can feel the passage of time in my bones. If
Speaker 2: the math says the universe is frozen, then the math has.
Speaker 3: To be wrong or our perception is wrong. This is
Speaker 3: what's known as the problem of change. If the fundamental
Speaker 3: equation of reality is timeless, how do we get the
Speaker 3: vivid experience of a Tuesday turning into a Wednesday. The
Speaker 3: leading theory to solve this is called emergence.
Speaker 2: Emergence, Okay, that's like how individual water molecules aren't wet,
Speaker 2: but if you put enough of them together, the property
Speaker 2: of wetness emerges.
Speaker 3: That's a great analogy, or closer to the analogy in
Speaker 3: the sources heat. An individual molecule isn't hot or cold,
Speaker 3: it just has a certain amount of kinetic energy. The
Speaker 3: concept of temperature is a statistical average of the motion
Speaker 3: of a huge number of molecules. It only makes sense.
Speaker 3: It only emerges at a macroscale.
Speaker 2: So time is like heat. It's not a real fundamental
Speaker 2: thing exactly.
Speaker 3: The idea is that at the most fundamental quantum level,
Speaker 3: there is no time. But as you zoom out and
Speaker 3: look at the relationships between all these different static quantum
Speaker 3: states of the universe, a variable emerges that looks and
Speaker 3: acts just like time does for us. It implies that
Speaker 3: time isn't a fundamental ingredient of the universe. It's a byproduct,
Speaker 3: a secondary effect.
Speaker 2: That absolutely blows my mind. We spend our entire lives
Speaker 2: ruled by the clock, obsessed with saving time or spending time,
Speaker 2: but the clock itself might just be a statistical illusion
Speaker 2: generated by a timeless reality.
Speaker 3: There is even a mention in the research of some
Speaker 3: modern ideas from string theory and holography, specifically something called
Speaker 3: the ad SCFT correspondence.
Speaker 2: I saw that it sounded incredibly technical, and I skipped.
Speaker 3: Right over it. It is, but the core idea is beautiful
Speaker 3: in this context. It models a universe where gravity exists
Speaker 3: in a higher dimensional bulk space. Think of it like
Speaker 3: the inside of a soda can, and then quantum fields
Speaker 3: exist on the lower dimensional boundary, like the label printed
Speaker 3: on the surface of the can.
Speaker 2: Okay, I think I can picture that.
Speaker 3: In some versions of this theory, time exists on the
Speaker 3: boundary on the label, but it emerges from a timeless
Speaker 3: bulk from the inside of the can. It just reinforces
Speaker 3: this idea that time might be an emergent property that
Speaker 3: depends on your perspective or even which dimension you're looking from.
Speaker 2: Okay, my brain is officially starting to melt a little bit. Yeah,
Speaker 2: we have a universe that's a fixed block, or it's
Speaker 2: a timeless, frozen quantum state. But I am sitting here,
Speaker 2: my heart is beating I'm feeling the seconds flow by.
Speaker 2: Why if physics says the block is real or the
Speaker 2: universe is fundamentally timeless, why is my experience so convincingly,
Speaker 2: so powerfully different?
Speaker 3: And that brings us to the final and maybe the
Speaker 3: hardest piece of the puzzle. This is the intersection of
Speaker 3: physics and neuroscience. The hard problem of consciousness meets the
Speaker 3: hard problem of time. If the universe is a static
Speaker 3: movie reel, why do we feel like we were watching
Speaker 3: the movie? Why aren't we just a series of static frames?
Speaker 2: Exactly? Why do I feel like I'm moving through the
Speaker 2: block universe.
Speaker 3: There is a concept from neuroscience called the specious present,
Speaker 3: and it suggests that what we call now isn't an
Speaker 3: infinitely thin, instantaneous point in time. It's actually a window.
Speaker 2: A window.
Speaker 3: Yes, your brain is constantly integrating sensory inputs over a
Speaker 3: short duration fractions of a second to maybe a few seconds.
Speaker 3: It takes the sight of my lips moving and the
Speaker 3: sound of my voice, which actually arrive at your brain
Speaker 3: at slightly different times, and it stitches them together into
Speaker 3: one coherent moment.
Speaker 2: So now is actually a construct. It's a smeared out delay.
Speaker 3: We are always living in a delayed broadcast, a processed,
Speaker 3: reconstructed version of reality. We live in a thick present,
Speaker 3: not a thin one, and this helps explain that feeling
Speaker 3: a flow, we aren't experiencing one static slice. We're experiencing
Speaker 3: a blurred integration of many slices at once.
Speaker 2: But that still assumes that we are moving from one
Speaker 2: set of slices to the next. It brings up that
Speaker 2: spotlight idea you mentioned earlier, the spotlight theory.
Speaker 3: This is the intuitive idea that our consciousness is like
Speaker 3: a spotlight that scans along the timeline of the block universe,
Speaker 3: illuminating slice after slice and making it present.
Speaker 2: That makes perfect sense to me. The whole movie is
Speaker 2: on the real but the bright light of the projector
Speaker 2: is what moves and creates the show.
Speaker 3: It does feel right, But here is the deep logical
Speaker 3: problem with the spotlight theory. What moves the spotlight?
Speaker 2: Ah, consciousness moves it. I move it.
Speaker 3: But if the spotlight moves, it has to move in time.
Speaker 3: You need a second layer of time, a hyper time
Speaker 3: for the spotlight to move through the regular time of
Speaker 3: the universe. And then what moves the spotlight in that
Speaker 3: second time? You need a third time to explain the second,
Speaker 3: it just.
Speaker 2: Becomes an infinite loop. It's circular logic exactly.
Speaker 3: It's a philosophical trap that doesn't actually explain anything.
Speaker 2: So if the spotlight doesn't move and the block doesn't change,
Speaker 2: and the whole thing is static, why do I feel
Speaker 2: like I have agency? Why do I feel like my
Speaker 2: choices matter? Why does it feel so powerfully like I
Speaker 2: can choose what to do next?
Speaker 3: This is where we have to get really careful and
Speaker 3: almost redefine what we mean by choice. In a block universe,
Speaker 3: your choice to raise your hand is a real event.
Speaker 3: It absolutely exists there in the block, and that event
Speaker 3: causes the event in the next slice where your hand
Speaker 3: is actually up.
Speaker 2: Okay, so there's still cause.
Speaker 3: And effect, yes, But the choice itself is a fixed,
Speaker 3: embedded part of the space time geometry. It's what the
Speaker 3: sources call a dependence relationship, not a creative act. The
Speaker 3: future slice depends on the present slice, but the present
Speaker 3: slice is already sitting there fully formed.
Speaker 2: That is a subtle but absolutely huge difference. My choice
Speaker 2: matters in that it's part of the causal chain. But
Speaker 2: my choice was also written.
Speaker 3: Written, or perhaps a better word is embedded. It's part
Speaker 3: of the pattern.
Speaker 2: But there was an interesting angle on this from information theory.
Speaker 2: In the notes, it says the flow of time is
Speaker 2: actually the flow of information. What does that mean?
Speaker 3: Yes, this is another way of looking at it. Think
Speaker 3: about it. Why do we remember the past and not the.
Speaker 2: Future because a past already happened?
Speaker 3: Or to put it in terms of entropy and information,
Speaker 3: the past is low entropy, information that has been organized
Speaker 3: and recorded in our brains. The future is high entropy.
Speaker 3: It's disordered, unprocessed information. From our perspective, the feeling of
Speaker 3: an open future is actually just a feeling of a
Speaker 3: profound lack of information.
Speaker 2: So when I say the future is open, what I'm
Speaker 2: really saying is I don't know what happens next.
Speaker 3: Precisely, if you could know the position and velocity of
Speaker 3: every particle in the universe, and you have a computer
Speaker 3: powerful enough to calculate all their interactions, the future would
Speaker 3: look just as rigid and recorded as the past does.
Speaker 3: Our powerful sense of free will is, in a very
Speaker 3: real way, a direct measure of our own ignorance.
Speaker 2: Ignorance is freedom.
Speaker 3: In a deterministic universe. It is the only freedom we have.
Speaker 2: So Okay, where does that leave us. We've crashed all
Speaker 2: these theories into each other. Let's try to synthesize this
Speaker 2: whole investigation. What's the final verdict? Do we live in
Speaker 2: a block, a branching tree, or just a statistical.
Speaker 3: Mess The verdict is that it's profoundly and fundamentally messy.
Speaker 3: The evidence is contradictory. You have relativity, which points very
Speaker 3: very strongly to the block universe the future exists.
Speaker 2: But then you have thermodynamics, which gives us the ero
Speaker 2: of time, but it has to rely on this unexplained
Speaker 2: miracle at the Big Bang to get started exactly.
Speaker 3: Then quantum mechanics comes in and offers this glimmer of
Speaker 3: true randomness. But then most of the popular interpretations like
Speaker 3: many worlds or hitty variables, snatch it right back toward
Speaker 3: a kind of super to terminism.
Speaker 2: And finally, quantum gravity, the deepest theory of all, hints
Speaker 2: that the whole stage, the whole concept of time, might
Speaker 2: just be an illusion of our perspective.
Speaker 3: It feels like the more we learn, the less time
Speaker 3: looks like that simple ticking clock on the wall. It
Speaker 3: feels like we're fish trying to describe water. It's so
Speaker 3: fundamental to our existence that we can't step outside of
Speaker 3: it to see what it really is.
Speaker 2: But there's a human takeaway here right at kind of
Speaker 2: silver lining in this source material. It seems to be
Speaker 2: that even if the future is absolutely fixed in some
Speaker 2: hyperdimensional space time, our experience of it is not.
Speaker 3: That's the key, because we can't read the script.
Speaker 2: We can't we are.
Speaker 3: Embedded inside the movie. We can't skip to the end.
Speaker 3: So for us living our lives from our limited perspective,
Speaker 3: the future is effectively open. Because we possess absolutely no
Speaker 3: information about it, we have no choice but to live
Speaker 3: as if it is open.
Speaker 2: So the open future might be a trick of perspective,
Speaker 2: a necessary illusion, but it's the trick that allows us
Speaker 2: to be human. If I don't make the choice to
Speaker 2: get out of bed in the morning, nothing happens in
Speaker 2: my timeline. The fact that me not getting out of
Speaker 2: bed was already written into the block doesn't change the
Speaker 2: fact that I am the one who has to go
Speaker 2: through the motions exactly.
Speaker 3: Your agency, your consciousness, is the mechanism by which the
Speaker 3: future becomes the past, even if the whole structure is
Speaker 3: static when viewed from the outside. You are the needle
Speaker 3: on the record player. The music is already pressed into
Speaker 3: the vinyl, but the song only happens because the needle
Speaker 3: moves along the groove.
Speaker 2: I like that we are the music.
Speaker 3: We are the music.
Speaker 2: I want to leave our listeners with the one final
Speaker 2: slightly provocative thought that came from the deeper end of
Speaker 2: the cosmology section we looked at. We talked a lot
Speaker 2: about the Big Bang being a brute fact, this incredibly
Speaker 2: low entropy, highly ordered start to everything.
Speaker 3: Yes, the initial push that got the whole arrow of
Speaker 3: time flying, and we.
Speaker 2: Talked about how that past event pushes us forward. But
Speaker 2: there was a fascinating suggestion in some of the research
Speaker 2: that the end of time, the far far future, might
Speaker 2: also have special boundary conditions.
Speaker 3: That is a wild and fascinating idea. Some cosmological models
Speaker 3: suggest the universe isn't just being pushed from the past,
Speaker 3: but it's also being pulled toward a very specific future state.
Speaker 3: It's like teleology, a purpose in a strange physical way. Yes,
Speaker 3: if the universe has to end in a certain configuration
Speaker 3: to satisfy the overall equations, maybe it has to settle
Speaker 3: into a specific vacuum state. Or end in a big
Speaker 3: crunch that mirrors the Big Bang. Then the future is
Speaker 3: constraining the present just as much as the past is.
Speaker 2: Imagine that for a second. We always always think of
Speaker 2: the past pushing us forward, but maybe the future is
Speaker 2: pulling us in. Maybe the script for the universe is
Speaker 2: written from both ends and we are just living out
Speaker 2: the part where they meet in the middle.
Speaker 3: It completely turns causality on its head. It would suggest
Speaker 3: that the choice you make today might, in some incomprehensible way,
Speaker 3: be determined by where the universe needs to be in
Speaker 3: a trillion years.
Speaker 2: And on that completely mind bending note, I think we
Speaker 2: are officially at a time, whether it exists or not,
Speaker 2: I suppose we are. This has been a heavy investigation.
Speaker 2: We broke the mug, we sliced the loaf of bread,
Speaker 2: and we split the universe into infinite copies. Thanks for
Speaker 2: listening to us. Try to put it all back together.
Speaker 3: And keep questioning the clock.
Speaker 2: We'll see you in the future, or I guess we'll
Speaker 2: see you the next slice.