Speaker 1: Welcome to the deep dive, where we plunge into the
heart of what we truly know and maybe more importantly,
what we really don't. For so much of our lives,
you know, we're kind of taught to find answers. We
go to school, we read, we research, assuming that for
every question there's a solid answer out there, someone somewhere
must have.
Speaker 2: It figured out right, that's the assumption.
Speaker 1: But what if the most profound, the most exciting questions
are the ones where humanity collectively just doesn't have a clue.
Speaker 2: It's an electrifying thought, isn't it. Our mission today isn't
just about laying out facts we do know. Instead, we're diving,
you know, headfirst into the truly unknown, these questions that well,
no matter how far we push science, they just remain
stubbornly beyond our grasp. It's an exploration into the grandest
mysteries that still.
Speaker 1: Confound us absolutely. I remember as a kid, I'd been
hours thinking about things like what does it actually feel
like to be a dog?
Speaker 2: Yeah?
Speaker 1: You know yeah? Or to fish feel pain? Even bigger
stuff like was the Big Bang just an accident? Or
is there a god? The big ones really big ones? Yeah?
And I genuinely thought some adult, a scientist, someone must know,
and then you realize, Nope, no one knows.
Speaker 2: That's a key moment, isn't it.
Speaker 1: It really is. And honestly, for many of those questions,
they puzzle me even more now. But that's the exciting part.
I think grappling with these questions it means you're standing
right at the frontier of human understanding and you just
never know what, like mind bending possibilities, you'll stumble upon there.
Speaker 2: And that's precisely what we're going to do in this
deep dive. We're going to tackle two specific, incredibly profound questions,
questions that currently stump even the well the brightest mount
on Earth. Okay, we'll explore the multitude of theories, the
confusing possibilities, and why these questions push us right to
the very limits of our comprehension.
Speaker 1: This is about stepping into the vast unknown of existence itself.
Pretty much, Yeah, all rights. Unpack this Our first question,
one that really takes us to the edge of what
we think is real. How many universes are there?
Speaker 2: Whoa starting big.
Speaker 1: Starting very big. To even begin to grasp this, we
have to talk about scale, think about the Sun huge, right,
big enough to fit a million earths inside it hard
to even picture exactly. Yet, even that giant star is
just a tiny pimprick in our Milky Way galaxy. Our
galaxy holds something like four hundred billion.
Speaker 2: Stars, four hundred billion.
Speaker 1: You can even see a hint of it on a
clear night, that sort of pale milky band across the sky.
It's humbling just thinking about its size.
Speaker 2: And if you think the Milky Way is vast, well
it gets even more astonishing. Our best telescopes can detect
maybe one hundred billion other galaxies beyond our own.
Speaker 1: One hundred billion galaxies.
Speaker 2: Yeah, to try and put that into perspective, imagine each
star was just a single grain of sand. Okay, the
stars in our Milky Way galaxy alone, that would be
enough sand to fill a beach, say thirty feet by
thirty feet and three feet deep.
Speaker 1: Wow, that's a lot.
Speaker 2: Of sand it is. And now get this, all the
booches on Earth combined wouldn't have enough sand to represent
all the stars in just the observable universe.
Speaker 1: Okay, that's really hard to wrap your head around.
Speaker 2: The sheer scale is truly unfathomable. It stretches so far
beyond our everyday experience.
Speaker 1: Wow, Okay, an incredible number of stars. Yeah, it really
does stretch the imagination. But what if even that vastness,
that observable universe, is just a tiny fraction of the
whole picture. M what are physicists suggesting might lie beyond
what we can actually see?
Speaker 2: Well, that's where it gets really interesting and maybe a
bit weird.
Speaker 1: Uh.
Speaker 2: Oh, well, our physical reality here on Earth is definitely
connected to those distant invisible galaxies. They're all part of
our single giant universe, right, same physical laws, same kinds
of atom.
Speaker 1: Right, one big system exactly.
Speaker 2: But recent theories in physics, well they're telling us there
could be countless of universes entirely.
Speaker 1: By other universes. Okay.
Speaker 2: One of the leading ideas, string theory, suggests these other
universes might be built on totally different types of particles,
have different properties, obey entirely different physical laws.
Speaker 1: So completely alien realities.
Speaker 2: Pretty much. Most of them probably couldn't even support life
as we know it. Maybe they flash in and out
of existence in a nanosecond, and they might exist and
get this up to eleven dimensions, eleven demandons. Yeah, where
these extra dimensions are like incredibly tiny and curled up.
That allows for all the different ways these fundamental strings
can vibrate, which basically creates the different universes with different properties.
Speaker 1: So we're talking about wonders beyond our wildest imagination here,
and string theory doesn't just say there might be other universes.
Speaker 2: Now, the leading version actually predicts a multiverse.
Speaker 1: A multiverse made up of what was that number.
Speaker 2: Ten to the five hundredth power universes, ten.
Speaker 1: To the five minuits. That's one followed by five hundred zeros. Yep, Okay,
how do you even visualize that? That sand analogy earlier
was already.
Speaker 2: Mind blowing, right, it's almost impossible. Imagine if every single
grain of sand on every beach on Earth represented a
whole universe, you'd still be astronomically short, like, not even close.
Speaker 1: So ten to the five hundredth power is it's basically incomprehensible.
It makes our entire observable universe seem like a single speck.
Speaker 2: Of dust in a potentially infinite library. Yeah, it really
is beyond comprehension.
Speaker 1: And yet even that number ten to the five hundred,
which sounds almost infinite. It's tiny compared to actual infinity.
Speaker 2: Right exactly. Some physicists actually believe the space time continuum
is literally infinite, genuinely genuinely infinite, and within that infinite
expanse there could be an infinite number of what they
call pocket universes, each one potentially having different properties. Your
brain doing okay with that?
Speaker 1: My brain is definitely stretched. It makes you wonder about
every choice you ever made, doesn't it if there's an
infinite me out there? Yeah, who chose differently? I mean,
what does that even mean for free will or anything?
Speaker 2: It raises huge philosophical questions, it really does.
Speaker 1: It's almost, I don't know, comforting in a weird way
to realize how much we just don't know. It feels
like we're only just scratching the surface of reality.
Speaker 2: Absolutely.
Speaker 1: And then, just to make things even more complicated, there's
quantum theory.
Speaker 2: Ah, yes, the physics of the very small.
Speaker 1: Right, which tells us particles can be in multiple places
at once or linked instantly across vast distances. Stuff that
just sounds impossible.
Speaker 2: The theory itself works perfectly. It makes predictions we can
test and verify. It's undeniably successful.
Speaker 1: But interpreting what it means.
Speaker 2: Ah, that's the baffling part. What does it actually mean
for our reality? Yeah, and some physicists argue, you can
only really make sense of quantum mechanics if you imagine
that huge numbers of parallel universes are being spawned constantly,
every single.
Speaker 1: Moment, spawning universes. Ye, like right now?
Speaker 2: According to this interpretation, Yes, many of these universes, they suggest,
would be very much like ours, and would even include multiple.
Speaker 1: Copies of you, multiple copies of me.
Speaker 2: Yeah. Imagine in one universe you graduated with honors, married
your dream person. Okay, in another, well, maybe things didn't
go quite so well. Different choices, different outcomes.
Speaker 1: Is quite a thought. It really puts your own life
in perspective.
Speaker 2: It does raises big questions about choice, destiny, you name it.
Speaker 1: Now. I can imagine someone listening might be thinking, Okay,
this sounds like pure science fiction. Come on, there's only
one universe.
Speaker 2: And that's a perfectly reasonable reaction.
Speaker 1: You wouldn't be alone in thinking that. Some scientists still
firmly hold that view. They insist the only meaningful answer
to how many universes is one period.
Speaker 2: It's a strong counter argument based on what we can
currently observe and test.
Speaker 1: And then, just to add another layer of complexity, you've
got some philosophers, some mystics who might even argue that
our universe, the one we experience, is itself just an illusion, right.
Speaker 2: The whole reality isn't realpec So where does that leave us.
Speaker 1: We've got one, we've got ten to the five hundred,
we've got infinity, we've got maybe zero if it's all
an illusion.
Speaker 2: What's fascinating and maybe a bit frustrating is that there's
absolutely no consensus on this right now, not even close.
Speaker 1: Really, no clear front runner, Nope.
Speaker 2: All we can really say for sure based on current
physics and theory is that the answer seems to lie
somewhere between zero and infinity.
Speaker 1: Between zero and infinity, that's a pretty wide range.
Speaker 2: Just a bit.
Speaker 1: So what does this profound uncertainty about our universe or
universes truly mean for us? It feels like more than
just a numbers game.
Speaker 2: Oh, absolutely, It challenges our most basic assumptions about reality,
about our place and the cosmos. Ye, it forces us
to maybe redefine what knowing something really means. It pushes
us towards perhaps the biggest paradigm shift in knowledge humanity
has ever seen.
Speaker 1: Where humility might be just as important as discovery.
Speaker 2: Precisely, it's realizing the vastness of our own ignorance.
Speaker 1: In a way, it's a truly thrilling time, though, isn't
it to be alive pondering these questions? Standing right at
this boundary of human understanding?
Speaker 2: It really is pretty cool time to be studying physics
or just thinking about these things.
Speaker 1: Okay, the sheer scale and the well potential multiplicity of
universes we've just talked about is truly humbling, mind bending even,
But that immensity, that staggering number of possible worlds out there,
it only makes our next big question even more pressing.
Oh yes, a question that's captivated people for decades now,
Why can't we see any evidence of alien life?
Speaker 2: That big one? Where is everybody?
Speaker 1: Exactly? If the cosmos is so vast, potentially so full
of worlds, where are they?
Speaker 2: This is the famous Fermi paradox, right, named after the
physicist Enrico Fermi, who supposedly asked it back in nineteen
fifty during a lunch conversation.
Speaker 1: Right, and look, some people claim UFOs are visiting all
the time. Governments are covering it up.
Speaker 2: Yeah, those theories are out there, but frankly, when you
look for solid scientific evidence, they're just not very convincing.
Speaker 1: Agreed, So that lives us with this profound riddle. We
have recent data, like from the Kepler space telescope suggesting
there could be what half a trillion planets just in
our Milky Way.
Speaker 2: Half a trillion an enormous number. And if even a
tiny fraction of those, a one in ten thousand has
conditions that might support life, which seems plausible, that's still
fifty million potentially life harboring planets right here in our
own galactic backyard.
Speaker 1: Fifty million. That number is just astounding. And here's the kicker.
Isn't it our Earth? Our Solar system? It didn't even
form until about nine billion years.
Speaker 2: After the Big Bank, relatively late to the party.
Speaker 1: Yeah, which means countless other planets in our galaxy should
have formed much much.
Speaker 2: Earlier, billions or at least many millions of years before
Earth even existed, giving life a huge head start elsewhere.
Speaker 1: Exactly, So, if just a few of those planets spawned
intelligent life, and that life developed.
Speaker 2: Technology, those technologies would have add millions, maybe billions of
years to grow in complexity and power. Think about it.
We've seen how dramatically technology can accelerate in just one
hundred years.
Speaker 1: Here on Earth, right from horse drawn carts to smartphones
in a blink, cosmically speaking.
Speaker 2: Exactly, So imagine what an intelligent alien civilization could achieve
in millions of years. They could have spread across the galaxy,
built giant energy harvesting structures.
Speaker 3: Around stars like Dyson'sphares potentially yeah, or launched fleets of
colonizing spaceships, or maybe created glorious works of art that
fill the night sky, things we couldn't possibly miss.
Speaker 1: Or at the very least, you'd think we'd pick up
some kind of signal, right, electromagnetic signals, maybe leaking unintentionally
or maybe sent deliberately.
Speaker 2: You would absolutely think so. And yet we see no
convincing evidence, none of it. Why the great silence is
it's sometimes called it's truly puzzling.
Speaker 1: And when you start thinking about possible answers, well, some
of them get pretty dark, don't they.
Speaker 2: They can, Yes, the implications are quite profound, Like.
Speaker 1: What if what if a single super intelligent civilization already
took over the galaxy ages ago, and now they're just
out there enforcing radio silence, maybe eliminating any potential competitors
that get too noisy or advanced.
Speaker 2: The dark forest hypothesis essentially a scary thought, just sitting there, monitoring,
ready to obliterate anything that looks like a threat.
Speaker 1: Chilling. Or maybe the evolution of intelligent technology creating life
is just far far rarer than we assume. I mean,
think about it, only happened once here on Earth in
four billion years of life. Maybe that was the incredible fluke.
Maybe we are, in fact the first such civilization in
our galaxy.
Speaker 2: The rare Earth idea that were genuinely unique or at
least exceptionally early, or another dark one. Yeah.
Speaker 1: Perhaps civilizations inegiably carry the seeds of their own destruction.
Speaker 2: Ah, the self destruction filter.
Speaker 1: Yeah, maybe they can't control the very technologies they create,
you know, RUNAWAYI or catastrophic climate change from energy use,
or maybe just blowing themselves up with advanced weapons.
Speaker 2: So bring thought that intelligence might have a built in
self destruct button. That the silence is the sound of
failed civilizations.
Speaker 1: Yeah, those are definitely chilling possibilities to consider makes you
look at our own situation a bit differently.
Speaker 2: But it's not all doom and gloom. There are also
numerous more hopeful explanations for the silence.
Speaker 1: Okay, good, let's hear some of those.
Speaker 2: Well, first start, maybe we're just not looking that.
Speaker 4: Hard really with all our telescope relatively speaking, Yeah, we're
spending honestly a pitiful amount of money on the dedicated
search for extraterrestrial intelligence.
Speaker 2: For SETI, only a tiny fraction of stars have ever
been closely examined for signals.
Speaker 1: Okay, that's a fair point. We haven't exactly scanned the
whole sky.
Speaker 2: Not even close, and it's entirely possible we're not looking
the right way. Perhaps as civilizations get really advanced, they
quickly discover communication methods far more sophistic then radio waves.
Speaker 1: Like what who knows?
Speaker 2: Maybe all the real interstellar communication happens using something we
barely understand, like manipulating dark matter or dark energy.
Speaker 1: Whoa communicating through dark energy?
Speaker 2: It sounds wild, I know, but these things make up
most of the universe's mass and energy. Maybe that's where
the advanced civilizations are operating, and we're just tuned to
the wrong channel effectively.
Speaker 1: That's a fascinating thought, though, I mean, dark matter and
dark energy are already concepts right at the edge of
our understanding.
Speaker 2: Oh absolutely.
Speaker 1: How plausible is it that aliens could actually use them
to communicate, or even that they'd choose to wouldn't like
regular radio waves be more universal?
Speaker 2: That's a very valid point. It definitely pushes the boundaries
of speculation, but it highlights the possibility that we might
be looking for I don't know, an iPhone signal using
a telegraph machine. Our methods might be primitive by galactic standards.
Speaker 1: Okay, fair enough.
Speaker 2: What else, Well, maybe we're looking at the wrong scale,
entirely scale. So perhaps really advanced civilizations eventually realize that
life at its core is just complex patterns of information
interacting information, And maybe they figure out that this complexity,
this interaction can happen far more efficiently with less environmental
impact at a very small scale.
Speaker 1: Smaller is better.
Speaker 2: Think about our own technology. Our clunky, old stereo systems
shrink down to tiny iPods, right, Our computers went from
room size to fitting in our pockets.
Speaker 1: Yeah, that's true.
Speaker 2: Maybe intelligent life itself follows that trend. Maybe to reduce
their footprint or increase efficiency. Advanced aliens have turned microscopic
microscopic aliens, So our own solar system could be absolutely
teeming with incredibly complex, intelligent alien life and we're just
not noticing them because we're looking for big spaceships and
radio signals.
Speaker 1: Wow, that's unexpected. Aliens under our noses.
Speaker 2: Potentially, potentially, And here is a truly wild thought, just
to really stretch your mind. Oh boy, go on, what
if the very ideas in our heads, What if they
are a form of alien.
Speaker 1: Life, ideas as in thoughts?
Speaker 2: Well, think about it. It sounds outlandish, but ideas do
seem to have a life of their own, don't they.
They spread, they evolve, they compete, They can certainly outlive
their creators.
Speaker 1: Hmm, like memes, but on a grander scale.
Speaker 2: Exactly, Maybe biological life like us is just a passing phase,
a temporary vessel, and information itself, pure thought is the ultimate,
most durable form of existence in the universe.
Speaker 1: Okay, that is a wild thought that concepts themselves could
be the aliens. It definitely sticks with you.
Speaker 2: It's out there, but it's one of the many possibilities
people have considered when faced with the silence.
Speaker 1: So given all this, what's next? Where do we go
from here in the search for alien life.
Speaker 2: Well, things are actually getting quite exciting on that front.
Within the next say, fifteen years or so, we should
start getting real spectroscopic data from promising nearby exoplanet.
Speaker 1: Spectroscopic data, so analyzing the light coming from their atmosphere exactly.
Speaker 2: That data could vie the composition of their atmospheres, telling
us if they have oxygen, water, vapor, methane signs that
they might actually be habitable or even inhabited.
Speaker 1: That would be huge, Yeah, actual chemical signatures of life
from another world.
Speaker 2: It would be revolutionary. And groups like SETI, the Search
for Extraterrestrial Intelligence, they're now releasing vast amounts of their
observational data to the public. Oh really, Yeah, inviting millions
of citizen scientists, maybe even you listening right now, to
help sift through it all using their own computers, bringing
the power of the crowd to this grand quest.
Speaker 1: That's fantastic, harnessing collective brain power.
Speaker 2: And right here on Earth there are some amazing experiments
happening trying to create life from scratch in the lab.
Speaker 1: Create life, yeah, like artificial life.
Speaker 2: Yeah, life that might be very different from the DNA
based forms we know. Understanding how life can arise in
whatever form will deepen our understanding of what life fundamentally is.
Speaker 1: Which would help us know what to look for out there.
Speaker 2: Precisely. This will help us chip away at that ultimate question,
is the universe teeming with life? Or are we, against
all odds, truly alone?
Speaker 1: And you know either answer, it's just staggering to contemplate,
Isn't it.
Speaker 2: Absolutely on inspiring either way.
Speaker 1: Because even if we are alone, the very fact that
we exist, that matter on this small planet somehow organized
itself into beings that can think and dream and ask
these monumental questions about the cosmos, Well, that might just
turn out to be one of the most important, most
incredible facts about the entire universe.
Speaker 2: It really puts our own existence into a profound context.
The quest for knowledge, for understanding. It never gets dull,
does it.
Speaker 1: No, it's actually the opposite. I find the more you learn,
the more amazing and mysterious the world seems.
Speaker 2: Couldn't agree more.
Speaker 1: And it's those crazy possibilities, those huge unanswered questions, the
ones that take us right to the very edge of
what we can even conceive those are the things that
really pull us forward, I think. Yeah, So stay curious,
keep pondering these things, because the biggest mysteries are often
the most profound, and who knows what answers might be
just around the corner.