Speaker 1: What if I told you that time travelers aren't just characters,
you know, stuck in sci fi movies or books. What
if they're actually already among us right now. And I'm
not talking about like Deloreans flashing through time or anything
like that. No fancy gadgets.
Speaker 2: Right, no flux capacitors needed, exactly.
Speaker 1: We're talking raw, undeniable physics. So today we're taking a
deep dive into whether time travel is actually real and.
Speaker 2: The truth might be well a lot stranger than fiction.
Speaker 1: Honestly, it sounds like it really redefines the whole idea,
doesn't it. Yeah, So okay, let's impact this. What does
it actually mean scientifically speaking to be a time traveler?
Speaker 2: That's absolutely the place we need to start, because, you know,
our gut feeling, our intuition about time, it's usually that
time is this constant river flowing the same for everyone everywhere.
Speaker 1: Yeah, like a big universal clock just taken away. Same
for me, same for you, same for someone on marketing.
Speaker 2: Exactly. We feel it's steady, but the science, the real
world data, it tells it well different. Story time is
much more fluid, maybe even personal. Yeah, So our mission
today in this deep dive it isn't just to lay
out the facts. It's really to try and shift your
perspective a bit, to get you thinking differently about time itself,
one of the most fundamental things in the universe. We'll
look at things we can actually see happening, some really
key experiments that frankly blew people's minds, and then we'll
dip into the more theoretical side. The goal isn't just
asking if time travel.
Speaker 1: Is possible, but how it's already happening.
Speaker 2: In a very real, measurable way. Yes, it's already part
of how things work, whether we notice it day to
day or not.
Speaker 1: Okay, so when you say time travelers are among us,
you're not hinting at like secret agents from the future.
Speaker 2: Huh No, definitely not that. We're talking about real people,
incredibly dedicated, smart people like Scott Kelly. You know, the
American engineer retired astronauts.
Speaker 1: Oh, yes, Scott Kelly did amazing work on the ISS.
Speaker 2: Exactly, multiple missions commanded the International Space Station, just incredible stuff.
But one mission in particular really brings this whole time
travel thing into focus.
Speaker 1: The year long one.
Speaker 2: That's the one well three hundred and forty days technically,
he was up there on the Iss, this giant lab
orbiting Earth, doing all this genius level stuff, improving water recycling,
testing how heat moves in microgravity, basically figuring out how
humans can live further out in space.
Speaker 1: Right, vital work for future exploration.
Speaker 2: Absolutely vital. But while he was doing all that, something
else was happening, something really counterintuitive. He was actually aging
differently compared to us down here on Earth.
Speaker 1: Eging differently, you mean slower or faster?
Speaker 2: Slower, just a tiny bit slower, but measurably slower. And
that's not just a quirky fact. It's a direct result
of his journey through space time.
Speaker 1: Wow. Okay, so how do we even know that? How
can you measure such a tiny difference in aging? Ah?
Speaker 2: Well, that's where it gets really neat. It comes down
to comparison, and Scott Kelly has the perfect comparison, his
identical twin brother, Mark Kelly, also an astronaut, also an astronaut. Yes, now,
Mark was actually born six minutes before Scott, so technically
Mark was the older twin by six minutes.
Speaker 1: Okay, makes sense.
Speaker 2: But then Scott does his three hundred and forty days
stand up on the ISS when he comes back. Scientists
did incredibly detailed comparisons biological markers, the telomeres in their DNA,
and critically super precise time measurements, and guess what.
Speaker 1: Mark was still older?
Speaker 2: He was older, yes, but more older than before. Mark
was now six minutes and five milliseconds older than Scott.
Speaker 1: Five millisecond. That's that's incredibly small.
Speaker 2: It is incredibly small to us, like the blink of
an eye, but in physics, that five millisecond difference is huge.
It's proof positive Scott aged just that little bit slower
because he was orbiting Earth at incredible speed.
Speaker 1: Speed is the key here.
Speaker 2: Speed is absolutely key the ISS. It doesn't just float,
it's zooms. We're talking seventeen thy five hundred miles per hour.
It orbits the Earth roughly every ninety.
Speaker 1: Minut that's blistering fast it is.
Speaker 2: And the fundamental rule here, cornerstone of modern physics, is this.
The faster you move through space, the slower you move
through time relative to something moving.
Speaker 1: Slower, so speed stretches out time.
Speaker 2: It dilates. Time is the technical term. Time stretches out
or slows down. For the faster object, the closer you
get to the speed of light, the universe's ultimate speed limit.
The more dramatic this effect becomes, you'd age much much
slower compared to someone's stationary.
Speaker 1: But did Scott Kelly feel time moving slower up there?
Did things seem in slow motion?
Speaker 2: No, not at all. And that's crucial. From Scott's perspective.
Inside the iss, time felt completely normal. Seconds ticked by,
just like they do for us. Clocks worked fine, He
lived his day normally. The difference, the time dilation, it's
only relative. It only shows up and you compare his
clock or his biological age to a clock or a
person back on Earth, like his twin brother Mark.
Speaker 1: So it's a comparison effect.
Speaker 2: Exactly, it's a compared effect. So pulling this all together,
this isn't some SI plot device. It's real, it's measured.
It happens. Every time an astronaut goes into orbit. They
have effectively leaped forward in time, just by tiny fractions
of a second relative to us.
Speaker 1: Leaped forward.
Speaker 2: And think about the implications for say, long term space travel.
Imagine a crew going to another star system, maybe traveling
for decades at very high speeds.
Speaker 1: They'd come back and Earth would be centuries older.
Speaker 2: Potentially yes, depending on the speed and duration. Imagine trying
to reconnect with family or society. The data they collected
might be ancient history by the time they returned. It
really blurs the lines, doesn't it. Small time differences now
could mean huge societal shifts down the line.
Speaker 1: That's absolutely mind bending. So just to clarify for everyone listening,
when we talk about real time travel here, we're not
talking back to the future style jumps.
Speaker 2: No instantaneous zapping through centuries.
Speaker 1: Right, It's more like living in the future, but at
a slightly different rate than someone else. Personal timestream is
flowing a bit faster or slower than one second per
second relative to another observer.
Speaker 2: Precisely, it's about the rate of time passing being different,
And like Scott Kelly shows us, it's measurable. It's happening now.
Speaker 1: And you mentioned it affects technology too, like GPS.
Speaker 2: Oh absolutely, GPS satellites are orbiting Earth very fast, and
they're also further away from Earth's gravitational pull, which also
affects time, something called gravitational time dilation, part of Einstein's
general relativity.
Speaker 1: So gravity affects time too, not just speed.
Speaker 2: Yes, gravity also works. Spacetime clocks tick slightly faster further
away from a massive object like Earth. Both speed and
gravity effects have to be calculated for GPS to work.
Without accounting for both special relativistic time dilation due to
speed and general relativistic time dilation due to gravity, your
GPS would become inaccurate incredibly quickly, like miles off within
a single day.
Speaker 1: So every time I use Google Maps and basically relying
on the physics time travel.
Speaker 2: In a very real sense, Yes, you're directly benefiting from
our understanding that time is an absolute.
Speaker 1: Okay, this is already stranger than I thought. So who
figured all this out? How do we get from time
is absolute? Too? Well?
Speaker 2: This, well, that brings us to the giant himself, Albert Einstein.
For centuries, the picture was dominated by Isaac Newton. Newton
saw time as while absolute, universal, unchanging like that cosmic
clock ticking the same everywhere.
Speaker 1: Yeah, that feels intuitive. My Tuesday feels like your tuesday.
Speaker 2: It does feel intuitive. It matches our daily experience perfectly,
clock seems synchronized, days pass predictably. But then early twentieth
century Einstein comes along and basically says, Hold on a second,
it's it's not quite that simple. He dropped the bombshell.
Time is relative.
Speaker 1: Time is relative. We hear that phrase all the time,
But what does it really mean, Because it seems to
change everything.
Speaker 2: It really does. What it means is that the amount
of time that passes between two events isn't necessarily the
same for everyone. It depends on how you're moving and
where you are compared to someone else observing the same events.
Speaker 1: So my five minutes might not be your five minutes.
Speaker 2: Under the right circumstances. Yes, that was the core of
his special theory of relativity. It starts with two postulates,
two fundamental ideas. One, the laws of physics are the
same for everyone who isn't accelerating.
Speaker 1: Okay, that seems reasonable.
Speaker 2: Two, the speed of light in a vacuum is constant.
It's the same for all observers, no matter how fast
they're moving. The second one, this is the one that
has really weird consequences.
Speaker 1: Constant speed of light. Ah, how does that lead to
relative time?
Speaker 2: Think about it. If the speed of light must be
constant for everyone, but speed is just distance divided by time,
then if observers moving differently relative to each other. Measure
light traveling the same speed over different distances. Something has
to give, and that something is time.
Speaker 1: Ah, time itself has to change to keep the speed
of light constant for everyone.
Speaker 2: Exactly, time has to stretch or shrink depending on your motion.
Let's use that analogy from the source material, the melting
ice cream.
Speaker 1: Okay, I'm going to park bench ice cream cone.
Speaker 2: Right suns out, it's melting. Let's say for you sitting there,
it takes exactly five minutes to melt completely. You time
it on your watch.
Speaker 1: Five minutes. Got it simple enough.
Speaker 2: Now imagine your friend whizzes past in a super fast spaceship.
Maybe it's say eighty percent the speed of light. They
look out the window and watch your ice cream melt
for them inside that speeding spaceship. That same event, the
ice cream melting takes less time according to their watch.
Maybe it only takes three minutes for them.
Speaker 1: Wait, the same melting takes less time for them, how.
Speaker 2: Because time itself is passing slower for them due to
their high speed relative to you on the bench. Again,
they wouldn't feel anything strange. Their thoughts, their heartbeat, their
clock on the wall, all would seem normal to them.
Speaker 1: But comparing their clock to my clock shows a difference.
Speaker 2: Precisely. That difference is time dilation. Time literally moves slower
for things moving faster relative to slower things. It's not perception,
it's physics. It's the heart of special relativity.
Speaker 1: Mind blown. Okay, so Einstein predicts this theoretically based on
the constant speed of light.
Speaker 2: That's a huge leap, a monumental leap. It completely re
wrote our understanding of space and time, merging them into
a single entity.
Speaker 1: Space time with theories are one thing. You mentioned experiments earlier.
How on earth did they prove something so bizarre back
then before super precise space.
Speaker 2: Measurements, right, Because these effects are usually tiny in everyday life.
You need either incredible speeds or incredibly sensitive instruments. And
that's where a really clever experiment from nineteen seventy one
comes in.
Speaker 1: Okay, what happened in seventy.
Speaker 2: One two physicists Jesse fa Fayle and Richard Keating. They
decided to test time dilation directly using atomic clocks.
Speaker 1: Atomic clocks, those are the super accurate ones.
Speaker 2: Right, insanely accurate. They measure time based on the resonance
frequencies of atoms, usually caesium. We're talking accuracy down to
nanoseconds billions of a seconds.
Speaker 1: Okay, so what do they do with them?
Speaker 2: It was elegantly simple, really. They took two of these
clocks and put them on regular commercial airplanes. One flew
eastward around the world. The other flew.
Speaker 1: Westwards on passenger flights.
Speaker 2: YEP, circumnavigating the globe. Meanwhile, a third identical atomic clock
stayed put on the ground at the US Naval Observatory
as the reference point.
Speaker 1: Okay, so they flew clocks around the world and compared them.
Why east and west? Does that matter?
Speaker 2: It matters hugely. Think about the Earth's rotation. The Earth
spins eastward. So the plane flying east was moving with
the Earth's rotation, meaning its speed relative to the center
of the Earth, or relative to a non rotating frame,
was its own speed plus the Earth's rotational speed. It
was moving.
Speaker 1: Faster, okay, faster overall speed exactly.
Speaker 2: The plane flying west was moving against the Earth's rotation,
so its net speed relative to that same frame was
its own speed minus the earth rotational speed. It was
moving slower overall.
Speaker 1: Clever, So you have one faster clock, one slower clock,
and one stationary.
Speaker 2: Clock, precisely, and after the trips they brought all three
clocks back together and compared the times recorded it.
Speaker 1: Did they see a difference? Please tell me they saw
a difference.
Speaker 2: They absolutely did, and it matched Einstein's predictions beautifully. The
clock that flew eastward, the faster one, had lost time
compared to the ground clock. It ran slightly slower, comer slower,
about fifty nine nanoseconds slower.
Speaker 1: Wow, okay, fifty nine billions of a second.
Speaker 2: And the clock that flew westward, the slower one, relative
to the non rotating frame, had gained time compared to
the ground clock. It rans slightly faster.
Speaker 1: Gain time how much?
Speaker 2: About two hundred and seventy three nano seconds faster? Wait,
let me double check that number from the source. Ah, yes,
the source says two hundred and thirty seven nanoseconds. Game
for the westward clock apologies, fifty nine lost eastbound, two
hundred and thirty seven gained westbound.
Speaker 1: Okay, fifty nine lost two hundred and thirty seven gained tiny,
tiny amounts, but.
Speaker 2: Consistent, consistent, and undeniable. These weren't errors. They were the
direct measured proof of time dilation predicted by both special
relativity due to speed and general relativity due to gravity.
Altitude also played a small role, mostly speed in this case,
but both effects were accounted for.
Speaker 1: So have you and Keaty nailed it? They proved Einstein
wright using airplanes and clocks.
Speaker 2: They absolutely did. It was a landmark experiment, and it
connects directly back to our astronauts. They're going way faster
than those planes and for much longer.
Speaker 1: So their time dilation is bigger than nanoseconds.
Speaker 2: Bigger, yes, though still small in human terms. You mentioned
Olig Kononenko earlier, the Russian cosmonaut who holds the record
for cumulative time and space over eight hundred and seventy
eight days by twenty twenty four. If you calculate his
total time dilation from all that time orbiting at iss speeds,
spending roughly one thousand days in space, means you'd effectively
jump about point zero two seven seconds into the future
relative to Earth.
Speaker 1: Okay, point zero two seven seconds still not exactly whisking
us off to next century, but it's real.
Speaker 2: It's absolutely real, a measurable leap forward in time. Which
inevitably brings us crashing back to the big question, the
one everyone really wants to know about.
Speaker 1: Can we go backwards? Can I go back and you
know ace that test I failed in high school? Or
invest in Applestock in nineteen eighty?
Speaker 2: Ah, the dream going back to fixed mistakes, witness history,
or maybe just relive the good old days. That's the
holy grail of time travel, isn't it?
Speaker 1: It really is. But based on your tone, I'm guessing
the science is less optimistic.
Speaker 2: That's putting it mildly. While forward time travel is proven,
backward time travel is well, let's say, it's deep in
the territory of theoretically maybe, but practically pretty.
Speaker 1: Much impossible, pretty much impossible. Okay, why what are the roadblocks?
Speaker 2: Well, the main theoretical doorway that physicists even consider for
backward time travel involves something called a wormhole.
Speaker 1: Wormholes like in the movies shortcuts through.
Speaker 2: Space sort of. Yeah, The idea comes from general relativity.
Imagine space time, this four dimensional fabric of the universe.
Gravity bends it, right, like a heavy ball on a
rubber sheet.
Speaker 1: Okay, the trampoline analogy again.
Speaker 2: Right, A wormhole would be like punching a hole through
that sheet and connecting it to another point on the sheet,
creating a tunnel, a shortcut. It could connect two distant
places in space, or potentially two different points in time.
Speaker 1: A tunnel connecting now to say yesterday.
Speaker 2: Theoretically, yes, an Einstein rosenbridge, as they're sometimes called. You
could potentially enter one end in the present and exit
the other end in the past.
Speaker 1: Okay, sounds promising. So where are the wormholes?
Speaker 2: Ah? Well, first, we've never actually seen one. They're purely
theoretical solutions to Einstein's equations. And second, even if they
could form, there's a huge problem stability.
Speaker 1: Stability.
Speaker 2: Remember how gravity pulls things inward. It wants to crush things.
A theoretical wormhole would be incredibly unstable the moment it formed.
The intense gravity would try to collapse the tunnel instantly,
sealing it shut before anything could get through.
Speaker 1: So it slams closed before you can use it. Not
very useful, not at all.
Speaker 2: To keep it open. To make it traversible, you'd need
something to prop the tunnel walls apart, pushing outwards against
that crushing gravity.
Speaker 1: Okay, what could possibly do that? Anti gravity?
Speaker 2: You're actually remarkably close. The theoretical solution requires something called
exotic matter, specifically matter with negative mass.
Speaker 1: Negative mass. What on Earth is negative mass because that
mean it weighs less than nothing.
Speaker 2: It's weirder than that. It's hypothetical stuff that would have
negative gravitational pull. Instead of pulling things together like normal mass,
it would push them away. It would fall up in
a gravitational fiell.
Speaker 1: Okay, that's just bizarre.
Speaker 2: It violates a lot of what we understand about energy
and matter. But mathematically, if you had enough of this
negative mass, you could theoretically use its repulsive anti gravity
properties to line the inside of a wormhole.
Speaker 1: Tunnel like structural supports.
Speaker 2: Exactly like cosmic braces, holding the throat of the wormhole open,
making it stable and traversible, potentially allowing passage to another
time or place.
Speaker 1: Okay, so the billion dollar question, have we ever found
any negative mass?
Speaker 2: Not a shred. It exists purely in the equations on paper.
We have absolutely no experimental evidence that negative mass is
real or even possible. To create it might require negative
energy density, which is also highly problematic.
Speaker 1: So wormholes need negative mass, but negative mass seems like
pure fantasy.
Speaker 2: Pretty much. It's a massive, maybe insurmountable roadblock without a
way to stabilize them. Wormholes remain firmly in the realm
of mathematical curiosities, not practical time machines. It's fascinating how
the mass allows it, but reality seems to forbid it.
Speaker 1: Okay, so building the time machine the wormhole is problem
number one, and it's a huge one. But let's say,
just for argument's sake, we somehow did it. We found
negative mass, built our stable wormhole back to the past.
Are we home free?
Speaker 2: Not by a long shot. Even if you could travel back,
you immediately run into another massive headache. Time paradoxes.
Speaker 1: Ah, the paradoxes like if you change something small and
accidentally erase yourself from.
Speaker 2: Existence exactly those kinds of problems. They highlight a fundamental
issue with causality. And there's a principle in physics that
speaks to this, called the Novikov self consistency principle.
Speaker 1: Self consistency meaning the universe tries to avoid contradicting itself.
Speaker 2: That's the essence of it. The principle suggests that the
universe inherently resists or maybe even forbids events that would
create causal contradictions or inconsistencies. Basically, you can't create a
situation where affect precedes cause in a paradoxical way.
Speaker 1: So time travelers can't actually change the past in a
way that creates a paradox.
Speaker 2: According to this principle. No, the most famous example, the
one everyone knows, is the grandfather paradox.
Speaker 1: Right, go back in time stop your grandparents from meeting.
Speaker 2: So your parents are never born, so you are never born. Right,
So how did you go back in time in the
first place to stop them?
Speaker 1: Yeah, it makes my head hurt just thinking about. It's
a total contradiction.
Speaker 2: It's a complete logical impossibility. It breaks the chain of
cause and effect, and the self consistency principle basically says Nope,
can't have and the universe simply wouldn't allow that sequence
of events.
Speaker 1: So how would the universe stop you? Would the time
machine break down? Would you slip on a banana peel
at the crucial moment?
Speaker 2: That's the million dollar question. The principle doesn't specify the mechanism,
only the outcome. It suggests that somehow events would conspire
to prevent the paradox. Your gun might jam, You might
get delayed, your grandfather might have already met your grandmother
earlier that day. Somehow history remains consistent, So no.
Speaker 1: Free will to change the past. Essentially, your actions are constrained.
Speaker 2: Within this framework. Yes, your ability to alter history in
paradoxical ways seems heavily restricted, if not impossible. There are
other paradoxes too, like the bootstrap paradox.
Speaker 1: Bootstrap, what's that?
Speaker 2: Imagine you love Shakespeare? You travel back in time with
a copy of Hamlet, meet Shakespeare and give it to him.
He copies it out and claims it as his own.
Centuries later, that play is preserved, and eventually a copy
ends up in your hand, which you then take back
to Shakespeare.
Speaker 1: Wait, so who actually wrote Hamlet? In that scenario?
Speaker 2: Exactly, the play exists, but it has no origin. It
was just bootstrapped into existence by the time loop. It's
information or an object without a creation point.
Speaker 1: Okay, that's weird too. And you mentioned predestination right.
Speaker 2: The predestination paradox is where your attempt to change the
past actually becomes the cause of the event you were
trying to prevent. You go back to stop a fire,
but you accidentally knock over the lantern that starts it.
Speaker 1: So you were destined to cause it all along. Wow,
that really underminds free will.
Speaker 2: It does. These paradoxes highlight the deep problems with tampering
with causality. Now, some physicists propose ways around paradoxes, like
the Many World's interpretation.
Speaker 1: Many Worlds like parallel universes.
Speaker 2: Exactly. The idea there is, if you go back and
change something, you don't change your past. You just branch
off into a new parallel timeline, whole new universe where
things are different. Your original timeline remains until So you could.
Speaker 1: Kill your grandfather in that timeline, but it wouldn't erase
you from your original one.
Speaker 2: According to Many Worlds, Yes, but that requires believing in
an infinite number of parallel universes constantly splitting off, which
is well, another huge theoretical leap with no direct evidence.
Speaker 1: It seems like every solution just creates more questions. Is
there any theoretical model for backward time travel that just
avoids paradoxes altogether?
Speaker 2: Well, there's one more really mind bending idea, one that
suggests maybe the problem isn't paradoxes, but our very idea
of time as a straight line.
Speaker 1: Okay, what's the alternative.
Speaker 2: What if time isn't a line but a loop, an
endless loop with no starting.
Speaker 1: Point, a loop like Groundhog Day sort.
Speaker 2: Of, but woven into the fabric of space time itself.
This is the realm of closed timelike curves or CTCs.
Speaker 1: Closed timelike curves. Okay, what does that mean.
Speaker 2: It means that the geometry of space time could theoretically
allow for PABs worldlines that loop back on themselves. Your
future could literally loop around and connect back to your past.
Speaker 1: So the past and present are just blended together in
one big loop.
Speaker 2: In a sense, Yes, within a CTC, there's no changing
things because everything that happens within the loop is already
part of the loop structure. It's eternally consistent.
Speaker 1: So if I were in a CTC, I couldn't change.
Speaker 2: Anything according to the theory. No, Let's take your example
from yesterday. You woke up, brush your teeth, worked eight whatever.
If you could travel back to yesterday via a CTC,
I'd just.
Speaker 1: Do it all again exactly the same.
Speaker 2: Way, exactly the same way, even if you consciously tried
to do something different skip brushing your teeth, call and sick.
The structure of the CTC would compel events to unfold
precisely as they already did within the.
Speaker 1: Loop, so my feeling of making choices would just be
an illusion. The loop dictates everything.
Speaker 2: That's the implication. In a CTC, You're not just moving
along a path. You are the path, and so is
every moment of reality within that loop. It has to
be self consistent. Models like the godal universe or the
theoretical Tippler cylinder explore these mathematical possibilities.
Speaker 1: But are these CTCs actually possible or just maths?
Speaker 2: Like wormholes? They require extreme conditions like an infinitely long,
rapidly rotating massive cylinder, or specific cosmological models that seem
physically impossible or don't match our observed universe. But the
concept is intriguing.
Speaker 1: Why what does it tell us?
Speaker 2: It tells us that this might be the only way
the universe could allow backward time travel without breaking causality.
If time travel inherently forces you into a self consistent
loop where paradoxes cannot form because everything is predetermined within
that loop, then history is safe.
Speaker 1: So even if we built a time machine, nature would
find a way, maybe through CTCs or the self consistency
principle to stop us from making a mess.
Speaker 2: That seems to be the strong theoretical suggestion. The universe
appears to have safeguards against paradox Whether it's the impossibility
of building the machine, the Novakov principle preventing changes, or
or the inherent determinism of a CTC, consistency seems to
be paramount.
Speaker 1: It's fascinating the universe protects itself, even if it means
sacrificing our notion of absolute free will in the past.
Speaker 2: It really highlights how intertwined time, causality, and the fundamental
laws of physics are.
Speaker 1: What an incredible journey today. Seriously, we've gone from astronauts
aging fractions of a second slower.
Speaker 2: Real proven science based on relativity confirmed.
Speaker 1: By atomic clocks whizzing around the globe.
Speaker 2: The hafelkeating experiment classic proof all the.
Speaker 1: Way to the mind bending theoretical hurdles of going backward,
needing impossible things like negative mass for.
Speaker 2: Wormholes, theoretical hurdles that seem well.
Speaker 1: Pretty darn high, and confronting the universe's apparent refusal to
allow paradoxes, whether through self consistency, or these bizarre closed
pime loops where history is immutable.
Speaker 2: It really shows how the scientific reality of time is
so much weirder and frankly more interesting than most fiction.
Speaker 1: Absolutely, so we have the subtle proof even forward leaves
happening now and the backward journey locked behind immense physical
barriers in paradoxes.
Speaker 2: That's a good summary. Forward travel is physics. Backward travel
is mostly philosophy and extremely speculative physics at this point, So.
Speaker 1: What does this all mean for you listening right now?
What's the big takeaway?
Speaker 2: I think the biggest takeaway is that our everyday perception
of time, you know, that's steady TikTok. It's just our
local view. It's not the whole picture. The universe operates
on a grander, more flexible timescale, where time is relative, malleable,
intertwined with space and gravity.
Speaker 1: Our experience is just one slice of reality exactly.
Speaker 2: And when you really internalize that that forward time travel
is a certainty, even if small for now, and backward
travel seems fundamentally constrained by causality, it does make you wonder,
doesn't it wonder about what well it poses this profound question.
If the universe works so hard to prevent paradoxes to
keep the timeline consistent. Does that mean our timeline is,
in some deep sense fixed? Is the future in some
way already written or at least heavily constrained to ensure
consistency with the past.
Speaker 1: So the question of free will comes roaring back.
Speaker 2: It absolutely does. If backward steps are forbidden or only
possible in predetermined loops, does that limit our freedom? Moving
forward to are we participants writing the story or are
we actors reading lines in a script that ensures the
universe remains logical.
Speaker 1: That's a heavy thought to end on fixed timeline versus
free will.
Speaker 2: It's one of the deepest questions prompted by these explorations
into the notture of time. There's no easy answer, but
thinking about it really stretches your understanding of reality itself.
It's why exploring these frontiers of physics is so vital.
It pushes us to question.
Speaker 1: Everything, keep asking questions, keep exploring. A perfect place to
leave it. Thank you so much for this incredible deep dive.
Speaker 2: My pleasure. It's always fascinating to talk about time