Speaker 1: Welcome to Bedtime Astronomy. Explore the wonders of the cosmos
Speaker 1: with our soothing Bedtime Astronomie podcast. Each episode offers a
Speaker 1: gentle journey through the stars, planets, and beyond, perfect for
Speaker 1: unwinding after a long day. Let's travel through the mysteries
Speaker 1: of the universe as you drift off into a peaceful
Speaker 1: slumber under the night sky.
Speaker 2: Imagine uh, stepping outside tonight, I assumeing it's a clear
Speaker 2: night wherever you happen.
Speaker 3: To be listening to this right, hopefully no clouds.
Speaker 2: Yeah, exactly, and you look up at the sky, you
Speaker 2: look past the street lights, past the airplanes, and you
Speaker 2: try to spot Elpha Centauri.
Speaker 3: Which is our nearest stellar neighbor.
Speaker 2: Right the closest star system to our own solar system.
Speaker 2: It just sits there in the darkness, glowing faintly. And
Speaker 2: because we call it the closest, it feels like it
Speaker 2: is just, you know, right next door in the grand
Speaker 2: cosmic scheme of things.
Speaker 3: It does feel that way.
Speaker 2: Yeah, But distance in space is just it's a really
Speaker 2: tricky concept to wrap your mind around because if you
Speaker 2: were to actually try to travel there right now, using
Speaker 2: the absolute pinnacle of our current rocket propulsion technology, the.
Speaker 3: Very best engines we've ever built.
Speaker 2: Exactly, you would be embarking on a journey that would
Speaker 2: take tens, if not hundreds of thousands of years.
Speaker 3: Hundreds of thousands, I mean, it is a timeline that
Speaker 3: completely defies human comprehension. Just to put that into perspective,
Speaker 3: human civilization as we know it, like recorded history, agriculture, cities,
Speaker 3: that's only about ten thousand years old.
Speaker 2: Yeah, yeah, so one hundred thousand years is.
Speaker 3: It's essentially forever. So a journey of one hundred thousand
Speaker 3: years means you aren't just sending a crew of astronauts,
Speaker 3: you are sending an entire civilization.
Speaker 2: A whole society in a can.
Speaker 3: Exactly, you would be launching a generationship where the people
Speaker 3: who actually arrive at Alpha centaury wouldn't even remember Earth.
Speaker 3: They would have to survive, evolve, and basically sustain themselves
Speaker 3: for countless generations in the void just to reach the closest.
Speaker 2: Star, which frankly makes interstellar travels seem practically impossible.
Speaker 3: It really does.
Speaker 2: It feels like this hard boundary drawn by the laws
Speaker 2: of physics. But today we're going to explore how that
Speaker 2: timeline is currently being challenged in a way that honestly
Speaker 2: sounds like pure science fiction.
Speaker 3: It really does sound like sci fi, but it's happening
Speaker 3: right now.
Speaker 2: Right because what if that mind boggling multimillennial journey could
Speaker 2: be compressed down to roughly twenty years.
Speaker 3: Twenty years a single human generation.
Speaker 2: Right, a single generation. A spacecraft launch today could actually
Speaker 2: be intercepted by the people who built it. We are
Speaker 2: talking about fundamentally escaping the limitations of traditional fuel heavy
Speaker 2: rocketry and entering an era where we propel objects through
Speaker 2: the vacuum of space using literally nothing but light.
Speaker 3: And that is the paradigm shift we are witnessing right now.
Speaker 3: We are basically moving away from the brute force of
Speaker 3: chemical explosions.
Speaker 2: Which is really all the traditional rocket is.
Speaker 3: Oh yeah, exactly, a highly controlled explosion, and we're stepping
Speaker 3: into this entirely new realm of optical propulsion and microscopic levitation.
Speaker 3: It's a shift from fire to photons.
Speaker 2: I want to frame this properly because the timing of
Speaker 2: this shift is just incredible to watch unfold. I mean,
Speaker 2: just recently, the world has been celebrating some absolutely massive
Speaker 2: milestones in the traditional space flat arena.
Speaker 3: Oh, absolutely huge achievements.
Speaker 2: Right, Like, we watched the Artemis the Second Mission preparations
Speaker 2: getting ready to send humans back around the Moon, and
Speaker 2: we saw Blue Origin making headlines by reusing the new
Speaker 2: Glenn booster. Down Florida. We are watching these colossal, towering
Speaker 2: metal skyscapers filled to the brim with volatile, highly explosive chemicals,
Speaker 2: roaring into the sky on pillars of fire. It is
Speaker 2: on spiring, it shakes the ground. It's an event. But
Speaker 2: at the exact same time, a quiet, almost totally invisible
Speaker 2: revolution is happening in a laboratory at Texas A and
Speaker 2: M University Texas A and M. Right scientists, there are
Speaker 2: literally level vitating and steering microscopic devices using lasers, using
Speaker 2: just light right, they call the metajets, and the underlying
Speaker 2: physics of these tiny metajets could ultimately render those massive
Speaker 2: chemical rockets completely obsolete for deep space exploration.
Speaker 3: The contrast there is just brilliant. I mean, you have
Speaker 3: the deafening roar and the massive thermal exhaust of the
Speaker 3: new Glenn booster on one side, yeah, pure power, and
Speaker 3: on the other you have complete silence and the invisible
Speaker 3: push of a laser beam in a pristine clean room.
Speaker 2: It's wild.
Speaker 3: The work coming out of the J. Mike Walker sixty six,
Speaker 3: Department of Mechanical Engineering at Texas A and M is
Speaker 3: fundamentally redefining how we even think about motion, momentum, and
Speaker 3: travel in space.
Speaker 2: So who is leading this?
Speaker 3: So there's doctor Schuffing Lawn. He's an assistant professor there
Speaker 3: and the director of the Lab for Advanced Nanophotonics. He
Speaker 3: recently published a groundbreaking study with his team in the
Speaker 3: journal Newton.
Speaker 2: The Journal Newton.
Speaker 3: Oukay right, And the paper is titled Optical Propulsion and
Speaker 3: Levitation of metajets, and it out lines exactly how they're
Speaker 3: achieving this controlled three dimensional motion using only laser light.
Speaker 2: Okay, before we get into the microscopic engineering of an
Speaker 2: actual metajet, I think we really need to establish why
Speaker 2: this research is so.
Speaker 3: Absolutely necessary, why we need it at all?
Speaker 2: Right, Like, why are we looking to completely abandon the
Speaker 2: chemical rocket technology that took us to the moon and
Speaker 2: it is taking this to Mars.
Speaker 3: It's a fair question.
Speaker 2: If you're listening to this on your commute right now,
Speaker 2: think about the engine in your car. It runs because
Speaker 2: you carry a heavy tank of gas with you. As
Speaker 2: you drive, you burn the gas and your car gets
Speaker 2: slightly lighter. But rockets take that concept to a pretty
Speaker 2: punishing extreme, don't they.
Speaker 3: They really do, and it is honestly a trap. Traditional
Speaker 3: rocketry is bound by this mathematical paradox known as the
Speaker 3: Siolkovsky rocket equation.
Speaker 2: The Silkowsky rocket area.
Speaker 3: Yes, in aerospace circles they often just refer to it
Speaker 3: as the tyranny of the rocket equation.
Speaker 2: The tyranny that sounds dramatic, well.
Speaker 3: It dictates a very harsh reality. It says that if
Speaker 3: you want to move a payload through space, you need fuel.
Speaker 3: But fuel has mass. It is heavy, right, So to
Speaker 3: push your payload and your heavy fuel, you need even
Speaker 3: more fuel.
Speaker 2: Oh, I see where this is going.
Speaker 3: And then you need more fuel to push that extra fuel.
Speaker 2: It's like, okay, it's like trying to plan a cross
Speaker 2: country road trip where there are absolutely no gas stations,
Speaker 2: so you have to bring all the gas for the
Speaker 2: whole trip in your trunk.
Speaker 3: That's a great way to think about it.
Speaker 2: But the weight of all that gas means your car
Speaker 2: gets terrible mileage, so you have to tow a trailer
Speaker 2: full of more gas which lowers your mileage even further. Exactly,
Speaker 2: you end up in this incredibly punishing cycle. You build
Speaker 2: a massive vehicle where ninety nine percent of the weight
Speaker 2: is just the explosive liquid required to get the remaining
Speaker 2: one percent, like the actual payload or the astronauts to
Speaker 2: where they need to go.
Speaker 3: That is a perfect way to visualize it, and that equation,
Speaker 3: as brutal as it is, works fine.
Speaker 2: For our local neighborhood, right going to the moon or whatever.
Speaker 3: Yeah, we can use it to get to Earth, orbit,
Speaker 3: can use it to get to the moon. We can
Speaker 3: even use it to send rovers to Mars, provided we
Speaker 3: are a patient and willing to wait months for them
Speaker 3: to arrive. Sure, but the moment you want to go
Speaker 3: incredibly fast, say a significant fraction of the speed of light,
Speaker 3: which is roughly one hundred and eighty six thousand miles
Speaker 3: per second, the math completely breaks.
Speaker 2: Down because the fuel gets too heavy.
Speaker 3: Exactly, to reach Alpha Centauri in twenty years, you need
Speaker 3: to travel at about twenty percent the speed of light.
Speaker 3: The amount of chemical fuel you would need to accelerate
Speaker 3: a traditional spacecraft to that speed is physically impossible.
Speaker 2: Like impossible, impossible.
Speaker 3: Yeah, possible, impossible. There isn't enough chemical energy in the
Speaker 3: known universe to make that equation balance out. The ship
Speaker 3: would be too massive to ever even move.
Speaker 2: Wow. Okay, so light powered propulsion completely sidesteps this tyranny.
Speaker 3: It completely ignores it.
Speaker 2: Yes, why doing what? Just leaving the gas station behind.
Speaker 3: In a manner of speaking, Yes, by leaving the power
Speaker 3: source behind.
Speaker 2: Okay, unpack that for me.
Speaker 3: Well, if you're an engine is a massive laser array
Speaker 3: sitting on Earth or maybe sitting in orbit around the Earth,
Speaker 3: your spacecraft doesn't have to carry a single drop of
Speaker 3: fuel to power its journey.
Speaker 2: Oh I see.
Speaker 3: It doesn't carry the engine, and it doesn't carry the propellant.
Speaker 3: It is just a payload and a sail riding the beam.
Speaker 2: I just love the elegance of leaving the heavy machinery
Speaker 2: at home. It totally solves the math problem.
Speaker 3: It really does.
Speaker 2: But I have to admit I struggle with the actual
Speaker 2: physical mechanics of this.
Speaker 3: That's fair. It's very counterintuitive.
Speaker 2: Because if I shine a really bright, high powered flashlight
Speaker 2: at a piece of paper sitting on my desk, the
Speaker 2: paper doesn't.
Speaker 3: Move, No, it doesn't.
Speaker 2: It might get warm if the flashlight is bright enough,
Speaker 2: but it doesn't like slide across the wood. How on
Speaker 2: Earth does light which is just photons? Right? And photons
Speaker 2: have zero rest mass? Correct, How does something with no
Speaker 2: mass actually push a physical object?
Speaker 3: It is highly counterintuitive because we don't experience the physical
Speaker 3: force of light in our daily macroscopic lives. Right, we
Speaker 3: don't feel We feel the heat of the sun absolutely,
Speaker 3: but we don't feel it pushing us down into the sidewalk.
Speaker 3: But to understand this, we have to look at the
Speaker 3: dual nature.
Speaker 2: Of light, a wave particle duality.
Speaker 3: Exactly, light is both a wave and a particle. The
Speaker 3: particles photons don't have mass in the traditional sense of
Speaker 3: a rock or a bowling ball, but according to the
Speaker 3: laws of quantum mechanics and relativity, they do possess momentum.
Speaker 2: Wait. Wait, if momentum is mass times velocity and a
Speaker 2: photon has zero mass, how does it have momentum?
Speaker 3: That is the exact question physicists wrestled with over a
Speaker 3: century ago.
Speaker 2: Okay, good, so it's not just me.
Speaker 3: No, not at all. The answer comes from James Clerk
Speaker 3: Maxwell and later Albert Einstein. While a photon has no
Speaker 3: rest mass, it has energy okay, and Einstein's extended equations
Speaker 3: show that energy and momentum are intrinsically linked. So even
Speaker 3: without mass, a photon carries a tiny discrete packet of momentum.
Speaker 2: A packet of momentum.
Speaker 3: Yeah, doctor Lan uses a very helpful tangible analogy in
Speaker 3: the research to explain and how this momentum actually transfers
Speaker 3: to an object. Imagine you are throwing ping pong balls
Speaker 3: at a surface.
Speaker 2: Okay, I am picturing throwing a bucket of ping pong
Speaker 2: balls at like a wooden board hanging from a string.
Speaker 3: Right exactly now, Even though a ping pong ball is
Speaker 3: very light, when it strikes the board and bounces off,
Speaker 3: it transfers a tiny bit of its forward momentum to
Speaker 3: the board before it redouns oh, I see, it physically
Speaker 3: pushes the board, making it swing slightly. Now, just scale
Speaker 3: that down. When a photon strikes an object and reflects
Speaker 3: off of it, it transfers its tiny packet of momentum
Speaker 3: to the object.
Speaker 2: So the light from a laser is essentially a continuous,
Speaker 2: highly focused brage of trillions upon trillions of microscopic pingkong
Speaker 2: balls bouncing off the surface of the spacecraft.
Speaker 3: That is the exact mechanism. It is an incredibly tiny
Speaker 3: microscopic force, which is why your flashlight doesn't move the
Speaker 3: paper on your.
Speaker 2: Desk right, because it's friction.
Speaker 3: Exactly. Yeah, the push of those photons from your flashlight
Speaker 3: is completely overwhelmed by the gravity of the Earth pulling
Speaker 3: the paper down, by the friction of the wood holding
Speaker 3: it in place, and even by the air pressure in
Speaker 3: the room pushing against it from all sides.
Speaker 2: But if you remove that friction, Yes, if you place
Speaker 2: an object in the vacuum of space, where there is
Speaker 2: absolutely no air resistance, no friction, and eventually no significant
Speaker 2: gravitational pull, that microscopic force becomes cumulative.
Speaker 3: Cumulative exactly because in.
Speaker 2: A vacuum, an object in motion stays in motion. So
Speaker 2: every single photon that bounces off at a tiny fractional
Speaker 2: bit of.
Speaker 3: Speed a tiny push.
Speaker 2: And because there is no drag, it never slows down.
Speaker 2: Over days, weeks, and years of continuous laser illumination, that continuous,
Speaker 2: gentle push accelerates the object to unbelievable speeds.
Speaker 3: Exactly, it's continuous acceleration. A chemical rocket burns all its
Speaker 3: fuel in a few minutes, giving the ship one massive
Speaker 3: shove and then it coasts for the rest of the journey.
Speaker 2: It's basically coasting on that one explosion.
Speaker 3: Right, A laser driven sail gets pushed constantly, second after second,
Speaker 3: year after year.
Speaker 2: Okay, that definitely helps clarify the physics of the push.
Speaker 2: The vacuum of space allows that tiny cumulative force to
Speaker 2: just keep building.
Speaker 3: Yes, it's all about the vacuum.
Speaker 2: But that brings up an entirely new, incredibly complex problem
Speaker 2: in my mind.
Speaker 3: Oh I bet, what's that.
Speaker 2: Well. Understanding that light can push an object is one thing,
Speaker 2: but how do you keep it from just tumbling wildly
Speaker 2: out of control?
Speaker 3: The stability issue, right, Because, to.
Speaker 2: Use another analogy, if I take a fire hose which
Speaker 2: is shooting a very powerful stream of water, and I
Speaker 2: blast a piece of cardboard with it, the cardboard doesn't
Speaker 2: fly perfectly straight away from.
Speaker 3: Me, No, it definitely wouldn't.
Speaker 2: The water hits it, the cardboard tilts slightly, the water
Speaker 2: catches an edge, and suddenly the cardboard is flipping and
Speaker 2: spinning and getting blasted off to the side, completely out
Speaker 2: of the stream.
Speaker 3: It just flies out of control exactly.
Speaker 2: And a laser beam is narrow If the spacecraft tilts
Speaker 2: even a fraction of a degree, Won't it just slide
Speaker 2: right off the beam and get lost in the dark.
Speaker 3: That is the million dollar question.
Speaker 2: So how are the sign scientists at Texas A and
Speaker 2: M actually controlling this motion?
Speaker 3: That exact question is what makes this research so revolutionary.
Speaker 3: The stability problem you just described is one of the
Speaker 3: biggest hurdles in all of optical propulsion. Okay, the answer
Speaker 3: to how they solve it lies in the specific materials
Speaker 3: these metajets are made of. They aren't just using flat,
Speaker 3: shiny mirrors. They are composed of what are called metasurfaces.
Speaker 2: Metasurfaces. Okay, we definitely need to break that down. What
Speaker 2: exactly are we looking at here? If I were holding
Speaker 2: a metajet in my hand, what would it look like?
Speaker 3: Well, honestly, you wouldn't be able to see it in
Speaker 3: your hand. Wait, really, really, to understand a metajet, you
Speaker 3: first have to understand the scale. We are talking about
Speaker 3: devices that are only tens of microns in size.
Speaker 2: Tens of microns. Just to give a listeners some real
Speaker 2: world context for that, a single human red blood cell
Speaker 2: is about eight microns across, right. A single human hair
Speaker 2: is roughly seventy to one hundred microns thick. So these
Speaker 2: entirely engineered functional devices are literally smaller than the width
Speaker 2: of a hair.
Speaker 3: They are truly microscopic. They are manufactured in specialized clean
Speaker 3: rooms like the aggifab Nanofabrication facility.
Speaker 2: At Texas A and m okay what goes on in there?
Speaker 3: They use advanced lithography techniques. These are environments where even
Speaker 3: a single speck of dust is a massive boulder that
Speaker 3: could ruin the entire device.
Speaker 2: Oh wow, so it has to be perfectly clean exactly.
Speaker 3: The researchers wear full protective bunny suits, working under special
Speaker 3: yellow lights to avoid exposing the photosensitive chemicals used in
Speaker 3: the manufacturing process.
Speaker 2: That is intense. And what are they actually manufacturing at
Speaker 2: that tiny scale? Like? What makes it a metasurface and
Speaker 2: not just a tiny piece of oil?
Speaker 3: So a metasurface is an ultra thin material that has
Speaker 3: been engineered with incredibly tiny, complex geometric patterns on its
Speaker 3: surface patterns. Yes, imagine a landscape of microscopic pillars, ridges, antennas,
Speaker 3: and valleys, all spaced apart at distances smaller than the
Speaker 3: wavelength of light.
Speaker 2: Itself, wait smaller than the wavelength of light.
Speaker 3: Yes, incredibly small when these patterns are explicitly designed to
Speaker 3: interact with electromagnetic waves, in this case, the incoming laser
Speaker 3: light in highly specific ways.
Speaker 2: So it's not just bouncing the light back like a
Speaker 2: dumb mirror. The physical shape of the material is doing
Speaker 2: something complex to the light. Yes.
Speaker 3: When we talk about manipulating light, we usually talk about
Speaker 3: manipulating its phase, its amplitude, and its polarization.
Speaker 2: Okay, let's pause unpack those terms for those of us
Speaker 2: who aren't optical physicists. Sure, when you say the metasurface
Speaker 2: changes the phase of the light, what does that actually
Speaker 2: mean in practice? Or we're talking about shifting the wave itself.
Speaker 3: Yeah, so think of light as an ocean wave. It
Speaker 3: has peaks and valleys. The phase refers to where you
Speaker 3: are in that wave cycle. Are you at the crest
Speaker 3: or are you in the trough?
Speaker 2: Okay, that makes sense.
Speaker 3: By engineering these microscopic pillars of varying heights and widths
Speaker 3: on the metasurface, you can actually slow down certain parts
Speaker 3: of the incoming LightWave just a tiny fraction of a
Speaker 3: second more than others. Oh, this shifts the peaks and valleys,
Speaker 3: altering the phase okay.
Speaker 2: And amplitude and polarization.
Speaker 3: So amplitude is essentially the intensity or the height of
Speaker 3: the wave, basically how bright it is right, and polarization
Speaker 3: refers to the orientation of the wave's oscillation. Is it
Speaker 3: waving up and down or left and right or maybe
Speaker 3: in a spire?
Speaker 2: Oh, like polarized sunglass is blocking certain ways exactly.
Speaker 3: A metasurface can change all of these properties simultaneously. Upon reflection,
Speaker 3: think about how a traditional glass magnifying lens works. Okay,
Speaker 3: it relies on the physical curvature and the thickness of
Speaker 3: the glass to bend and focus the light passing through it.
Speaker 2: Right, the glass itself bends it right.
Speaker 3: A metasurface does the exact same thing. It shapes, bends, focuses,
Speaker 3: and steers the light, but it does it on a
Speaker 3: vastly smaller, thinner, and perfectly flat.
Speaker 2: Scale without the curved glass.
Speaker 3: Exactly. It uses those nanoscale geometric patterns to manipulate the light.
Speaker 2: The level of nanoscale fabrication required to build something like
Speaker 2: that is just mind bending.
Speaker 3: It is an engineering marvel.
Speaker 2: It's almost like building a macroscopic p ball machine, or
Speaker 2: like a pachinko board where you carefully place all the
Speaker 2: bumpers and pegs so that when a ball or in
Speaker 2: this case, a photon drops in, you know exactly which
Speaker 2: direction it's going to bounce out.
Speaker 3: That is a highly accurate way to visualize it. You
Speaker 3: are engineering the microscopic bumpers to dictate the bounce.
Speaker 2: I love that.
Speaker 3: And here is the crucial distinction that really stood out
Speaker 3: about the Texas A and M approach. Historically, when people
Speaker 3: talked about moving things with lasers, the prevailing idea was
Speaker 3: that you had to perfectly shape and aim a highly
Speaker 3: complex adaptive laser beam to keep the object balanced right
Speaker 3: to stop.
Speaker 2: It from sliding off like my cardboard example.
Speaker 3: Huh exactly. The idea was if the object started to tilt,
Speaker 3: the laser beam on Earth would have to instantly detect
Speaker 3: that tilt and change its own shape to correct it.
Speaker 3: You had to do all the complicated work at the
Speaker 3: light source.
Speaker 2: Which sounds like a nightmare. If your spacecraft is a
Speaker 2: light year away, it would be impossible, right because the
Speaker 2: signal delay would be a year. If it tilts, you
Speaker 2: won't know for a year, and your correction won't reach
Speaker 2: it for another year. By then the ship is totally gone.
Speaker 3: Exactly the problem. But doctor Land's team flipped that entire
Speaker 3: paradigm on its head. Instead of trying to dynamically control
Speaker 3: the laser beam from afar, they built the control mechanism
Speaker 3: directly into the material itself.
Speaker 2: Oh wow, so the smarts are in the sail not
Speaker 2: the wind.
Speaker 3: Yes, yes, beautifully said. By carefully designing the shape, the orientation,
Speaker 3: and the placement of every single nanoscale feature on that metasurface,
Speaker 3: the scientists are dictating exactly how the light will bounce off,
Speaker 3: regardless of minor fluctuations in the beam.
Speaker 2: So if the laser hits a specific pattern of microscopic
Speaker 2: pillars on the left side of the metajet, the light
Speaker 2: is purposely deflected at a specific angle, say down into
Speaker 2: the left right. And because of Isaac Newton's third law,
Speaker 2: every action has an equal and opposite reaction or the
Speaker 2: conservation of momentum. If the metasurface shoots the light down
Speaker 2: and left, the metajet itself gets pushed up into the right.
Speaker 3: That is the fundamental mechanism. The material basically acts as
Speaker 3: its own steering mechanism. That is wild, It tells the
Speaker 3: light how to push it. By altering the pattern across
Speaker 3: the surface, they can create restorative forces.
Speaker 2: Restorative forces.
Speaker 3: Yeah, so if the sail starts to drift to the
Speaker 3: edge of the beam, the engineered pattern on that edge
Speaker 3: interacts with the light in a way that automatically pushes
Speaker 3: it back into the center.
Speaker 2: Oh so it is totally self stabilizing exactly. Well, if
Speaker 2: the material is doing all the steering automatically, what does
Speaker 2: that actually look like in practice? How much control do
Speaker 2: they really have over a device that is smaller than
Speaker 2: a red blood cell.
Speaker 3: This leads us to the major first that doctor Land's
Speaker 3: team achieved and published in the journal Newton. They demonstrated
Speaker 3: full three dimensional maneuverability of these metajets using only a
Speaker 3: single laser source.
Speaker 2: Three dimensional. Okay, that is a massive leap because when
Speaker 2: I usually think of optical propulsion, I think of the
Speaker 2: concept of solar sales. We've seen these tested in space,
Speaker 2: like the Japanese Icoros mission. Right, the iker and a
Speaker 2: solar sail is essentially a one dimensional pusher. The sunlight
Speaker 2: hits the giant flat foil square and the sail just
Speaker 2: gets blown forward away from the sun. It's like a
Speaker 2: leaf blowing straight in the wind.
Speaker 3: Yeah. Simple. One D pushing is relatively straightforward. You just
Speaker 3: need a reflective surface. But levitating an object with a
Speaker 3: laser and then intentionally steering it left, right, up and
Speaker 3: down purely by controlling how the light interacts with the metasurface,
Speaker 3: that is a whole different level of complexity.
Speaker 2: I can't even imagine.
Speaker 3: To the team's knowledge, this is the very first time
Speaker 3: full three D maneuvering has been demonstrated using this specific
Speaker 3: type of optical propulsion approach. They aren't just pushing the
Speaker 3: meta jet, they are actively flying it.
Speaker 2: Okay, I have to jump in here with a serious
Speaker 2: mechanical question. Please do, because I'm really struggling with a
Speaker 2: three D aspect, specifically the vertical movement.
Speaker 3: Ah, the up and down right.
Speaker 2: If the sail is just a flat surface and a
Speaker 2: laser is hitting it from directly below, pushing up against gravity,
Speaker 2: I get how it goes up you turn it, the
Speaker 2: laser power rises, sure, but how does it go down
Speaker 2: against the pressure of the laser. How do you pull
Speaker 2: something toward the light source using the light itself.
Speaker 3: It is a phenomenal question, and it relies on incredibly
Speaker 3: subtle optical forces. Okay, When light interacts with these nanoscale structures,
Speaker 3: it doesn't just create a simple scattering force, which is
Speaker 3: the forward push we talked about with the Pingkong balls.
Speaker 3: It also creates what are called gradient forces.
Speaker 2: Gradient forces, Okay, explain that.
Speaker 3: Think of a laser beam. It is brightest in the
Speaker 3: very center, and the intensity fades as you move toward
Speaker 3: the edges of the beam, like.
Speaker 2: A flashlight being fading at the edges.
Speaker 3: Exactly, that change in brightness is a gradient. When you
Speaker 3: engineer the metasurface correctly, the electromagnetic fields of the light
Speaker 3: interact with the material in a way that actually pulls
Speaker 3: the object toward the area of highest light intensity.
Speaker 2: We pulls it.
Speaker 3: Yes, In certain configurations, the researchers can manipulate these gradient
Speaker 3: forces to counteract the scattering force, essentially create a an
Speaker 3: optical trap, an optical track. Yeah. So, by subtly tuning
Speaker 3: the polarization or the alignment of the laser, they can
Speaker 3: alter the balance between the forward push and the gradient pull,
Speaker 3: allowing the metajet to move downward closer to the source
Speaker 3: without actually turning the laser off.
Speaker 2: That is staggering. They are using the internal structure of
Speaker 2: the light beam itself as a physical track to slide
Speaker 2: up and down off exactly. It's brilliant. But that brings
Speaker 2: me to my next bit of skepticism regarding how they
Speaker 2: actually prove.
Speaker 3: This skepticism is good. Let's hear it.
Speaker 2: If these metajets are smaller than a human hair and
Speaker 2: they are being manipulated by the incredibly delicate, invisible force
Speaker 2: of bouncing photons and gradient fields, wouldn't an experiment like
Speaker 2: that be completely impossible to run on Earth?
Speaker 3: You'd think so, wouldn't you right?
Speaker 2: Because I feel like even a slight draft from the
Speaker 2: HVAC system and the laboratory, or just the ambient gravity
Speaker 2: of the planet pulling down one hundred times stronger than
Speaker 2: the light is pushing up, would instantly ruin the experiment.
Speaker 2: Oh for sure, the meta would just fall to the
Speaker 2: floor or get blown across the room. Yeah, how do
Speaker 2: you prove this works when you are stuck at the
Speaker 2: bottom of Earth's gravity?
Speaker 3: Well, you are touching on one of the most difficult
Speaker 3: aspects of experimental design in this entire field. You are
Speaker 3: completely right. The force generated by the laser is microscopic,
Speaker 3: and Earth's gravity is relentless. If they just place the
Speaker 3: metajet on a dry glass slide and shine a laser
Speaker 3: on it, it wouldn't levitate.
Speaker 2: It would just sit there exactly.
Speaker 3: Gravity and static friction would hold it down firmly. The
Speaker 3: researchers at Texas A and M had to come up
Speaker 3: with a very clever workaround to isolate these tiny optical forces.
Speaker 3: They conducted these experiments in a fluid environment.
Speaker 2: A fluid environment, so they submerged the metajets in a liquid.
Speaker 3: What kind of liquid they typically use? Dnized water or
Speaker 3: specific optical oils.
Speaker 2: Okay, why liquid.
Speaker 3: By placing the metajets in a fluid, they utilize the
Speaker 3: physical principle of buoyancy. The upward buoyant force of the fluid,
Speaker 3: which is determined by the density of the liquid compared
Speaker 3: to the density of the metajet, helped to counterbalance the
Speaker 3: downward pull of gravity.
Speaker 2: Oh.
Speaker 3: It essentially created a pseudo weightless environment.
Speaker 2: Oh, that is a brilliant workaround. It's like astronauts training
Speaker 2: in the neutral Buoyancy laboratory that giant swimming pool down
Speaker 2: in Houston to simulate spacewalks. Yes, the water makes them
Speaker 2: neutrally buoyant so they don't sink or float, allowing them
Speaker 2: to practice moving massive pieces of equipment using very little force.
Speaker 3: It is the exact same concept, just scaled down to
Speaker 3: the microscopic level. By neutralizing gravity with buoyancy, they created
Speaker 3: an environment where those incredibly delicate light induced forces were
Speaker 3: no longer overwhelmed.
Speaker 2: So they could actually see what they were doing exactly.
Speaker 3: They could shine the laser watch the metajet respond to
Speaker 3: the momentum transfer and the gradient forces and accurately observe
Speaker 3: and measure its three dimensional motion under a microscope.
Speaker 2: But wait, if they're operating in a fluid, doesn't that
Speaker 2: introduce a whole new set of problems.
Speaker 3: It absolutely does, because.
Speaker 2: Water might make it. But to an object that is
Speaker 2: ten microns wide, water isn't just water at that microscopic scale.
Speaker 2: Doesn't water behave more like thick syrup?
Speaker 3: You are referring to life at a low Reynolds number
Speaker 3: Renold's number. Yeah, it's a fluid dynamics concept. Basically, Yes.
Speaker 3: At the microscale, viscous forces absolutely dominate inertial forces. To
Speaker 3: a metajet, moving through water is like a human trying
Speaker 3: to swim through a pool of cold honey.
Speaker 2: Oh wow, that sounds awful.
Speaker 3: It creates immense drag, and on top of that you
Speaker 3: have Brownian motion.
Speaker 2: Remind me what Brownian motion is.
Speaker 3: It's the constant random bombardment of the metajet by the
Speaker 3: vibrating water molecules themselves, which creates this jittery random movement.
Speaker 2: Oh so the water is actively hitting it constantly. So
Speaker 2: they had to prove their laser steering work despite the
Speaker 2: metajet being constantly battered by water molecules and fighting through microscopic.
Speaker 3: Molasses, which makes the fact that they achieved controlled three
Speaker 3: D maneuverability even more impressive. Ye, the optical forces generated
Speaker 3: by the metasurface were strong enough and precise enough to
Speaker 3: overcome both the viscosity of the fluid and the chaos
Speaker 3: of Brownian motion.
Speaker 2: The fluid bath proves the concept and it proves that
Speaker 2: the metasurface design works right. The material is successfully steering
Speaker 2: the light to create precise three D movement against heavy resistance.
Speaker 2: But a fluid bath in a Texas laboratory is definitely
Speaker 2: not the vacuum of interstellar space.
Speaker 3: No, it is not.
Speaker 2: If you're trying to prove a frictionless interstellar drive. Testing
Speaker 2: it in microscopic molasses is a bit of a paradox,
Speaker 2: isn't it a bit?
Speaker 3: Yes?
Speaker 2: How are they planning to get these things into a
Speaker 2: true vacuum to see their actual top speed and behavior.
Speaker 3: The fluid environment was an absolutely necessary stepping stone for
Speaker 3: the initial proof of concept, but as you pointed out,
Speaker 3: fluid brings drag. It creates friction that the metajet has
Speaker 3: to constantly fight against. To unleash the true efficiency and
Speaker 3: the staggering speed potential of light driven propulsion, you really
Speaker 3: have to get out of the fluid and into a
Speaker 3: vacuum where there is no gravity, no buoyancy required, and
Speaker 3: no drag out in space exactly, which brings us to
Speaker 3: the next massive hurdle for doctor Land's team. They are
Speaker 3: currently pursuing external funding to take these metajets and test
Speaker 3: them in actual microgravity environments.
Speaker 2: We are talking about getting these microscopic devices off the
Speaker 2: planet entirely.
Speaker 3: Yes, The goal is to test them on platforms like
Speaker 3: the International Space Station or perhaps utilizing parabolic flights.
Speaker 2: Parabolic flights those are the airplanes often called the vomit
Speaker 2: comet right, the ones that fly in steep.
Speaker 3: Parabolic arcs, yes, exactly those.
Speaker 2: They climb sharply and then die, creating brief periods of
Speaker 2: weightlessness about twenty to thirty seconds inside the cabin before
Speaker 2: they have to pull up again.
Speaker 3: Correct In those true microgravity environments, whether for thirty seconds
Speaker 3: on a plane or maybe months on the iss, the
Speaker 3: pure physics of the optical propulsion can be isolated and
Speaker 3: studied without the interference of buoyancy or fluid dynamics.
Speaker 2: That makes sense.
Speaker 3: They can place the meta jet in a vacuum chamber
Speaker 3: in microgravity, hit it with the laser, and finally see
Speaker 3: how it behaves when the only forces acting upon it
Speaker 3: are the photons.
Speaker 2: And it is worth noting that Texas A and M
Speaker 2: isn't operating in a vacuum here pardon the pun, nice one.
Speaker 2: There is a massive global race happening right now to
Speaker 2: crack the code on light power propulsion. This isn't just
Speaker 2: one lab's pet project, not at all. The scientific community
Speaker 2: worldwide sees the writing on the wall regarding the limits
Speaker 2: of chemical rockets. We know that there are research groups
Speaker 2: all over Europe working on related optical concepts.
Speaker 3: Oh absolutely.
Speaker 2: And here in the US you have brilliant minds at
Speaker 2: the California Institute of Technology focusing heavily on propulsion stability.
Speaker 3: Coltext work is fascinating. They are deeply focused on that
Speaker 3: writing the beam problem we discussed earlier.
Speaker 2: So the slipping off the beam issue, right, if.
Speaker 3: You are pushing a macroscopic spacecraft with a laser, it
Speaker 3: is inherently unscable. It's like trying to balance a bowling
Speaker 3: ball on the tip of a pencil, or maybe a
Speaker 3: marble on a beach ball.
Speaker 2: Right, the slightest deviation and it slides off exactly.
Speaker 3: Caltic is working on theoretical nanoscale structures that inherently self correct,
Speaker 3: much like what anm is demonstrating.
Speaker 2: Practically, you also have the Rochester Institute of Technology tackling
Speaker 2: the problem using diffractive grading platforms. What does that mean?
Speaker 2: Diffractive gradings?
Speaker 3: So, a diffractive grading is an optical component with a
Speaker 3: periodic structure that splits and diffracts light into several beams
Speaker 3: traveling in different directions.
Speaker 2: Wait, give me a visual.
Speaker 3: Think of the back of a CD or a DVD.
Speaker 2: Oh yeah, and how it reflects a rainbow of colors.
Speaker 3: Yes, that's a simple diffraction grading. Rochester is exploring how
Speaker 3: those specific types of structures can be used to generate
Speaker 3: and control propulsive forces somewhat parallel to the metasurface approach.
Speaker 3: It is a full court press from the scientific community.
Speaker 2: With all these heavy hitters, Celtech, Rochester, European space agencies.
Speaker 2: What makes texas A and M's specific contribution so vital
Speaker 2: in this global race, what sets the Newton paper apart,
Speaker 2: What makes.
Speaker 3: Doctor Land's work so foundational is that they aren't just
Speaker 3: building a one off device that happens to work through.
Speaker 2: Trial and error, right, They aren't just guessing.
Speaker 3: No, they are advancing the entire field by developing a
Speaker 3: broader mathematical and physical framework. They are establishing the fundamental
Speaker 3: physics principles that universally describe exactly how light generates force
Speaker 3: across these engineered surfaces.
Speaker 2: Oh I see, So they are writing the foundational rule
Speaker 2: book exactly. They are establishing the core math and the
Speaker 2: governing equations that everyone else, whether you're ed, Caltech or Rochester,
Speaker 2: can use to build and optimize their own devices.
Speaker 3: Precisely, they are providing the underlying grammar for this new
Speaker 3: language of optical mechanics. And if those fundamental physics hold
Speaker 3: true as they move from the fluid bath into microgravity testing.
Speaker 3: It leads us to the ultimate question, the holy grail,
Speaker 3: the real holy grail of this research. How do we
Speaker 3: go from a microscopic herewith device levitating in a lab,
Speaker 3: to a massive spacecraft capable of carrying actual human payloads
Speaker 3: or heavy scientific instruments to alpha centauri.
Speaker 2: Here is where the data gets really interesting, And honestly,
Speaker 2: this is the part of the research that completely blew my.
Speaker 3: Mind me too.
Speaker 2: Honestly, when you look at how traditional rocketry scales up,
Speaker 2: it's a nightmare of engineering.
Speaker 3: Oh it's terrible.
Speaker 2: If you have a small rocket and you decide you
Speaker 2: want to carry twice as much cargo, you can't just
Speaker 2: make the rocket ten percent bigger.
Speaker 3: No, it doesn't work that way.
Speaker 2: You have to completely redesign the engines to provide more thrust.
Speaker 2: To fuel those larger engines, you need exponentially more.
Speaker 3: Fuel, which means heavier tanks, right.
Speaker 2: And those heavier tanks require stronger, heavier structural materials to
Speaker 2: handle the immense stress of launch. It is a nonlinear
Speaker 2: compounding problem.
Speaker 3: It's why the sat n V was the size of
Speaker 3: a skyscraper just to send three men to the moon.
Speaker 2: Exactly, but the most vital scaling principle discovered in this
Speaker 2: texas A and M research is entirely different. The force
Speaker 2: generated by this optical propulsion depends on the power of
Speaker 2: the light, not the size of the device.
Speaker 3: I want to pause and really emphasize how profound that
Speaker 3: realization is. Please do The propulsive force depends on the
Speaker 3: optical power available, not the physical dimensions of the metajet.
Speaker 2: Wow.
Speaker 3: The underlying physics dictate that the exact same principles, the
Speaker 3: exact same equations, and the exact same nanoscale metasurface patterns
Speaker 3: that are currently pushing a ten micron device in a
Speaker 3: fluid bath can push a massive interstellar spacecraft.
Speaker 2: That is just It's like we just invented a completely
Speaker 2: scalable engine.
Speaker 3: It is entirely scalable.
Speaker 2: If you build a microscopic metajet, you use a small
Speaker 2: laser pointer. If you want to move a larger ship,
Speaker 2: you don't need to fundamentally reinvent the physics of the metasurface.
Speaker 2: You just need to shine a more powerful laser at it.
Speaker 2: It is a completely linear path to scaling.
Speaker 3: It separates the vehicle from the propulsion system completely and
Speaker 3: When you extrapolate that out, you start to envision an
Speaker 3: infrastructure for the future of space exploration that looks completely
Speaker 3: different from what we have today.
Speaker 2: We are talking about building massive permanent infrastructure. Yes, imagine
Speaker 2: enormous laser arrays, perhaps built on the dark side of
Speaker 2: the Moon to avoid atmospheric distortion, or maybe orbiting the Earth,
Speaker 2: powered by square miles of solar panels, harvesting raw energy
Speaker 2: from the Sun.
Speaker 3: It's incredible to picture.
Speaker 2: These laser stations would act as the permanent engines for
Speaker 2: the entire Solar.
Speaker 3: System, and the spacecraft themselves would be completely passive, right,
Speaker 3: no engines. They wouldn't have massive fuel tanks, they wouldn't
Speaker 3: have complex combustion chambers or delicate exhaust nozzles that could
Speaker 3: melt or explode.
Speaker 2: They're just empty shells.
Speaker 3: Basically. They would essentially be engineered hulls covered in these
Speaker 3: highly specific nanoscale metasurfaces. You would have a fleet of
Speaker 3: fuelss ships traversing the Solar System, ferrying cargo to Mars
Speaker 3: and eventually venturing beyond the Ort Cloud, all riding on
Speaker 3: beams of concentrated light.
Speaker 2: It turns the spacecraft into a sailboat. We control the
Speaker 2: wind a perfect analogy. It fundamentally lowers the cost and
Speaker 2: complexity of the vehicle itself. You build the massive laser
Speaker 2: engine once, and you can use it to push one
Speaker 2: thousand different ships over its lifetime, exactly by let me
Speaker 2: play Devil's Advocate here for a second.
Speaker 3: Go for it.
Speaker 2: Because space is not completely empty, No it's not. There
Speaker 2: is the interstellar medium, tiny grains of dust, stray hydrogen atoms.
Speaker 2: If we are pushing at spacecraft to twenty percent the
Speaker 2: speed of light using these delicate nanoscale structures, what happens
Speaker 2: when it hits a speck of space dust at thirty
Speaker 2: seven thousand miles per second.
Speaker 3: That's a huge problem.
Speaker 2: Won't that instantly obliterate the metasurface and leave the ship stranded?
Speaker 3: That is one of the most critical engineering challenges for
Speaker 3: the actual implementation of an interstellar mission.
Speaker 2: I would assume so.
Speaker 3: At relativistic speeds, a grain of sand hits with the
Speaker 3: kinetic energy of a bomb. So yes, the metasurfaces will
Speaker 3: undoubtedly suffer degradation. Solutions currently being theorized involve heavily shielding
Speaker 3: the front of the craft and maybe putting the propulsive
Speaker 3: metasurfaces on the rear.
Speaker 2: Oh effectively pulling the craft rather than pushing.
Speaker 3: It exactly, or alternatively creating highly redundant metasurface patterns where
Speaker 3: large portions can be destroyed without losing stability.
Speaker 2: Like having thousands of extra sales.
Speaker 3: Right, the material science will have to evolve to meet
Speaker 3: the harp reality of the interstellar medium, But the key
Speaker 3: takeaway from doctor Land's research is that the propulsive mechanism
Speaker 3: itself is viable.
Speaker 2: The engine works now, we just have to figure out
Speaker 2: how to build the chassis to survive the trip precisely,
Speaker 2: and that separation of power source from the vehicle really
Speaker 2: is the only realistic way we are currently aware of
Speaker 2: to achieve the speeds necessary to reach Alpha century in
Speaker 2: a human lifetime.
Speaker 3: It's our best bet.
Speaker 2: A chemical rocket has a terminal velocity dictated by the
Speaker 2: chemical energy of its fuel. It can only push so hard.
Speaker 2: But a light sail driven by a massive sustained laser
Speaker 2: array can theoretically continue to accelerate up to a significant
Speaker 2: fraction of the speed of light, continuously adding velocity year
Speaker 2: after year.
Speaker 3: It is basically breathtaking to think about the speeds detainable,
Speaker 3: but you know this research isn't just a hypothetical win
Speaker 3: for the astronauts and explorers of the distant future. No,
Speaker 3: the development of this technology is having a very tangible,
Speaker 3: immediate impact right now on the ground, specifically in how
Speaker 3: we educate the next generation of engineers.
Speaker 2: Oh, that's a great point. We often forget the human
Speaker 2: element of these massive technological.
Speaker 3: Shifts, right, People actually have to build this.
Speaker 2: A paradigm shift this large doesn't happen overnight, and it
Speaker 2: doesn't happen in a vacuum. It requires a tremendous amount
Speaker 2: of intellectual labor apps. And what's really inspiring about the
Speaker 2: work at the Lab for Advanced Dandopototics is who is
Speaker 2: actually doing the heavy lifting. The design, the complex mathematical modeling,
Speaker 2: and the incredibly delicate experimental validation of these metajets were
Speaker 2: led by doctoral students in Doctoral life Lands group.
Speaker 3: That is the beauty of the university research system. Yeah,
Speaker 3: the doctoral students are the ones in the clean rooms
Speaker 3: at the aggifab nanofabrication facility wearing the bunny suits, operating
Speaker 3: the electron beam lithography machines, actually manufacturing these nanoscale patterns.
Speaker 2: We're doing the actual science.
Speaker 3: They are the ones setting up the microscopes and running
Speaker 3: the fluid bath experiments, agonizing over the data when Brownian
Speaker 3: motion throws off their readings.
Speaker 2: They are literally on the absolute frontier. Yeah, and the
Speaker 2: ripple effect of their work is already reshaping the curriculum
Speaker 2: and Texas A and M.
Speaker 3: It really is.
Speaker 2: Doctor Land noted that the underlying physics of these light
Speaker 2: induced forces have already been incorporated into graduate coursework. They
Speaker 2: are literally writing the textboats on optical mechanics as they
Speaker 2: discover it.
Speaker 3: Which means we are witnessing a profound generational handover in engineering.
Speaker 3: Think about the aerospace engineers who trained in the nineteen
Speaker 3: fifties and sixties.
Speaker 2: The Apollo generation exactly.
Speaker 3: There were masters of fluid dynamics, combustion, and thermodynamics. They
Speaker 3: learn how to control controlled explosions. Now the curriculum is
Speaker 3: having to shift to accommodate a completely new paradigm. The
Speaker 3: students today are learning quantum optics, nano manufacturing, and electromagnetic
Speaker 3: momentum transfer.
Speaker 2: It's a massive pivot, massive a technological leap of this magnitude.
Speaker 2: Cutting one hundred thousand year journey down to twenty years
Speaker 2: is a multi generational project.
Speaker 3: Oh for sure.
Speaker 2: The doctoral students who are learning how to manipulate the
Speaker 2: momentum of photons today, and the undergraduates who are rushing
Speaker 2: to join these research opportunities because they read about metajets,
Speaker 2: they are the ones who will be the veteran senior
Speaker 2: engineers decades from now.
Speaker 3: They will be the ones sitting in mission control or
Speaker 3: maybe standing on the lunar surface monitoring the laser array
Speaker 3: when the first actual interstellar probe powered by light leaves
Speaker 3: our solar system.
Speaker 2: That gives me chills.
Speaker 3: By integrating this cutting edge research directly into the curriculum,
Speaker 3: the university is ensuring that the pipeline of talent is
Speaker 3: deeply fluent in this entire, highly new language of physics,
Speaker 3: and it.
Speaker 2: Really ties into this broader scientific renaissance we are seeing
Speaker 2: across the material science landscape.
Speaker 3: We're seeing it everywhere.
Speaker 2: The traditional boundaries of what we thought was possible are
Speaker 2: constantly being broken. We are seeing other researchers discovering hidden
Speaker 2: properties of light to power nanomachines in completely different contexts.
Speaker 2: We're seeing teams using those same parabolic flights we talked
Speaker 2: about earlier to test things like graphene aerogels moving under
Speaker 2: laser power.
Speaker 3: Grapphine aerogels are another fantastic example of this paradigm shift.
Speaker 2: What are those exactly?
Speaker 3: They are incredibly porous, sponge like structures made of carbon
Speaker 3: that are lighter than air because they have such low density,
Speaker 3: but absorb and emit energy so efficiently. Researchers are finding
Speaker 3: they can be pushed and manipulated by light in very
Speaker 3: similar ways to these metasurfaces.
Speaker 2: Well interesting, So the university systems are having to adapt
Speaker 2: in real time just to keep up with how fast
Speaker 2: the physics are changing. Exactly, we are training a generation
Speaker 2: of students to view light not just as a way
Speaker 2: to illuminate a room or a way to transmit data
Speaker 2: through a fiber optic cable, but as a physical tool,
Speaker 2: a literal wrench, right, a tool you can use to build,
Speaker 2: to levitate, and to propel objects.
Speaker 3: It is a profound evolution in humanity's relationship with the
Speaker 3: electromagnetic spectrum. We are learning to harness the physical force
Speaker 3: of light itself.
Speaker 2: It really is. So let's take a step back and
Speaker 2: look at the incredible journey we've just charted today.
Speaker 3: We covered a lot of ground, We really did.
Speaker 2: We started by looking at the harsh reality of the
Speaker 2: rocket equation and how it traps us in our local
Speaker 2: solar system, the tyranny, the tyranny. Then we looked at
Speaker 2: a microscopic device, a metajet smaller than a single human
Speaker 2: red blood cell. We explored how scientists engineered its ultra
Speaker 2: thin metasurface with nanoscale precision, building the three D steering
Speaker 2: controls directly into the geometry of the material itself.
Speaker 3: Putting the smarts in the sale exactly.
Speaker 2: We saw how they successfully levitated and maneuvered it against
Speaker 2: the resistance of a fluid bath in a Texas laboratory,
Speaker 2: proving definitively that the tiny cumulative momentum of photons can
Speaker 2: be harnessed and directed.
Speaker 3: And from that microscopic proof of concept we trace the
Speaker 3: path forward. Right, we looked at the impending lead into
Speaker 3: microgravity testing, where the true efficiency of the design can
Speaker 3: be unleashed away from the friction of.
Speaker 2: Earth on the iss or the vomit comet.
Speaker 3: Yeah, we discussed the monumental realization that this technology scales
Speaker 3: linearly based on the power of the light, not the
Speaker 3: size of the device, opening the door for massive macroscale
Speaker 3: spacecraft powered by off board laser arrays.
Speaker 2: And finally we saw how this exact research is actively
Speaker 2: cultivating the next generation of scientific minds who will turn
Speaker 2: this theory into reality.
Speaker 3: It's super exciting, which.
Speaker 2: Brings us all the way back to our nearest stellar neighbor,
Speaker 2: Alpha Centauri, back to the night sky. Right. We started
Speaker 2: this conversation talking about one hundred thousand year journey in
Speaker 2: a massive explosion powered rocket, a journey that would require
Speaker 2: generations to complete.
Speaker 3: A civilization in a can exactly.
Speaker 2: But if this technology fulfills its promise, If our primary
Speaker 2: method of moving through the cosmos transitions from carrying heavy
Speaker 2: volatile chemical fuel to simply riding continuous, silent beams of light,
Speaker 2: it fundamentally changes humanity's relationship with space.
Speaker 3: It changes everything.
Speaker 2: It takes the vast empty darkness that separates the stars
Speaker 2: and turns it into a navigable ocean of light.
Speaker 3: It changes the very definition of distance in astrophysics. The
Speaker 3: universe basically becomes smaller.
Speaker 2: It really does. Yeh, So I want to leave you
Speaker 2: with a profound thought to mull over as you go
Speaker 2: about your day.
Speaker 3: Let's hear it.
Speaker 2: If distance in space is no longer measured by how
Speaker 2: much fuel you could physically carry on a ship, but
Speaker 2: is instead limited simply by how bright of a light
Speaker 2: you can shine from Earth. What other seemingly impossible boundaries
Speaker 2: are about to disappear,