Prática de Shadowing: 20% Speed of Light!! NEW Light Engine is INSANE! - Aprenda a falar inglês com vídeo
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In 2016, the world's most powerful billionaire set out to build a spacecraft that could reach another star within our lifetime.
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They handed over 100 million dollars to Silicon Valley's best engineers to make it real, and today it's stuck by a physics problem no code can solve.
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The secret to interstellar travel isn't building a better computer.
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It's a microscopic piece of glass sitting in Texas with no engine,
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no moving parts, no AI that can steer itself more precisely than any drone ever built.
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And it might be the only thing that actually gets us to another star.
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Chapter 1.
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The 100 Million Dollar Ghost Ship Alpha Centauri, the target of breakthrough starshot, is 4.37 light years from the Earth.
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That's 25 trillion miles away.
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But how far is that really?
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One of the fastest objects humanity has ever launched is the New Horizons probe.
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It was moving at roughly 36,000 miles per hour when it launched from Earth.
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Still, if you put New Horizons on a track and aimed it at Alpha Centauri, it would arrive in approximately 78,000 years.
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Which is to say not in your lifetime, or your children's lifetimes, or during the lifetimes of any civilization that would even recognize the people who built it.
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78,000 years ago, the great wave of modern humans hadn't swept across the globe yet.
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We hadn't even invented agriculture, writing, the wheel, government, money, or organized religion.
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All of that entire timeline fits inside the travel time of our fastest spacecraft to the nearest star.
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And if you're wondering, the Apollo moon ships, the fastest piloted spacecraft humanity has ever flown, would do far worse.
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They would take a staggering 114,000 years to reach the Alpha Centauri system.
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That makes New Horizons' 78,000 years feel almost optimistic.
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When Yuri Milner, a Russian billionaire physicist, stood on a stage in New York in 2016, this was the time and distance problem he set out to solve.
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Forget chemical rockets, stop trying to carry fuel across trillions of miles, because fuel has mass, and mass requires more fuel to move it,
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which adds more mass, which requires more fuel, it's a spiral.
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And that's exactly why rockets are mostly just fuel tanks to begin with.
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Instead, leave the fuel on the ground and a massive array of lasers,
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then build a spacecraft so small and light it weighs just 0.03 ounces or one gram.
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At its center is a chip the size of a postage stamp carrying a camera, a processor, a battery, and a transmitter,
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and attach it all to a sail 13 feet wide but only a few hundred atoms thick.
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All of that means that the pressure of light itself can push the craft through space.
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Breakthrough Starshot called it the Star Chip, and it seemed simple in theory fire lasers at its sail
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and then watch it accelerate to over 37,200 miles per second in a matter of minutes.
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At 20% of the speed of light, it would only take 20 years to arrive at Alpha Centauri, and that's quite an improvement on the whole 78,000.
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The timeline has been condensed into a single generation, not all of the generations.
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And just to improve the odds that at least some survived the journey, they would send not one star chip but a fleet of a thousand of them.
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Even Milner's team knew that redundancy is cheaper than regret.
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A twenty-year journey is a number humans can hold in their head.
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Never mind the fact that when Star Chip finally arrives at Alpha Centauri, the distances will be
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so staggering it would take four years alone to beam the images back to Earth via its own onboard lasers.
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Four years is a drop in the bucket.
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We could at least conceivably be alive to see that data come back.
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And so the crowd at the 2016 event applauded, because this idea was genuinely worth applauding.
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What the Enterprise did not spend a lot of time talking about was the all-important laser array.
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That alone would need to generate 100 gigawatts of power to function.
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That's roughly the combined electrical output of approximately 100 nuclear power plants, all firing simultaneously.
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The entire United Kingdom, every light, every factory, every phone charger, and every coffee machine in every office in London,
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generally runs on less than 40 gigawatts on a normal day.
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So Starshot's lasers would need two and a half times the entire power grid of Britain aimed at a stamp in space.
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It's not like this was any secret.
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The engineers knew the project's logistical parameters, and they set it anyway.
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There was a plan, apparently, to solve this energy problem later.
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They didn't.
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They also didn't solve the other problem, the one that would have killed the tiny spacecraft before it left the solar system, regardless of how much power was available.
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The problem that the 100 million dollar budget could not touch.
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Chapter 2.
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The Slippery Beam The massive laser beam, the one propelling the tiny spacecraft that takes an insane amount of energy to operate, is also the beam that absolutely destroys it.
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This will happen immediately by design, as a direct consequence of the laws of physics the moment the sail drifts even slightly off-center.
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Which it inevitably will.
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The universe is not a laboratory with controlled conditions.
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The laser has to travel through hundreds of miles of churning, turbulent atmosphere before it even reaches the spacecraft.
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Imagine balancing a marble on top of another marble.
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It is theoretically possible.
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The geometry allows it, but the instant that the top marble moves even a fraction of a millimeter to the side, gravity won't be there to gently nudge it back.
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It accelerates away.
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The more it moves, the faster it goes.
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The instability feeds itself.
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Now imagine the top marble is a spacecraft, made of material thinner than a soap bubble.
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The bottom marble is a laser beam carrying the energy output of a hundred nuclear power plants, and falling off means instant vaporization.
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That is beam-riding instability.
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Researchers who study this problem found something almost poetically discouraging.
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A flat sail is never stable on a laser beam.
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Even if you spin it or modify the shape any way you want, a flat sail is never stable.
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Full stop.
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At gentle speeds, this is an annoying engineering problem.
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You might even be able to correct for it by installing sensors that detect wobble, onboard computers to process the error,
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or maybe some thrusters to just nudge the spacecraft back to center.
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That whole loop might take a few hundred milliseconds, which is workable.
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But this is all theoretically taking place at 20% the speed of light.
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At those speeds, a few hundred milliseconds is an eternity.
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By the time the sensors detected the wobble, processed it, and sent the signal to the thruster, and then waited for it to fire,
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the spacecraft will have traveled almost 11,200 miles.
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That correction window, or just the gap between the wobble beginning and the spacecraft ceasing to exist, is measured in microseconds.
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One millionth of a second.
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The fastest thrusters on the earth can't act upon a correction loop that fast.
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The spacecraft would vaporize before the mechanical valves even had time to open.
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And that is before we get to the space dust.
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The path from Earth to Alpha Centauri contains an estimated 100 sextillion particles including dust, hydrogen, and helium atoms.
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At 20% the speed of light, each one hits the spacecraft like a bullet.
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Researchers at the Korea Astronomy and Space Science Institute ran the numbers
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and they They found that a steel spacecraft would accumulate craters 0.15 inches wide
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and 0.04 inches deep across its surface long before it reached its destination.
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A sufficiently large dust particle would destroy the craft entirely.
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Breakthrough Starshot was conceived as a Silicon Valley project, and Silicon Valley's answer to this is simply write better code, faster code, smarter code.
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If the correction loop is too slow, why not just optimize the correction loop?
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Well, if the processor can't keep up, design a faster processor.
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This approach works on essentially every problem that software has ever been asked to solve, and that's why it is the default response of an entire
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generation of engineers who have watched software eat the world and concluded that software can eat anything.
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But it can't eat the scale of this journey.
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Because traveling to another star system isn't a software problem dressed up as a hardware problem.
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at light speed is not a bug you could easily troubleshoot.
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The signal that tells the thruster to fire still has to pass through physical hardware.
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But the spacecraft is moving at incredible speeds, so even a tiny delay means it's already covered in an enormous amount of distance by the time anything responds.
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And that is not a software problem you can optimize, because physics moves faster than code.
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You have to respect the original Breakthrough Starshot team.
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Before the project got off the ground, they publicly posted an engineering challenges list for the project, and made it admirably transparent.
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The list acknowledged this problem directly.
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Beam instabilities are everything, as are those differential forces on the sail and the differential heating.
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It reads like a coroner's report before the patient was even born.
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They sat with this problem for nine years.
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Nine years of small grants, academic conferences, hopeful papers, and the dawning awareness
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that the correction problem could not be solved with with the tools and budget the project had brought to solve it.
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You cannot out-compute a wobble that kills the spacecraft faster than computation is physically possible.
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What you would need is a spacecraft that corrects the wobble before it knows the wobble happened.
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A spacecraft that doesn't detect instability and respond to it.
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A spacecraft that simply can't become unstable, by virtue of what it's made of regardless of what the beam does to it.
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Now that sounds like science fiction.
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It also sounds like exactly what a team of doctoral students in Texas spent the last several years building.
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Chapter 3.
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The Dart and the Texans The doctoral students in Dr. Shofeng Lun's lab at Texas A&M University were not,
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by any conventional measure, the people you would expect to solve this.
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A $100 million Silicon Valley initiative had already failed, and they were backed by some of the most famous scientists alive.
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They didn't have the benefit of any celebrity spokespeople or press events in New York.
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Instead, they were working with a fabrication facility on a campus in College Station, Texas, a city best known for football and being roughly two hours from anywhere else.
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What they built is called a MetaJet.
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The current prototypes are tens of microns across.
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For reference, a single strand of human hair is roughly 50 to 120 microns wide.
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Which means you could line up a small fleet of MetaJets across something you previously considered too small to see.
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The whole device weighs less than a paperclip.
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It has no thrusters, no moving parts, no onboard computer, and no steering system of any kind.
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And the best part?
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A laser still propels it, but the structure of the material itself keeps it on course, the same way a groove keeps a needle in a record.
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Or in other words, the beam does one job and the material does another.
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Here's why that second part matters so much.
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Even if breakthrough Starshot solved the beam riding problem, managed to build a sail that stays perfectly centered on the laser
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and the craft survived the thermal load while accelerating to 20% the speed of light, there is still a massive problem waiting on the other side of that journey.
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You don't know where you're going.
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Space is not empty.
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There are rogue particles, gravitational tugs from objects hundreds of billions of kilometers away, and absolutely no landmarks.
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A spacecraft crossing 4.37 light years is subject to every one of those influences for every second of a twenty-year journey.
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Each nudge is tiny, but they add up.
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The Starshot engineers defined a successful arrival as getting within one astronomical unit of Alpha Centauri.
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That doesn't sound like much until you realize what one astronomical unit actually means.
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It allows for a missed distance of up to 93.2 million miles.
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That's roughly the distance from the Earth to the Sun.
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And that was them being generous.
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The bullseye was already the size of Earth's entire orbit, and an unsteered light sail couldn't reliably hit it.
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Their own researchers admitted
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that the tiny vibrations in the laser array alone were many orders of magnitude away from the accuracy the mission required.
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Even with help, the probe would probably still miss the target the size of a planet's entire orbital path.
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Imagine throwing a dart from New York City and trying to hit a bullseye in London, but you can't see the target, and the target is moving,
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and once the dart leaves your hand And you won't be able to adjust it for 20 years.
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That's the navigation problem.
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As we know, any conventional fix to the steering problem adds mass.
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Add mass on a spacecraft whose entire propulsion system is light pressure, and that can lead to an inevitable collapse.
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The steering system that saves the mission is also the steering system that makes the mission impossible.
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That is, the specific, elegant, maddening trap that breakthrough Starshot never escaped.
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The MetaJet escapes it by refusing to play.
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There's no steering system to add mass because the steering isn't a system, it's a property, built into the material before the ship even leaves the ground.
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Which means understanding how it works requires getting very small very fast.
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Chapter 4.
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The Groove in the Record The MetaJet is built from a class of material called MetaSurface, an ultra-thin sheet of silicon covered in arrays of nanoscale pillars.
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The pillars are far smaller than the width of a human hair.
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They're also so small
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that the patterning across a mere surface the size of your fingernail contains enough structural variation to encode an entire multi-volume encyclopedia.
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The height, the diameter, and the spacing of those metasurface pillars are precisely designed to control exactly what happens to light when it strikes the surface.
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Change one pillar by a few nanometers and you change the trajectory of your ship.
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The entire navigation of an interstellar spacecraft is encoded in measurements you could not resolve with a standard lab microscope.
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Here's what those pillars do.
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When you hold a garden hose and water shoots straight forward, the hose kicks straight back in your hands.
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That's basic physics.
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Newton's third law, the water goes one way, your hand gets pushed the other.
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Now put a bent nozzle at the end of it.
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Suddenly, the water exits at an angle and the hose kicks sideways instead of backwards.
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It's the same water pressure, enacting a completely different direction of force.
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The nozzle doesn't add any energy, it simply changes where the water went, and the reaction follows automatically.
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The Meta-Surface pillars are the nozzle, and the laser is the water pressure.
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When light strikes a conventional reflective surface like a mirror, it bounces straight back and pushes the sail straight forward.
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The Meta-Jet's pillars are designed to bend the outgoing light at a precise angle, so If the light exits sideways, the sail is pushed sideways.
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Nobody or nothing is required on board to program the nozzle.
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The shape is the program.
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That's the beauty of this system.
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The further it drifts, the harder it gets pushed back into position.
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It literally can't stay off course.
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As for the heat, which we were told would vaporize any conventional reflective materials under full laser load,
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the metasurface survives as a consequence of its ability to reflect light, not absorb it.
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The photons do all the work, changing the direction and transferring momentum, rather than dumping all their energy into the material as heat.
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For context, the previous best answer to this problem was graphene, one of the strongest materials humans have ever produced.
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Then, to survive the dust particles during the journey,
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researchers proposed folding the sail into a needle-like profile to minimize the cross-sectional area hitting the particles.
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The MetaJet silicon metasurface is a different answer entirely.
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just stronger, smarter.
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In laboratory testing, Lens' team demonstrated full three-dimensional movement using a single fixed laser beam.
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They got the MetaJet prototype to go forward, sideways, and lift from all one light source with no fuel, no steering input, or any contact of any kind.
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It was the first time any optical propulsion system had ever achieved this, and to the team's knowledge, nobody else has done it.
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The beam does one job, the material does the other.
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And the material never gets tired, runs out of propellant, or never has to wait for a computer to tell it what to do.
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Chapter 5.
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4.37 Light Years, Give or Take Lant's team is not alone.
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Researchers at Caltech have been working on a similar stability problem for laser drive light sales, and other groups have been working on the same problem from other angles.
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The fact multiple serious research teams have independently converged on material-based
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solutions to the steering problem posed by Breakthrough Starshot is no coincidence.
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The field has realized
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that the Silicon Valley instinct to throw software at it was always the wrong tool for this particular job.
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The MetaJet prototypes are currently tens of microns across.
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A real interstellar sail needs to be feet wide, and nobody at Texas A&M or anywhere else is pretending that that gap is small.
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But here's what makes it bridgeable in a way no previous approach was.
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The physics scale with laser power, not device size.
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The same principles that move a micron-scale prototype in a laboratory tank will move a meter-scale sail under gigawatt-class beams.
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The mechanism doesn't change, only the engineering does, and engineering unlike physics, negotiates.
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The next milestone is microgravity testing, demonstrating that the metajet behaves in space conditions the way it behaves in the lab.
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Landsteam is currently applying for funding to make that happen.
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Certainly a quieter, smaller, less photogenic task than a press conference at One World Trade Center with Stephen Hawking in attendance.
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It will also, if it works, mean considerably more.
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In the end, Breakthrough Starshot threw millions of dollars and nine years at the stars and quietly ran out of road.
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A group of doctoral students in College Station spent roughly the same period asking a different question entirely.
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Instead of building a better computer for the ship, what if the ship didn't need one at all?
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The device that may eventually carry humanity's first message to another star has no engine, No steering computer or moving parts, it weighs less than an eyelash,
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and it steers using light the same way a bowling ball uses a hill.
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Alpha Centauri is still 4.37 light years away.
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That number hasn't changed.
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What did change in a fabrication lab two hours away from
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anywhere is whether we as a species have any business believing we might actually get there.
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And we just might.
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Because every attempt to go further into space keeps running into the same truth, you have to solve the problems closest to home first, find out why NASA wants to go back to the moon,
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or watch this instead.
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Vocabulário e dicas de fala para esta lição
Esta aula de conversação de nível B2 usa o vídeo “20% Speed of Light!! NEW Light Engine is INSANE!”. As palavras que mais se repetem: spacecraft, laser, beam, sail. Este vídeo tem 224 frases e 3234 palavras para praticar shadowing. A fala dura 18:33. O falante fala em ritmo natural, cerca de 174 palavras por minuto, próximo de uma conversa do dia a dia. Apenas 76% das palavras estão entre as 3.000 mais comuns do inglês, por isso o vocabulário é exigente.
Vocabulário principal deste vídeo
As 15 palavras mais avançadas do vídeo, com pronúncia e significado:
| Palavra | Pronúncia | Significado |
|---|---|---|
| laser substantivo | /ˈleɪzɚ/ | laser, lêiser |
| sail substantivo | /seɪl/ | vela |
| beam substantivo | /ˈbiːm/ | trave, viga |
| steer verbo | /stɪɹ/ | direcionar, guiar |
| breakthrough substantivo | /ˈbɹeɪk.θɹuː/ | brecha |
| silicon substantivo | /ˈsɪləˌkɑn/ | silício |
| wobble verbo | /ˈwɑbl̩/ | cambalear, vacilar |
| pillar substantivo | /ˈpɪlɚ/ | pilar |
| researcher substantivo | /ˈɹiˌsɝ.t͡ʃɚ/ | pesquisador, pesquisadora |
| correction substantivo | /kəˈɹɛkʃən/ | correção |
| marble substantivo | /ˈmɑɹ.bəl/ | mármore |
| nozzle substantivo | /ˈnɒzəl/ | bocal |
| prototype substantivo | /ˈpɹəʊtətaɪp/ | protótipo |
| particle substantivo | /ˈpɑɹtək(ə)l/ | partícula |
| interstellar adjetivo | interestelar |
Phrasal verbs que você vai ouvir
| Palavra | Significado |
|---|---|
| come back verbo | voltar |
| fall off verbo | cair |
| find out verbo | descobrir |
| get off verbo | sair |
| hand over verbo | entregar, transferir |
| keep up verbo | manter |
Gramática neste vídeo
As estruturas que o falante mais usa, com as palavras exatas do vídeo:
| Estrutura | No vídeo |
|---|---|
| Present perfect have/has + particípio passado — uma ação passada que ainda importa agora | has ever launched · has ever flown · has been condensed |
| Voz passiva be + particípio passado — o foco está no que acontece, não em quem faz | has been condensed · is measured · was conceived |
| Orações relativas who / which + oração — informação extra sobre uma pessoa ou coisa | people who built · milliseconds, which is |
Pronúncia para ficar de olho
O falante usa 27 contrações e formas reduzidas, como can't, didn't, doesn't. Diga-as na forma curta, do jeito que você ouve.
- Os sons de “th”: breakthrough /ˈbɹeɪk.θɹuː/, thruster /ˈθɹʌ.stɚ/, thermal /ˈθɜːməl/
- Os sons de “sh” e “zh”: correction /kəˈɹɛkʃən/, fabrication /fæbɹɪˈkeɪʃən/, propulsion /pɹəˈpʌlʃən/, differential [dɪfəˈɹənʃəɫ], navigation /nævɪˈɡeɪʃən/
- Palavras longas — acerte a sílaba tônica: instability /ɪnstəˈbɪlɪti/, astronomical /ˌæs.tɹəˈnɑm.ɪ.kəl/, fabrication /fæbɹɪˈkeɪʃən/, millisecond /ˈmɪlɪˌsɛkənd/, differential [dɪfəˈɹənʃəɫ]
Sons difíceis para falantes de português:
- Consoante final — sem acrescentar um “i” depois: spacecraft /ˈspeɪsˌkɹæft/, prototype /ˈpɹəʊtətaɪp/, dart /dɑɹt/, onboard /ɒnˈbɔːd/, detect /dɪˈtɛkt/
- /l/ final — a língua toca o céu da boca, não vira “u”: sail /seɪl/, marble /ˈmɑɹ.bəl/, nozzle /ˈnɒzəl/, particle /ˈpɑɹtək(ə)l/, doctoral /ˈdɒktəɹəl/
- /h/ — um sopro suave, diferente do “r”: hose /hoʊz/, behave /bɪˈheɪv/
Como praticar com este vídeo
- Ouça o vídeo inteiro uma vez sem falar e anote as palavras que você não conhece.
- Comece na velocidade 0,75×, faça shadowing frase por frase e volte à velocidade normal quando ficar fácil.
- Grave a sua voz e compare com o original, prestando atenção a palavras como laser, sail, beam.
O que é a Técnica de Shadowing?
Shadowing é uma técnica de aprendizado de idiomas com base científica, originalmente desenvolvida para o treinamento de intérpretes profissionais. O método é simples, mas poderoso: você ouve áudio em inglês nativo e repete imediatamente em voz alta — como uma sombra seguindo o falante com 1-2 segundos de atraso. Pesquisas mostram melhora significativa na precisão da pronúncia, entonação, ritmo, sons conectados, compreensão auditiva e fluência na fala.