Prática de Shadowing: This giant laser can simulate a planet’s core - Aprenda a falar inglês com vídeo

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This building contains a truly gigantic laser.
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The National Ignition Facility...
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is about a hundred feet tall...
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as big as three football fields...
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And packed to the brim with tubes and wires that look the bowels of a spaceship.
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It makes sense that one of the Star Trek movies shot a few scenes there.
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"Do you know what this is?!" "It’s a warp core." Actually, it’s NIF’s “target chamber”.
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The laser beam starts over here in this room as a tiny pulse of light about as weak as a regular laser pointer.
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But then it bounces around the building getting amplified over and over until it’s a quadrillion times stronger.
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And then, it’s focused onto a single point.
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So... what do you do with a laser this big?
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Well, right now, scientists are using it to study the secret inner lives of planets.
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It started in second grade, when I was younger my teacher showed me pictures of Jupiter.
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I remember in class vividly that she said that no one knows what's on the inside of the planet.
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I was like oh well, maybe I could be the one that figures that out!
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Now, Tanja Kovecivic is a planetary scientist at UC Berkeley and she and her colleagues are asking broader questions.
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Why are we here?
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How did our solar system form?
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How planets form, how the moon formed and especially now with the search for exoplanets...
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How do we find a habitable planet?
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What does that look like?
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How did earth or anything else go from a molten ball to something that we can all now survive on.
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The features that define Earth: its rich atmosphere...
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its vast oceans...
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its magnetic field...
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its solid but shifting crust...
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these features that fostered life as we know it they were shaped by unseen processes hidden deep within the globe.
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If we want to understand the engines that sculpted Earth, or Jupiter or the thousands of recently discovered worlds we need to look under the hood.
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But that’s not easy.
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On the surface of the Earth, we exist under very unique conditions.
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We’re here, in this tiny range of relatively low temperatures and low pressures.
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But if we drill deeper.
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Most of the matter, even within Earth, exists under extreme temperatures and pressures.
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A trip into Jupiter is even more intense.
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At these depths, the laws of physics predict that familiar substances will start to act...
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pretty weird.
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When you're subjecting matter to intense pressure, you're squishing it right?
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So you're actually causing the atoms to re-orient themselves.
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When you heat it up, you're also causing vibration.
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You're just kind of irritating this thing into being a whole new material sometimes.
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For a long time, physicists have theorized that deep within a planet iron can flow like water.
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And those swirling currents generate Earth’s magnetic field.
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Also in theory, sodium can turn completely transparent.
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Water can form a hot black ice that conducts electricity.
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And hydrogen condenses into a metallic liquid.
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To understand the strange chemistry and geology and physics happening inside planets we have to study substances we’d never encounter on the surface.
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And it’s not like we can just go down there in an elevator.
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The closest humans have gotten to the Earth’s core is the Kola Superdeep Borehole in Northwest Russia: 7.6 miles straight down.
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But that’s less than 0.2% of the way to the center of the Earth.
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A probe we shot into Jupiter, stopped transmitting when it was just 0.1% of the way to that planet’s core.
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Our instruments can’t survive in the very temperatures and pressures we want to study.
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But scientists have come up with a few different ways to get around this problem.
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The first is to create detailed computer models.
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So we have oxygen or little white hydrogens.
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All the little brown ones are going to magnesium.
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You can look at it in 3D.
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Oh it rotates!
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Yeah. Tanja programmed this collection of 300 some atoms.
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It’s a tiny microcosm of a barrier between rock and ice inside a planet.
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Her model simulates how each atom and every last one of its electrons will act and interact.
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It’s a simulation of just a few billionths of a second.
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But it takes one of the most powerful supercomputers in the world a bit longer than that to complete.
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138 hours. OK gotcha.
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Little by little, painstaking simulations like these are starting to paint a picture of what’s happening inside planets.
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And they’re helping guide experiments in the real world.
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We don't have that much time and facilities that we can sort of go out and sample all kinds of worlds material that all the conditions.
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And so they say hey, maybe you should look in this direction.
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There could be something interesting there.
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So we have all these questions.
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We have all these theories.
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But we want to confirm that with “real world experiments”.
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Yeah. What does that look like?
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That looks like a few different things: the first one of those would be a diamond anvil cell.
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You take very high purity diamonds.
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You think of the diamond in the diamond wedding band.
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You basically compress a sample within just the between the two.
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This setup can create some of the temperatures and pressures seen inside earth.
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And if you want to go further, you can use...
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The gas gun method.
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With a gas gun you're launching basically a plate of metal into the sample that you care about.
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Temperature and pressure spike on impact.
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That’s pretty good.
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But sometimes, you want to peer even deeper into a giant planet.
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The third, and kind of most extreme of those would be laser compression.
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And for that, you need a truly gigantic laser.
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NIF wasn’t built to explore other worlds — not at all - it was built to save our own.
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In the 1970s, scientists were trying to harness nuclear fusion: the reaction that powers our sun.
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It would be cheap, it would be clean, it would be...
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the ultimate energy.
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The dream was (and still is) to hit a tiny fuel pellet with powerful lasers and create a miniature star here on earth "We need to build a laser 1000 times more powerful than any laser presently available." Scientists have spent decades designing and building larger and larger lasers.
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Lawrence Livermore National Laboratory built NIF.
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And the University of Rochester built their giant OMEGA laser system.
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These facilities are still plugging away at understanding nuclear fusion but they've also become important tools for astrophysicists and material scientists.
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Researchers at the Center for Matters at Atomic Pressures use OMEGA and NIF to recreate the interiors of planets and stars and create revolutionary states of matter.
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Instead of loading up a target chamber with pellets of fusion fuel they put in a sample, like a tiny speck of iron.
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We have to place it inside of this little apparatus which you can actually hold in the palm of your hand.
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It looks like this.
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And it happens to be the same semicircular shape as UC Berkeley’s Greek Theater.
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Which is where I interviewed Mercedes.
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So if we imagine that we're standing inside of the apparatus we could imagine this would be the sample not much thicker than a hair.
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—Teeny-tiny. —Yeah.
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So our sample is mounted right on the front of that little hole in the center there.
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Which, in the Greek Theater, would be at the doors at the back of the stage.
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Then we would actually have another layer of material right behind it.
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We call that layer the ablator.
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Our laser is going to come in from this direction...
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they're going to hit the back surface of this ablator.
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That's going to cause a kind of a mini localized explosion...
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Which drives the compression waves towards our sample.
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The temperature and pressure within the sample skyrockets.
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You'd have to have a comet colliding at 20-30,000 miles an hour to start reaching the conditions that NIF can do on a daily basis.
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The experiment only lasts about 30 billionths of a second but that’s long enough to take an X-ray snapshot.
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The x-rays bounce off the sample...
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and leave patterns on the walls of the device that scientists can later decode.
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The x-rays are telling us what's going on inside the sample, you know, is it melting?
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Does it stay solid?
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Is it changing the arrangement of the atoms itself?
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Using NIF, Rick saw that iron will be a liquid under pressures found in giant rocky planets much bigger than Earth – and so planets like that could also have magnetic fields.
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Other high pressure experiments have shown that sodium does become clear.
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And water can form hot, black ice.
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And hydrogen does turn metallic.
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Scientists think there’s an immense ocean of this form of hydrogen beneath Jupiter’s clouds and its currents generate Jupiter’s magnetic field.
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All these phases of matter that we had predicted, potentially existed now we're able to theoretically prove through models and through experimentation that they do exist.
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By peering at a handful of atoms a little crumb of matter - for just a tiny fraction of a second scientists are unraveling the billion year histories of massive planets millions of miles away.

Sobre Esta Lição

Nesta lição, você irá praticar o inglês com o tema fascinante das ciências planetárias. Através da descrição de um enorme laser usado para simular o núcleo de planetas, você expandirá seu vocabulário técnico e desenvolverá a capacidade de discutir tópicos científicos complexos. A prática do listening permitirá que você melhore sua compreensão auditiva, especialmente em contextos onde o tom e a velocidade são importantes. Estaremos focando em como as ciências, como física e geologia, se entrelaçam em questões como a formação dos planetas e as condições extremas existentes em seus núcleos.

Vocabulário e Frases Chave

  • gigante laser - gigantic laser
  • núcleo planetário - planetary core
  • pressões extremas - extreme pressures
  • campo magnético - magnetic field
  • sistemas solares - solar systems
  • materiais estranhos - strange materials
  • profundezas - depths
  • química e geologia - chemistry and geology

Dicas de Prática

Para aproveitar ao máximo a prática de shadowing, recomendamos que você ouça o vídeo várias vezes. Na primeira audição, apenas preste atenção ao conteúdo sem se preocupar em repetir. Na segunda vez, comece a imitar a pronúncia e entonação de quem fala. O vídeo possui um tom acessível, mas é aconselhável prestar atenção às partes onde a informação é densamente apresentada, tentando capturar a essência e a ideia principal. Ao usar um shadowing site, como o Shadowspeak, você poderá repetir frases mais lentas, aprimorando sua confiança e clareza. Praticar sua habilidade de melhorar a pronúncia em inglês neste contexto de aprendizado avançado permite que você desenvolva um entendimento mais profundo do idioma, além de habilidades técnicas, tornando-se mais fluente em discussões científicas.

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.