Prática de Shadowing: The Last Star in the Universe – Red Dwarfs Explained - Aprenda a falar inglês com vídeo

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One day the last star will die and the universe will turn dark forever.
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It will probably be a red dwarf, a tiny kind of star that's also one of our best bets to find alien life
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and might be the last home of humanity before the universe becomes uninhabitable.
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So what do we know about them and why are they our last hope?
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At least 70% of stars in the universe are red dwarfs.
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They are the tiniest stars out there, with only about 7-50% of the mass of our Sun.
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Not that much bigger than our planet Jupiter, which is still huge though.
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They are also very dim.
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It's impossible to see them with the naked eye.
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You've never seen one in the night sky.
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Even with all our technology, we can only clearly observe red dwarfs in our neighborhood.
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Approximately 20 of the 30 stars close to Earth are red dwarfs.
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Like all stars, red dwarfs fuse hydrogen into helium.
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But while more massive stars accumulate all the fuse helium in their cores, red dwarfs stay convective, meaning that the helium and hydrogen constantly mix.
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So they use up their fuel incredibly slowly before they're extinguished.
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Red dwarfs burn so slowly that their average lifespan is between 1 and 10 trillion years.
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By comparison, the Sun will survive for another 5 billion years.
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Because the universe is only 13.75 billion years old, not a single red dwarf has reached later development stages.
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Every single one of the trillions that exist is still a baby.
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Speaking of babies, the smallest star in the entire universe is also a red dwarf, because small red dwarfs are right on the verge of being a star at all,
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just a tiny bit less hydrogen, and they are mere brown dwarfs, failed stars that cannot sustain a fusion reaction for long.
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So what about aliens, or a new home for humanity?
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Since our sun will die one day, we'll eventually need to look for a new home.
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And where there are habitable planets, there might also be aliens.
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The Kepler Space Observatory found
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that at least half of all red dwarfs host rock planets between half and four times the mass of our Earth.
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Many of them are in the habitable zone, the area around a star where water can be liquid.
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But since red dwarfs burn at relatively cold temperatures, a planet would need to be really close to be hospitable, probably as close as Mercury to our Sun, or even closer.
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Which brings with it all kinds of problems.
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For example, a planet this close to a star would probably be tidally locked, meaning the same side would always face it.
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This side would be incredibly hot, while the shadow side would be frozen, which makes it hard for life to develop.
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Although a planet with a big enough ocean might be able to distribute the star's energy and create some kind of stability.
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All the gravitational forces of the red dwarf could squeeze the planet
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and heat it up so much that it might lose all its water over time.
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These planets could end up like Venus, a hot, burning hell.
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Another problem is that many red dwarfs vary in their energy output.
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They can be covered in star spots that can dim their emitted light by up to 40% for months, which would cause oceans on planets to freeze over.
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At other times they can emit powerful solar flares, sudden outbursts of energy incredibly powerful.
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These red dwarfs can double their brightness in minutes, which could strip away sizeable portions of a planet's atmosphere and burn it, rendering it sterile.
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On the other hand, their extremely long lifespan is a big plus.
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A red dwarf with just moderate levels of activity could be an amazing place for a planet that hosts life.
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Life on Earth has existed for about 4 billion years, and we have about a billion years left before the Sun becomes so hot that complex life on Earth will become impossible.
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We will either die out or leave Earth and look for a new home.
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We could build a civilization for potentially trillions of years around a red dwarf with the right conditions.
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About 5% of the red dwarfs in the Milky Way may host habitable, roughly Earth-sized planets.
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That would be more than 4 billion in total.
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But life may not even need a planet like Earth.
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Candidates for life around a red dwarf may be the moons of gas giants or so called super earths, really massive rocky planets.
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All in all there are an estimated 60 billion potentially habitable planets around red dwarfs and that's in the Milky Way alone.
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So red dwarfs might become really important for our survival in the future.
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But everything has to die at some point, even red dwarfs.
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When in trillions of years the life of the last red dwarf in the universe is about to end, it will not be a very spectacular event.
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As its hydrogen runs out it shrinks, becoming a blue dwarf burning out completely.
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After its fuel is spent, it's transformed into a white dwarf, an object about as small as Earth,
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packed very densely and made of degenerate gases, mostly of helium-4 nuclei.
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no more source of energy, it will cool extremely slowly over trillions of years until it becomes its final form, a cold, black dwarf.
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White and black dwarfs are so fascinating that they deserve their own video.
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Anyway, it's going to be a long time before the last stars in the universe vanish.
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It's kind of uplifting to know that if humanity succeeds in venturing into space, we have plenty of time before the universe turns out the lights.
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Our videos are made thanks to your support on Patreon.com.
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If you want to help us make more of them, we really appreciate your support.

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Vocabulário e dicas de fala para esta lição

Esta aula de conversação de nível C1 usa o vídeo “The Last Star in the Universe – Red Dwarfs Explained”. As palavras que mais se repetem: dwarf, planet, star, Earth, universe. Este vídeo tem 61 frases e 976 palavras para praticar shadowing. A fala dura 5:45. O falante fala em ritmo natural, cerca de 170 palavras por minuto, próximo de uma conversa do dia a dia. 82% das palavras estão entre as 3.000 mais comuns do inglês; vale a pena estudar o restante antes de começar.

Vocabulário principal deste vídeo

As 15 palavras mais avançadas do vídeo, com pronúncia e significado:

PalavraPronúnciaSignificado
habitable adjetivo/ˈhæbɪtəbəl/habitável
helium substantivo/ˈhiː.li.əm/hélio
hydrogen substantivo/ˈhaɪdɹəd͡ʒ(ə)n/hidrogênio, hidrogénio
emit verbo/iˈmɪt/emitir
fuse substantivo/fjuːz/pavio, rastilho
accumulate verbo/əˈkjuːmjʊˌleɪt/acumular
degenerate adjetivo/dɪˈd͡ʒɛnəɹɪt/degenerado
extinguish verbo/ɪkˈstɪŋ.ɡwɪʃ/extinguir, apagar
fascinate verbo/ˈfæsɪneɪt/fascinar
gravitational adjetivo/ˌɡɹævɪˈteɪʃənəl/gravitacional
hospitable adjetivo/hɑsˈpɪtəbl̩/hospitaleiro
outburst verbo/ˌaʊ̯tˈbɝst/surto
sterile adjetivo/ˈstɛɹəl/estéril
uninhabitable adjetivo/ˌʌnɪnˈhæbɪtəbəl/inabitável
vanish verbo/ˈvænɪʃ/desaparecer, esvair

Phrasal verbs que você vai ouvir

PalavraSignificado
burn out verboapagar-se
die out verbodesaparecer
end up verboterminar, acabar
run out verboficar sem
turn out verboterminar

Gramática neste vídeo

As estruturas que o falante mais usa, com as palavras exatas do vídeo:

EstruturaNo vídeo
Voz passiva be + particípio passado — o foco está no que acontece, não em quem fazwould be frozen · can be covered · is spent
Present perfect have/has + particípio passado — uma ação passada que ainda importa agoraYou've never seen · has reached · has existed
Orações relativas who / which + oração — informação extra sobre uma pessoa ou coisaJupiter, which is · frozen, which makes

Pronúncia para ficar de olho

O falante usa 3 contrações e formas reduzidas, como they're, we'll, you've. Diga-as na forma curta, do jeito que você ouve.

  • Os sons de “sh” e “zh”: extinguish /ɪkˈstɪŋ.ɡwɪʃ/, gravitational /ˌɡɹævɪˈteɪʃənəl/, vanish /ˈvænɪʃ/, civilization /ˌsɪv.ɪ.laɪˈzeɪ.ʃən/, fusion /ˈfjuː.ʒən/
  • Palavras longas — acerte a sílaba tônica: habitable /ˈhæbɪtəbəl/, accumulate /əˈkjuːmjʊˌleɪt/, degenerate /dɪˈd͡ʒɛnəɹɪt/, gravitational /ˌɡɹævɪˈteɪʃənəl/, uninhabitable /ˌʌnɪnˈhæbɪtəbəl/

Sons difíceis para falantes de português:

  • Consoante final — sem acrescentar um “i” depois: emit /iˈmɪt/, accumulate /əˈkjuːmjʊˌleɪt/, degenerate /dɪˈd͡ʒɛnəɹɪt/, fascinate /ˈfæsɪneɪt/, outburst /ˌaʊ̯tˈbɝst/
  • /l/ final — a língua toca o céu da boca, não vira “u”: habitable /ˈhæbɪtəbəl/, gravitational /ˌɡɹævɪˈteɪʃənəl/, sterile /ˈstɛɹəl/, uninhabitable /ˌʌnɪnˈhæbɪtəbəl/
  • /h/ — um sopro suave, diferente do “r”: habitable /ˈhæbɪtəbəl/, helium /ˈhiː.li.əm/, hydrogen /ˈhaɪdɹəd͡ʒ(ə)n/, hospitable /hɑsˈpɪtəbl̩/, uninhabitable /ˌʌnɪnˈhæbɪtəbəl/

Como praticar com este vídeo

  1. Ouça o vídeo inteiro uma vez sem falar e anote as palavras que você não conhece.
  2. Comece na velocidade 0,75×, faça shadowing frase por frase e volte à velocidade normal quando ficar fácil.
  3. Grave a sua voz e compare com o original, prestando atenção a palavras como habitable, helium, hydrogen.

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.

Técnica de shadowing: leia o guia completo passo a passo →