Luyện nói tiếng Anh bằng Shadowing qua video: How to Move the Sun: Stellar Engines
Đang tạo bài học...
1
Nothing in the universe is static.
2
In the Milky Way, billions of stars orbit the galactic center.
3
Some, like our Sun, are pretty consistent, keeping a distance of around 30,000 light years from the galactic center,
4
completing an orbit every 230 million years.
5
This dance is not an orderly ballet, more like a skating rink filled with drunk toddlers.
6
This chaos makes the galaxy dangerous.
7
Our solar neighborhood is constantly changing, with stars moving hundreds of kilometers every second.
8
Only the vast distances between objects protect us from the dangers out there.
9
But we might get unlucky in the future.
10
At some point we can encounter a star going supernova, or a massive object passing by and showering Earth with asteroids.
11
If something like this were to happen, we would likely know thousands, if not millions of years in advance.
12
But we still couldn't do much about it.
13
Unless we move our whole solar system out of the way.
14
To move the solar system, we need a stellar engine, a megastructure used to steer a star through the galaxy.
15
It's the kind of thing
16
that might be built by an advanced civilization with Dyson Sphere
17
level technology that's thinking about their future millions of years ahead of time.
18
But how do we possibly move the hundreds of thousands of objects in the solar system?
19
The good news is we can ignore all of that.
20
We only need to move the sun, or the other stuff is glued to it by gravity and will follow it wherever it decides to go.
21
There are lots of ideas about what a stellar engine might look like and how it would work.
22
We've picked two grounded in our current understanding of physics that could be built in theory.
23
The simplest kind of stellar engine is the Shkadov thruster, a giant mirror.
24
It works on the same principle as a rocket.
25
Like rocket fuel, the photons released as solar radiation carry momentum.
26
Not a lot, but a bit.
27
For example, if an astronaut turned on a flashlight in space, it would push them backwards very, very slowly.
28
A stellar engine will work a little better than a flashlight because the The sun produces a lot of photons.
29
The basic idea of the Shkadov thruster is to reflect up to half of the solar radiation to create thrust
30
and slowly push the sun where we want it to go.
31
In order for the Shkadov thruster to work, it must be kept in the same place, not orbiting the sun.
32
Although the sun's gravity will try to pull it in, it would be supported by radiation pressure which props the mirror up.
33
This means the mirror would have to be very light, made of micron-thin reflecting foil from materials like aluminium alloys.
34
The mirror's shape is important too.
35
Enveloping the sun in a giant spherical shell wouldn't work because that would refocus light back to the sun, heating it up and creating all sorts of unpleasant problems.
36
Instead, we use a parabola, which sends most of the photons around the sun and in the same direction, which maximizes thrust.
37
To prevent accidentally burning or freezing Earth with too much or too little sunlight, the only safe place to build a Skadov thruster is over the Sun's poles.
38
This means we can only move the Sun vertically in the plane of the solar system
39
and one direction in the Milky Way, which limits our travel options a bit.
40
But that is basically it.
41
For a civilization capable of building a Dyson Sphere, this is a relatively simple endeavor.
42
Not complicated, just very hard to build.
43
At full throttle, the solar system could probably be moved by about 100 light years over 230 million years.
44
Over a few billion years, it gives us near complete control over the sun's orbit in the galaxy.
45
But in the short term, this might not be fast enough to dodge a deadly supernova.
46
That's why we thought we could do better.
47
So we asked our astrophysicist friend if he could design a faster stellar engine for this video.
48
He did and wrote a paper about it that's been published in a peer-reviewed journal.
49
You can find it in our sources document.
50
We're going to call our new stellar engine the Kaplan thruster.
51
It works a lot like a traditional rocket.
52
Shoot exhaust one way to push yourself the other.
53
It's a large space station platform powered by a Dyson sphere that gathers matter from the sun to power nuclear fusion.
54
It shoots out a very fast jet of particles at nearly 1% the speed of light out of the solar system.
55
A second jet pushes the sun along like a tugboat.
56
The Kaplan thruster requires a lot of fuel, millions of tons per second.
57
To gather this fuel, our thruster uses very large electromagnetic fields to funnel hydrogen
58
and helium from the solar wind into the engine.
59
The solar wind alone doesn't provide enough fuel though.
60
And that's where the Dyson Sphere comes in.
61
Using its power, sunlight can be refocused to the surface of the sun.
62
This heats small regions to extreme temperatures, lifting billions of tons of mass off the sun.
63
This mass can be collected and separated into hydrogen and helium.
64
The helium is burned explosively in thermonuclear fusion reactors.
65
A jet of radioactive oxygen at a temperature of nearly a billion degrees is expelled
66
and becomes our primary source of propulsion from our stellar engine.
67
To prevent the engine from just crashing into the sun, it needs to balance itself itself.
68
To do this, we accelerate the collected hydrogen with electromagnetic fields using particle accelerators and shoot a jet back at the Sun.
69
This balances the thruster and transfers the thrust of our engine back to the Sun.
70
In as little as a million years, this engine can move the Sun by 50 light-years, more than enough to dodge a supernova.
71
At full throttle, the solar system can be completely redirected in its galactic orbit in 10 million years.
72
But wait, won't we use up the Sun this way?
73
Fortunately, the Sun is so massive that even billions of tons of material will barely scratch the surface.
74
In fact, this megastructure will actually extend our Sun's life since lower-mass stars burn slower,
75
keeping the solar system inhabitable for many more billions of years.
76
With a Kaplan thruster, we could turn the entire solar system into our spaceship.
77
For example, by orbiting backwards in the galaxy and colonizing hundreds or thousands of stars as we pass by them.
78
It may even be possible to escape the galaxy entirely and expand beyond the Milky Way.
79
Stellar engines are the kind of machines built by civilizations thinking not in terms of years or decades, but eons.
80
Since we know that our Sun will die one day, a stellar engine could allow the far future descendants of humans
81
to travel to other stars without ever having to venture into the terrifying dark abyss of interstellar space.
82
Until we build a stellar engine, we're adrift and subject to the whims of the galactic sea.
83
We may not like where it leads us.
84
Maybe our descendants will set sail and become an interstellar species for millions of years to come.
85
This was our last video for the year 12,019 of the human era and what a year it was.
86
So much stuff happened everywhere to so many different people.
87
Calendars and holidays are just imaginary, but they help us to cut our lives into pieces pieces that our brains can handle.
88
We're leaving 12019 behind with a weird mixture of disillusion and hope.
89
The world is screwed up, but we can fix it.
90
In a few days, this year will be over, and we'll get to try again.
📺 Cùng kênh
C1105
Can Earth Run Out of Water?
IELTS PrepTOEFL PrepUniversity Students
C1536
What If You Never Slept?
IELTS PrepTOEFL PrepUniversity Students
C11
Your Skeleton Is Electric
IELTS PrepTOEFL PrepUniversity Students
C171
Could Humans Evolve Flight?
IELTS PrepTOEFL PrepUniversity Students
B21
Would You Upload Your Mind?
IELTS PrepTOEFL PrepUniversity Students
C164
What the Flu Does to Your Body
IELTS PrepTOEFL PrepUniversity Students
C11
Your Brain on Magic Mushrooms
IELTS PrepTOEFL PrepUniversity Students
C17
3 Reasons Why Nuclear Energy Is Terrible! 2/3
IELTS PrepTOEFL PrepUniversity Students
B21
We Finally Know More About Humanity’s First Civilization
Cambridge Exam PrepUniversity Students
C13
What Is Life? Is Death Real?
University StudentsWorking Adults
C1148
How Antidepressants Work
IELTS PrepTOEFL PrepUniversity Students
C12
Is War Over? — A Paradox Explained
IELTS PrepTOEFL PrepUniversity Students
C1757
How Stress Changes Your Brain
IELTS PrepTOEFL PrepUniversity Students
C15
How ADHD Medication Works
Daily ConversationUniversity StudentsWorking Adults
C11
The Most Complex Language in the World
IELTS PrepTOEFL PrepUniversity Students
C14
Your Brain Peaked at Birth
University StudentsWorking Adults
C170
We Won’t Explore the Galaxy...
IELTS PrepTOEFL PrepUniversity Students
B25
Let’s Steal a New Moon
IELTS PrepTOEFL PrepUniversity Students
C13
What Happens AFTER Nuclear War?
IELTS PrepTOEFL PrepUniversity Students
C11
3 Reasons Why Nuclear Energy Is Awesome! 3/3
IELTS PrepTOEFL PrepUniversity Students
✨ Video gợi ý
C16
113 câu
What If Earth got Kicked Out of the Solar System? Rogue Earth
IELTS PrepTOEFL PrepUniversity Students
C12
155 câu
Let There Be Light: Maxwell's Equation EXPLAINED for BEGINNERS
IELTS PrepTOEFL PrepUniversity Students
C11
277 câu
SpaceX Is Ready to Send Starship Into Orbit | This Week in Spaceflight
IELTS PrepTOEFL PrepUniversity Students
B22
224 câu
20% Speed of Light!! NEW Light Engine is INSANE!
IELTS PrepTOEFL PrepUniversity Students
B23
61 câu
RE3 Unit 7A
IELTS PrepTOEFL PrepUniversity Students
C12
47 câu
We Found Galaxies Too Old for the Universe
IELTS PrepTOEFL PrepUniversity Students
C16
73 câu
Superfluid Dark Matter
IELTS PrepTOEFL PrepUniversity Students
C14
104 câu
Why Are You Alive – Life, Energy & ATP
IELTS PrepTOEFL PrepUniversity Students
C12
143 câu
You Live Inside a Cosmic Hole... And there's a problem
IELTS PrepTOEFL PrepUniversity Students
B218
41 câu
Unit 6: Living on Mars
IELTS PrepTOEFL PrepUniversity Students
C11
270 câu
The Most Misunderstood Concept in Physics
IELTS PrepTOEFL PrepUniversity Students
C15
28 câu
How to Blow Up the Earth - Nuclear Engineer Reacts to Zack D. Films
IELTS PrepTOEFL PrepUniversity Students
Từ vựng và ghi chú luyện nói cho bài học này
Video này có 90 câu và 1298 từ để luyện shadowing. Phần lời nói dài 8:29. Người nói nói với tốc độ tự nhiên, khoảng 153 từ mỗi phút, gần với hội thoại hằng ngày. Chỉ 79% số từ nằm trong 3.000 từ tiếng Anh thông dụng nhất, nên từ vựng khá khó.
Từ vựng quan trọng trong video
15 từ đáng học trong video, kèm phiên âm và nghĩa:
| Từ | Phiên âm | Nghĩa |
|---|---|---|
| orbit danh từ | /ˈɔɹ.bɪt/ | quỹ đạo |
| galaxy danh từ | /ˈɡæl.ək.si/ | thiên hà |
| sphere danh từ | /sfɪɚ/ | mặt cầu |
| mirror danh từ | /ˈmiɹɚ/ | gương, kiếng |
| rocket danh từ | /ˈɹɑk.ɪt/ | động cơ tên lửa, tên lửa |
| ton danh từ | /tʌn/ | tấn |
| radiation danh từ | /ˌɹeɪ.diˈeɪ.ʃən/ | phóng xạ, bức xạ |
| civilization danh từ | /ˌsɪv.ɪ.laɪˈzeɪ.ʃən/ | văn minh |
| hydrogen danh từ | /ˈhaɪdɹəd͡ʒ(ə)n/ | hiđrô, hi-đrô |
| reflect động từ | /ɹɪˈflɛkt/ | phản chiếu |
| collect động từ | /ˈkɑlɪkt/ | thu thập, gom góp |
| dodge động từ | /dɑd͡ʒ/ | tránh, né |
| particle danh từ | /ˈpɑɹtək(ə)l/ | hạt |
| sunlight danh từ | /ˈsʌnˌlaɪt/ | ánh nắng, ánh sáng mặt trời |
| electromagnetic tính từ | /ɪˌlɛk.tɹoʊ.mæɡˈnɛ.tɪk/ | điện từ |
Phát âm cần chú ý
Người nói dùng 9 dạng rút gọn, ví dụ we're, couldn't, doesn't. Hãy nói theo dạng ngắn đúng như bạn nghe.
- Âm “th”: thrust /θɹʌst/, gather /ˈɡæðɚ/, thin /ˈθɪn/, thruster /ˈθɹʌ.stɚ/, throttle /ˈθɹɔ.tl̩/
- Âm “sh” và “zh”: radiation /ˌɹeɪ.diˈeɪ.ʃən/, civilization /ˌsɪv.ɪ.laɪˈzeɪ.ʃən/, fusion /ˈfjuː.ʒən/, shell /ʃɛl/, flashlight /ˈflæʃˌlaɪt/
- Từ dài — đặt trọng âm cho đúng: radiation /ˌɹeɪ.diˈeɪ.ʃən/, civilization /ˌsɪv.ɪ.laɪˈzeɪ.ʃən/, electromagnetic /ɪˌlɛk.tɹoʊ.mæɡˈnɛ.tɪk/, complicated /ˈkɑm.plɪˌkeɪ.tɪd/, accidentally /ˌæk.sɪˈdɛnt(ə)li/
Cách luyện với video này
- Nghe hết video một lần, chưa cần nói, và ghi lại những từ bạn chưa biết.
- Bắt đầu ở tốc độ 0,75×, nói đuổi từng câu, rồi quay lại tốc độ bình thường khi đã quen.
- Ghi âm giọng mình rồi so với bản gốc, chú ý các từ như orbit, galaxy, sphere.
Phương Pháp Shadowing Là Gì?
Shadowing là kỹ thuật học ngôn ngữ có cơ sở khoa học, ban đầu được phát triển cho chương trình đào tạo phiên dịch viên chuyên nghiệp và được phổ biến rộng rãi bởi nhà đa ngôn ngữ học Dr. Alexander Arguelles. Nguyên lý cốt lõi đơn giản nhưng cực kỳ hiệu quả: bạn nghe tiếng Anh của người bản xứ và lặp lại to ngay lập tức — như một "cái bóng" (shadow) đuổi theo người nói với độ trễ chỉ 1–2 giây. Khác với luyện ngữ pháp hay học từ vựng bị động, Shadowing buộc não bộ và cơ miệng phải đồng thời xử lý và tái tạo ngôn ngữ thực tế. Các nghiên cứu khoa học xác nhận phương pháp này cải thiện đáng kể phát âm, ngữ điệu, nhịp điệu, nối âm, kỹ năng nghe và độ lưu loát khi nói — đặc biệt hiệu quả cho người luyện IELTS Speaking và muốn giao tiếp tiếng Anh tự nhiên như người bản ngữ.