쉐도잉 연습: How Bitcoin Works in 5 Minutes (Technical) - 영상으로 영어 말하기 배우기

연습 모드 선택

각 모드는 전체 화면 연습실로 열립니다.

29 문장

문장이 너무 짧거나 길면 Edit를 눌러 조정하세요.

At a very basic level, Bitcoin is just a digital file or ledger that contains names and balances, and people exchange money by changing this file. When Bob sells Carol a lawn mower for 5.2 Bitcoins, Bob's balance goes up by 5.2, and Carol's down by 5.2. There's no gold or government issued money backing these numbers.

Bob is only willing to trade his real-life lawn mower for a higher number in this digital file because he has faith that other people will also trust the system.

So who maintains this ledger and makes sure no one cheats? One goal of Bitcoin is to avoid any centralized control, so every participant maintains their own copy of the ledger.

One surprising consequence of this is that everyone can see everyone else's balances, although the real system only uses account numbers and not names, so there's some level of anonymity.

If everyone maintains their own ledger, how are all the ledgers kept in sync as money is transferred? At a basic level, when you want to send money, you simply tell everyone else by broadcasting a message with your account number, the receiver's, and the amount.

Everyone across the entire world then updates their ledger.

As a quick aside, I'm describing how Bitcoin works for power users--people who help maintain the system. You can also just use the system to send a receive money, though, without maintaining a ledger.

If sending money is as simple as creating a message with some account numbers, what's to stop a thief, Alice, from spending Bob's money by using his account number? Like a pen and paper check, Bitcoin requires a kind of signature to prove that the sender is the real owner of an account, but it's based on math rather than handwriting.

When a new account number is created, it comes along with a private key mathematically linked to that account number. If you've heard of a Bitcoin wallet, these keys are what it holds, and are what allow you to create signatures.

To create a signature, a private key and the text from a transaction are fed into a special cryptographic function. Another function allows other people to check the signature, making sure it was created by the account owner, and that it applies to that specific transaction.

Unlike the handwritten version, these signatures can't be copied and reused in the future, as they're unique to each transaction.

While the mathematical signatures prove who sent a transaction, they can't prove when it was sent, and this turns out to be problematic.

In our traditional banking system, if Alice wrote two checks, but only had enough money to cover one of them, the bank would pay the first person attempting to cash his check, but refuse the 2nd, because Alice's account would be empty.

So the order of these checks is critical, because it determines who should get paid.

Unfortunately, order is much harder to determine in Bitcoin, where instead of single bank, there are individuals all over the world. Network delays might cause transactions to arrive in different orders at different places, and fraudsters could lie about timestamps.

Two recipients might both think their transaction is first and ship a product, effectively allowing Alice to spend her money twice! Bitcoin prevents this by providing a way for the entire world to decide on transaction order.

As new transactions are created, they go into a pool of pending transactions. And from here, they'll be sorted into a giant chain that locks in their order.

To select which transaction is next, a kind of mathematical lottery is held. Participants select a pending transaction of their choice, and begin trying to solve a special problem that will link it to the end of the chain. The first person to find a solution wins, and gets to have their transaction selected as the next in the chain.

So what's this linking problem? It's based on a special function called a cryptographic hash. As scary as this sounds, it just mixes up its inputs and spits out a number, but it's special because it's irreversible. There's no easy way to start with an output and then find an input that generates it other than making lots of guesses. And this is literally what people are doing in Bitcoin--feeding this function random numbers until the output meets certain criteria.

Besides a random guess, you also input a transaction from the pending pool and chain, which is where the linking part comes in.

So the lottery provides a way for the entire world to decide which transaction is next, but the math behind it also helps ensure that everyone agrees about past transactions, too.

Suppose you're joining the network for the first time, and request a copy of the transaction chain to get caught up, but receive several different versions. Which one should you trust?

Ideally, you would trust the one that the majority of people are using, but determining this on the internet is difficult. What would stop a single person from voting millions of times? Bitcoin prevents this by requiring people to solve math problems to vote. This causes each vote to have a cost in computing power, making it unlikely that a single person or group could ever afford to outvote or out-compute the majority of users.

The transaction ordering process described before actually provides the voting system.

Part of the input to the linking problem is a transaction from the end of a chain, so each guess is effectively a vote for that chain. But how are all the votes tallied?

Because the cryptographic hash function has well defined statistical properties, you can look at any given answer and estimate how many guesses it took to find it, just like estimating how many coin flips it would take to get 100 heads in a row. So the links in a chain not only put transactions in order, but also act as an effective vote tally, making it easy to see which chain most people are using.

Finally, how does the money get created? Every time someone wins the lottery to pick the next transaction in the chain, new Bitcoins are created out of thin air and awarded to their account.

Solving these problem is commonly called "mining," as this is how money enters the system, but the main purpose of the math is to make sure everyone's ledgers agree. The math simply provides a convenient way to randomly distribute money into the world. In fact, sometime around 2140, no more money will be created, and participants will only be paid from fees added on to transactions.

I hope this gives you a quick sense for how Bitcoin works. If you'd like a more detailed summary, check out my 22 minute video: How Bitcoin Works Under the Hood.

앱 다운로드

유창하게 말하는 데 필요한 모든 것

AI 발음 평가문장마다 점수 확인

IPA 발음 연습모든 소리 마스터

단어 학습나만의 단어장 만들기

단어 게임놀면서 외우기

QR 스캔

Download on theApp Store Get it onGoogle Play

FOR YOU

이 레슨의 어휘와 말하기 포인트

이 영상에는 섀도잉할 문장 29개와 단어 1139개가 있습니다. 말하는 구간의 길이는 5:18입니다. 화자는 분당 약 215단어로 빠르게 말하므로 연음과 약하게 발음되는 소리가 많습니다. 영어에서 가장 많이 쓰이는 3,000단어에 속하는 단어가 80%뿐이라 어휘가 어려운 편입니다.

이 영상의 핵심 어휘

영상에 나오는 익혀 둘 만한 단어 15개를 발음, 뜻과 함께 정리했습니다.

단어	발음	뜻
transaction 명사	/tɹænˈzækʃən/	처리
signature 명사	/ˈsɪɡ.nə.t͡ʃə/	서명, 사인
mathematics 명사	/mæθ(.ə)ˈmæt.ɪks/	수학
select 동사	/sɪˈlɛkt/	고르다
solve 동사	/sɒlv/	해결하다
lottery 명사	/ˈlɑtɚi/	복권
participant 명사	/pɑːɹˈtɪsəpənt/	참가자
output 명사	/ˈaʊtpʊt/	출력
lawn 명사	/lɔːn/	풀밭, 초지
hash 명사	/ˈhæʃ/	해시
thin 형용사	/ˈθɪn/	가늘다, 얇다
delay 명사	/dɪˈleɪ̯/	지연, 지체
broadcast 명사	/ˈbɹɔːd(ˌ)kɑːst/	방송
refuse 동사	/ɹɪˈfjuːz/	거절하다
arrive 동사	/əˈɹaɪv/	도착하다

영상에 나오는 구동사

단어	뜻
go up 동사	올라가다

이 영상의 문법

화자가 가장 많이 쓰는 문형을 영상 속 실제 표현과 함께 정리했습니다.

문형	영상 속 표현
수동태 be + 과거분사 — 누가 하는지보다 무슨 일이 일어나는지에 초점	is transferred · is created · are fed
관계절 who / which + 절 — 사람이나 사물에 대한 추가 정보	people who help · chain, which is

주의할 발음

화자는 can't, I'm, they'll 같은 축약형과 약화된 형태를 8번 사용합니다. 들리는 대로 짧게 발음하세요.

“th” 소리: mathematics /mæθ(.ə)ˈmæt.ɪks/, mathematical /ˌmæθ(.ə)ˈmæt.ɪ.kəl/, thin /ˈθɪn/, thief /ˈθiːf/
“sh”와 “zh” 소리: transaction /tɹænˈzækʃən/, hash /ˈhæʃ/
긴 단어 — 강세 위치에 주의: mathematics /mæθ(.ə)ˈmæt.ɪks/, participant /pɑːɹˈtɪsəpənt/, mathematical /ˌmæθ(.ə)ˈmæt.ɪ.kəl/, statistical /stəˈtɪs.tɪ.kəl/, recipient /ɹəˈsɪp.i.ənt/

이 영상으로 연습하는 방법

먼저 말하지 않고 영상을 끝까지 듣고 모르는 단어를 적어 둡니다.
0.75배속으로 한 문장씩 섀도잉을 시작하고, 익숙해지면 보통 속도로 돌아갑니다.
자신의 목소리를 녹음해 원본과 비교하고, transaction, signature, mathematics 같은 단어에 특히 주의합니다.

쉐도잉이란? 영어 실력을 빠르게 키우는 과학적 방법

쉐도잉(Shadowing)은 원래 전문 통역사 훈련을 위해 개발된 언어 학습 기법으로, 다언어 학자인 Dr. Alexander Arguelles에 의해 대중화된 방법입니다. 핵심 원리는 간단하지만 매우 강력합니다: 원어민의 영어를 들으면서 1~2초의 짧은 지연으로 즉시 소리 내어 따라 말하는 것——마치 '그림자(shadow)'처럼 화자를 따라가는 것입니다. 문법 공부나 수동적인 청취와 달리, 쉐도잉은 뇌와 입 근육이 동시에 실시간으로 영어를 처리하고 재현하도록 훈련합니다. 연구에 따르면 이 방법은 발음 정확도, 억양, 리듬, 연음, 청취력, 말하기 유창성을 크게 향상시킵니다. IELTS 스피킹 준비와 자연스러운 영어 소통을 원하는 분들에게 특히 효과적입니다.

섀도잉 방법: 단계별 전체 가이드 읽기 →

쉐도잉 연습: How Bitcoin Works in 5 Minutes (Technical) - 영상으로 영어 말하기 배우기

연습 모드 선택

앱 다운로드

추천 영상

What is Bitcoin? Bitcoin Explained Simply

Everything Valuable from an MBA in 25 minutes

Distributed Transactions Explained: 2 Phase Commit vs Saga Pattern

How a CPU Works in 100 Seconds // Apple Silicon M1 vs Intel i9

Exposing The Flaw In Our Phone System

How to Feel Rich When Your Bank Account Doesn't Agree Yet

World Models explained in 10min..

The Most Confused Concepts in Engineering

Podcast Nâng Cao - Cùng Mình Nói Về Tiền | Học 37 Từ Vựng Hàng Ngày | Tập 23

System Design: Why is Kafka fast?

How to Make Anything - Learn to Think Like an Engineer

How Ad Blockers Work