A Brief History of Time

핵심 요약

• 시공간은 하나로 엮여 있으며, 질량은 천 위의 추처럼 이를 휘어지게 합니다
• 우주는 팽창하고 있습니다. 즉, 뜨겁고 빽빽했던 시작점이 있었다는 뜻입니다
• 거대한 세계는 상대성 이론이, 미세한 세계는 양자역학이 지배합니다
• 블랙홀은 완전히 검지 않습니다. 복사를 내뿜으며 서서히 증발할 수 있습니다
• 엔트로피가 증가하기에 시간에 방향이 생기고, 과거를 기억할 수 있습니다

이 비트의 내용

1. 가장 쉬운 언어로 풀어낸 우주

   A scientist gives a public lecture on astronomy and an elderly listener insists the world rests on the back of a giant turtle. Asked what the turtle stands on, she replies that it is turtles all the way down.

2. Space and time bend

   For centuries, people thought of time as a universal clock ticking the same everywhere. Einstein overturned that.

3. 모든 것이 멀어지고 있습니다

   In the 1920s, Edwin Hubble noticed that distant galaxies are moving away from us, and the farther away they are, the faster they recede. This is what an expanding universe looks like from the inside.

4. 극미의 세계를 지배하는 기묘한 규칙들

   Relativity governs stars and galaxies, but a different set of rules runs the world of atoms. Quantum mechanics says that you cannot know both the exact position and exact speed of a particle at once; nature has a built-in fuzziness.

5. Black holes and the arrow of time

   A black hole forms when a massive star collapses so far that not even light can escape its gravity. For decades it was assumed nothing could ever come out.

6. 직접 적용해 보기

   This week, step outside on a clear night and pick one star, remembering that the light entering your eye left it years or centuries ago, so you are looking at the past. Watch a short explainer on how GPS satellites correct for relativity, and you will see Einstein's ideas at work in your phone.