Astrophysics for People in a Hurry

핵심 요약

• 부엌에서부터 가장 먼 은하까지, 동일한 물리 법칙이 적용됩니다
• 우주의 거의 대부분은 아직 볼 수 없는 암흑 물질과 암흑 에너지입니다
• 우리 몸의 원자는 오래전 폭발한 별의 내부에서 만들어졌습니다
• 빛은 타임머신입니다. 먼 곳을 보는 것은 과거를 보는 것입니다
• 우주적 관점은 인간의 다툼을 하찮게 만들고 호기심을 소중하게 만듭니다

이 비트의 내용

1. The cosmos in coffee breaks

   You are waiting for a delayed train, phone in hand, with 10 spare minutes. Neil deGrasse Tyson wrote this book for exactly that moment: short, self-contained chapters that give a busy person a working sense of how the universe operates.

2. One set of laws everywhere

   The most powerful idea in astronomy is that physics is universal. Gravity that drops a mango from a tree in Ratnagiri is the same gravity that keeps the Moon in orbit and the Milky Way spinning.

3. Most of the universe is dark

   Here is an uncomfortable fact: everything you can see, every star, planet, and person, makes up only around 5 percent of what is out there. Galaxies spin so fast that they should fly apart, yet they hold together, which means something unseen is providing extra gravity.

4. You are made of stardust

   Where did the calcium in your bones and the iron in your blood come from? Not from Earth originally.

5. Light is a time machine

   Light is fast but not infinitely fast, and that single fact turns telescopes into time machines. Sunlight takes about 8 minutes to reach you, so you always see the Sun as it was 8 minutes ago.

6. 직접 적용해 보기

   This week, download a free sky app and identify one planet and one constellation from your balcony or terrace, even through city lights. When you next see the Sun rise, remind yourself that you are watching light that is 8 minutes old.