Day 1-2

It followed that a heavy body should fall faster than a light one.

govern the universe

pure thought

So no one until Galileo bothered to see whether bodies of different weight  did in fact fall at different speeds.

let go of a ball on a slope that drops by one meter per second after one second

air resistance

perform an experience

explicit : precisely and clear expressed or readily observable

It's an explicit statement.

According to Newton's second law, these two effects will exactly cancel each other, so the acceleration will be the same in all cases.

elliptical 椭圆的

If one carried out experiments with moving bodies on the train, all Newton's laws would would still hold.

refute: overthrow by argument, evidence or proof

The speaker refuted his opponent's  arguments.

infrared 红外线的

Einstein is usually given the credit for the new theory, but Poincare is remembered by having his name attached to an important part of it.

postulate 为证实一个理论的正确性而进行的假设

assume 指有很少或完全无根据的武断推测或不合逻辑的推测

intrinsic 本身的，固有的    intrinsic mass 固有质量

pulse 脉冲

velocity 速率
coordinate 坐标

spatial : pertaining to or involving or having the nature of space

geodesic 测地线的 the shortest line between two points on a mathematically defined surface (as a straight line on a plane or an arc of a great circle on a sphere)

ionic: containing or involving or occurring in the form of ions(离子)

Their measurement had been sheer luck, or a case of knowing the result they wanted to get, not an uncommon occurrence in science.

advent: arrival that has been awaited (especially of something momentous)

the advent of the computer

This is a twins paradox, but it is a paradox only if one has the idea of absolute time at the back of one's mind.

hypothesis 书面用词，指有待作进一步验证或证实的假设

assumption 侧重主观推测或主观设想

repugnant 矛盾的

a by-law must not be repugnant to the general law of the country

apocryphal: questionable

contemplative: spending a lot of time thinking seriously and quietly

in a contemplative mood

celestial: of the sky or of the heaven

celestial light/music

Day 3

Day 4

When I was reading this passage, I found that it is not hard to translate it as long as I can understand the knowledge at the back of the words. So translating is not only about words but the things between the lines.

I've learnt some of things in the passage when I was a high school student, like Newton's laws, general relativity. But what I've learned is limited. I can use what I know to solve the problems in an exam while it's still not enough to elaborate the theory. However, because of what I have learned in high school, things in the passage come quiet familiar to me. It reminds me a lot of my high school life. At that time, students complainted a lot about the exams, holding that is useless for them and without any practical help if they won't study in the related field. I agreed with them. Only after reading the things about physics, chemistry, biology, only when it was written in English, I came to realize the purpose of high school education. It was not easy to understand when I was still in it because it seems just to be something for exams as if it would never end. Now I know it's about "general education". No matter what your major is in college, no matter what you learned before, you should know something about the subject that seems to be irrelevant to you.

After all, it's a lifelong-learning age.