Aristotelian
adj.of or relating to Aristotle or to his philosophy.
n.1. A follower of Aristotle or his teachings.
2. A person whose thinking and methods tend to be empirical, scientific, or commonsensical.
in accord with
If one person, action, or fact is in accord with another, they are in agreement and there is no conflict between them. You can also say that two people or things are in accord. (FORMAL)
...this military action, taken in accord with United Nations resolutions
Propagation
Physics The act or process of propagating, especially the process by which a disturbance, such as the motion of electromagnetic or sound waves, is transmitted through a medium such as air or water.
Infrared
Adj.a type of light that feels warm but cannot be seen:
Their pilots are guided by an infrared optical system that shows images clearly even at night.
n.Infrared light or the infrared part of the spectrum./IR
Ultraviolet
Ultraviolet light or radiation is what causes your skin to become darker in colour after you have been in sunlight. In large amounts ultraviolet light is harmful.
The sun's ultraviolet rays are responsible for both tanning and burning.
Gamma rays
Gamma raysare a type of electromagnetic radiation that has a shorter wavelength and higher energy than X-rays.
Hitherto
adv.(FORMAL)until now or until a particular time:
Mira revealed hitherto unsuspected talents on the cricket pitch.
Postulate
If you postulate something, you suggest it as the basis for a theory, argument, or calculation, or assume that it is the basis. (FORMAL)
...arguments postulating differing standards for human rights in different cultures...
Freud postulated that we all have a death instinct as well as a life instinct.
Diagonal line
Adj.1A diagonal line is straight and sloping, not horizontal or vertical, for example joining two opposite corners of a square or other four-sided flat shape:
The book has a diagonal black stripe on the cover.
2moving in a diagonal line:
Peters received a diagonal pass and headed the ball into the net.
Inconsistent
Adj.If a reason, idea, opinion, etc. is inconsistent, different parts of it do not agree, or it does not agree with something else:
These findings are inconsistent with those of previous studies.
Geodesic
n.Mathematics The shortest line between two points on any mathematically defined surface.
Elongate
v.to become or make something become longer, and often thinner:
The cells elongate as they take in water.
Ellipse
n.An ellipse is an oval shape similar to a circle but longer and flatter.
The Earth orbits in an ellipse.
Advent
The advent of an important event, invention, or situation is the fact of it starting or coming into existence. (FORMAL)
...the leap forward in communication made possible by the advent of the mobile phone.
Proportional
Adj.If two amounts are proportional, they change at the same rate so that the relationship between them does not change:
Weight is proportional to size.
with respect to
You use with respect to to say what something relates to. In British English, you can also sayin respect of. (FORMAL)
Parents often have little choice with respect to the way their child is medically treated...
stub
v~ sth (against/on sth)strike (esp one's toe) accidentally against sth hard
I've stubbed my toe on a rock.
Intrinsic
Adj.being an extremely important and basic characteristic of a person or thing:
works of little intrinsic value/interest
Maths is an intrinsic part of the school curriculum.
Follow from
result from sth; happen as a consequence
It follows from Newton’s laws that there is no unique standard of rest.
Impulse
Physics The product obtained by multiplying the average value of a force by the time during which it acts. The impulse equals the change in momentum produced by the force in this time interval.
【物理学】冲量，推进力：力的平均值与它的作用时间相乘的结果。等于力在其作用时间段内产生的动量的变化
Speed
Physics The rate or a measure of the rate of motion.
【物理学】速率：运动的速率或限度
Air resistance
A force that tends to oppose or retard motion.
阻力：倾向于妨碍或阻滞运动的力量
Newton's Laws of Motion
http://www.physics4kids.com/files/motion_laws.html
Acceleration
Abbr.a Physics The rate of change of velocity with respect to time.
缩写a【物理学】加速度：速度相对于时间变化的速率
Mass
Abbr.m Physics The measure of the quantity of matter that a body or an object contains. The mass of the body is not dependent on gravity and therefore is different from but proportional to its weight.
缩写m【物理学】质量：物体内所包含的物质的量。物体质量不受重力影响，因此与物体的重量不同，但是与其成比例
Cancel
To neutralize one another; counterbalance:
抵消，中和：使彼此中和；抵消：
two opposing forces that canceled out./ cancel each other
Orbits
n.The path of a celestial body or an artificial satellite as it revolves around another body.
运行轨道：天体绕另一天体或人造卫星绕一天体旋转所运行的轨道
Events
Physics A phenomenon or occurrence located at a single point in space-time, regarded as the fundamental observational entity in relativity theory.
【物理学】事件：在时空中位于一点的现象或事件，被认为是相对论中基本的观察实体
electromagnetic field
PhysicsA region of space characterized by a physical property, such as gravitational or electromagnetic force or fluid pressure, having a determinable value at every point in the region.
【物理学】场，磁场：有物理性质，如引力或电磁力或液压的空间区域，在此区域中每一点有一定值
Ether
1.Etheris a colourless liquid that burns easily. It is used in industry and in medicine as an anaesthetic.
...a sweetish smell of ether and iodine.
2.Physics An all-pervading, infinitely elastic, massless medium formerly postulated as the medium of propagation of electromagnetic waves.
【物理学】以太，能媒：一种在以前被假定为电磁波的传播媒质并具有绝对连续性、高度弹性的极其稀薄的媒体
Coordinates
Mathematics Any of a set of two or more numbers used to determine the position of a point, line, curve, or plane in a space of a given dimension with respect to a system of lines or other fixed reference.
【数学】坐标：由两个或多个数值组成的数组中的任一数值，用来在一个直线系统或其它固定参照数值方面决定点、直线、曲线或平面在已知范围空间内的位置
Alpha Centauri
n.amultiple star in Centaurus whose three components represent the brightest object in the constellation, 4.4 light-years from Earth.
半人马座阿尔法星：人马座中的聚星，其三个组成部分是星座中最亮的部分，距地球4.4光年
light cone 光锥
n.a light cone is the path that a flash of light, emanating from a single event (localized to a single point in space and a single moment in time) and traveling in all directions, would take through spacetime.
Curvature
n.MathematicsThe ratio of the change in the angle of a tangent that moves over a given arc to the length of the arc.
【数学】曲率：切线通过给定弧线的角度变化与弧线长度之间的比率
Reading notes:
1.About the book
In this chapter, Hawking tries to introduce the theory of relativity in plain language. Firstly, he starts with Galileo's famous experiment, proving that each body increases its speed at the same rate, no matter what its weight. Newton uses these measurements as foundations for his laws of motion. Then Hawking turns to Newton's laws of motion. Newton believes that the effect of force is to change the speed of a body instead of keeping it moving. He also discovers the law of gravity, telling that the farther apart the bodies, the smaller the force. When Hawking compares the trio( Aristotle, Galileo and Newton), he finds the big difference is the idea of preferred state of rest. Because of the lack of an absolute standard of rest, one can not determine the time and postion of events in space. But both Aristotle and Newton believes in absolute time. So people tries to unveil the mystery. That is how the propagation of light is found. At the same time, they know that the speed of light is finite, high, certain and fixed. They also discover "ether"-a media present everywhere.
However, Einstein points out that the whole idea of an ether is unnecessary and one should abandon the idea of aboslute time. He later puts forward the theory of relativity, which is revolutionary. In the theory of relativity, we need to define distance in terms of time and the speed of light. We must accept that time is not completely separate from and independent of space, but is combined with it to form an object called space-time. The theory also points out the truth ( at least for now...) of gravity and the speed of light. In the end, Hawking gives the example of twins paradox, offering a new way of thinking in space and time.
2.About my opinions
Although Mr. Hawking tries to explain the theory in a plain way as much as possible, I still find it too difficult for me. The previous examples of Galileo and Newton are much easier because I've learned it at high school. But the theory of relativity is a suffering. Annie's podcast has solved some puzzles but I am still stay in the coventional thinking. What I need to do is a change of thinking.(which may take a long time...) But I do feel the spirit of science: challenge the authority. Think of that, Einstein's greatness comes not from his theory but from his courage.He dares to say no to the accepted idea and he has proved himself in his theory. And recently, I am reading a biography of Einstein. (Einstein: his life and universe Kindle.mobi ) The book breaks my prejudice against scientists. I used to think that scientists were a group of geeks who bend their heads in the lab everyday. However, Einstein is not one of them. He loves music and plays voilin well ; he likes writing poems to his wife, saying that " without you my life is not life"; he keeps his childlike capacity for wonder; he shows his optimistic look even in his dark days. He is a paramount icon for many people. His name is the synonym for genius. But it is his engaging humanity and relentless empathy that make him world-famous.
" A foolish faith in authority is the worst enemy of truth." --by Einstein
