Vocabulary
1.elliptical
: shaped like a flattened circle : oval
The moon follows an elliptical path around the Earth.
: using few words and therefore hard to understand
a writer with an elliptical style
2. Newton's first law
Newton's First Law states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force. It may be seen as a statement about inertia, that objects will remain in their state of motion unless a force acts to change the motion. Any change in motion involves an acceleration, and then Newton's Second Law applies; in fact, the First Law is just a special case of the Second Law for which the net external force is zero.
Newton's First Law contains implications about the fundamental symmetry of the universe in that a state of motion in a straight line must be just as "natural" as being at rest. If an object is at rest in one frame of reference, it will appear to be moving in a straight line to an observer in a reference frame which is moving by the object. There is no way to say which reference frame is "special", so all constant velocity reference frames must be equivalent.
3. Newton's Second Law
Newton's Second Law as stated below applies to a wide range of physical phenomena, but it is not a fundamental principle like the Conservation Laws. It is applicable only if the force is the net external force. It does not apply directly to situations where the mass is changing, either from loss or gain of material, or because the object is traveling close to the speed of light where relativistic effects must be included. It does not apply directly on the very small scale of the atom where quantum mechanics must be used.
Data can be entered into any of the boxes below. Specifying any two of the quantities determines the third. After you have entered values for two, click on the text representing to third to calculate its value.
Newtons = kg * m/s2
pounds = slugs * ft/s2
Limitations of Newton's Second Law
4. Jupiter 木星
Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a giant planet with a mass one-thousandth that of the Sun, but two and a half times that of all the other planets in the Solar System combined.
5. disturbance
A disturbance is a noisy commotion that causes a hubbub or interruption. It can also be a worried mental state.
In hotels, people put up "Do not disturb" signs when they want to be left alone. That's a good clue to what a disturbance is: something, usually noisy or rowdy, that bothers people. An audience member yelling during a piano concert would be a disturbance. Disturbances can also be interruptions, like a disturbance in cable service when the cable goes out. Disturbances can also be mental: if you're worried or anxious, that's a type of internal disturbance.
6.infrared 红外线的
Infrared radiation, or simply infrared or IR, is electromagnetic radiation (EMR) with longer wavelengths than those of visible light, and is therefore invisible, although it is sometimes loosely called infrared light.
7. ether
乙醚
Ether，化学物质，别称diethyl ether，ethyl ether，透明无色易挥发液体，易燃具爆炸性。
8. notable
Notable=Someone or something that is notable is important or interesting.notable 则指重要的或有趣的.
Noticeable=ADJ-GRADED( 能被表示程度的副词或介词词组修饰的形容词) 容易注意到的;显著的;明显的 Something that is noticeable is very obvious,so that it is easy to see,hear,or recognize.
9.postulate 辨析
suppose 普通用词，指对事物进行假设、设想，所假设的事可能是真实的，也可能是虚
构的（从句需用虚拟语气）。
1）Supposehe is absent, what shall we do?
假设缺席了，我们该怎么办？
2）Let’s supposethat they had not helped us.What would have happened?
假定他们不曾帮助我们，会发生什么情况呢?
3）Sopposethat one day scientists pick up a transmission which they thinkis
generated by aliens.
假设有一天科学家收到了他们认为是外星人发射的信号。
4）Myths are accounts of important events that aresupposed to have occurred
some time during a culture’sformative years.
神话是描述那些据说是发生的时间在某一个文化的形成年的代重要事件。
assume指主观上毫无根据的武断推测或不合逻辑的推理。
1）It is entirelywrong to assume that your wealth entitles you tospecial
respect.
你认为财富能使你享特特殊礼遇，那就大错特错了。
2）I assumed that he wouldnot come to attend the funeral.
我猜想他不会来参加葬礼。
3）Some people assume that thereis life on the other planets when they see
UFOs.
有些人看到了不明飞行物就想当然地推测其他的行星上有生命。
presume 与assume一样，指对事物进行推测，不同的是侧重指以过去的经验或
根据现实的情况作出合乎逻揖的推测和设想。
1）We cannot presume theexistence of life on other planets.
我们不能推定其他行星上没有生物。
2）John didn’t say whenhe would return, but I presume that he’ll be backfor
dinner.
约翰没有说他什么时候回来,但我推测他将回来吃晚饭的。
3）One is presumed to beinnocent before the judge makes the final decision
that he isguilty ofthe crime.
在法官作出最终的判决一个人有罪之前，他是被假定无罪的。
postulate 多用于指证实某一说法或理论而进行的假设。
1）Scientists don't know why dinosaurs wereextinct, but sometheroies
postulate that changes in geography,climate, and sea levels were
responsible.
科学家不知道恐龙为何绝种,有些理论推测是地理变化、气候和海平面的变化造成的。
2）Evenif we postulate that he had a motive for themurder, that still
doesn’tmean he did it.
即使我们假设他有谋杀的动机，那也并不意味着是他干的。
3）Freud postulated that weall have a death instinct as well as a life
instinct.
弗洛伊德曾假定我们所有人都有生存本能和死亡本能。
10. intrinsic
belonging to a thing by its very nature:
the intrinsic value of a gold ring.
Anatomy.(of certain muscles, nerves, etc.) belonging to or lying within a given part.
11.theory of relativity
The theory of relativity usually encompasses two interrelated theories by Albert Einstein: special relativity and general relativity.[1] Special relativity applies to elementary particles and their interactions, describing all their physical phenomena except gravity. General relativity explains the law of gravitation and its relation to other forces of nature.[2] It applies to the cosmological and astrophysical realm, including astronomy.[3]
The theory transformed theoretical physics and astronomy during the 20th century, superseding a 200-year-old theory of mechanics created primarily by Isaac Newton.[3][4][5] It introduced concepts including spacetime as a unified entity of space and time, relativity of simultaneity, kinematic and gravitational time dilation, and length contraction. In the field of physics, relativity improved the science of elementary particles and their fundamental interactions, along with ushering in the nuclear age. With relativity, cosmology and astrophysics predicted extraordinary astronomical phenomena such as neutron stars, black holes, and gravitational waves.[3][4][5]
12.radar pulse
Pulse radar is a well-known method of detecting objects by emitting short pulses of radar energy into space and then detecting the energy that bounces back after it hits an object. To determine the object’s distance, the radar system measures the length of time a pulse travels to and from the object. Pulse radar has important functions in air traffic, naval and military object detection, weather surveillance and space exploration, among other uses.
13. cesium
铯 [sè]
金属铯是一种金黄色，熔点低的活泼金属，在空气中极易被氧化，能与水剧烈反应生成氢气且爆炸。铯在自然界没有单质形态，铯元素以盐的形式极少的分布于陆地和海洋中。铯也是制造真空件器、光电管等的重要材料。放射性核素Cs-137是日本福岛第一核电站泄露出的放射性污染中的一种。[1]
14. spacetime
Space-time is a mathematical model that joins space and time into a single idea called a continuum. This four-dimensional continuum is known as Minkowski space.
Combining these two ideas helped cosmology to understand how the universe works on the big level (e.g. galaxies) and small level (e.g. atoms).
15. Piccadilly
Piccadilly (/ˌpɪkəˈdɪli/) is a road in the City of Westminster, London to the south of Mayfair, between Hyde Park Corner in the west and Piccadilly Circus in the east. It is part of the A4 road that connects central London to Hammersmith, Earl's Court, Heathrow Airport and the M4 motorway westward.
皮卡迪利(Piccadilly)实际上是一个很广义的词，词源于17世纪的英国。当时的一名裁缝因为制作销售一种很流行的皮卡迪利(Piccadilly)衣领，而逐渐发家。从此之后，皮卡迪利(Piccadilly)这个词在整个英国甚至是世界上开始有名。
16.Alpha Centauri
半人马座阿尔法星（Alpha Centauri）。半人马座阿尔法星是距离我们最近的星系，在大约4.3光年（40万亿公里）外。
Alpha Centauri (α Centauri, abbreviated Alpha Cen, α Cen) is the closest star system to the Solar System at a distance of 4.37 light-years (1.34 pc).[5] It consists of three stars: the pair Alpha Centauri A (also named Rigil Kentaurus[12]) and Alpha Centauri B together with a small and faint red dwarf, Alpha Centauri C (also named Proxima Centauri[12]), that may be gravitationally bound to the other two.
17. Snapshot
In computer systems, a snapshot is the state of a system at a particular point in time. The term was coined as an analogy to that in photography. It can refer to an actual copy of the state of a system or to a capability provided by certain systems.
也就是快照技术，在backup时被广泛采用。很早就被应用到阵列和主机中，主要采用Copy on Write的算法。这些详细的技术细节，可以去snia.org上查找。通常，他们都是基于卷，在block级别进行处理。各种大型的array中都有支持，主机OS上的卷管理器，如VxVM上就可以做快照
18. cone
圆锥体
A cone is a three-dimensional geometric shape that tapers smoothly from a flat base (frequently, though not necessarily, circular) to a point called the apex or vertex.
19. warp
弄弯，变歪;扭曲，曲解
Left out in the heat of the sun, tapes easily warp or get stuck in their cases
如果放在太阳下暴晒，磁带很容易翘曲或在磁带盒里黏结。
20. elongate
To shape or elongate(a wire,for example)by pulling through dies.
补充：
1. apart
原文：For example, suppose our Ping-pong ball...hitting the table twice on the same spot one second apart.
图片发自简书App
图片发自简书App
图片发自简书App
2.Absolute time and space
Originally introduced by Sir Isaac Newton in Philosophiæ Naturalis Principia Mathematica, the concepts of absolute time and space provided a theoretical foundation that facilitated Newtonian mechanics.[3] According to Newton, absolute time and space respectively are independent aspects of objective reality:[4]
Absolute, true and mathematical time, of itself, and from its own nature flows equably without regard to anything external, and by another name is called duration: relative, apparent and common time, is some sensible and external (whether accurate or unequable) measure of duration by the means of motion, which is commonly used instead of true time ...
According to Newton, absolute time exists independently of any perceiver and progresses at a consistent pace throughout the universe. Unlike relative time, Newton believed absolute time was imperceptible and could only be understood mathematically. According to Newton, humans are only capable of perceiving relative time, which is a measurement of perceivable objects in motion (like the Moon or Sun). From these movements, we infer the passage of time.
Absolute space, in its own nature, without regard to anything external, remains always similar and immovable. Relative space is some movable dimension or measure of the absolute spaces; which our senses determine by its position to bodies: and which is vulgarly taken for immovable space ... Absolute motion is the translation of a body from one absolute place into another: and relative motion, the translation from one relative place into another ...
— Isaac Newton
These notions imply that absolute space and time do not depend upon physical events, but are a backdrop or stage setting within which physical phenomena occur. Thus, every object has an absolute state of motion relative to absolute space, so that an object must be either in a state of absolute rest, or moving at some absolute speed.[5] To support his views, Newton provided some empirical examples: according to Newton, a solitary rotating sphere can be inferred to rotate about its axis relative to absolute space by observing the bulging of its equator, and a solitary pair of spheres tied by a rope can be inferred to be in absolute rotation about their center of gravity (barycenter) by observing the tension in the rope.
Absolute time and space continue to be used in classical mechanics, but modern formulations by authors such as Walter Noll and Clifford Truesdell go beyond the linear algebra of elastic moduli to use topology and functional analysis for non-linear field theories.[6]
3.propagation
宣传;传播，传输，蔓延，扩展，波及深度;〔生〕繁殖法，〔地〕传导;培养
The propagation of stress waves in solids can be considered as a part of the field of acoustics or ultrasonics depending on the conditions
4.equivalence
1a : the state or property of being equivalentb : the relation holding between two statements if they are either both true or both false so that to affirm one and to deny the other would result in a contradiction
2 : a presentation of terms as equivalent
3 : equality in metrical value of a regular foot and one in which there are substitutions
