Albert Einstein’s Special Theory of Relativity
Einsteinsscientificachievement,爱因斯坦的科学成就
Einsteinsscientificachievement,爱因斯坦的科学成就All his life Albert Einstein was interested in trying to understand the laws of the Universe. He was atheoretical physicist, asking probing questions and carrying out experiments in his mind.In his Special Theory of Relativity, Einstein revolutionised the thinking about space and time. This theory provided the basis for the development of the famous equation E = mc2 which illustrates that matter and energy are interchangeable, and that a small amount of mass is made up of a large amount of energy.The year 1905 is sometimes called Einstein's annus mirabilis (miracle year). In that year he published four outstanding scientific papers:An explanation of the photoelectric effect indicating that light energy came in chunks or quanta.This changed thinking on the nature of light.A discussion of Brownian motion demonstrating the existence of molecules.The nature of space and time.The dynamics of individual moving bodies.These last two formed the basis of Einstein's Special Theory of Relativity and led to that famous equation,E = mc2.In 1921, Einstein was awarded the Nobel Prize for Physics 'for his services to theoretical physics and in particular for his discovery of the law of the 'photoelectric effect'. When he made his delayed acceptance speech in 1923, he ignored the citation and spoke on his theory of relativity.Einstein was a great intellect. He came up with explanationswhich at the time could not be verifiedexperimentally and many of his theories took a long time to be accepted even within the scientific world.Greater credence was attached to his theories as science and technology advanced sufficiently to allow experimentation involving high speed travel and nuclear reactions.It is still difficult for many people to accept or understand his theories since they require thinking beyond normal experiences.Following is an outline of the principles that Einstein developed in a number of scientific fields.Special Theory of RelativityRelativity explains the way an object appears to be relative to an observer. You can understand this if you consider yourself in a car, observing other cars. Imagine you are observing a car travelling at 20 km/h. If your car is stationary, then the other car's speed relative to you is 20 km/h. However if you are travelling alongside the car also doing 20 km/h, then the other car seems to be stationary compared to you. Its speed relative to you is zero! (Ever been at the traffic lights when another car has moved away and you thought you were rolling backwards?)Einstein developed the special theory of relativity by thinking about travelling alongside a light beam at the same speed as the light. He determined that the speed of light is constant, no matter what you are doing or how fast you are travelling, light always travels through empty space at 'the speed of light'. This means that time and length are not absolute, but depend on the relative motion of the object and the observer. If you are stationary, an object that is moving seems to get shorter and heavier, and time slows down for the object. In everyday situations, the slight changes are immeasurable, but they becomeobvious as the speed increases towards the speed of light. As the object travels closer to the speed of light, the length of the object appears closer to zero. Its height stays the same unless it moves up or down —the contraction only happens in the direction of movement. However if you are travelling at the same speed as the object, then everything looks normal! The 'contraction' of moving objects is the contraction of space itself not the object within space.In moving through space, time changes. Space and time are two parts of one whole called spacetime. If you stand still, you are only moving through time. If you move at the speed of light, you move throughspace only and not through time —time stands still. In between, you move partly through one and partly through the other!So the famous twin trip example: Twin A travels round the world at fast pace in a space ship while the twin B stands still. When twin A returns, (s)he will be younger than twin B. Twin B has moved only through time, twin A has moved partly through space and only partly through time —less time than the twin who stayed still.The Special theory of relativity also led to the most famous equation which first appeared in an article by Einstein in 1907. There is a fundamental relationship between rest energy and mass according to the equation E = mc2 where E is the rest energy of an object, m is the mass of the object and c is the velocity of light. The mass of something is a measure of the energy within it; matter and energy are interchangeable, and a small amount of mass is made up of a large amount of energy.In the 1930s nuclear fission was discovered. This gave a wayto release the energy stored in the nuclei of atoms, and the possibility of nuclear weapons was realised.The General Theory of RelativityThe Special Theory applies to objects moving in straight lines at constant speeds. Shortly after its publication, Einstein started work on generalising the theory to include curved paths and accelerating objects, considering the motion that makes planets move in orbit, and the fall of objects to the earth. This led to the equivalence principle which states that in free fall the acceleration and the force due to gravity are equivalent, and the force due to gravity is neutralised, ie in freefall you are weightless.In 1907 Einstein developed the ideas that space and time are not constant, but they change, and that gravity was a property of spacetime rather than being an external force. As he put it: "Matter tells space how to bend and space tells matter how to move." A glimpse into the workings of Einstein's four dimensional spacetime can be gained by imagining the spacetime as a rubber sheet. Stars and planets have mass and cause the sheet close to them to change shape and curve around them. Another massive object coming close will have its motion affected by this deformation of spacetime.The general theory predicted that a light beam passing near a massive object would actually be bent, and by how much. This prediction was supported during a total eclipse of the Sun in May 1919, and again by observations of a total eclipse in Australia in 1922.One of the predictions of the general theory is that the Universe is expanding, giving a basis for the 'big bang' theory of the origins of the Universe. It has also been used to explain black holes and quasars. Quantum TheoryThe nature of light had been debated for many years. Was it made up of particles or waves? Isaac Newton believed light to be made up of particles, Christiaan Huygens stated it was a wave phenomenon, and this was reinforced when Thomas Young demonstrated interference. Later Maxwell suggested and Hertz proved that light was part of the electromagnetic spectrum.In 1905 Einstein reintroduced the particle theory of light. A few years earlier, Max Planck had proposed that energy in an atom occurs in little chunks called quanta. Einstein suggested that light also existed in chunks or quanta. These quanta are now called photons. He concluded this by examining the photoelectric effect – the release of electrons from metals when light shines on them. To make this happen, the light needed to be high frequency (ultraviolet). Low frequency light (red) would not make it happen, no matter how bright the light was. Einstein explained this by thinking of light in terms of photons. Each electron is pushed out from the metal by one photon — as long as that photon has enough energy. Only high frequency light has photons with enough energy. Low frequency light has low energy photons, and no matter how many there are, none of them has enough energy to dislodge an electron.Between 1916 and 1925, Einstein made other contributions to the study of light, including the idea of stimulated emission of radiation – a concept which led to the development of the laser.Unified Field TheoryThe quest to explain gravity and electromagnetism together as aspects of a common phenomenon occupied Einstein's scientific thoughts for much of the last thirty years of his life until he died in 1955. He wanted to provide a basis to explain the Universe in a way other than quantum mechanics whichdescribed activities in terms of probabilities. He did not succeed. Since then the weak and strong nuclear forces have been discovered.Electromagnetism and the nuclear forces can be explained using quantum mechanics, and the search continues for a theory to explain everything!。
The Relativity of Wrong
1 Isaac Asimov I s a a c A s i m o vThe Relativity of Wrongreceived a letter the other day. It was handwrit-ten in crabbed penmanship so that it was very diffi-cult to read. Nevertheless, I tried to make it out just in case it might prove to be important. In the first sentence, the writer told me he was majoring in En g lish literature, but felt he needed to teach me science. (I sighed a bit, for I knew very few En g lish Lit majors who are equipped to teach me science, but I am very aware of the vast state of my ignorance and I am prepared to learn as much as I can from anyone, so I read on.)It seemed that in one of my innumerable essays, I had expressed a certain gladness at living in a century in which we finally got the basis of the universe straight.I didn’t go into detail in the matter, but what I meant was that we now know the basic rules governing the universe, together with the gravitational inter-relationships of its gross components, as shown in the theory of relativity worked out between 1905 and 1916. We also know the basic rules governing the subatomic particles and their interrelationships, since these are very neatly described by the quantum theory worked out between 1900 and 1930. What’s more, we have found that the galaxies and clusters of galaxies are the basic units of the physical universe, as discovered between 1920 and 1930.1These are all twentieth- c entury discoveries, you see.The young specialist in En g lish Lit, having quoted me, went on to lectureme severely on the fact that in every century people have thought they under-stood the universe at last, and in every century they w ere proved to be wrong. It follows that the one thing we can say about our modern “knowledge” is that it is wrong. The young man then quoted with approval what Socrates had said on learning that the Delphic oracle had proclaimed him the wisest man in Greece.2 “If I am the wisest man,” said Socrates, “it is because I alone know that I know nothing.” The implication was that I was very foolish because I was under the impression I knew a great deal.My answer to him was, “John, when people thought the earth was flat, they w ere wrong. When people thought the earth was spherical, they w ere wrong. But if you think that thinking the earth is spherical is just as wrong as thinking the earth is flat, then your view is wronger than both of them put together.”1. A lbert Einstein (1879–1955) announced the special theory of relativity in 1905 and developed the general theory of relativity over the next de c ade; physicist Maxwell Planck (1858–1947) and others developed quantum theory; astronomer Edwin Hubble (1889–1953) demonstrated the existence of external galaxies in 1924.2. S ocrates (c. 470–399 b.c.e.), ancient Greek phi l os o p her; Delphic oracle or Pythia, priestess of the Temple of Apollo on Mount Parnassus.I Published in the Skeptical Inquirer (1989), the journal of the Committee for Scientific Investigation of Claims of the Paranormal (CSICOP), now the Committee for Skeptical Inquiry.5The Relativity of Wrong 2 The basic trouble, you see, is that people think that “right” and “wrong” are absolute; that everything that isn’t perfectly and completely right is totally and equally wrong.However, I don’t think that’s so. It seems to me that right and wrong are fuzzy concepts, and I will devote this essay to an explanation of why I think so.When my friend the En g lish literature expert tells me that in every cen-tury scientists think they have worked out the universe and are always wrong, what I want to know is how wrong are they? Are they always wrong to the same degree? Let’s take an example.In the early days of civilization, the general feeling was that the earth was flat. This was not because people w ere stupid, or because they w ere intent on believing silly things. They felt it was flat on the basis of sound evidence. It was not just a matter of “That’s how it looks,” because the earth does not look flat. It looks chaotically bumpy, with hills, valleys, ravines, cliffs, and so on.Of course there are plains where, over limited areas, the earth’s surface does look fairly flat. One of those plains is in the Tigris- E uphrates area, where the first historical civilization (one with writing) developed, that of the Sumerians.Perhaps it was the appearance of the plain that persuaded the clever Sume-rians to accept the generalization that the earth was flat; that if you somehow evened out all the elevations and depressions, you would be left with flatness. Contributing to the notion may have been the fact that stretches of water (ponds and lakes) looked pretty flat on quiet days.Another way of looking at it is to ask what is the “curvature” of the earth’s surface. Over a considerable length, how much does the surface deviate (on the average) from perfect flatness. The flat- e arth theory would make it seem that the surface d oesn’t deviate from flatness at all, that its curvature is 0 to the mile.Nowadays, of course, we are taught that the flat- e arth theory is wrong; that it is all wrong, terribly wrong, absolutely. But it isn’t. The curvature of the earth is nearly 0 per mile, so that although the flat- e arth theory is wrong, it happens to be nearly right. That’s why the theory lasted so long.There w ere reasons, to be sure, to find the flat- e arth theory unsatisfactory and, about 350 B.C., the Greek phi l os o p her Aristotle summarized them. First, certain stars disappeared beyond the Southern Hemi s phere as one traveled north, and beyond the Northern Hemi s phere as one traveled south. Second, the earth’s shadow on the moon during a lunar eclipse was always the arc of a circle. Third, h ere on the earth itself, ships disappeared beyond the horizon hull- fi rst in what e ver direction they w ere traveling.All three observations could not be reasonably explained if the earth’s sur-face w ere flat, but could be explained by assuming the earth to be a sphere.What’s more, Aristotle believed that all solid matter tended to move toward a common center, and if solid matter did this, it would end up as a sphere. A given volume of matter is, on the average, closer to a common center if it is a sphere than if it is any other shape what e ver.About a century after Aristotle, the Greek phi l os o p her Eratosthenes noted that the sun cast a shadow of different lengths at different latitudes (all the 10 153 Isaac Asimov shadows would be the same length if the earth’s surface w ere flat). From the difference in shadow length, he calculated the size of the earthly sphere and it turned out to be 25,000 miles in circumference.The curvature of such a sphere is about 0.000126 per mile, a quantity very close to 0 per mile, as you can see, and one not easily mea s ured by the techniques at the disposal of the ancients. The tiny difference between 0 and 0.000126 accounts for the fact that it took so long to pass from the flat earth to the spherical earth.Mind you, even a tiny difference, such as that between 0 and 0.000126, can be extremely important. That difference mounts up. The earth cannot be mapped over large areas with any accuracy at all if the difference isn’t taken into account and if the earth isn’t considered a sphere rather than a flat sur-face. Long ocean voyages c an’t be undertaken with any reasonable way of locat-ing one’s own position in the ocean unless the earth is considered spherical rather than flat.Furthermore, the flat earth presupposes the possibility of an infinite earth, or of the existence of an “end” to the surface. The spherical earth, however, postulates an earth that is both endless and yet finite, and it is the latter pos-tulate that is consistent with all later findings.So, although the flat- e arth theory is only slightly wrong and is a credit to its inventors, all things considered, it is wrong enough to be discarded in favor of the spherical- e arth theory.And yet is the earth a sphere?No, it is not a sphere; not in the strict mathematical sense. A sphere has certain mathematical properties— f or instance, all diameters (that is, all straight lines that pass from one point on its surface, through the center, to another point on its surface) have the same length.That, however, is not true of the earth. Various diameters of the earth dif-fer in length.What gave people the notion the earth w asn’t a true sphere? To begin with, the sun and the moon have outlines that are perfect circles within the limits of mea s ure m ent in the early days of the telescope. This is consistent with the sup-position that the sun and the moon are perfectly spherical in shape.However, when Jupiter and Saturn w ere observed by the first telescopic observers, it became quickly apparent that the outlines of those planets w ere not circles, but distinct ellipses. That meant that Jupiter and Saturn w ere not true spheres.Isaac Newton,3 toward the end of the seventeenth century, showed that a massive body would form a sphere under the pull of gravitational forces (exactly as Aristotle had argued), but only if it w ere not rotating. If it w ere rotating, a centrifugal effect would be set up that would lift the body’s substance against gravity, and this effect would be greater the closer to the equator you progressed. The effect would also be greater the more rapidly a spherical object rotated, and Jupiter and Saturn rotated very rapidly indeed.3. E n g lish mathematician and physicist (1642–1727).2025The Relativity of Wrong 4 The earth rotated much more slowly than Jupiter or Saturn so the effect should be smaller, but it should still be there. Actual mea s ure m ents of the cur-vature of the earth w ere carried out in the eigh t eenth century and Newton was proved correct.The earth has an equatorial bulge, in other words. It is flattened at the poles. It is an “oblate spheroid” rather than a sphere. This means that the vari-ous diameters of the earth differ in length. The longest diameters are any of those that stretch from one point on the equator to an opposite point on the equator. This “equatorial diameter” is 12,755 kilometers (7,927 miles). The shortest diameter is from the North Pole to the South Pole and this “polar diam-eter” is 12,711 kilometers (7,900 miles).The difference between the longest and shortest diameters is 44 kilome-ters (27 miles), and that means that the “oblateness” of the earth (its departure from true sphericity) is 44/12755, or 0.0034. This amounts to 1/3 of 1 percent.To put it another way, on a flat surface, curvature is 0 per mile everywhere. On the earth’s spherical surface, curvature is 0.000126 per mile everywhere (or 8 inches per mile). On the earth’s oblate spheroidal surface, the curvature var-ies from 7.973 inches to the mile to 8.027 inches to the mile.The correction in going from spherical to oblate spheroidal is much smaller than going from flat to spherical. Therefore, although the notion of the earth as a sphere is wrong, strictly speaking, it is not as wrong as the notion of the earth as flat.Even the oblate- s pheroidal notion of the earth is wrong, strictly speaking. In 1958, when the satellite Vanguard I was put into orbit about the earth, it was able to mea s ure the local gravitational pull of the earth— a nd therefore its shape— w ith unpre c e d ented precision. It turned out that the equatorial bulge south of the equator was slightly bulgier than the bulge north of the equator, and that the South Pole sea level was slightly nearer the center of the earth than the North Pole sea level was.There seemed no other way of describing this than by saying the earth was pear- s haped, and at once many people decided that the earth was nothing like a sphere but was shaped like a Bartlett pear dangling in space. Actually, the pear- like deviation from oblate- s pheroid perfect was a matter of yards rather than miles, and the adjustment of curvature was in the millionths of an inch per mile.In short, my En g lish Lit friend, living in a mental world of absolute rights and wrongs, may be imagining that because all theories are wrong, the earth may be thought spherical now, but cubical next century, and a hollow icosahe-dron the next, and a doughnut shape the one after.What actually happens is that once scientists get hold of a good concept they gradually refine and extend it with greater and greater subtlety as their instruments of mea s ure m ent improve. Theories are not so much wrong as incomplete.This can be pointed out in many cases other than just the shape of the earth. Even when a new theory seems to represent a revolution, it usually arises out of small refinements. If something more than a small refinement w ere needed, then the old theory would never have endured.30 355 Isaac Asimov Copernicus 4 switched from an earth- c entered planetary system to a sun- centered one. In doing so, he switched from something that was obvious to something that was apparently ridiculous. However, it was a matter of finding better ways of calculating the motion of the planets in the sky, and eventually the geocentric theory was just left behind. It was precisely because the old the-ory gave results that w ere fairly good by the mea s ure m ent standards of the time that kept it in being so long.Again, it is because the geological formations of the earth change so slowly and the living things upon it evolve so slowly that it seemed reasonable at first to suppose that there was no change and that the earth and life always existed as they do today. If that w ere so, it would make no difference whether the earth and life w ere billions of years old or thousands. Thousands w ere easier to grasp.But when careful observation showed that the earth and life w ere chang-ing at a rate that was very tiny but not zero, then it became clear that the earth and life had to be very old. Modern geology came into being, and so did the notion of biological evolution.If the rate of change w ere more rapid, geology and evolution would have reached their modern state in ancient times. It is only because the difference between the rate of change in a static universe and the rate of change in an evolutionary one is that between zero and very nearly zero that the creationists can continue propagating their folly.Since the refinements in theory grow smaller and smaller, even quite ancient theories must have been sufficiently right to allow advances to be made; advances that w ere not wiped out by subsequent refinements.The Greeks introduced the notion of latitude and longitude, for instance, and made reasonable maps of the Mediterranean basin even without taking sphericity into account, and we still use latitude and longitude today.The Sumerians w ere probably the first to establish the principle that plan-etary movements in the sky exhibit regularity and can be predicted, and they proceeded to work out ways of doing so even though they assumed the earth to be the center of the universe. Their mea s ure m ents have been enormously refined but the principle remains.Naturally, the theories we now have might be considered wrong in the sim-plistic sense of my En g lish Lit correspondent, but in a much truer and subtler sense, they need only be considered incomplete.4. N icolaus Copernicus (1473–1543), Polish astronomer.4045mla citationAsimov, Isaac. “The Relativity of Wrong.” 1989. The Norton Reader: An Anthology of Nonfiction . Ed. Melissa A. Goldthwaite et al. 14th ed. New York: Norton,2016. 824–28. Print.Q u e s t i o n s1. I saac Asimov frames his essay as a response to a letter from a “young special-ist in En g lish Lit” (paragraph 5) whom he calls “wronger” (paragraph 6) than thoseThe Route to Normal Science 6 people of the past who thought the earth was flat or spherical. What does Asimovmean by “wronger”?2. H ow would you characterize the tone of Asimov’s essay? Does his tone make you more or less receptive to his argument?3. A simov illustrates his point that scientific theories “are not so much wrong as incomplete” (paragraph 37) with a single extended example: the history of hu -mans trying to determine the size and shape of the earth. Why does Asimov select this par t ic u l ar example?4. A simov frames his essay as a response to a letter from a “young specialist in En g lish Lit.” Continue the exchange by writing a letter of your own to Asimov.。
Unit4-Albert-Einstein
Albert EinsteinGerman-born American Physicist and Nobel Laureate1879～1955“Imagination is more important than knowledge. ” ---- Albert EinsteinA Brief Introduction to Albert EinsteinAlbert Einstein, whose Special Theory of Relativity and General Theory of Relativity revolutionized scientific perceptions of the universe, is acknowledged, along with Newton, as one of history’s greatest physicists.Son of free-thinking, cultured Jews, Einstein was unable to speak until he was three and displayed no special promise. Anti-Semitism also hampered his talent when it began to emerge. He became a Swiss citizen in 1901, obtaining a doctorate from the University of Bern in 1905. His research, which ended in the famous equation E=mc2, was published in the same year.After World War I, Einstein’s fame extended beyond the scientific community and in 1921 he was awarded the Nobel Prize for physics. During the 1920s he regarded the rise of the Nazis in Germany with horror, eventually emigrating to the U.S. where, in 1933, he took up a post at Princeton University. In 1939 his early warnings of German scientific attempts to make an atomic bomb prompted the start of the Manhattan Project.•Einstein’s ChronologyTheory of Relativity1. A brief introductionIn 1905 Einstein received his doctorate from the University of Zurich for a theoretical dissertation on the dimensions of molecules, and he also published three theoretical papers of central importance to the development of 20th-century physics.On the basis of the General Theory of Relativity, Einstein accounted for the previously unexplained variations in the orbital motion of the planets and predicted the bending of starlight in the vicinity of a massive body such as the sun. The confirmation of this latter phenomenon during an eclipse of the sun in 1919 became a media event, and Einstein’s fame spread worldwide.2. Einstein explains the equivalence of energy and matter“It followed from the Special Theory of Relativity that mass and energy are both but different manifestations of the same thing — a somewhat unfamiliar conception for the average mind. Furthermore, the equation E is equal to mc squared, in which energy is put equal to mass, multiplied by the square of the velocity of light, showed that very small amounts of mass may be converted into a very large amount of energy and vice versa. The mass and energy were in fact equivalent, according to the formula mentioned before. This was demonstrated by Cockcroft and Walton in 1932, experimentally.”Atomic BombWhen Hitler came to power, Einstein immediately decided to leave Germany for the United States. He took a position at the Institute for Advanced Study at Princeton, New Jersey. In 1939 Einstein collaborated with several other physicists in writing a letter to President Franklin D. Roosevelt, pointing out the possibility of making an atomic bomb and the likelihood that the German government was embarking on such a course. The letter, which bore only Einstein’s signature, helped lend urgency to efforts in the U.S. to build the atomic bomb, but Einstein himself played no role in the work and knew nothing about it at the time.Fame and Social ActivitiesAfter 1919, Einstein became internationally renowned. He accrued honors and awards, including the Nobel Prize in physics in 1921, from various world scientific societies. His visit to any part of the world became a national event; photographers and reporters followed him everywhere.After the war, Einstein was active in the cause of international disarmament and world government but declined the offer made by leaders of the state of Israel to become president of that country. In the U.S. during the late 1940s and early 1950s he spoke out on the need for the nation’s intellectuals to make any sacrifice necessary to preserve political freedom. Einstein died in Princeton on April 18, 1955.The Yo-YoThe Yo-Yo is a simple toy consisting of a grooved double disk with a string about the center. The player holds the end of the string which unwinds itself as the disk is dropped. Then by a slight jerk on the string, the player causes it to rewind itself, and to reel up back to the hand. The toy is said to have originated in the Philippines. Since 1930 it has become a popular toy and even today children in different countries play the Yo-Yo and compete in various contests.The Nobel PrizeNobel Prizes are annual monetary awards granted to individuals or institutions for outstanding contributions in the fields of physics, chemistry, physiology or medicine, literature, international peace, and economic sciences. The Nobel Prizes are internationally recognized as the most prestigious awards in each of these fields. The prizes were established by Swedish inventor and industrialist Alfred Bernhard Nobel, who set up a fund for them in his will. The first Nobel Prizes were awarded on December 10, 1901, the fifth anniversary of Nobel’s death.Woolworth’sFrank Winfield Woolworth (1852~1919), an American merchant, was born in Rodman, New York. He established in 1879 a five-cent store at Utica, New York, which failed, and the same year he started a successful five-and-ten-cent store at Lancaster, Pennsylvania. Woolworth opened many others and soon extended business throughout the United States and to several foreign countries. In 1911 the F. W. Woolworth Company was incorporated with ownership of over 1,000 five-and-tens, and he became director of various financial firms. (The last Woolworth stores were closed in 1998.) Woolworth had the Woolworth Building erected in New York City in 1913, the highest building in the world (792 ft / 241.4 m) at that time.。
The special theory of relativity
D 17.4m before decaying, from which we conclude that
they decay the lifetime
mineaatsimureedgifvoernpiboynDsvat
63.7ns, rest.
much
larger
than
This effect, called “time dilation”, which cannot be explained by Newtonian physics. In Newtonian physics time is a universal coordinate having identical values for all observers.
1. Troubles with our ideas about time The pions ( or ) created at rest are observed
to decay ( to other particles ) with an average lifetime of only 26.0ns .
2. The first postulate declares that the laws of physics are absolute, universal, and same for all inertial observers.
The Second postulate is much more difficult to accept, because it violates our “ common sense”, which is firmly grounded in the Galilean kinematics that we have learned from everyday experiences.
南艺英语课文Unit 10(附课后全习题)附翻译
Unit 10Text)With many tragedies,comedies and tragicomedies, he is considered to be the greatest dramatist of all time.William ShakespeareWilliam Shakespeare is the greatest playwright in the world and the finest poet who has written in the English language. He is also the most popular writer. No other writer has been read so widely in so many countries. Shakespeare understood people more than other writers.He could create characters that have meaning beyondthe time and places of his plays. His characters are individualhuman beings. They struggle justas people do in real life, sometimessuccessfully and sometimes with painful andtragic results. Shakespeare wrote at leastthirty-seven plays, which showed hisknowledge on various subjects. These subjectsinclude music, law, the Bible, militaryscience, the stage, art, politics, the sea,history, hunting, and sports. Shakespeare wasborn to middle-class parents in a small town, shortly after he married at theage of 18, he left his hometown and went to London. Within a few years,he became one of the city's leading actors and playwrights. By 1612, he wasEngland's most popular playwright.William Shakespeare was the greatest literary genius of the Englishlanguage. Although principally remembered today as the premier Englishdramatist, he early attained widespread popularity in the 1590's as a lyricand narrative poet with the publication of Venus and Adonis and The Rapeof Lucrece. He first attained success as a playwright after the production ofHenry Ⅳ, PartⅠ . Over the next two decades he wrote a succession ofwidely acclaimed plays which may be categorized roughly into three groups?histories, comedies, and tragedies or tragicomedies. Both his histories andcomedies are of great success. But undoubtedly Shakespeare's worldwidereputation as a dramatist rests on the profound exploration of the humancondition portrayed in his great tragedies Romeo and Juliet, Othello, Hamlet, etc. After having dominated the London theatrical scene for sometwenty years, Shakespeare retired to his hometown, where he lived inrelative ease and comfort until his death in 1616.Study and PracticeComprehension of the TextI. Answer the following questions.1.Where was Shakespeare born?2.According to the text, why could Shakespeare create characters that havemeaning beyond the time and places of his play?3.On what subjects did Shakespeare's plays show his knowledge?4.Was Shakespeare only a playwright? What else did he do?5.How many groups may Shakespeare's plays be categorized into? What are they?Summary WritingⅡ. Use no more than 85 words to write a summary of the text.VocabularyⅢ.Match the items in column A to the phrases describing them in column B.A B1.shortly a. ten years.2.popular b. freedom from work and discomfort.3.playwright c. get through effort.4.tragic d. soon.5.principally e. mainly.6.attain f. dramatist.7.decade g. liked and admired.8.ease h. sad.Ⅳ.Fill in the blanks with the words or expressions given below. Change the form where necessary.1.．．It is well-known that lung cancer is＿＿＿partly caused by smoking too much.2.．． _ After＿＿＿＿from work, my parents moved to the countryside where theyhad spent a few years after marriage.3.．． _____________ Success in management ultimately ＿＿＿good judgment.4.．． __________ Miss Tan is one of the most ＿＿＿＿＿teachers in our school.5.．． ______ I n the past few＿＿＿＿, there has been a great increase in the amount ofresearch done on human brain.6.．．Albert Einstein's Special Theory of Relativity was so＿＿that only a few scientists could understand.7.．．_ The old man ＿＿＿ his master's degree at the age of 72.8.．．___________ Young people shouldn't seek ＿＿＿and shirk hardship.9.．．_____ I don't feel at＿＿＿in front of camera.10. Romeo and Juliet is a ＿＿＿＿story of love in medieval Europe.StructureV. Use "just as" to rewrite the following sentences after the model.Model: The characters in Shakespeare's plays struggle. People struggle in real life.The characters in Shakespeare's plays struggle just as people do in real life.1. The Americans spend Christmas Day.The Chinese spend the Spring Festival.＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿2. English is taught in your country.Spanish is taught in their country.＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿3. Animals feel pain.We feel pain.＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿4. He is keen on disco.I am fond of classical music.＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿"Ⅵ. Rewrite the following sentences after the model.Model: Shakespeare wrote at least thirty-seven plays. This showed his knowledge on various subjects.Shakespeare wrote at least thirty-seven plays,which showed his knowledge on various subjects.1. He was ill for about one month. This set him back a lot in his studies.＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿2. It was raining hard, and this kept us indoors.＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿3. He said he had lost the book, but this was untrue.＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿4. Jim's first novel was published, and you may hardly believe it.＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿ClozeⅦ- Fill in the blanks; each word can be used only once. Make changes where necessary.Christopher Reeve was born in New York City in 1952. After college, he studiedacting and became famous (1) "Superman" in the movies about the comic-book hero who(2) through the air and saved people's ＿＿＿＿(3). But hemay be remembered longest for his activities during the last part of his life. He wasthrown from a horse in 1995 and broke his neck and was ＿＿(4) to move hisbody. He was even unable to breathe for long periods ＿＿＿(5) mechanical help.＿＿＿ (6) later, he exercised hard on special equipment. Doctors expressed great＿＿＿(7) at the progress he made long after his injury. He also was a strong activistfor medical research. He urged scientists to work to _____ (8) disabilities caused by back and neck injuries and disease. He continued acting even after his riding accident. Most recently he directed a television film and wrote two books. He died on October10, 2004 at age 52. He had suffered a ____ (9) infection resulting ＿＿＿(10)his inability to move.翻译单元10文本）由于许多悲剧，喜剧和悲喜剧，他被认为是所有时代最伟大的剧作家。
(完整)南艺学位英语卷10
(完整)南艺学位英语卷10 English Qualification Test for a Bachelor's DegreeNanjing Arts InstitutePart I Vocabulary and Structure （ 25％ ) （识记、掌握）Directions:There are 25 incomplete sentences in this part. For each sentence there are four choices marked A， B， C and D。
Choose the ONE answer that best completes the sentence。
Then put your choices on the answer sheet。
1.I am sure that he will act on the doctor’s ____ advice.A. evidentB. reasonable C。
alluring D。
energetic(B易）2. The unpopular mayor was under ____ attack in the newspaper。
A. constant B。
convincing C. evident D。
evidence(A较易)3. We were ____ a discussion about yesterday’s examination when the teacher walked into the classroom.A. caught up inB. caught up withC。
catching up on D. catching up with(A难)4。
How do you ____ your spare time usually？A。
convince B. develop C. employ D。
爱因斯坦做出的贡献的英文作文
爱因斯坦做出的贡献的英文作文阿尔伯特·爱因斯坦，这位二十世纪最伟大的理论物理学家之一，以其深邃的洞察力、无与伦比的创造力和对宇宙奥秘的不懈探索，为人类科学知识体系做出了诸多里程碑式的贡献。
他不仅彻底颠覆了人们对时空、物质和能量的传统认知，更奠定了现代物理学的两大基石——相对论和量子力学。
(English)：Albert Einstein, one of the greatest theoretical physicists of the 20th century, made numerous landmark contributions to humanity's scientific knowledge system with his profound insights, unparalleled creativity, and relentless exploration of cosmic mysteries. He not only fundamentally upended traditional notions of space, time, matter, and energy but also laid the twin cornerstones of modern physics: relativity and quantum mechanics.Paragraph 2 (中文)：爱因斯坦首先在1905年提出了狭义相对论，这是对牛顿力学框架的一次革命性突破。
他揭示了时间和空间并非绝对不变，而是相互关联、随观察者运动状态而变化的统一四维时空。
著名的质能方程E=mc²，便是这一理论的核心成果，它表明能量（E）与质量（m）之间存在着直接等价关系，且能量的转换蕴含着巨大的潜能。
这一发现不仅为核能的开发提供了理论基础，也深刻影响了我们对宇宙起源、星体演化等宏观现象的理解。
英语介绍爱因斯坦发现相对论高中英语作文
英语介绍爱因斯坦发现相对论高中英语作文全文共10篇示例，供读者参考篇1Einstein is a really smart guy who discovered something super cool called the Theory of Relativity. He was like asuper-duper genius and everyone thinks he's awesome.So like, Einstein was born in Germany in 1879 and he was really good at math and science. When he was older, he moved to America and became a professor at a super famous university called Princeton. He was like a big deal in the world of science.The Theory of Relativity is all about how time and space are connected. It says that time can go faster or slower depending on how fast you're moving. It's like time is a big jelly that can be squished and stretched. It's so crazy!Einstein's theory changed the way we think about the universe. It explained stuff like why things get heavier when they move really fast and why light always travels at the same speed. It was like a light bulb moment for scientists around the world.Even though Einstein was a super serious scientist, he had a fun side too. He loved playing the violin and sailing on boats. He was a real character.So yeah, Einstein was a total rockstar in the world of science. His Theory of Relativity is still blowing minds today. He's definitely one of the coolest scientists ever.篇2Einstein Finded the Special Relativity TheoryHey everyone! Do you know about a super smart guy named Albert Einstein? He was a famous scientist who discovered the theory of relativity! Today, I'm going to tell you all about how he found the special relativity theory.So, basically, Einstein was thinking about how things move and how time works. He realized that time is actually different for different people depending on how fast they are moving. This is called time dilation. Isn't that crazy?Then, Einstein thought about how light always travels at the same speed, no matter how fast you are moving. That's when he came up with the idea that time and space are actually connected in a cool way. He called it the space-time continuum.After a lot of thinking and working out math stuff (which was probably really hard), Einstein finally published his special relativity theory in 1905. It was a big deal because it changed the way we think about the universe!Thanks to Einstein, we now know that time is relative and that space and time are connected in a special way. Isn't that amazing? Einstein was a true genius who opened up a whole new world of understanding for us all.And that's the story of how a super smart guy named Albert Einstein discovered the special relativity theory. Isn't science awesome?篇3Hey guys, do you know who Einstein is? He is like super famous for discovering something called relativity. So, I'm gonna tell you all about it!Okay, so Einstein was this super smart guy who came up with the theory of relativity. Basically, he said that time and space are not always the same for everyone. Like, if you are in a fast car, time actually goes slower for you compared to someone just standing still. It sounds crazy, right?Einstein also said that nothing, not even light, can go faster than the speed of light. That's like the fastest thing ever! And he used this idea to explain how gravity works too. He said that big things like planets and stars actually bend space and time around them.I know it's a lot to take in, but basically, Einstein's theory of relativity changed the way we think about the world. It's like a whole new way of looking at things! And even though it's super complicated, it's also really cool to think about.So yeah, that's Einstein and his theory of relativity in a nutshell. Isn't it amazing how one person can come up with such a big idea? Einstein was really a genius!篇4Einstein is a really smart guy in history. He's super famous for coming up with the Theory of Relativity. This theory is all about how time and space are all connected, and it's super cool!Back in the day, Einstein was a super smart scientist. He did all these experiments and thought really hard about how things work in the world. One day, he had this big idea about how time and space can bend and stretch. It was like, whoa!Einstein's Theory of Relativity says that time and space are all mixed up together. He said that the faster you go, the slower time goes for you. It's like time can change depending on how fast you're moving. Crazy, right?And not just that, Einstein also said that gravity can bend and curve space. He called it the bending of light. This means that big things like stars and planets can actually bend light around them. It's like they're bending reality!Einstein's Theory of Relativity has changed the way we think about the universe. It's helped us understand how things work in space and time. Einstein was a real genius, and his ideas are still blowing our minds today!So, next time you're thinking about how things work in the world, remember Einstein and his Theory of Relativity. He was a real smarty pants, and his ideas are out of this world!篇5Oh, hi there! Today, I wanna tell you guys about this super smart guy named Albert Einstein. He was like a super genius scientist who discovered something really cool called the theory of relativity.Okay, so let me break it down for you. Basically, Einstein came up with this idea that time and space are not separate things, but they are actually connected. This means that time can change depending on how fast you're moving or how strong the gravity is around you. It's like, whoa, mind blown!And get this, Einstein's theory also says that nothing can go faster than the speed of light. Like, nothing, not even a superhero or a spaceship. It's like a cosmic speed limit, you know?Einstein's theory of relativity totally changed the way we think about the universe. It's super important for understanding things like black holes, the Big Bang, and even GPS systems. So yeah, he was like the OG of modern physics!So yeah, that's the scoop on Einstein and his theory of relativity. He was a total brainiac and his ideas are still super important today. Pretty cool, right?篇6Hey guys! Today I want to tell you all about Albert Einstein and his discovery of the theory of relativity. It's super cool and I think you'll love learning about it!So, Albert Einstein was a super smart scientist who lived a long time ago. He was kind of like a superhero of science! He was born in Germany in 1879 and he did a lot of really cool experiments and research.One day, Albert Einstein was thinking about how space and time worked. He came up with this idea that everything is relative – that means different things can be true for different people depending on how fast they are moving. It's like if you're on a train and someone is standing still, they might see things differently than you do.Einstein also figured out that nothing can travel faster than the speed of light – which is really, really fast! This was a big deal because it changed the way scientists thought about the universe.The theory of relativity has had a huge impact on how we understand the world around us. It's used in lots of different ways, like in GPS systems and even in space travel!So, next time you look up at the stars, remember that Albert Einstein was the one who helped us understand how everything works. He was a true genius and his discoveries are still changing the world today. Cool, right?篇7Hey guys, do you know about Albert Einstein? He was a super smart scientist who came up with something called the theory of relativity. I'm gonna tell you all about it!So, one day Einstein was thinking really hard about how things move in space. He realized that time and space are actually connected, and they can change depending on how fast you're going. This was a totally mind-blowing idea at the time!Einstein's theory of relativity has two parts: special relativity and general relativity. Special relativity talks about how things change when you're moving really fast, like close to the speed of light. And general relativity explains how gravity works and how it can bend space and time.One really cool thing about Einstein's theory is that it showed us that our ideas about space and time were all wrong. He totally changed the way scientists think about the universe!Einstein's theory of relativity is super important in physics and it's been tested and proven right many times. It's used in lots of things, like GPS systems and even in studying black holes.So, next time you hear about Einstein and his theory of relativity, remember how cool and smart he was to figure all that out! Einstein rocks!篇8Oh hi everyone! Today I want to tell you all about Albert Einstein and how he discovered the theory of relativity. It's super cool and interesting, so listen up!So Albert Einstein was a really smart scientist from Germany. He was like a super genius and he thought about things in a totally different way than anyone else. He was really curious about how the universe worked and he wanted to figure out the secrets of physics.One day, Einstein came up with this amazing idea called the theory of relativity. Basically, it says that everything is relative and there is no one fixed point of view in the universe. So time and space can change depending on how fast you are moving.Einstein's theory of relativity totally changed the way people thought about the world. It helped us understand how gravity works, and it even led to the invention of things like GPS. Can you imagine if we didn't have GPS to help us find our way around? Thanks, Einstein!So yeah, Albert Einstein was a total rockstar scientist and his discovery of the theory of relativity was a game-changer for the world of physics. He's like the superhero of science!篇9Hey guys, today I want to tell you about Albert Einstein and his discovery of the theory of relativity. It's super cool and mind-blowing!So, Albert Einstein was a super smart scientist who lived a long time ago. He thought a lot about how things work in the universe. One day, he came up with this amazing idea called the theory of relativity. It basically says that time and space are connected and can change depending on how fast you're moving.Einstein's theory of relativity changed the way we think about the world. It helped us understand things like how gravity works and how light travels. It's so cool to think that time can bend and stretch depending on how fast you're going!Thanks to Einstein's awesome discovery, we now have things like GPS that help us get around using satellites in space. Isn't that amazing?So, let's give a big cheer for Albert Einstein and his amazing discovery of the theory of relativity. He was a super smart guy who changed the world with his big ideas. Yay, Einstein!篇10Hey guys, do you know about Albert Einstein? He was a super smart dude who discovered something called the theory of relativity. It's like, really famous and important in physics and stuff. Let me tell you more about it!So, back in the olden days, like in the early 1900s, Einstein was thinking about how space and time work together. He realized that they're actually connected and can affect each other. It's crazy, right? He came up with this idea that everything is relative, meaning that it all depends on the observer's point of view.Einstein's theory of relativity has two parts: the special theory and the general theory. The special theory is all about how things change when they move really fast, like how time can slow down or speed up. The general theory is even cooler because it talks about how gravity can bend space and time. Imagine that!Thanks to Einstein, we now understand the universe in a whole new way. His theory of relativity is like a giant puzzle piece that fits perfectly into our understanding of how the world works. It's mind-blowing stuff, for sure.So next time you hear someone talking about Einstein and his theory of relativity, you'll know all about it. He was a total genius who changed the way we see the world. Pretty awesome, right? Einstein rocks!。
六章狭义相对论SpecialTheoryofRelativity-资料
x xvt
y y z z
或者
t t
xxvt y y z z t t
写成矢量形式为：
r r t
t t
这就是伽利略变换，它集中地反映了牛顿的绝对 时空观。
根据伽利略变换，可得事件的速度变换：
d r d (r t) d r d t d r
大家知道，自由粒子在其中作匀速运动的坐 标系称为惯性系。经典力学中的一个基本原理也 就是伽利略相对性原理 , 它表示：运动定律从一个 惯性系变换到另一个惯性系时，运动定律的形式 保持不变。也就是说，一切作机械运动的惯性系 是等价的。
在牛顿力学中，认为空间距离和时间间隔是 绝对的,与参考系无关。这种认为也称绝对时空观。
第六章 狭义相对论
Special Theory of Relativity
Albert · Einstein 阿尔伯特 · 爱因斯坦
(1879—1955)
相对论的创始人:
Albert · Einstein（阿尔伯特 · 爱因斯坦）
1905年，狭义相对论
（Special Theory of Relativity）
3、迈克尔逊—莫雷（Michelson-Morley)实验
由于在伽利略变换下，Maxwell’s equations不能 保持其形式不变，这是因为从Maxwell’s equations 得到电磁波在真空中的传播速度为c的结论。如果 Maxwell’s equations在伽利略变换下保持不变，则 在任何惯性系中电磁波在真空中的各个方向速率都 应该等于c，那么在另一个与它有相对运动的惯性系 中，该电磁波的传播速度不可能各向都是c。由此可 见，在不同的惯性系中，电动力学的规律并不相同。
中考英语人物成就描述练习题50题(答案解析)
中考英语人物成就描述练习题50题(答案解析)1. Albert Einstein showed great talent in physics when he was young. He published his special theory of relativity at the age of _____.A. 26B. 30C. 35D. 40答案：A。
解析：阿尔伯特·爱因斯坦在1905年发表了狭义相对论，当时他26岁。
这一理论对现代物理学产生了深远的变革性影响，是爱因斯坦早期在物理学领域极为重要的成就。
2. Mozart was a musical prodigy. He started composing music at a very young age. By the age of 11, he had already written his first _____.A. operaB. symphonyC. sonataD. concerto答案：A。
解析：莫扎特是音乐天才，他11岁时就创作了第一部歌剧。
歌剧是一种包含音乐、戏剧、诗歌等多种艺术形式的大型作品，莫扎特早期的歌剧创作展现了他极高的音乐天赋，这在音乐史上是非常了不起的成就。
3. Pele, the great football player, made his first appearance in a major international tournament at the age of _____.A. 16B. 18C. 20D. 22答案：A。
解析：贝利16岁时就出现在大型国际赛事中。
他在足球领域有着非凡的成就，年少就在国际舞台上崭露头角，之后更是成为足球界的传奇人物，他的球技和成就对全世界的足球发展都有着巨大的推动作用。
4. Marie Curie made important contributions to the field of radioactivity early on. She was the first woman to win a Nobel Prize, and she won it at the age of _____.A. 36B. 40C. 44D. 48答案：A。
介绍最著名的科学家英语作文
Title: Introducing the World's MostRenowned ScientistsThroughout the annals of history, science has been shaped by a select few individuals whose groundbreaking contributions have revolutionized our understanding of the universe and its inner workings. Among these giants of knowledge, three scientists stand out as the most renowned for their remarkable achievements and lasting impact on humanity: Albert Einstein, Isaac Newton, and Charles Darwin. Albert Einstein, a German-born theoretical physicist,is best known for his theory of relativity, which彻底改变了我们对时间、空间和物质的理解。
His special theory of relativity revolutionized our understanding of time, space, and matter, introducing the concept of the speed of lightas an absolute constant and revolutionizing our view of the universe. Einstein's general theory of relativity further expanded this framework, introducing the idea of gravity as a curvature of spacetime, a concept that has since underpinned much of modern cosmology and astrophysics.Isaac Newton, an English physicist and mathematician, was a pivotal figure in the scientific revolution of the17th century. His three laws of motion, formulated in his Philosophiæ Naturalis Principia Mathematica, provided a mathematical framework for describing the motion of objects and the forces acting upon them. Newton's laws have since been applied in almost every field of physics, engineering, and even economics, serving as the foundation for classical mechanics.Charles Darwin, an English naturalist, revolutionized our understanding of the origin and diversity of species with his theory of natural selection. Darwin's On the Origin of Species, published in 1859, introduced the concept that species evolve through a process of natural selection, driven by the competition for resources and the survival of the fittest. This theory has since been widely accepted and expanded upon, providing a scientific explanation for the diversity of life on Earth and informing much of modern biology and ecology.These three scientists, each in their own way, haveleft an indelible mark on the history of science. Their theories and discoveries have not only expanded our knowledge of the universe but have also shaped our view ofthe world and our place within it. Their contributions continue to inspire generations of scientists and laymen alike, reminding us of the power of human curiosity and the potential for understanding the mysteries of the universe. **中国篇：介绍最著名的科学家**在人类历史的长河中，科学的发展离不开一些杰出的个体。
狭义相对论Special relativity
狭义相对论Special relativity (SR, also known as the special theory of relativity or STR) is the physical theory of measurement in an inertial frame of reference proposed in 1905 by Albert Einstein in the paper "On the Electrodynamics of Moving Bodies".[1]It extends Galileo's principle of relativity—that all uniform motion is relative, and that there is no absolute and well-defined state of rest (no privileged reference frames)—to account for the constant speed of light[2]—which was previously observed in the Michelson-Morley experiment—and postulates that it holds for all the laws of physics, including both the laws of mechanics and of electrodynamics, whatever they may be.[3]This theory has a wide range of consequences which have been experimentally verified,[4] including counter-intuitive ones such as length contraction, time dilation and relativity of simultaneity. It has replaced the classical notion of invariant time interval for two events with the notion of invariant space-time interval. Combined with other laws of physics, the two postulates of special relativity predict the equivalence of mass and energy, as expressed in the mass–energy equivalence formula E = mc2, where c is the speed of light in vacuum.[5][6] The predictions of special relativity agree well with Newtonian mechanics in their common realm of applicability, specifically in experiments in which all velocities are small compared with the speed of light. Special relativity reveals that c is not just the velocity of a certain phenomenon—namely the propagation of electromagnetic radiation (light)—but rather a fundamental feature of the way space and time are unified as spacetime. One of the consequences of the theory is that it is impossible for any particle that has rest mass to be accelerated to the speed of light.The theory was originally termed "special" because it applied the principle of relativity only to the special case of inertial reference frames, i.e. frames of reference in uniform relative motion with respect to each other.[7] Einstein developed general relativity to apply the principle in the more general case, that is, to any frame so as to handle general coordinate transformations, and that theory includes the effects of gravity.The term is currently used more generally to refer to any case in which gravitation is not significant. General relativity is the generalization of special relativity to include gravitation. In general relativity, gravity is described using noneuclidean geometry, so that gravitational effects are represented by curvature of spacetime; special relativity is restricted to flat spacetime. Just as the curvature of the earth's surface is not noticeable in everyday life, the curvature of spacetime can be neglected on small scales, so that locally, special relativity is a valid approximation to general relativity.[8] The presence of gravity becomes undetectable in a sufficiently small, free-falling laboratory.。
译林版九年级英语上册unit5知识点
译林版九年级英语上册unit5知识点Unit 5: Discoveries of Modern ScienceIntroductionIn this unit, we will explore the fascinating world of modern science and its many remarkable discoveries. From the depths of the ocean to the mysteries of outer space, human curiosity and innovation have led to groundbreaking achievements. Let's delve into some key knowledge points of Unit 5 from the textbook, "译林版九年级英语上册."1. Marie Curie - Pioneer of RadioactivityMarie Curie was a trailblazing scientist whose discoveries revolutionized the field of radioactivity. She was the first woman to win a Nobel Prize and remains the only person to have received Nobel Prizes in two different sciences. Her work laid the foundation for advancements in medical imaging and cancer treatment. Curie's story is an inspiration, emphasizing the importance of perseverance and dedication in scientific pursuits.2. Special Relativity - Einstein's TheoryAlbert Einstein's theory of special relativity forever transformed our understanding of time, space, and energy. This theory introduced the concept of spacetime, where measurements of time and space become relative depending on the observer's frame of reference. The famous equation, E=mc², demonstrates the equivalence of energy and mass. Einstein's theory has had a profound impact on physics and has opened the door to future discoveries, such as quantum physics.3. The Human Genome Project - Decoding Our DNAThe Human Genome Project was an international scientific endeavor that aimed to sequence and map the entire human genome. Completed in 2003, this project identified and cataloged all the genes present in our DNA. It has unlocked new avenues for research in genetics, medicine, and personalized healthcare. The project's findings have shed light on the complexity of human biology and provided insights into the causes of various diseases.4. The Hubble Space Telescope - Unveiling the UniverseThe Hubble Space Telescope, launched in 1990, has revolutionized our understanding of the universe. By capturing breathtaking images of distant galaxies, nebulas, and stars, Hubble has allowed scientists to study the history and expansion of the universe. Its observations have led to the discovery of dark energy, the acceleration of cosmicexpansion, and the existence of exoplanets. The Hubble continues to provide invaluable data, furthering our knowledge of the cosmos.5. CRISPR-Cas9 - Gene Editing BreakthroughCRISPR-Cas9 is a groundbreaking technology in genetic engineering that enables precise editing of DNA sequences. It has the potential to revolutionize medicine, agriculture, and biotechnology. This powerful tool allows scientists to modify specific genes, potentially treating genetic diseases and creating genetically modified organisms. While ethically debated, CRISPR-Cas9 holds immense promise for advancing scientific knowledge and improving human life.ConclusionThe discoveries discussed in this unit highlight the incredible advancements made by scientists in various fields. From groundbreaking research in radioactivity to unraveling the mysteries of the cosmos, human curiosity and ingenuity have propelled us forward. It is essential to foster a sense of wonder and encourage young minds to explore the world of science further. By doing so, we can inspire future generations to continue unraveling the wonders of the universe and make new discoveries that shape our world.。
爱因斯坦详细介绍【英文】Einstein Chris Mason
• Einstein’ຫໍສະໝຸດ theory meant that Newton’s Laws needed to be modified. • gravity • Space and time are not absolute - and the universe we live in is not actually the one Newton "discovered.“ • spacetime
Thank You Mr. Einstein!
Einstein’s new Theory of Gravity
1919
• A solar eclipse proves Einstein right, and he becomes an overnight celebrity. • An experiment had confirmed that light rays from the sun were deflected by the gravity of the sun in just the amount Einstein had predicted in his theory of gravity, General Relativity.
1921
• Albert Einstein is awarded the Nobel Prize "for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect"
1928
• Einstein begins pursuing his idea of a unifying theory that ties everything in the universe together.
爱因斯坦__Albert_Einstein_
Albert Einstein Quotes阿尔伯特〃爱因斯坦语录（英译中：CYN）With Charlie Chaplin.和查理·卓别林合影“When you sit with a nice girl for two hours,it seems like two minutes.When you sit on a hot stove fortwo minutes,it seems like two hours.That’s relativity.”“如果你跟一个好姑娘在一起坐两个钟头，那不过像两分钟。
但如果你在热火炉上坐两分钟，那就像两个钟头。
这就是相对论“The oldest picture, at age 7.最老的照片，7岁时拍摄。
“If I had only known, I would have been alocksmith.”“如果我以前早知道的话，我很可能成为一个锁匠”“Gravity cannot be heldresponsible for peoplefalling in love.”“人们堕入爱河--万有引力不能承担责任。
”“Education is that which remainswhen one has forgotteneverything learned in school.”“当一个人忘掉了在学校学到的一切，剩下来的就是教育。
”“Only two things are infinite, theuniverse and human stupidity,and I am not sure about theformer.”“只有两种东西是无穷的---宇宙和人类的愚蠢，而我对前者还没有把握。
”At age 14. 14岁留影。
High school diploma, in 1896 at age 17.5 1896年17岁半时的高中毕业证书Wedding with Mileva,in 1903 at age 24.1903年24岁时和米勒娃结婚。
相对论英文原版
相对论英文原版1简介Relativity Theory,or the Theory of Relativity,is a fundamental concept in modern physics.First proposed by Albert Einstein in1905,it fundamentally transformed our understanding of space,time,and the universe as a whole. The theory has two main components,the Special Theory of Relativity and the General Theory of Relativity.2特殊相对论The Special Theory of Relativity,introduced by Einstein in1905,postulates that the laws of physics are the same for all non-accelerating observers in uniform motion relative to one another.This includes the speed of light,which remains constant regardless of the relative motion of the observer and the source of the light.One of the most significant consequences of Special Relativity is time dilation,which means that time passes more slowly for objects in motion.This effect becomes significant at velocities approaching the speed of light and has been experimentally verified.Another consequence of Special Relativity is length contraction,which means that objects in motion appear shorter in the direction of their motion than they would at rest.This effect is also experimentally verified.3广义相对论The General Theory of Relativity,published by Einstein in1915,builds upon the principles of Special Relativity and introduces the concept of a curved spacetime.According to General Relativity,the curvature of spacetime is determined by the distribution of matter and energy within it.One consequence of General Relativity is the prediction of gravitational waves,which are ripples in spacetime caused by the motion of massive objects.These waves were first detected in2015by the Laser Interferometer Gravitational-Wave Observatory(LIGO).Another consequence of General Relativity is the prediction of black holes,which are regions of spacetime where the curvature is so extreme that nothing,not even light,can escape.Black holes have been observed indirectly through their effects on nearby matter,and directly through the recent imaging of the supermassive black hole at the center of the galaxy M87.4应用The concepts of Relativity Theory have many practical applications in modern technology.For example,GPSsatellites rely on the principles of Special Relativity to make accurate measurements of time and distance.The use of atomic clocks on these satellites allows them to account for the time dilation effect of their high velocities.The development of gravitational wave detectors has the potential to revolutionize our understanding of the universe, allowing us to observe events that are invisible totraditional telescopes.The recent detections ofgravitational waves from merging black holes and neutron stars have already provided unprecedented insights into the nature of these extreme objects.5结论In conclusion,Relativity Theory has profoundly impacted our view of the universe and has led to many technological advancements.While the concepts it introduces can seem strange and counterintuitive,they have been extensively tested and are now widely accepted as fundamental components of our understanding of the physical world.。
关于爱因斯坦的英语作文
Albert Einstein,one of the most renowned physicists of all time,was born on March 14,1879,in Ulm,Germany.His groundbreaking work in theoretical physics revolutionized our understanding of the universe and laid the foundation for modern physics.Einsteins early life was marked by a keen interest in mathematics and philosophy.He was not particularly interested in the rote learning style of the schools he attended,but he was deeply curious about the world around him.This curiosity led him to question the nature of reality and the laws that govern it.In1905,Einstein published four papers that would change the course of science.The first paper introduced the concept of the photon and laid the groundwork for quantum theory. The second paper,known as the miracle year paper,introduced the special theory of relativity,which fundamentally altered our understanding of space and time. Einsteins work on the special theory of relativity led to the famous equation Emc²,which shows that energy and mass are interchangeable.This equation has had farreaching implications,not only in physics but also in our understanding of the universes energy sources.In1915,Einstein published his general theory of relativity,which expanded on the special theory and introduced the concept of gravity as a curvature of spacetime.This theory has been confirmed through numerous experiments and observations,including the recent detection of gravitational waves.Einsteins contributions to science did not stop with his theories.He was also a passionate advocate for peace and social justice.He was a vocal critic of the arms race and nuclear weapons,and he used his influence to promote diplomacy and international cooperation.Despite his many accomplishments,Einstein remained humble and curious throughout his life.He once said,The most beautiful thing we can experience is the mysterious.It is the source of all true art and science.His insatiable curiosity and dedication to understanding the universe continue to inspire scientists and thinkers to this day.In conclusion,Albert Einsteins life and work have had a profound impact on our understanding of the world.His theories have shaped the field of physics and continue to influence scientific research.His legacy as a scientist,thinker,and humanitarian endures, reminding us of the power of curiosity and the importance of pursuing knowledge for the betterment of humanity.。
六年级英语短文带翻译_有关爱因斯坦的英语小短文带翻译
六年级英语短文带翻译_有关爱因斯坦的英语小短文带翻译爱因斯坦(18791955),是现代物理学的开创者和奠基人,是20世纪最具人文精神知识分子。
小编精心收集了有关爱因斯坦的英语小短文带翻译，供大家欣赏学习!有关爱因斯坦的英语小短文带翻译篇1Einstein(爱因斯坦).Born: 14 March 1879Birthplace: Ulm, GermanyDied: 18 April 1955 (heart failure)Best Known As: Creator of the theory of relativityThanks to his theory of relativity, Albert Einstein became the most famous scientist of the 20th century. In 1905, while working in a Swiss patent office, Einstein published a paper prop osing a “special theory of relativity,” a groundbreaking notion which laid the foundation for much of modern physics theory. (The theory included his famous equation e=mc².) Einstein's work had a profound impact on everything from quantum theory to nuclear power and the atom bomb. He continued to develop and refine his early ideas, and in 1915 published what is known as his general theory of relativity. By 1920 Einstein was internationally renowned; he won the Nobel Prize in 1921, not for relativity but for his 1905 work on the photoelectric effect. In 1933 Einstein moved to Princeton, New Jersey, where he worked at the Institute for Advanced Studies until the end of his life. Einstein's genius is often compared with that of Sir Isaac Newton; in 2000 Time magazine named him the leading figure of the 20th century.Einstein was famously rumpled and frizzy-haired, and over time his image has become synonymous with absent-minded genius... He sent a famous letter to Franklin Roosevelt in 1939, warning that Germany was developing an atomic bomb and urging Allied research toward the same goal... Einstein married Mileva Maric in1903. They had two sons: Hans Albert (b. 1904) and Eduard (b. 1910). They also had a daughter born before their marriage, Leiserl (b. 1902). She apparently was given for adoption or died in infancy. Mileva and Albert were divorced in 1914... He married his cousin Elsa Löwenthal in 1919, and they remained married until her death in 1936... The Institute for Advanced Studies has no formal link to Princeton University; however, according the IAS website, the two institutions “have many historic ties and ongoing relationships”... The Albert Einstein College of Medicine opened in New York City in 1955. It is part of Yeshiva University. Einstein did not create the school, but gave his permission to have his name used.中文:出生日期：1879年3月14号出生地：Ulm ，德国死亡：55年4月18日(心脏衰竭)最佳称为：创造相对论由于他的相对论，爱因斯坦成为最有名的科学家在20世纪。
爱因斯坦的英语作文
爱因斯坦的英语作文Einstein's Theory of Relativity。
Albert Einstein, one of the greatest minds in the history of science, is renowned for his groundbreaking theories and contributions to the field of physics. One of his most well-known theories is the Theory of Relativity, which revolutionized the way we understand space, time, and gravity. In this essay, we will explore the key concepts of Einstein's Theory of Relativity and its impact on the scientific community.The Theory of Relativity consists of two major components: the Special Theory of Relativity and the General Theory of Relativity. The Special Theory of Relativity, published by Einstein in 1905, introduced the concept that the laws of physics are the same for all observers, regardless of their relative motion. This means that the speed of light in a vacuum is constant for all observers, regardless of their motion. This theory alsoproposed that time and space are not separate entities but are interconnected in a four-dimensional continuum known as spacetime.The General Theory of Relativity, published by Einstein in 1915, expanded on the ideas of the Special Theory of Relativity and introduced the concept of gravity as the curvature of spacetime. According to this theory, massive objects such as planets and stars cause a distortion in the fabric of spacetime, which we perceive as the force of gravity. This theory also predicted the phenomenon of gravitational waves, which were later observed and confirmed by the LIGO experiment.The Theory of Relativity has had a profound impact on various aspects of physics and has been confirmed by numerous experiments and observations. One of the most famous experiments that confirmed the predictions of the Theory of Relativity is the bending of light around massive objects. During a solar eclipse in 1919, the bending of starlight around the Sun was observed, providing strong evidence for the theory.Moreover, the Theory of Relativity has important implications for our understanding of the universe at large scales. It has been instrumental in the development of cosmology, the study of the origin and evolution of the universe. The theory suggests that the universe is expanding and that the rate of expansion is accelerating, a concept that was later confirmed by observations of distant galaxies.Furthermore, the Theory of Relativity has practical applications in modern technology. For instance, the Global Positioning System (GPS) relies on the precise measurement of time and the correction of time dilation effects predicted by the theory. Without the Theory of Relativity, GPS would not be as accurate as it is today.In conclusion, Albert Einstein's Theory of Relativity has revolutionized our understanding of space, time, and gravity. The concepts introduced in this theory have been confirmed by experiments and observations, and it has had a significant impact on various fields of physics. From thebending of light to the expansion of the universe, the Theory of Relativity continues to shape our understanding of the cosmos.。