10大你不得不知的科学定律

10大你不得不知的科学定律 译者： 禾木原作者：Jacob Silverman 发表时间：2011-02-08浏览量：9476 生命如何起源？时间和空间到底是何物？宇宙最深邃之处蕴藏着何种奥妙？10大科学定律为你一一解答。 10 Scientific Laws and Theories You Really Should Know 10大你不得不知的科学定律 Whether we're launching a space shuttle or trying to discover another Earth-like planet, we rely on scientific laws and theories to guide us. Scientists have many tools available to them when attempting to describe how nature and the universe at large work. Often they reach for laws and theories first. What's the difference? A scientific law can often be reduced to a mathematical statement, such as E = mc2; it's a specific statement based on empirical data, and its truth is generally confined to a certain set of conditions. For example, in the case of E = mc2, c refers to the speed of light in a vacuum. 无论我们要发射宇宙飞机或是试图发现另一颗类似于地球的行星，我们都有赖于科学定律和理论的指引。当科学家们想要描述自然和整个宇宙的运作之时，他们有许多可以运用的工具。通常他们会首先寻求定律和理论。那么这有何不同呢？一条科学定律通常可简化为数学表达式，例如 E = mc2；这是基于经验数据而得出的特定表达式，一般而言，该等式在特定条件下方成立。比如在E = mc2 这个例子中，c代表真空中的光速。 A scientific theory often seeks to synthesize a body of evidence or observations of particular phenomena. It's generally -- though by no means always -- a grander, testable statement about how nature operates. You can't necessarily reduce a scientific theory to a pithy statement or equation, but it does represent something fundamental about how nature works. 科学理论通常试图将有关于某一特定现象的证据和观察加以总结。这在一般情况下——尽管并非总是成立——从宏观的角度揭示了自然的运作方式，并且可以加以验证。科学理论无法简化成表达式或方程式，但它确实代表了自然运作的一些规律。 Both laws and theories depend on basic elements of the scientific method, such as generating a hypothesis, testing that premise, finding (or not finding) empirical evidence and coming up with conclusions. Eventually, other scientists must be able to replicate the results if the experiment is destined to become the basis for a widely accepted law or theory. 科学定律和理论都建立于科学方法中的基本元素之上，包括提出假设，验证假设，搜集（或不搜集）实验证据，以及得出结论。最后，若该实验要构成普遍接受的定律或理论的基础，那么其他的科学家必须能重现该实验结果。 In this article, we'll look at 10 scientific laws and theories that you might want to brush up on, even if you don't find yourself, say, operating a scanning electron microscope all that frequently. We'll start off with a bang and move on to the basic laws of the universe, before hitting evolution. Finally, we'll tackle some headier material, delving into the realm of quantum physics. 在本文中，我们将会谈到10条你或许想知道的科学定律和理论。这么说吧，即便你没有发现自己是如此频繁地使用扫描电子显微镜，你也会想知道这些。我们以大爆炸理论为起点，继而谈到宇宙基本规律，再触及人类进化，并最终着眼于较为深奥的问 题 快递公司问题件快递公司问题件货款处理关于圆的周长面积重点题型关于解方程组的题及答案关于南海问题 ，深入至量子物理学领域。 10: Big Bang Theory 10：大爆炸理论 you're going to know one scientific theory, make it the one that explains how the universe arrived at its present state. Based on research performed by Edwin Hubble, Georges Lemaitre and Albert Einstein, among others, the big bang theory postulates that the universe began almost 14 billion years ago with a massive expansion event. At the time, the universe was confined to a single point, encompassing all of the universe's matter. That original movement continues today, as the universe keeps expanding outward. 如果你打算了解一些科学理论，那么你就应该选择这个解释宇宙如何发展至今的理论。大爆炸理论基于爱德文·哈勃、乔治斯·勒梅特，阿尔伯特·爱因斯坦以及其他人士的研究之上，该理论假定宇宙开始于140亿年前的一次巨型爆炸。当时，宇宙只是一个奇点，包囊了宇宙中的所有物质。宇宙持续向外扩张，因而可以得知最初的爆炸一直延续至今。 The theory of the big bang gained widespread support in the scientific community after Arno Penzias and Robert Wilson discovered cosmic microwave background radiation in 1965. Using radio telescopes, the two astronomers detected cosmic noise, or static, that didn't dissipate over time. Collaborating with Princeton researcher Robert Dicke, the pair confirmed Dicke's hypothesis that the original big bang left behind low-level radiation detectable throughout the universe. 阿尔诺·彭齐亚斯和罗伯特·威尔逊在1965年发现了宇宙微波背景辐射，这使得大爆炸理论在科学界获得了广泛支持。这两位天文学家利用无线电望远镜检测出了宇宙噪声(或是天电干扰)，而且并不随着时间消散。他们与普林斯顿大学的研究者罗伯特·迪克合作，验证了迪克提出的假设，也就是最初的大爆炸使得整个宇宙都充满了可以检测到的微弱辐射。 9: Hubble's Law of Cosmic Expansion 9：哈勃宇宙膨胀定律 Hubble and his famous law helped to quantify the movement of the universe's galaxies.Let's stick with Edwin Hubble for a second. While the 1920s roared past and the Great Depression limped by, Hubble was performing groundbreaking astronomical research. Hubble not only proved that there were other galaxies besides the Milky Way, he also discovered that these galaxies were zipping away from our own, a motion he called recession. 哈勃以及著名定律帮助量化了宇宙各星系的运动。让我们来继续了解下爱德文·哈勃吧。当20世纪20年代倏忽而过，经济大萧条踉跄前行之时，哈勃正进行着开创性的天文研究。哈勃不仅证明了除了银河系外还有其他星系的存在，也发现了这些星系正远离银河系，他讲这种运动称之为星系后退。 In order to quantify the velocity of this galactic movement, Hubble proposed Hubble's Law of Cosmic Expansion, aka Hubble's law, an equation that states: velocity = H0 × distance. Velocity represents the galaxy's recessional velocity; H0 is the Hubble constant, or parameter that indicates the rate at which the universe is expanding; and distance is the galaxy's distance from the one with which it's being compared. 为了测算这种星系运动的速度，哈勃提出了哈勃宇宙膨胀定律，也称哈勃定律。可用等式表述为：速度=H0× 距离。其中，速度表示星系后退的速度，H0为哈勃常数，也即宇宙膨胀速率的 参数 转速和进给参数表a氧化沟运行参数高温蒸汽处理医疗废物pid参数自整定算法口腔医院集中消毒供应 ，而距离指的是星系与相比较星系之间的距离。 Hubble's constant has been calculated at different values over time, but the current accepted value is 70 kilometers/second per megaparsec, the latter being a unit of distance in intergalactic space [source: White]. For our purposes, that's not so important. What matters most is that Hubble's law provides a concise method for measuring a galaxy's velocity in relation to our own. And perhaps most significantly, the law established that the universe is made up of many galaxies, whose movements trace back to the big bang. 随着时间的推移，哈勃常数的值也发生着变化，但是现在所接受的值为70千米/（秒·百万秒差距），百万差距为天体距离的单位。但这对我们而言并不那么重要。至关重要的是，哈勃定律提供了精确测量银河系相关星系的运动速度。或许哈勃定律最为重要的意义在于其提出了宇宙由许多星系组成，而这些星系的运动可追溯至最初的大爆炸。 8: Kepler's Laws of Planetary Motion 8：开普勒的行星运动定律 For centuries, scientists battled with one another and with religious leaders about the planets' orbits, especially about whether they orbited our sun. In the 16th century, Copernicus put forth his controversial concept of a heliocentric solar system, in which the planets revolved around the sun -- not the Earth. But it would take Johannes Kepler, building on work performed by Tyco Brahe and others, to establish a clear scientific foundation for the planets' movements. 数百年来，科学家和宗教领袖一直就行星的运行轨道争论不休，对于地球是否围绕太阳运行这一问题尤为如此。16世纪，哥白尼提出了颇具争议的日心说，认为行星围绕太阳运转而非地球。然而直到约翰内斯·开普勒在第谷·布拉赫及他人成果的基础上做了进一步研究之后，行星运动的科学基础才得以建立。 Kepler's three laws of planetary motion -- formed in the early 17th century -- describe how planets orbit the sun. The first law, sometimes called the law of orbits, states that planets orbit the sun elliptically. The second law, the law of areas, states that a line connecting a planet to the sun covers an equal area over equal periods of time. In other words, if you're measuring the area created by drawing a line from the Earth to the sun and tracking the Earth's movement over 30 days, the area will be the same no matter where the Earth is in its orbit when measurements begin. 开普勒于17世纪初提出了行星运动三大定律，揭示了行星围绕太阳运转的方式。开普勒第一定律，也称椭圆定律，指出每一个行星沿椭圆轨道围绕太阳。开普勒第二定律，也即面积定律，指出从太阳到行星所联接的直线在相等时间内扫过同等的面积。换言之，如果你想测量地球和太阳间直线扫过的面积并且对地球30天的运动进行记录，那么你会发现无论测量开始时地球位于轨道何处，得到的面积总是相等。 The third one, the law of periods, allows us to establish a clear relationship between a planet's orbital period and its distance from the sun. Thanks to this law, we know that a planet relatively close to the sun, like Venus, has a far briefer orbital period than a distant planet, such as Neptune. 开普勒第三定律，也即调和定律，清楚地表明了行星公转周期与其离日距离之间的关系。正因为了有这条定律，我们才能得知例如金星这样离日相对较近的行星的公转周期要短于离日较远的行星，例如海王星。 7: Universal Law of Gravitation 7：万有引力定律 Thanks to Newton's universal law, we can figure out the gravitational force between any two objects. We may take it for granted now, but more than 300 years ago Sir Isaac Newton proposed a revolutionary idea: that any two objects, no matter their mass, exert gravitational force toward one another. This law is represented by an equation that many high schoolers encounter in physics class. It goes as follows: F = G × [(m1m2)/r²] 正是有了牛顿的万有引力定律，我们才能计算出任意两物体间的引力。或许如今我们对此已习以为常，然而艾萨克·牛顿先生300多年前提出的观点在当时颇具颠覆意义：任意两物体，无论质量如何，彼此之间具有引力。这条定律可由如下等式表示，许多中学生在物理课上都会学到该等式。 F = G × [(m1m2)/r²] F is the gravitational force between the two objects, measured in Newtons. M1 and m2 are the masses of the two objects, while r is the distance between them. G is the gravitational constant, a number currently calculated to be 6.672 × 10-11 N m2 kg-2 [source: Weisstein]. F表示两物体之间产生的引力，单位为牛顿。M1和M2表示两物体的智力，r则表示两物体之间的距离。G是万有引力常数，近似等于6.672 × 10-11 N m2 kg-2。 The benefit of the universal law of gravitation is that it allows us to calculate the gravitational pull between any two objects. This ability is especially useful when scientists are, say, planning to put a satellite in orbit or charting the course of the moon. 万有引力定律令我们能够计算出任意两物体之间的引力。当科学家 计划 项目进度计划表范例计划下载计划下载计划下载课程教学计划下载 将一颗人造卫星送上月球轨道时，这种计算能力便显得尤为重要。 6: Newton's Laws of Motion 6：牛顿运动定律 As long as we're talking about one of the greatest scientists who ever lived, let's move on to Newton's other famous laws. His three laws of motion form an essential component of modern physics. And like many scientific laws, they're rather elegant in their simplicity. 既然我们正在谈论史上最伟大的科学家之一，那么我们就来看看牛顿其他的一些著名定律吧。牛顿的运动三定律是现代学力学的重要组成部分。正如许多其他科学定律一样，运动三定律因其简练而彰显优雅。 The first of the three laws states an object in motion stays in motion unless acted upon by an outside force. For a ball rolling across the floor, that outside force could be the friction between the ball and the floor, or it could be the toddler that kicks the ball in another direction. 牛顿第一运动定律指出在不受外力作用下，动者恒动。对于一个在地面上滚动的球而言，外力可能是球与地面之间的摩擦力或者幼童相反方向踢球产生的力。 The second law establishes a connection between an object's mass (m) and its acceleration (a), in the form of the equation F = m × a. F represents force, measured in Newtons. It's also a vector, meaning it has a directional component. Owing to its acceleration, that ball rolling across the floor has a particular vector, a direction in which it's traveling, and it's accounted for in calculating its force. 牛顿第二运动定律指出了物体质量和其加速度之间的联系，表达式为：F = m × a。F代表合外力，单位为牛顿。合外力同时也是一个矢量，表示其具有方向。由于具有加速度，在地面滚动的球有着特定的运动方向，而在计算球所受的合外力时要将该方向考虑在内。 The third law is rather pithy and should be familiar to you: For every action there is an equal and opposite reaction. That is, for every force applied to an object or surface, that object pushes back with equal force. 牛顿第三运动定律极为简练，应当为人所熟知：任意作用力必有其反作用力。也就是说，对于任一物体或表面施加的作用力，该物体或表面必会产生相同的反作用力。 5: Laws of Thermodynamics 5：热力学定律 The British physicist and novelist C.P. Snow once said that a nonscientist who didn't know the second law of thermodynamics was like a scientist who had never read Shakespeare. Snow's now-famous statement was meant to emphasize both the importance of thermodynamics and the necessity for nonscientists to learn about it. 英国物理学家和小说家C·P斯诺曾说过一个不是科学家的人不知道热力学定律的话就如同一个科学家未曾看过莎士比亚的著作一般。斯诺的这番话现在十分有名，这不仅强调了热力学的重要性，也强调了大众了解热力学定律的必要性。 Thermodynamics is the study of how energy works in a system, whether it's an engine or the Earth's core. It can be reduced to several basic laws, which Snow cleverly summed up as follows [source: Physics Planet]:·You can't win. ·You can't break even. ·You can't quit the game. 热力学定律研究了一系统中能量的运动方式，这系统既可以是引擎也可以是地核。热力学定律可简化为几条基本定律。斯诺将其归纳如下： ·你赢不了 ·你不能达成平衡 ·你不能退出这场游戏 Let's unpack these a bit. By saying you can't win, Snow meant that since matter and energy are conserved, you can't get one without giving up some of the other (i.e., E=mc2). It also means that for an engine to produce work, you have to supply heat, although in anything other than a perfectly closed system, some heat is inevitably lost to the outside world, which then leads to the second law. 让我们对此稍加理解。“你赢不了”，这句话斯诺指出因为物质和能量都是守恒的，你不可能在没有损耗的情况下获得能量（也即E=mc2）。这还指出你必须提供热量才能使引擎工作。尽管除了完全封闭的系统之外，热量必然传递给外界，从而发生损耗。这就引出了第二条规律。 The second statement -- you can't break even -- means that due to ever-increasing entropy, you can't return to the same energy state. Energy concentrated in one place will always flow to places of lower concentration. 规律二——你不能达成平衡——指出由于熵的不断增加，你不可能回到同一能量状态。因为能量总是由热处转到冷处。 Finally, the third law -- you can't quit the game -- refers to absolute zero, the lowest theoretical temperature possible, measured at zero Kelvin or (minus 273.15 degrees Celsius and minus 459.67 degrees Fahrenheit). When a system reaches absolute zero, molecules stop all movement, meaning that there is no kinetic energy, and entropy reaches its lowest possible value. But in the real world, even in the recesses of space, reaching absolutely zero is impossible -- you can only get very close to it. 最后，规律三——你不能退出这场游戏——指的是绝对零度，这是理论上能到达的最低温度，即0开摄氏度（也可表示为-273.15摄氏度或-459.67华摄氏度）。当一系统达到绝对零度时，分子停止一切运动，意味着此时不再有动能，而熵也达到了其可能的最低值。然而在真实世界中，即便在宇宙深处，也不可能达到绝对零度——你只能无限接近绝对零度。 4: Archimedes' Buoyancy Principle 4.：阿基米德浮力原理 Buoyancy keeps everything from rubber ducks to ocean liners afloat.After he discovered his principle of buoyancy, the ancient Greek scholar Archimedes allegedly yelled out "Eureka!" and ran naked through the city of Syracuse. The discovery was that important. The story goes that Archimedes made his great breakthrough when he noticed the water rise as he got into the tub [source: Quake]. 浮力让从橡胶鸭到远洋轮船的一切物体都能浮于水面之上。在阿基米德发现浮力原理之后，这位古代希腊学者大声叫着：“我找到了！”并且光着身子在锡拉丘兹市跑着。这个发现极为重要。 据说阿基米德发现当自己进入浴盆之时，盆中的水便会上升，因为才有了这个重大突破。 According to Archimedes' buoyancy principle, the force acting on, or buoying, a submerged or partially submerged object equals the weight of the liquid that the object displaces. This sort of principle has an immense range of applications and is essential to calculations of density, as well as designing submarines and other oceangoing vessels. 浸没或部分浸没在水中的物体所受的浮力等于其排开的水的重力。该原理适用范围很广，对于密度的计算和潜艇和远洋船只的设计极其重要。 3: Evolution and Natural Selection 3：演化与天择 Now that we've established some of the fundamental concepts of how our universe began and how physics play out in our daily lives, let's turn our attention to the human form and how we got to be the way we are. According to most scientists, all life on Earth has a common ancestor. But in order to produce the immense amount of difference among all living organisms, certain ones had to evolve into distinct species. 既然现在我们对于宇宙的起源和物理在日常生活中的作用已经有了基本认识，那么让我们转而关注人类以及其演化方式。很多科学家认为地球上的一切生命都拥有相同的祖先。但是为了在所有生物体之间产生巨大的差异，一些生物必须进化为独特的物种。 In a basic sense, this differentiation occurred through evolution, through descent with modification [source: UCMP]. Populations of organisms developed different traits, through mechanisms such as mutation. Those with traits that were more beneficial to survival such as, a frog whose brown coloring allows it to be camouflaged in a swamp, were naturally selected for survival; hence the term natural selection. 基本而言，通过演化和后代的改良，差异才得以形成。通过例如基因突变等机制，生物体进化出了不同的特性。这些特性经过自然选择得以出现，有利于生物的生存。例如，青蛙的棕褐体色使其可以伪装于沼泽之中。这便是自然选择。 It's possible to expand upon both of these theories at greater length, but this is the basic, and groundbreaking, discovery that Darwin made in the 19th century: that evolution through natural selection accounts for the tremendous diversity of life on Earth. 这些理论均可进行深层延展，但是达尔文在19世纪的发现却是最为基本，最具突破性意义的：借由自然选择进行的进化正是地球生物多样性的原因 2: Theory of General Relativity 2：广义相对论 Albert Einstein's theory of general relativity remains an important and essential discovery because it permanently altered how we look at the universe. Einstein's major breakthrough was to say that space and time are not absolutes and that gravity is not simply a force applied to an object or mass. Rather, the gravity associated with any mass curves the very space and time (often called space-time) around it. 阿尔伯特·爱因斯坦的广义相对论至今仍是极为重要且意义非凡的一项发现，因为这永远转变了我们理解宇宙的方式。爱因斯坦的重大突破在于指出了空间和时间并非绝对之物，重力也并非仅仅只是施加于物体之上的力。相反，重力与物体周围的空间和时间（常称为时空）弯曲有关。 To conceptualize this, imagine you're traveling across the Earth in a straight line, heading east. After a while, if someone were to pinpoint your position on a map, you'd actually be both east and far south of your original position. That's because the Earth is curved. To travel directly east, you'd have to take into account the shape of the Earth and angle yourself slightly north. (Think about the difference between a flat paper map and a spherical globe.) 为了更直观地理解上述 内容 财务内部控制制度的内容财务内部控制制度的内容人员招聘与配置的内容项目成本控制的内容消防安全演练内容 ，可想象一下你正在以直线方式向东穿越地球。过了一会，如果有人要在地图上指出你的位置，那么实际上你既在初始点东边也在其极南的位置上。向正东走，你得考虑到地球的形状然后稍偏北行进。（试想下平面地图和球形地球之间的区别。） Space is pretty much the same. For example, to the occupants of the shuttle orbiting the Earth, it can look like they're traveling on a straight line through space. In reality, the space-time around them is being curved by the Earth's gravity (as it would be with any large object with immense gravity such as a planet or a black hole), causing them to both move forward and to appear to orbit the Earth. 空间也是如此。例如，对于环绕地球的航天飞机内的宇航员而言，他们似乎是以直线方式在太空中运行的。实际上，他们周围的时空已经被地球的重力所弯曲了（正如这时空可以被例如行星或黑洞等重力巨大的物体弯曲一样），这是的飞船能向前运行并且显得围绕地球运转。 Einstein's theory had tremendous implications for the future of astrophysics and cosmology. It explained a minor, unexpected anomaly in Mercury's orbit, showed how starlight bends and laid the theoretical foundations for black holes. 爱因斯坦的理论对于日后的天体物理学和宇宙学意义非凡。其揭示了水星运行轨道中出人意料的细微不规则现象，也展现了星光的弯曲方式，并且为对于黑洞的研究奠定了理论基础。 1: Heisenberg's Uncertainty Principle 1：海森堡测不准原理 Einstein's broader theory of relativity told us more about how the universe works and helped to lay the foundation for quantum physics, but it also introduced more confusion into theoretical science. In 1927, this sense that the universe's laws were, in some contexts, flexible, led to a groundbreaking discovery by the German scientist Werner Heisenberg. 爱因斯坦的广义相对论令我们更了解宇宙的运作方式并且为量子物理学打下了基础，但是也为理论科学带了了更大的困惑。1927年，基于宇宙规律在某些情况下可发生变化这一认识，德国科学家华纳·海森堡做出了突破性的发现。 In postulating his Uncertainty Principle, Heisenberg realized that it was impossible to simultaneously know, with a high level of precision, two properties of a particle. In other words, you can know the position of an electron with a high degree of certainty, but not its momentum and vice versa. 在对测不准原理做出假设时，海森堡发现无法同时精准地获知粒子的两种特性。换言之，你可以准确地知道电子的外置，但无法同时知道其动量，反之亦然。 Niels Bohr later made a discovery that helps to explain Heisenberg's principle. Bohr found that an electron has the qualities of both a particle and a wave, a concept known as wave-particle duality, which has become a cornerstone of quantum physics. So when we measure an electron's position, we are treating it as a particle at a specific point in space, with an uncertain wavelength. When we measure its momentum, we are treating it as a wave, meaning we can know the amplitude of its wavelength but not its location. 尼尔斯·玻尔之后所做的发现帮助解释了海森堡的理论。玻尔发现电子同时具有粒子和波的性质，这便是波粒二象性。波粒二象性构成了量子物理学的基石。因此当我们测量一电子的位置是，我们将其当做处于空间某一点的粒子，拥有不确定的波长。而当我们测量器动量时，我们将其当做波，这意味着我们能知其波长的振幅，但却无法获知其位置。