－Prof．Yang＇s email： -杨教授电子邮件：
yangyj＠sustech．edu．cn
－TA：He Hui（何惠）email： -TA：何惠（He Hui）email：
－QQ group for this class： -本班的 QQ 小组：
713379401
12331099＠mail．sustech．cn
（3）2025年石平EOE100 （3）2025 年石平 eoe100
－All course－related materials ıгисur iıvieo，assignment，notice，etc．） will be posted in this QQ group！ -所有与课程相关的资料，包括视频、作业、通知等，都将在此 QQ 群中发布。）将在此 QQ 群中发布
Course schedule 课程表
Introduction, Class overview 简介、班级概况
Big Bang, the birth of the universe 宇宙大爆炸
Origin of the Elements and Molecules 元素和分子的起源
Formation of the Solar System 太阳系的形成
The age of the universe and the earth 宇宙和地球的年龄
Interior modifications of the Earth 地球内部的变化
Plate Tectonics 板块构造
Natural extreme events 自然极端事件
Origin and Evolution of Life 生命的起源与进化
Oxygen production and consumption 氧气的产生和消耗
The Ocean 海洋
The Secret of the sea floor 海底的秘密
Life in the Ocean 海洋生命
How did this amazing place come about? 这个神奇的地方是如何诞生的？
And what is the relationship 它们之间的关系是什么？
between Earth and this amazing species? 地球和这一神奇物种之间的关系？
Natural Questions about the Universe??? 关于宇宙的自然问题？
-How big is the universe? -宇宙有多大？
-How old is the universe? -宇宙有多古老？
-Was there a beginning? -有开始吗？
The Planets 行星
The speed of light is ∼300,000km//s\sim 300,000 \mathrm{~km} / \mathrm{s}. 光速为 ∼300,000km//s\sim 300,000 \mathrm{~km} / \mathrm{s} 。
The circrumference of Earth is ∼40,000km\sim 40,000 \mathrm{~km}, taking ∼0.13s\sim 0.13 \mathrm{~s} for light to travel. 地球的圆周率为 ∼40,000km\sim 40,000 \mathrm{~km} ，光的传播需要 ∼0.13s\sim 0.13 \mathrm{~s} 。
The distance of Earth to the Moon is ∼384,400km\sim 384,400 \mathrm{~km} km, taking ∼1.28s\sim 1.28 \mathrm{~s} for light to travel. 地球到月球的距离为 ∼384,400km\sim 384,400 \mathrm{~km} 千米，光的传播距离为 ∼1.28s\sim 1.28 \mathrm{~s} 千米。
The distance of Earth to Sun is 150.87 million km, taking ~8.3 minutes for light to travel. 地球到太阳的距离为 1.5087 亿千米，光的传播时间约为 8.3 分钟。
and is about 100,000 light-years across 直径约为 10 万光年
Distance Scales 距离标尺
Q1: How big is the universe: finite or infinite? 问题 1：宇宙有多大：有限还是无限？
A1: if we assume it is infinite? A1：如果我们假设它是无限的？
Dark Sky Paradox is an argument that says that the darkness of the night sky conflicts with the assumption of an infinite and eternal static universe. 黑天悖论是指夜空的黑暗与无限和永恒静态宇宙的假设相冲突。
Proposed by Heinrich Olbers in 1826 海因里希-奥尔伯斯于 1826 年提出
If Universe is infinite and at steady state, the sky should be light everywhere 如果宇宙是无限的，并且处于稳定状态，那么天空应该到处都是光亮的
Dark Sky Paradox 黑暗天空悖论
Graphic: U. of Arizona 图片亚利桑那大学
Dark Sky Paradox is an argument that says that the darkness of the night sky conflicts with the assumption of an infinite and eternal static universe. 黑天悖论是指夜空的黑暗与无限和永恒静态宇宙的假设相冲突。
Proposed by Heinrich Olbers in 1826 海因里希-奥尔伯斯于 1826 年提出
If Universe is infinite and at steady state, the sky should be light everywhere 如果宇宙是无限的，并且处于稳定状态，那么天空应该到处都是光亮的
Schematic illustration of one aspect of Olber's paradox 奥尔伯悖论的一个方面示意图
The black background between the stars seemed to demand either that 星星之间的黑色背景似乎要求
(1) the universe has a finite extent or (1) 宇宙的范围是有限的，或
(2) that the light from the most distant stars is being intercepted by dark matter in the voids of space. (2) 来自最遥远恒星的光线被太空空隙中的暗物质拦截。
If there is dark matter in between 如果两者之间存在暗物质
Dark Sky Paradox 黑暗天空悖论
If there is dark matter in between, the light from very distant stars is intercepted by dark clouds of dust and gas along its path to the Earth-is also unacceptable. 如果在这两者之间存在暗物质，那么来自非常遥远恒星的光线在到达地球的途中会被尘埃和气体黑云拦截--这也是不可接受的。
In this situation, the light from stars at intermediate distances would also be affected. We should see a glow of scattered light similar to that in the night sky over a great city or from headlights approaching through fog. No such glow is seen! 在这种情况下，中间距离的恒星发出的光也会受到影响。我们应该看到类似于大城市夜空中的散射光，或者穿过雾气的车灯发出的光。但我们并没有看到这样的光芒！
A2: So the universe must be finite A2：所以宇宙一定是有限的
If Universe is finite and static it should collapse 如果宇宙是有限的、静态的，它就应该坍缩
Galaxies on "edge" feel inward tug of gravity 处于 "边缘 "的星系感受到向内的引力牵引
Solution? 解决方案？
Proposed by George LeMaitre 1927 乔治-勒梅特尔提议 1927 年
Universe is not infinite 宇宙不是无限的
Universe is not static but expanding - “exploding egg” 宇宙不是静止的，而是不断膨胀的--"爆炸的蛋"
Big Bang, the birth of the universe 宇宙大爆炸
What is the Big Bang? 什么是宇宙大爆炸？
How Everything Began? 一切是如何开始的？
Newton and Light 牛顿与光
Electromagnetic Radiation 电磁辐射
Propagation of energy involving coupled electric and magnetic waves. 涉及耦合电波和磁波的能量传播。 >> Waves have a particular wavelength , ( lambda\lambda ) >> 波有特定的波长 , ( lambda\lambda ) >> And since all of these waves travel with the speed of light ( 3x3 x10^(8)m//s10^{8} \mathrm{~m} / \mathrm{s} ) they have a frequency that depends on their wavelength ^(9){ }^{9} >> 由于所有这些波都以光速传播（ 3x3 x10^(8)m//s10^{8} \mathrm{~m} / \mathrm{s} ），因此它们的频率取决于其波长 ^(9){ }^{9} 。
Chemists were discovering the elements and their properties. Each element has its own characteristic wavelengths of light. 化学家们发现了各种元素及其特性。每种元素都有自己特有的光波长。
Each element has electrons that can move from one energy state to another. The jumps in energy either absorb or emit light of a very specific wavelength. 每种元素都有可以从一种能量状态移动到另一种能量状态的电子。能量的跃迁会吸收或发射特定波长的光。
Light and element 光与元素
So by looking at the wavelengths emitted, you can tell what elements are present 因此，通过观察发射的波长，就能知道存在哪些元素
From the intensity of the light you can say something about how much of the element is present. 从光线的强度可以看出元素的含量。
Say- we could look at the light form the Sun and see what it is made of! 比方说，我们可以观察太阳光，看看它是由什么组成的！
"Fraunhofer spectrum" "弗劳恩霍夫光谱"
A hot, dense object (star) will emit a continuous spectrum of radiation of different wavelengths 高温、高密度的天体（恒星）会发出不同波长的连续辐射光谱
The cooler gas in the outer atmosphere absorbs photons with the characteristic wavelengths corresponding to the transitions between different energy levels of the atoms in the gas. 大气层外较冷的气体会吸收与气体中原子的不同能级之间的跃迁相对应的特征波长的光子。
This leads to dark lines in the spectrum. 这导致光谱中出现暗线。
Elements in a star's outer layer will absorb light, each element with its own spectral fingerprint 恒星外层的元素会吸收光线，每种元素都有自己的光谱指纹
So of course if you were an astronomer, having seen the Sun’s spectrum, you would ask- I wonder what the spectrum looks like from other stars, and from distant galaxies? 当然，如果你是天文学家，在看到太阳的光谱后，你会问--我想知道其他恒星和遥远星系的光谱是什么样的？
And for light from other galaxies the dark bands occurred in the same pattern, but shifted towards the red: “the red shift” 而对于来自其他星系的光线，暗带也以同样的模式出现，但却向红色偏移："红移"
Doppler effect 多普勒效应
Source moving with v_(s)=c\mathrm{v}_{\mathrm{s}}=\mathrm{c} (Mach 1 - breaking the sound barrier ) 源以 v_(s)=c\mathrm{v}_{\mathrm{s}}=\mathrm{c} 的速度运动（1 马赫 - 突破音障）
Doppler Effect 多普勒效应
Source and observer are at rest 源和观察者都处于静止状态
Source is moving towards Source is moving away from the observer who is at rest the observer who is at rest 源正在向静止的观察者移动 源正在远离静止的观察者 静止的观察者
f=(v)/( lambda)f=\frac{v}{\lambda}
Wavelength ( lambda\lambda ) and frequency (f) of sound waves emited by the source, and are moving with a velocity v 声源发出的声波的波长（ lambda\lambda ）和频率（f），并以速度 v
lambda^(')=(v-v_(s))/(f)quadf^(')=(v)/(v-v_(5))f quadlambda^('')=(v+v_(s))/(f)quadf^('')=(v)/(v+v_(s))f\lambda^{\prime}=\frac{v-v_{s}}{f} \quad f^{\prime}=\frac{v}{v-v_{5}} f \quad \lambda^{\prime \prime}=\frac{v+v_{s}}{f} \quad f^{\prime \prime}=\frac{v}{v+v_{s}} f
Motion of the source that is moving with velocity v_(s)v_{s} relative to the observer alters the wavelength ( lambda^('),lambda^('')\lambda^{\prime}, \lambda^{\prime \prime} ) and frequency (f^('),f^(''))\left(f^{\prime}, f^{\prime \prime}\right) of sound waves 相对于观察者以 v_(s)v_{s} 速度运动的声源会改变声波的波长 ( lambda^('),lambda^('')\lambda^{\prime}, \lambda^{\prime \prime} ) 和频率 (f^('),f^(''))\left(f^{\prime}, f^{\prime \prime}\right) 。
All galaxies are moving away from us. 所有星系都在远离我们。
The universe is expanding. 宇宙在膨胀
Olbers paradox resolved 解决奥伯斯悖论
Measuring distance 测量距离
Meanwhile, another natural question to ask is “how far away are stars and galaxies?” 与此同时，另一个自然的问题是 "恒星和星系有多远？
So for this astronomers had to devise ways to measure distance to distant objects. 因此，天文学家必须设计出测量遥远天体距离的方法。
Ways to Determine Distance 确定距离的方法
Geometry 几何学
“Standard Candles” "标准蜡烛"
Size and luminosity 尺寸和亮度
Geometry 几何学
Triangulation 三角测量
Angles are measurable only for nearby stars in our galaxy Not useful for determining expansion of universe 角度只有银河系附近的恒星可以测量 无法用于确定宇宙的膨胀
Standard Candle Methods 标准蜡烛方法
A closer object will appear brighter than a more distant one. 较近的物体会比较远的物体更亮。
The farther you are, the energy is dispersed over a larger area, so is less bright 距离越远，能量分散的面积越大，因此亮度越低
Standard Candle：Cepheid Stars
（造父变星） 标准烛光：倒频谱星（造父变星）
＞Henrietta Leavitt（1912）：Studied stars in the Milky Way． She discovered the existence of particular type of star whose energy output varies in a periodic way ＞Henrietta Leavitt（1912 年）：研究银河系中的恒星。 她发现存在一种特殊类型的恒星，其能量输出呈周期性变化。
Illustration of the change in magnitude (intensity of light) of a pulsating star in a nearby galaxy 附近星系中一颗脉动恒星的星等（光强）变化示意图
For very distant Galaxies: 对于非常遥远的星系
The assumption is made that the galaxies in very distant clusters have a 假设非常遥远的星系团中的星系具有一个
similar spectrum of sizes and brightness as the ones in “nearby” clusters 与 "附近 "星团中的大小和亮度光谱相似
For largest distances, insight comes from the apparent size of the galaxy 对于最远的距离，我们可以从星系的表观大小中获得启示
－Hubble discovered in 1929 that measurements of velocity by the red shift correlated with measurements of distance． -哈勃在 1929 年发现，通过红移测量速度与测量距离相关。
－What could this mean？ -这意味着什么？
爱德温 哈勃（Edwin P．Hubble） 爱德温 哈勃（Edwin P．）
Observations of redshifts from nebula 星云红移观测
Relationship between galactic distance and galactic recession velocity 星系距离与星系衰退速度之间的关系
Distance and recession velocity are linearly related! ( v=H_(0)L,quadH_(0)=v=H_{0} L, \quad H_{0}= Hubble constant) 距离和后退速度呈线性关系！( v=H_(0)L,quadH_(0)=v=H_{0} L, \quad H_{0}= 哈勃常数)
Straight line means everything started at one place at one time ( 1//H_(0)=1 / \mathrm{H}_{0}= age of Universe) -13.7 billion years ago 直线意味着万物始于同一时间的同一地点（ 1//H_(0)=1 / \mathrm{H}_{0}= 宇宙年龄）-137 亿年前
Evolution of the distance-velocity relationship 距离-速度关系的演变
Since all galaxies are moving away from us, does this mean we are at the center of the Universe? 既然所有星系都在远离我们，这是否意味着我们处于宇宙的中心？
What do we mean by an expanding universe? 宇宙膨胀是什么意思？
If all the stars are moving away from us (i.e., the earth), does that mean we are at the center of the universe? 如果所有恒星都远离我们（即地球），这是否意味着我们处于宇宙的中心？
No, because what Hubble’s Law really describes is an expansion of space in such a manner that the shape or configuration of space remains the same. 不，因为哈勃定律真正描述的是空间的膨胀，其方式是空间的形状或构造保持不变。
Review: First evidence for the Big Bang 回顾：宇宙大爆炸的首个证据
Distance and retreat velocity are linearly related! 距离和撤退速度呈线性关系！
Further evidence for the Big Bang 宇宙大爆炸的进一步证据
Understand “blackbody radiation” 了解 "黑体辐射"
H//He\mathrm{H} / \mathrm{He} ratio of the universe as evidence of the Big Bang H//He\mathrm{H} / \mathrm{He} 宇宙比例是大爆炸的证据
Two additional pieces of evidence for the Big Bang 宇宙大爆炸的另外两个证据
The omnipresent background radiation of the universe (blackbody radiation) 无所不在的宇宙背景辐射（黑体辐射）
The H/He ratio of universal matter 宇宙物质的 H/He 比率
Blackbody Radiation 黑体辐射
All objects emit radiation 所有物体都会发出辐射
The wavelength and intensity vary with temperature 波长和强度随温度变化
If the temperature gets high enough, some of the radiation enters the visible part of the spectrum 如果温度足够高，部分辐射就会进入光谱的可见光部分
If the temperature gets too hot, the radiation gets harmful (e.g. welders arc) 如果温度过高，辐射就会对人体有害（如电焊弧）
Demos of blackbody radiation here 黑体辐射演示
infrared thermometer 红外线温度计
Penzias and Wilson discovered the cosmic microwave background. 彭齐亚斯和威尔逊发现了宇宙微波背景。
With their discovery of the cosmic microwave background in 1964, Arno Penzias and Robert Wilson placed the seal of approval on the Big Bang Theory and shared the 1978 Nobel Prize in Physics for their discovery 1964 年，阿诺-彭齐亚斯和罗伯特-威尔逊发现了宇宙微波背景，为宇宙大爆炸理论盖上了印章，并因这一发现分享了 1978 年诺贝尔物理学奖。
Black Body Radiation 黑体辐射
perfect, isotropic 2.7 K blackbody spectrum of photons 完美、各向同性的 2.7 K 黑体光子光谱
Cosmic Background Explorer (COBE) 宇宙背景探测器（COBE）
The Cosmic Microwave Background Radiation WMAP (2003) 宇宙微波背景辐射 WMAP（2003 年）
The Cosmic Microwave Background Radiation 宇宙微波背景辐射
CBR is the energy released during the Big Bang. CBR 是宇宙大爆炸时释放的能量。
The CBR is a nearly uniform radiation received from all regions of the sky. CBR 是一种从天空所有区域接收到的近乎均匀的辐射。
The evidence is apparent as a radio signal with a temperature of 2.7 K and is thought to be the cooled after glow of the Big Bang. 该证据明显是一个温度为 2.7 K 的无线电信号，被认为是宇宙大爆炸的冷却余辉。
H//He\mathrm{H} / \mathrm{He} ratio of the universe H//He\mathrm{H} / \mathrm{He} 宇宙比率
Hydrogen Atom 氢原子
Mass =1.00AmU=1.00 \mathrm{AmU} 质量 =1.00AmU=1.00 \mathrm{AmU}
Helium Atom 氦原子
Mass =4.00AMU=4.00 \mathrm{AMU} 质量 =4.00AMU=4.00 \mathrm{AMU}
Proton 质子
Neutron 中子
The H//He\mathrm{H} / \mathrm{He} ratio of universal matter 宇宙物质的 H//He\mathrm{H} / \mathrm{He} 比率
hydrogen and helium make up nearly all of the nuclear matter in the universe. 氢和氦几乎构成了宇宙中所有的核物质。
hydrogen, accounts for 74%74 \% of the mass while helium contributes 25%25 \%. Heavier elements comprise less than 1%1 \% of the total. 较重的元素占总质量的 1%1 \% 以下。
The observed 3:1 ratio of hydrogen to helium yield critical clues about the density, temperature, and expansion rate of the early universe. 观测到的氢氦比例为 3:1，为早期宇宙的密度、温度和膨胀率提供了重要线索。
The correlations between these observations and the predictions of the Big Bang model are striking pieces of evidence in support for the theory. 这些观测结果与宇宙大爆炸模型预测之间的相关性是支持该理论的有力证据。
Will the Universe collapse into a "Big Crunch"? 宇宙会坍缩成 "大紧缩 "吗？
Notice the slight curvature of the data: more distant galaxies are moving away faster! 请注意数据的轻微弯曲：越远的星系移动得越快！
Some repulsive force is overcoming gravitational attraction 某种排斥力正在战胜引力
A repulsive (dark) force may be acting on the galaxies causing rate of expansion to increase 可能有一种排斥力（暗力）作用在星系上，导致星系膨胀速度加快
This diagram shows how the universe slowed down and then rewed up since the Big Bang. The concentric red circles denote that galaxies are migrating apart at a slower rate during the first half of the cosmos. Then a mysterious, dark force overcame gravity and began pushing galaxies apart at an ever-faster rate, signified by the green circles. Astronomers found evidence of the universe’s deceleration when they observed the farthest supernova ever seen, which detonated so long ago that the universe was still slowing down. 这幅图显示了宇宙自大爆炸以来是如何变慢然后又变快的。同心红圈表示星系在宇宙的前半部分以较慢的速度分开。然后，一种神秘的黑暗力量战胜了引力，开始以越来越快的速度将星系推开，绿色圆圈表示这种力量。天文学家在观测史上最远的超新星时，发现了宇宙减速的证据。
We are not made of the same type of matter as most of the Universe! 我们与宇宙中大部分物质的构成不同！
Dark energy and dark mattermost of the universe 宇宙中的暗能量和暗物质
James Webb Space Tele 詹姆斯-韦伯太空望远镜
JWST was launched on Dec. 25, 2021 and enables a broad range of investigations across the fields of astronomy and cosmology, including observations of some of the the formation of the first galaxies, and allowing detailed atmospheric characterization of potentially habitable exoplanets. JWST 于 2021 年 12 月 25 日发射升空，能够在天文学和宇宙学领域开展广泛的研究，包括观测最初星系形成的一些过程，以及对可能宜居的系外行星进行详细的大气特征描述。
PLAnetary Transits and Oscillations of stars (PLATO) 恒星的行星凌日和振荡（PLATO）
is a space telescope under development by the European Space Agency for launch in 2026. The emphasis of the mission is on earth-like planets in the habitable zone around sun-like stars where n 是欧洲航天局正在开发的空间望远镜，将于 2026 年发射。该任务的重点是类太阳恒星周围宜居带中的类地行星，其中 n
Redshift: the wavelength of the light is stretched, so the light is seen as ‘shifted’ towards the red part of the spectrum. 红移：光的波长被拉长，因此光被视为向光谱的红色部分 "偏移"。
The velocity of galaxies can be determined from their red shift- they are all moving away from us. 星系的速度可以从它们的红移中确定--它们都在远离我们。
The distance of galaxies can be determined by standard candles and galaxy size. 星系的距离可以通过标准烛光和星系大小来确定。
Velocity and distance correlate, showing that all the galaxies 13.7 billion years ago were at the same spot at the same time- the Big Bang. 速度和距离相互关联，表明 137 亿年前的所有星系都在同一时间出现在同一地点--宇宙大爆炸。
Further evidence that supports the Big Bang: The omnipresent background radiation of the universe (blackbody radiation) and The H//He\mathrm{H} / \mathrm{He} ratio of universal matter. 支持宇宙大爆炸的进一步证据宇宙无处不在的背景辐射（黑体辐射）和宇宙物质的 H//He\mathrm{H} / \mathrm{He} 比率。
Next Lecture: Origin of the Elements and Molecules (Chapter 3&4) 下一课元素和分子的起源（第 3 和第 4 章）
