暗淡蓝点

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1990 photograph of the Earth captured by NASA’s Voyager 1 spacecraft, courtesy of NASA
This is what Carl Sagan said about the photo:

1990年卡尔·萨根力排众议,让正在远离地球的旅行者1号(Voyager 1是美国宇航局研制的一艘无人外太阳系空间探测器,于1977年9月5日发射)调转镜头,回望地球和太阳系,于是就有了改变很多人世界观的那张照片,地球是一个暗淡蓝点。

Consider again that dot. That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every “superstar”, every “supreme leader”, every saint and sinner in the history of our species lived there — on a mote of dust suspended in a sunbeam.

The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds.
Our posturings, our imagined self-importance, the delusion that we have some privileged position in the Universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves.

The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand.
It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we’ve ever known.

— as mentioned in Pale Blue Dot: A Vision of the Human Future in Space (1994)
人类历史上的每一个圣人与罪犯,都在这里,一粒悬浮在阳光中的微尘之上。

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*A History of Physics

2023-11

A History of Physics Florian Cajori 物理学简史 地震出版社 董康康译
(最近的几本物理学史的书要对比一下,这本算是详实一类。也预定了卡约里的《数学简史》,最好也能和之前读的基本数学史比较一下。)
“我认为将老一辈物理学者思想生活和经验中必不可少的物理学发展轮廓,向青年一代的物理学生阐释清楚是很有必要的。”1928年11月
“当前,在对年轻人进行科学教育方面存在缺陷,即现今的科学教育缺乏历史感,同时在对科学大厦得以屹立不倒的根基的一些重大研究方面,关注程度不够。”1898年11月

巴比伦人和埃及人
早期的苏美尔人(两河流域(幼发拉底河和底格里斯河中下游)早期的定居民族,现今伊拉克东南部)和巴比伦人在时间和角度方面,为后人贡献了十分重要的测量单位。
巴比伦人最开始将7天定为1周,将白昼和黑夜各定为12小时,普遍使用60进制…
[?]发现了岁差的黄道二分点的缓慢运动(指地球自转轴长期进动,引起春分点沿黄道西移,致使回归年短于恒星年的现象。)(一直没有遇到地理特别擅长的学生以好好学习一下)

希腊人
与作出的大量关于自然界的理论推断相比,希腊人所进行的与之相关的实验少得可怜。他们很少甚至没有尝试通过实验证据来验证他们提出的猜想。亚里士多德曾证明过世界是完美的。
亚里士多德曾指出,组成世界的物质是固体,因为它是三维的,所以三就是最完美的数字,也是所有数字中的第一个。因为我们一般不会把一当做一个数字来看;在说二的时候,我们一般会说双。这样来看,在所有的数字中,三就是打头的。此外,三这个数字有开始、中间和结尾。
中世纪和文艺复兴时期,亚里士多德的权威可谓如日中天。
在力学研究方面,亚里士多德是远远比不上阿基米德的,阿基米德是力学这门科学真正的创始人,重心理论、杠杆理论的提出都要归功于他。(Archimedes:触碰它,你就可以撬动地球)[?]

2023-11

从阿基米德那个时代开始,一些极具智慧的人在液体压力方面也曾推导出一些错误的结论。我们更加佩服阿基米德在进行研究时所展现出来的概念的清晰性和近乎完美的逻辑严谨性。(A跨越时代的人)
(A proof that the area of the parabolic segment in the upper figure is equal to 4/3 that of the inscribed triangle in the lower figure from Quadrature of the Parabola)(阿基米德三角形也很有趣,圆锥曲线上弦与弦两点切线构成的三角形,中线过中心…)
希腊人发明了比重计,时间很可能是公元4世纪,没有决定性的证据能证明比重计是阿基米德发明的。最初在医学领域中用于测定饮用水的水质,在那个时代,硬水通常被认为是不健康的。
139年曾经在亚历山大城大放异彩的天文学家托勒密测定了光的入射角和折射角,并将其绘制成了表格。他发现在角度小的情况下,入射角和折射角度成比例式近似正确的。(1621年荷兰,Snell’s law)
公元前300年的欧几里得曾著《反射光学》,探讨了光的反射,在该书中,人们发现了最早关于球面镜焦点的论述。
毕达哥拉斯、德谟克利特等人人为,视觉是由所见物体散发出的微粒投射到瞳孔中产生非。另一方面,恩培多克勒(公元前400年)、柏拉图和欧几里得则持有一种十分奇怪的眼睛光束理论,人的眼睛本人会发射出某种光束,当这些光束遇到其他物体所散发出来的光束时,就产生了视觉。

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