In the early 17th century, German astronomer Kepler summarized the observational data of Danish astronomer Tycho Brahe and proposed the three laws of planetary motion: first, planets move in elliptical orbits with the Sun at one focus of the ellipse; second, a line segment joining a planet and the Sun sweeps out equal areas during equal intervals of time; third, the square of a planet’s orbital period (the time it takes to complete one orbit) is directly proportional to the cube of the semi-major axis of its orbit.
Although planetary orbits are elliptical, their ellipticity is very slight and not visible to the naked eye. The Sun is not at the center of the ellipse but at one focus, and the distance from the focus to the center is expressed by eccentricity. Except for Mercury, the eccentricities of other planets are very small. Mercury’s orbital eccentricity is 0.2, making the focus’s offset from the center visible to the naked eye, though the flattening is only 0.02.
The closer a planet is to the Sun, the faster it moves, sweeping out equal areas in equal times. This is determined by the balance between the Sun’s gravitational force and the planet’s centrifugal force. To avoid being pulled into the Sun by gravity, a planet must balance this force with the centrifugal force generated by its motion. If this balance is broken, the planet would either be drawn into the Sun or drift away from it. Since the gravitational pull exerted by the Sun is equal over equal areas, a planet must sweep out equal areas in equal times, leading to faster motion when closer to the Sun and slower motion when farther away. Similarly, planets farther from the Sun move more slowly, resulting in the following average orbital speeds from nearest to farthest: Mercury at 47.36 km/s, Venus at 35.02 km/s, Earth at 29.78 km/s, Mars at 24.07 km/s, Jupiter at 13.07 km/s, Saturn at 9.64 km/s, Uranus at 6.8 km/s, and Neptune at 5.43 km/s.
Based on Kepler’s second and third laws, the orbital periods and velocities of other planets at different distances can be accurately calculated by comparing them to Earth. The calculation method for a planet’s orbital period is to first find the cube of its distance and then the square root of that number. For instance, if a planet is four times farther from the Sun than Earth, its orbital period would be eight times longer (4 cubed is 64, and the square root of 64 is 8), and its orbital speed would be half that of Earth. For example, Neptune, at 30.06869 times the distance from the Sun compared to Earth, has an orbital period of 164.79132 years (30.06869 cubed is 27186, and the square root of 27186 is 164.9, with slight errors due to Neptune’s larger mass compared to Earth). The calculation can also be reversed, using the orbital period data to find the distance from the Sun.
According to Kepler’s third law, the mass of a planet (with satellites) can be accurately calculated based on its distance from the Sun in kilometers. The calculation method is to first find the respective quotients for the Sun and the planet and then divide the Sun’s quotient by the planet’s quotient to obtain the mass ratio, which is then used to calculate the planet’s mass. Sun quotient = cube of the planet’s distance from the Sun in kilometers ÷ square of the planet’s orbital period in days; planet quotient = cube of the satellite’s distance from the planet in kilometers ÷ square of the satellite’s orbital period in days. All planets have very similar Sun quotients, and the primary planet quotients for all satellites should also be similar.
For example, Earth: Sun quotient = 3347930000000000000000000 (cube of Earth’s distance from the Sun, 149597887.5 km) ÷ 133412 (square of Earth’s orbital period, 365.24219 days) = 25095000000000000000; Earth quotient = 56800000000000000 (cube of the Moon’s distance from Earth, 384400 km) ÷ 746 (square of the Moon’s orbital period, 27.32 days) = 76140000000000; 25095000000000000000 (Sun quotient) ÷ 76140000000000 (Earth quotient) = 329590 (the Sun is 329,590 times the mass of Earth).
For Jupiter: Sun quotient = 471905280000000000000000000 (cube of Jupiter’s distance from the Sun, 778547200 km) ÷ 18771336 (square of Jupiter’s orbital period, 4332.59 days) = 25139700000000000000; Jupiter quotient = 1230542000000000000 (cube of Ganymede’s distance from Jupiter, 1070400 km) ÷ 51 (square of Ganymede’s orbital period, 7.1545296 days) = 24128000000000000; 25139700000000000000 (Sun quotient) ÷ 24128000000000000 (Jupiter quotient) = 1042 (the Sun is over 1040 times the mass of Jupiter).
一个混世魔王的内心世界
---- 评毛泽东的七律长征
毛泽东治下的中国，不让人读古诗古词，全国人民，只能读毛诗毛词唱赞歌。结果是大多数和我同龄的中国人，一提到诗词，脑子里自然冒出来的，都是他的句子。直到现在，不由自主地哼哼唱，一哼哼，不是毛主席走遍祖国大地，就是共产党的恩情比海深。我这可不是个别现象。与我同龄的朋友中，即使极端不喜欢毛，但是同意他是大诗人的，大有人在。
不过批评人，要客观公道。说毛诗毛词，有多烂多不像话，我也不赞成。 现代人，作诗作词，要超过古人，是不可能的事，他能写出声调算是合规矩的诗，也算是难能可贵。至于模仿古人，谁都难免。天下的雅句， 都被诗圣写完了，好的俗句，也给白乐天说尽了。要么不写，写就不可能不模仿，也不可能有古人的雅致。毛泽东中国古文化的素养，比江核心写打油诗用英文背林肯的三民显摆自己有文化，总还是强不少。
言归正传，我们现在就评一评大家都知道的七律《长征》。先把原诗抄在这里：
红军不怕远征难
万水千山只等闲
五岭逶迤腾细浪
乌蒙磅礴走泥丸
金沙水拍云崖暖
大渡桥横铁索寒
更喜岷山千里雪
三军过后尽开颜
起首两句，开得平直自然，人物事情，也交代得简洁明了。不怕，只等闲，气势情绪，都表达得清楚。声调音韵，也中规中矩。第三第四句，就不好了。五岭逶迤，乌蒙磅礴，不错，但是接腾细浪，走泥丸，就成了故作惊奇之语，有很重的生造的痕迹。特别是走泥丸三字，是全诗的败笔，接乌蒙磅礴，不但意思表达不到位，而且不雅。虽然没有他后来的不须放屁那么粗俗不堪，但是好不到哪里。这两句，要表达的意思 也清楚，但是表达本身，完全失去了作诗的分寸。
第五第六句，说的是长征中红军生死存亡的两件事。诗人的表述没毛病，但是太过平淡。第七句的更喜二字，又是败笔，岷山的千里雪，对每一个红军战士，包括对他自己，都不可能有一点点的可喜之处。想说爬过来了，心情不坏，没什么不对，但是这样的表达，意思不对。词不达意。
红军长征，说是远征也好，逃亡也罢，有一点是肯定的，那就是极端的艰难困苦。我读过一个美国人重走了红军长征的全程，沿途采访以后写的一本书，书名是《长征，前所未闻的故事》。 他说长征在人类史上，也是少有的在极端的环境下求生存的艰苦卓绝的故事。今天我们能看到的所有经历过长征的人写的回忆录，都验证了这句话，这些回忆录，都是满纸的辛酸血泪。但是在毛泽东的这首诗里，除了第一句的最后，平平常常的一个难字，全体红军战士经历的苦难牺牲，都被他抹掉了。他是这个历经艰辛苦难的人群的领袖，是最后带他们走出来的人。你不可能说，这些艰难困苦，苦痛灾难，他不了解。三十万人从江西出发，再加上四方面军的十万精兵，爬雪山，过草地，最后剩下了不到三万人。如此灾难性的死里逃生，让人不忍卒读的惨痛，在这首诗里，你看不到，也读不到。
最可怕的是，这首诗，是毛泽东对长征的真实的个人感受。他不是一个多么出色的诗人，但是说他的性格里，有诗人的气质，是过得去的。诗言志，诗是诗人表达情感的最直接了当，最简便的方式。所以这首诗，表达的是毛泽东对长征的真实感受。什么样的感受呢？是终于松了一口气，是这几十万人的极端的苦难伤痛都不算什么，是老子终于可以开颜大笑了的洋洋自得。被冻死在雪山上，被草地吞食了的成千上万人的性命呢？他们的悲惨而又短暂的人生，在诗人的眼里，什么都不值，也什么都不是。
文革中解这首诗，说诗人是在表达红军战士的革命的浪漫主义，乐观主义的精神情怀。一提到这个浪漫情怀，我就想爆粗口。有谁去问过那些成千上万，冻饿而死在路上的原本是鲜活的生命，他们的真实感受？不错，诗人感受到的，也表达得明了不过的，是乐观浪漫的情绪。但是诗人对他的部下经历的极度的苦难，没有一点同情同理之心。这是什么样的彻底泯灭了人性的乐观浪漫呢？对死在雪山草地上的人，他这是趴在你身上，吃完了你的肉，喝完了你的血，然后笑话你极度脑残。这种洋洋得意，志得意满的灭绝人性的浪漫，是一个混世魔王的毫无人性，绝对真实的内心世界。
更多我的博客文章>>> 认识自己（2）：人心也有善 认识自己（1）：人性必须恶 近代西方（5）：一切围绕钱的运作 近代西方（4）：一只看不见的巨手 近代西方（3）：现代社会的诞生
邓喜闲。
哈
谁解其中味。
哈
毫无人文情怀。全诗弥漫着老子刀尖上舔血，终于从死人堆里爬出来了的得意。
早有定论。
您其实也想让我shut up, 封我的号。这个是人的天性使然。与民主不民主，没关系。听懂了没有？
In the early 17th century, German astronomer Kepler summarized the observational data of Danish astronomer Tycho Brahe and proposed the three laws of planetary motion: first, planets move in elliptical orbits with the Sun at one focus of the ellipse; second, a line segment joining a planet and the Sun sweeps out equal areas during equal intervals of time; third, the square of a planet’s orbital period (the time it takes to complete one orbit) is directly proportional to the cube of the semi-major axis of its orbit.
Although planetary orbits are elliptical, their ellipticity is very slight and not visible to the naked eye. The Sun is not at the center of the ellipse but at one focus, and the distance from the focus to the center is expressed by eccentricity. Except for Mercury, the eccentricities of other planets are very small. Mercury’s orbital eccentricity is 0.2, making the focus’s offset from the center visible to the naked eye, though the flattening is only 0.02.
The closer a planet is to the Sun, the faster it moves, sweeping out equal areas in equal times. This is determined by the balance between the Sun’s gravitational force and the planet’s centrifugal force. To avoid being pulled into the Sun by gravity, a planet must balance this force with the centrifugal force generated by its motion. If this balance is broken, the planet would either be drawn into the Sun or drift away from it. Since the gravitational pull exerted by the Sun is equal over equal areas, a planet must sweep out equal areas in equal times, leading to faster motion when closer to the Sun and slower motion when farther away. Similarly, planets farther from the Sun move more slowly, resulting in the following average orbital speeds from nearest to farthest: Mercury at 47.36 km/s, Venus at 35.02 km/s, Earth at 29.78 km/s, Mars at 24.07 km/s, Jupiter at 13.07 km/s, Saturn at 9.64 km/s, Uranus at 6.8 km/s, and Neptune at 5.43 km/s.
Based on Kepler’s second and third laws, the orbital periods and velocities of other planets at different distances can be accurately calculated by comparing them to Earth. The calculation method for a planet’s orbital period is to first find the cube of its distance and then the square root of that number. For instance, if a planet is four times farther from the Sun than Earth, its orbital period would be eight times longer (4 cubed is 64, and the square root of 64 is 8), and its orbital speed would be half that of Earth. For example, Neptune, at 30.06869 times the distance from the Sun compared to Earth, has an orbital period of 164.79132 years (30.06869 cubed is 27186, and the square root of 27186 is 164.9, with slight errors due to Neptune’s larger mass compared to Earth). The calculation can also be reversed, using the orbital period data to find the distance from the Sun.
According to Kepler’s third law, the mass of a planet (with satellites) can be accurately calculated based on its distance from the Sun in kilometers. The calculation method is to first find the respective quotients for the Sun and the planet and then divide the Sun’s quotient by the planet’s quotient to obtain the mass ratio, which is then used to calculate the planet’s mass. Sun quotient = cube of the planet’s distance from the Sun in kilometers ÷ square of the planet’s orbital period in days; planet quotient = cube of the satellite’s distance from the planet in kilometers ÷ square of the satellite’s orbital period in days. All planets have very similar Sun quotients, and the primary planet quotients for all satellites should also be similar.
For example, Earth: Sun quotient = 3347930000000000000000000 (cube of Earth’s distance from the Sun, 149597887.5 km) ÷ 133412 (square of Earth’s orbital period, 365.24219 days) = 25095000000000000000; Earth quotient = 56800000000000000 (cube of the Moon’s distance from Earth, 384400 km) ÷ 746 (square of the Moon’s orbital period, 27.32 days) = 76140000000000; 25095000000000000000 (Sun quotient) ÷ 76140000000000 (Earth quotient) = 329590 (the Sun is 329,590 times the mass of Earth).
For Jupiter: Sun quotient = 471905280000000000000000000 (cube of Jupiter’s distance from the Sun, 778547200 km) ÷ 18771336 (square of Jupiter’s orbital period, 4332.59 days) = 25139700000000000000; Jupiter quotient = 1230542000000000000 (cube of Ganymede’s distance from Jupiter, 1070400 km) ÷ 51 (square of Ganymede’s orbital period, 7.1545296 days) = 24128000000000000; 25139700000000000000 (Sun quotient) ÷ 24128000000000000 (Jupiter quotient) = 1042 (the Sun is over 1040 times the mass of Jupiter).
不会用，您水平能力太差，在这儿说话都多余。：）