克莱因瓶是一个不可定向的二维紧流形，而球面或轮胎面是可 克莱因瓶 克莱因瓶 定向的二维紧流形。如果观察克莱因瓶，有一点似乎令人困惑－－克莱因瓶的瓶颈和瓶身是相交的，换句话近代科学兴起的先驱者、是捍卫科学真理并为此献身的殉道士。有另一种说法认为，近代以来关于罗马梵蒂冈的地心说和哥白尼的日心说的斗争是被严重夸大的。布鲁诺1600年遭受火刑的原因，并非因知行星围绕太阳作圆周运动。然而，人们是否能接受哥白尼提出的新的宇宙模式呢？全世界的人——尤其是权力极大的天主教会是否相信太阳是宇宙中心这一说法呢？由于害怕教会的惩罚，哥白尼在世时不敢公开他的发现。1543年，这一发现才公诸天下。即使在那个时候，哥白尼的发现还不断受到教会高无上的真理，凡是违背圣经的学说，Eighteen months passed. The Chief was in Quebec with Hannah and Abbie awaiting the arrival of Rug, who had been sent by his father to the Mother Land to dispose of two cargoes of timber. It was an unusually cold evening in June. Snow had been falling all day. The neighboring hills were covered with large feathery crystals, which, however, soon melted as the sun appeared for a moment before sinking behind the gray walls of the Castle St. Louis. Just as the evening gun was fired, news had reached the union Hotel that a vessel had been sighted near the Island of Orleans. It was ascertained that it was the Dorris, in command of Captain French, and that Rug was on board. They were soon speeding down Mountain Street in a caleche to the docks, where they secured passage in a small row-boat which was going out to the vessel. The genial captain invited them to take tea with him, and said that Rug was below supervising and arranging with the Customs Officer about the baggage of his numerous protégés, and would be on deck shortly. Hannah burst into a paroxysm of tears when she caught sight of her long-lost lover, who had been compelled to leave only a few weeks after their marriage. He looked twenty years older, and appeared careworn, haggard and ill. As they were seated round the table he gave an account of his travels. "When I received your letter," he said, addressing his father, "I chartered two vessels and persuaded Archie and Jonathan Campbell to go with me for a pleasure trip. We were nearly three months tossing about at the mercy of wind and wave when a hurricane swept the deck of the vessel, carrying with it the main-mast and sails. Water began to pour in at an alarming rate, and after a desperate struggle at the pumps the captain ordered all hands on deck. We felt that we had to prepare for the worst. The sailors had abandoned the pumps from exhaustion, and Jonathan and I took their places and worked until we, too, were exhausted, and as others took our places we retired to the stern, where we found Archie in a sheltered nook, seated upon a coil of rope, playing his violin, apparently oblivious of our perilous condition. "For two days the work at the pumps was a matter of life and death, and when at last the wind subsided we drifted about helplessly until a passing vessel saw our signals of distress and towed us from the Bay of Biscay to Bristol, where the necessary repairs were made to enable us to proceed to Liverpool. We soon disposed of the timber at good profit, and Jonathan, Archie and I took the stage-coach for London, where we had the honor of being presented at Court to gay Prince Geordie, who is acting as Regent, owing to his father s mental derangement. I wish you could have seen the Carleton House," he said, turning to Hannah. "He built it at a cost of ￡250,000 sterling, and had to sell his stud of race-horses and discharge most of his servants to meet the demands of the creditors, for he had led such a wild, dissipated life that the King and Parliament refused for a long time to help him out of his difficulties. "We visited many places of interest in London and 保护自然，  珠峰之殇  中国的一道“禁令”， 让美联社、卫报、每日邮报争相报道。外网轰动一时， 国内却沉默无声：珠穆朗玛峰封山清理， 每年只允许300人于春季攀登。任何单位和个人， 不得进入绒布寺以上核心区域旅游。珠峰封山本是常事， 为何全世界都争相报道？每个中国人都骄傲， 我们的西藏有顶好的风光：山鹰当空盘旋， 天是纯粹的蓝， 雪山是圣洁的白。但是诸多伪文青， 看了《冈仁波齐》， 就激动不已急着去朝圣。读了仓央嘉措， 就要来一场说走就走的旅行。结果在这片心灵净土， 留下了一地避孕套！——别误会，那是套在鞋上， 防止雨雪水渗进鞋里的。诸多假驴友， 为了去圣地打卡， 在318国道川藏线上 拍下自己竖起大拇指吃泡面的样子， 相机一关，就把泡面盒 扔到了路边草地上！更有国内外无数登山爱好者， 带着熊熊的征服欲前来。无论成功或失败， 都会在雪山上留下， 帐篷、氧气管、塑料袋等一山的垃圾！连牦牛都在垃圾堆里觅食。可是该为珠峰环境破坏买单的， 明明是人类。每年的4月到6月， 10万人蜂拥至珠峰大本营观光。几百支登山队伍爬在珠峰上。这里的环境无法建造厕所， 每个人都像原始人一样随地排泄。每年人潮退去后， 会留下整整12吨屎。1953年， 第一个人类征服了珠峰。之后的56年里， 4000位攀登者齐心协力， 留下了45000公斤垃圾， 和200多具尸体。“去了珠峰才知道，这里的路标是尸体” 你不知道这句话有多悲伤。珠峰路标，名为“绿靴子”的尸体 这些垃圾，珠峰脆弱的生态自然无法分解。只能由当地的村民，一步一步爬上山，一筐一筐背下来，倒进坑道后慢慢脱水。分解它们需要长达数年的时间。搬运不了的垃圾， 只能就地焚烧。原本氧气就稀薄， 高原的空气也被污染。珠峰的垃圾、粪便和尸体， 早已污染了山脚下的水源。   藏民老人不得不背着背篓， 一路弯腰捡垃圾， 步履蹒跚，严寒缺氧。但是不捡， 水就脏了，空气就浑浊了。除了豁出性命保护自己的家园， 他们别无他法。不止是高原。亚洲水源大量依赖冰川溶解， 喜马拉雅就是“亚洲水塔”。一旦珠峰被污染， 不安全水源会波及到的人， 足足有十亿！雪崩时， 没有一片雪花是无辜的。造孽时， 他们本以为事不关己。2018年， 尼泊尔制作了一部， 9.0分的纪录片：《珠峰清道夫》。画面无比粗糙， 却看哭了亿万人。它记录了一次清理珠峰的志愿活动， 20位志愿者， 每个人， 都做好了死的准备。珠峰海拔8000米以上的地带， 被称作“死亡地带”。没有当地的夏尔巴人当向导， 很少有人能活着下山。这次的志愿者里， 有11位夏尔巴村民。但是要完成一个月清理9万斤垃圾 外带一具尸体的任务， 小队不得不争分夺秒。越赶时间，缺氧头痛就越重。普通人登顶珠峰一次， 就要炫耀一辈子。这支志愿队伍， 为了让身体适应山顶的气候， 要反复登顶、下山数次。每登一次山， 都要掉10斤体重。为了避开高温导致的融冰， 在零下40度的凌晨2点， 志愿者们正式开始捡垃圾。一想到营地外的一地尸体， 他们也吓得迈不开腿， 却还是硬着头皮去完成自己的使命。冒着大风雪， 把自己挂在一根绳子上缓慢挪动。你能想象， 人在65度的斜坡上吃饭睡觉吗？一旦滑倒，必死无疑。他们却要这样生存29天：我不管是谁扔的垃圾， 让村子喝上干净的水， 是我们的责任。  外界一直流传着这样的风凉话：夏尔巴人登山很厉害，能轻易把垃圾运下来，就算乱丢他们也会清理…… 其实，夏尔巴人的每一次登山，都是搭上性命的赌博。他们中很多人没有手指脚趾，那是冻伤截肢了。凭什么你有征服自然的私心，买单的却是无辜村民的性命？他们一遍遍呼喊着：珠峰是我们的女神，我们的母亲，能不能，别再污染她…… 但是，雄心勃勃的登山者们听不见。离顶峰只有咫尺之遥时，许多登山者不得不牺牲人性来换取生存。在这里，氧气瓶被偷是常事。在呼吸艰难、随时会失去意识的高海拔地带，人们能坚持住呼吸就已不易。更别说顾着环保。在珠峰面前，人们的素质高下立现。有些地方，人类就不该去！你可以挑战生命的极限， 可以冲刺人生的新巅峰。但是你也必须知道， 那些你在极限情况下无力带走的垃圾， 会成为珠峰，和珠峰脚下村民的噩梦。你是得到了朋友圈的一百个赞， 却不知替你负重前行的人， 付出了怎样的代价。那些在藏地乱扔垃圾的人， 请别自作多情了！凭什么你一手污染了藏地， 还让藏地净化你的心灵？西藏根本没在等你， 你若不去，才是西藏的福气。曾经的圣地， 部分地区成了垃圾场。如果不得不去，也请你牢记：除了照片，什么都别拿；除了时间，什么都别偷；除了脚印，什么都别留。乱扔垃圾的人， 你就算登顶一万次， 也改变不了自己的平庸。保护雪山的人， 你们basket of eggs, which he disposed of at a shilling per dozen, and so we continued on until the domes and towers of Quebec came in sight and I began to realize the inexpressible joy of being at home once more."* * Diary of Rev. Robert Bell and letters of R. Wright. Rug was a young man of great executive ability, a young man whose word could be relied upon with absolute certainty, a young man who proved himself the very soul of honor in all his business transactions.都被斥为“异端邪说”，凡是反对神权统治的人，都被处以火刑。新兴的资产阶级为自己的生存和发展，掀起了一场反对封建制度和教会迷信思想的斗争，出现了人文主义的思潮。他们使用的战斗武器，就是未被神学染污的古希腊的哲学、科学和文艺。这就是震撼欧洲的文艺复兴运动。文艺复兴首先发生于意大利，很快就扩大到波兰及欧洲其他国家。与此同时，商业的活跃也促进了对外贸易的发展。在“黄金”这个符咒的驱使下，许多欧洲冒险者远航非洲、印度及整个远东地区。远洋航行需要丰富的天文和地理知识，从实际中积累起来的观测资料，使人们感到当时流行的“地静天动”的宇宙 CHAPTER IV. AN INDIAN SUITOR. 1803. Machecawa and his friend O Jawescawa became frequent visitors at the Wigwam. They would come in the morning, uninvited, and sit silently all day long before the open fire and observe all that was going on. The spinning-wheel and hand-loom were objects of unceasing interest to them, and though it proved a great distraction to the children in their studies, and to the girls in the performance of their domestic duties, to have them there, they were always treated not only with respect but with consideration and kindness. One morning Machecawa stood gazing intently into the fire. His face wore an expression of perplexity. At length he turned to the White Chief, who was explaining a mathematical problem to one of his boys, and said: "Big Injun, he want to speak his thoughts from books. He want to know white man s Manitou." "May I teach him, father? Just for an hour every day?" said Chrissy, a tall, fair, thoughtful girl of seventeen, who was known throughout the settlement as the "Saint," for she had been led to take a serious view of life by a Quaker friend in the old school at Woburn. "It would be such a pleasure for me to lead him to a knowledge of the truth." The father readily granted the request, and it was arranged that he should receive instruction from Chrissy every morning while the younger boys were having their lessons. Never had teacher a more apt, humble, or willing pupil. Never had pupil a more considerate, patient, kind-hearted instructor. Over and over again did she repeat words and sentences until at last the Indian found, to his unspeakable joy, that he was beginning to acquire the words pretty freely. The morning hour with Machecawa proved of such interest that it was not an uncommon thing to see the White Chief and all the children listening intently to Chrissy and the Indian as they compared their respective creeds. One morning, after she had been giving an account of the creation and the deluge, she said, "Now, tell me what you think of these things. Do the Indians ever think of how the world was made? Did they ever hear of a flood?" Machecawa replied in broken English, the interpretation of which is as follows: The Indian believes that the great Manabozo is king of all other animal kings. The West Wind is his father, and his mother is grand-daughter of the Moon. Sometimes he is a wolf; sometimes a hare; sometimes he is a wicked spirit. Manabozo was hunting with his brother, a wolf, who fell through the ice in a lake and was eaten by snakes. Manabozo was very cross and changed himself into the stump of a tree and surprised the king of the serpents and killed him. The snakes were all Manitous, and they made the water flood the world. Manabozo climbed a tree which grew and grew as the flood came up and was saved from the wicked spirits. Manabozo looked over the waters and he saw a loon, and he cried to the loon for help to save the world. The loon went under the water to look for mud to build the world again, but he could not find the bottom. Then a muskrat tried, but he came up on his back nearly dead. Manabozo looked in his paws and found a little mud, and he took the mud and the dead body of the loon and with it created the world anew again. "And do you believe that?" said the White Chief. "Our tribe she believe like that," replied the Indian. "What is that thing tied round your neck, Machecawa?" said Bearie, the second son, a short, well knit, sturdy-looking youth of eighteen, whose every expression reflected a bright, happy, generous di 一个真正有阅历的人，经历足够多的人，发现身边可以责怪的人越来越少，因为懂得，人人都有他的难处。一个朋友最近刚从从老家重新杀回广州。前段时间他妈妈病了，动了一次大手术。他回了一趟家，又回来了。回到广州后，他整个人都变了，变得和颜悦色，温柔平和。以前，他总非常鄙视那些从北上广背着包回家去的人。按照他的标准，那都是没能力在这座城市生存下去所以被抛弃的人，都是弱者、失败者。不管是出于什么原因，离开自己奋斗的地方，就是撤退，而撤退就是宣告自己无能。他的价值观也很硬，认为世界非黑即白，用成功和失败作为衡量人生的唯一价值尺度，认为成功者就应该站在领奖台上，万众瞩目，接受鲜花掌声；认为失败者就应该躲到角落里，暗自啜泣，接受自己和他人的责骂。他这次重回广州，话风完全不一样，不再那么充满鸡血，开始包容，对手下的人也没那么苛刻，不再要求他们一味地加班，甚至劝告他们多花些时间在家人和朋友身上。  而对于那些准备从北上广撤退回家当公务员的朋友，他也不像以前，跳起来指着人家鼻子骂你个怂货，这么容易就认输了。他很真诚地跟别人说：“想清楚了吧，想清楚了就决定，每个人都有每个人的难处，毕竟只有你自己知道，什么才是最重要的。” 他说：“我现在越来越能理解我身边的人，理解他们的处境和选择。” 这一切改变源自一年前，他得到消息说母亲病了，而且非常严重，需要尽快手术。他匆匆请假回家陪着妈妈，他原本以为只要请几天假陪妈度过手术这段时间就可以回广州工作了，但是手术术后恢复周期实在太长，而且他看到他妈妈躺在病床上，实在不忍心一个人跑回广州去谈所谓的奋斗和成功。于是他心一横，辞职了，空档了将近一年，专门陪着他妈妈做手术、住院、出院，陪着在家唠嗑，出去旅游。在这一年里，他还遇到了很多之前在北上广打拼的朋友，了解他们在老家的生活，也知道了他们为什么最终选择了回家。他想明白了很多事情。他说：“以前我妈妈没病的时候，我不懂那些回家照顾父母的人，我觉得他们是找借口，是失败，如果有钱，干嘛不找个保姆照顾呢？现在发现，父母真的是需要自己去照顾。” “而且我最近也在思考，父母、家庭、事业，究竟什么才是最重要的，不同的人选择不同，会有不同的人生，而这些选择，其实都应该是没有失败的。人，其实只有经历以后，才会懂得。” 人生的确即是如此，只有真正经历过很多事情之后，我们才会站在更高的维度去看待这个世界，而不是很单纯地用自己私人的视角去苛责别人，去评判世界。同样的情况，也常常发生在我们对父母的理解上。最近，看到一位母亲写的文章，她说：“以前妈妈总是让我做这做那，让我注意这个注意那个，那个时候我总是很不耐烦，觉得她啰嗦，总是责怪她。现在自己当了妈，才知道她当时的处境、想法。就像我妈经常说的，孩子，等你当了妈你就知道了。” 是的，年轻时，我们总是觉得与父母隔阂甚重。觉得他们思想陈旧，观念老套，跟不上新的时代，难以与他们沟通。甚至，我们还会觉得他们反倒成了成长路上的拦路虎。那个时候，不太懂得家这个概念，只想着自己，想着未来，想着长大。后来，自己求学工作，结婚生子，把当年父母经历的那些阶段和事情都重新经历了一遍，这才慢慢长大，有所感悟。当你成家了以后，你就会发现，需要考虑的事情，考虑的问题很多，家庭收入、家人健康、孩子成长、孩子教育等等，你就会开始懂得当初父母的那些话，做的那些事。也许你现在正在喋喋不休责怪你的父母；也许你现在正在责怪身边的朋友同事，责怪他们为什么不能坚持，为什么放弃，为什么做出这样的选择，等等。但是等你经历了一些事情之后，你终究会明白他们。你也会懂得，生活，其实没有一个简单的标准，任何用成败来评判他人的人，都很简单粗暴，也非常幼稚。一个真正成熟的人，一个真正有所经历的人，会发现身边可以责怪的人越来越少，因为他越来越明白，人人都有他的难处，所以越来越能理解别人。sposition. "She am my Manitou," replied the Indian. "What is a Manitou? Every Indian you meet with seems to differ on the subject." "Some tam she am wan ting, some tam she am anodder." "That is evading the question," said Chrissy. "What kind of a Manitou have you got inside of that little bag which is tied round your neck?" persisted Bearie. "Will you let me see it?" "No! No!! No!!!" he said excitedly. "My Manitou she am not be pleese." "Come, now, old man," he said. "Tell us all about it." "What is it?" "How did you get it?" "What is it for?" "Waal," he said, reluctantly, "When I am a boy, me, just become a man, my fadder, he say,  Machecawa, tam you got a manitou.  My face he paint black, black. He say, heem,  you no eat no teeng seex days.  By em by I am dream some teeng, me, dat some teeng she am my manitou. She help me kill beeg bear; she mak dem Iroquois dogs run like one wild moose. My fadder she am pleese; she make my manitou on my arm—see!" he said, rolling up his sleeve. On his shoulder was the rude outline of a fish, which had been tatooed with sharp bones and with the juice of berries rubbed in. "But what is in the little bag?" asked Bearie. "Will you let me see it?" After a good deal of reluctance he gave in at last, and two curious boys untied the precious parcel, while the others, equally curious, looked over his shoulders at a few old broken fish bones which were all the little bag contained. "Well, old man," said Bearie, slowly replacing the sacred relics, "we put our faith in something better than that. The white man trusts the Great Spirit in heaven to care for him and to take him to heaven when he dies." "Any bear in hebben?" asked the Indian. "No," said Bearie, "only good people." "Dat hebben she am no good for big Injun," said Machecawa, sadly. "De happy hunting ground she am full of moose, buffalo, bear, beaver. She am far, far away at de end of land, where de sun she sleep—two, tree moons away. One beeg dog she am cross, an  she bark at dead Injun, but he go on, an  on, an  on, an  den he am glad." It began to dawn upon the vigilant mother at length that it was not so much the wonders of civilization nor the desire to "speak his thoughts from books" that led Machecawa day after day to the Wigwam, as an ever-increasing interest in her fun-loving daughter, Abbie, who was a year younger than Chrissy, and who seemed unconscious of the fact that the eyes of the red chief were ever upon her.学说值得怀疑，这就要求人们进一步去探索宇宙的秘密，从而推进了天文学和地理学的发展。1492年，意大利著名的航海家哥伦布发现新大陆，麦哲伦和他的同伴绕地球一周，证明地球是圆形的，使人们开始真正认识地球。[4] 对他国的影响 在教会严密控制下的中世纪，也发生过轰轰烈烈的宗教革命。因为天主教的很多教义不符合圣经的教诲，而加入了太多教皇的个人意志以及各类神学家的自身成果，所以很多信徒开始质疑天主教的教义和组织，发起回归圣经的行动来。捷克的爱国主义者、布拉格大学校长扬·胡斯（1369～1415年）在君士坦丁堡的宗教会议上公开谴责德意志封建主与天主教会对捷克的压迫和剥削。他虽然被反动教会处以火刑，但他的革命活动在社会上引起了强烈的反应。捷克农民在胡斯党人的旗帜下举行起义，这次运动也波及波兰。1517年，在德国，马丁·路德（1483～1546年）反对教会贩卖赎罪符，与罗马教皇公开决裂。1521年，路德又在沃尔姆国会上揭露罗马教廷的罪恶，并提出建立基督教新教的主张。新教的教义得到许多国家的支持，波兰也深受影响。 

• 废物式养老，是对老人最大的羞辱。

“姥姥你已经不是二三十岁的年轻人了，你都70多岁了，能不能让我们省点心，别起早贪黑出去工作了？”

• 真正的尊重，是倾听老人的想法。

• 不服老，才能绽放自己的光彩。

“父母的家永远是孩子的家，子女的家从来不是父母的家。生孩子是任务，养孩子是义务，靠孩子是错误。”