C********g 发帖数: 9656 | 1 http://my.cnd.org/modules/wfsection/article.php?articleid=30039
绝对的转动
经典物理的开山之作“自然哲学之数学原理”发表于1687年。书中,牛顿第一个讲到的
物理实验是水桶实验。
牛顿说,用一根长的软吊绳提一桶水,把吊绳拧成麻花状。如果你握住吊绳,不让麻花
状的绳子松开,桶及桶中的水是相对是静止的,水面是平的。突然放开手,麻花开始放
松,吊绳旋转,水桶也随着吊绳旋动。最初,桶中的水并不转动,只有桶在旋转,桶和
桶中的水有相对转动。慢慢地,水被桶带动,也开始转动。最后,水和桶一样转动。这
时,水和桶之间又是相对静止的,不转动的。但水面却呈凹状,中心低,桶边高。牛顿
爵士特别说“ I have experienced”。他亲自做过这实验。
这个实验很容易,任何有水桶和软绳的人都可以试试。我也多次做过这个实验。 1957
冬 - 1958年春, 我在河北省赞皇县南邢郭村下放劳动。天天要用软吊绳的桶从约十米
深的井中打水。水桶的姿态只能用软吊绳控制。没有十天半个月的练习,是学不会水桶
姿态控制的。结果是,任凭你让吊桶十五次七上八下... 阅读全帖 |
|
e**5 发帖数: 645 | 2 ·方励之·
绝对的转动
经典物理的开山之作“自然哲学之数学原理”发表于1687年。书中,牛顿第一个讲到的
物理实验是水桶实验。
牛顿说,用一根长的软吊绳提一桶水,把吊绳拧成麻花状。如果你握住吊绳,不让麻花
状的绳子松开,桶及桶中的水是相对是静止的,水面是平的。突然放开手,麻花开始放
松,吊绳旋转,水桶也随着吊绳旋动。最初,桶中的水并不转动,只有桶在旋转,桶和
桶中的水有相对转动。慢慢地,水被桶带动,也开始转动。最后,水和桶一样转动。这
时,水和桶之间又是相对静止的,不转动的。但水面却呈凹状,中心低,桶边高。牛顿
爵士特别说“ I have experienced”。他亲自做过这实验。
这个实验很容易,任何有水桶和软绳的人都可以试试。我也多次做过这个实验。 1957
冬 - 1958年春, 我在河北省赞皇县南邢郭村下放劳动。天天要用软吊绳的桶从约十米
深的井中打水。水桶的姿态只能用软吊绳控制。没有十天半个月的练习,是学不会水桶
姿态控制的。结果是,任凭你让吊桶十五次七上八下,每次提上来的水,大多不过是半
桶水,而且在旋转。常被同吃同住同劳动的老农(其实不老,同我年龄相仿,但农活经
验老道... 阅读全帖 |
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C********g 发帖数: 9656 | 3 【 以下文字转载自 History 讨论区 】
发信人: Communipig (共产猪), 信区: History
标 题: 方励之:牛顿的水桶1687-2011
发信站: BBS 未名空间站 (Fri Sep 23 15:54:24 2011, 美东)
http://my.cnd.org/modules/wfsection/article.php?articleid=30039
绝对的转动
经典物理的开山之作“自然哲学之数学原理”发表于1687年。书中,牛顿第一个讲到的
物理实验是水桶实验。
牛顿说,用一根长的软吊绳提一桶水,把吊绳拧成麻花状。如果你握住吊绳,不让麻花
状的绳子松开,桶及桶中的水是相对是静止的,水面是平的。突然放开手,麻花开始放
松,吊绳旋转,水桶也随着吊绳旋动。最初,桶中的水并不转动,只有桶在旋转,桶和
桶中的水有相对转动。慢慢地,水被桶带动,也开始转动。最后,水和桶一样转动。这
时,水和桶之间又是相对静止的,不转动的。但水面却呈凹状,中心低,桶边高。牛顿
爵士特别说“ I have experienced”。他亲自做过这实验。
这个实验很容易,任何有水桶和软绳... 阅读全帖 |
|
m****m 发帖数: 2211 | 4 【 以下文字转载自 History 讨论区 】
发信人: Communipig (共产猪), 信区: History
标 题: 方励之:牛顿的水桶1687-2011
发信站: BBS 未名空间站 (Fri Sep 23 15:54:24 2011, 美东)
http://my.cnd.org/modules/wfsection/article.php?articleid=30039
绝对的转动
经典物理的开山之作“自然哲学之数学原理”发表于1687年。书中,牛顿第一个讲到的
物理实验是水桶实验。
牛顿说,用一根长的软吊绳提一桶水,把吊绳拧成麻花状。如果你握住吊绳,不让麻花
状的绳子松开,桶及桶中的水是相对是静止的,水面是平的。突然放开手,麻花开始放
松,吊绳旋转,水桶也随着吊绳旋动。最初,桶中的水并不转动,只有桶在旋转,桶和
桶中的水有相对转动。慢慢地,水被桶带动,也开始转动。最后,水和桶一样转动。这
时,水和桶之间又是相对静止的,不转动的。但水面却呈凹状,中心低,桶边高。牛顿
爵士特别说“ I have experienced”。他亲自做过这实验。
这个实验很容易,任何有水桶和软绳... 阅读全帖 |
|
g********n 发帖数: 2314 | 5 【 以下文字转载自 History 讨论区 】
发信人: Communipig (共产猪), 信区: History
标 题: 方励之:牛顿的水桶1687-2011
发信站: BBS 未名空间站 (Fri Sep 23 15:54:24 2011, 美东)
http://my.cnd.org/modules/wfsection/article.php?articleid=30039
绝对的转动
经典物理的开山之作“自然哲学之数学原理”发表于1687年。书中,牛顿第一个讲到的
物理实验是水桶实验。
牛顿说,用一根长的软吊绳提一桶水,把吊绳拧成麻花状。如果你握住吊绳,不让麻花
状的绳子松开,桶及桶中的水是相对是静止的,水面是平的。突然放开手,麻花开始放
松,吊绳旋转,水桶也随着吊绳旋动。最初,桶中的水并不转动,只有桶在旋转,桶和
桶中的水有相对转动。慢慢地,水被桶带动,也开始转动。最后,水和桶一样转动。这
时,水和桶之间又是相对静止的,不转动的。但水面却呈凹状,中心低,桶边高。牛顿
爵士特别说“ I have experienced”。他亲自做过这实验。
这个实验很容易,任何有水桶和软绳... 阅读全帖 |
|
k********k 发帖数: 5617 | 6 http://es-us.noticias.yahoo.com/el-hurac-n-sandy-obliga-cancela
El huracán Sandy obliga a cancelar miles de vuelos
The Hurricane Sandy Forces the Cancellation of Thousands of Flights
颶風“三弟”迫使取消上千航班
Por Por The Associated Press | Associated Press – Hace 3 horas
美聯社西班牙文電訊
NUEVA YORK (AP) — El huracán Sandy obligó a cancelar miles de vuelos del
noreste de Estados Unidos el lunes y alteró planes de viaje en todo el
mundo, varando a pasajeros desde Hong Kong hasta Europa.
La gigantesca tormenta amen... 阅读全帖 |
|
k********k 发帖数: 5617 | 7 http://es-us.noticias.yahoo.com/el-hurac-n-sandy-obliga-cancela
El huracán Sandy obliga a cancelar miles de vuelos
The Hurricane Sandy Forces the Cancellation of Thousands of Flights
颶風“三弟”迫使取消上千航班
美聯社西班牙文電訊
Por Por The Associated Press | Associated Press – Hace 3 horas
NUEVA YORK (AP) — El huracán Sandy obligó a cancelar miles de vuelos del
noreste de Estados Unidos el lunes y alteró planes de viaje en todo el
mundo, varando a pasajeros desde Hong Kong hasta Europa.
La gigantesca tormenta amen... 阅读全帖 |
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w****j 发帖数: 5581 | 8 我们前面强调过, Battle of Allia是罗马历史的一个分水岭。罗马的政治,军事和社
会生活在这之后都有比较大的改变。而且从历史学的角度讲,Battle of Allia之前的
历史越久就传说的成分越重,也就越不可靠,这是因为Gaul人攻陷罗马城后,罗马的档
案记录都被毁掉了。
Battle of Allia也让罗马人从入侵者手里学到不少东西,比如武器制造(一些历史学
家认为当时Gaul人的炼铁技术更好,而且前面提到的几个古典历史学家都反复强调过高
卢人的武器)和战术(比如testudo)。在外交上,Gaul人入侵使得拉丁城邦更加紧密
的和罗马团结在一起,因为Gaul人的军事威胁实在不是一个或少数几个城邦所能应对的
。而在内政和经济发展方面,这次危机对罗马的影响也是深远的。我们已经知道,罗马
从公元前5世纪起开始的崛起(变得越来越富裕和强大)伴随着的是贵族统治秩序变得
越来越不稳定。在连续不断的对外战争中,贵族不止一次被迫对平民让步以换取平民对
战争的参与。而随着罗马控制下的土地不断扩大,非贵族出身的土地所有者也在不断增
加。这一方面是平民通过各种手段向贵族争取到的,另一方面是... 阅读全帖 |
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y***l 发帖数: 6963 | 9 Why do so many Japanese care so much whether the Koreans invented the Chines
e characters? One Korean scholar used probable historical evidences to make
a point. Besides this there is another recent discovery that the ancestors o
f the Koreans were called 揝u-Mafound in some old text writeen in Chines
e chareters and it desicribes some of these Su-Ma people migrated west and
some Koreans think they became the original SuMArians backed up by an old
reginal belief that the Sumerians looked more lik... 阅读全帖 |
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w********r 发帖数: 3183 | 10 Roberta Beach Saint Paul, MN
Dixie Electric Ltd. Minneapolis, MN
Libson Twin City Auto – Truck Parts & Service Minneapolis, MN
Golden Ring Trucking, Inc. Fergus Falls, MN
McAlister Services St. Francis, MN
Huepenbecker Transportation Norwood Young America, MN
Todd Stiles Zimmerman, MN
Miki Express Rogers, MN
Transport Designs Inc. New Prague, MN
Gold Country Trucking Saint Joseph, MN
Alternators Starters & Parts, Inc. Mendota Heights, MN
Lares Corporation Cambridge, MN
Meisch Brothers Garage, LL... 阅读全帖 |
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x**********i 发帖数: 4964 | 12 今天看邻居一大家在新大切里面 就一个感觉: 安全
感觉32k的 Lared 4x4 是midsize suv这个级别性价比最高的了 这不就是个平民M-
Class或者 X5么 8速zf=smooth shifts+ 17/25 mpg 内饰也非常赞
不过看了看dealer库存 4x4就基本没有 也难怪斯巴鲁在南方不火
大切 Laredo 和limited 有什么本质的区别么 除了皮椅 camera 和外观一些点缀 |
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b****t 发帖数: 5743 | 13 hc4box 4××××
lares Puerto Rico
00669
邮箱? 倒爷中转站?hc4box是什么玩意? |
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x*****3 发帖数: 8 | 14 转让奶票,coupon
奶票:
Enfamil: 计$20
$5.00*4 Expires:July 31,2010
GoodStart:计$55
$11.00*1 Expires:9/15/1010;
$6.00*1,$3.00*1 Expires:9/1/2010;
$1.00*1,$8.00*3,$5.00*2 Expires:10/1/2010
胖子:
Similac: 计$4
$2.00 Off on any one Similac lare size powder(23.2oz or larger)*2 Expires:7/
14/2010
另有宝宝用品coupon随机奉送。
5折+0.5邮费,站内M联系。 |
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a*****g 发帖数: 19398 | 15 长篇文章:Why Do Americans Stink at Math?
When Akihiko Takahashi was a junior in college in 1978, he was like most of
the other students at his university in suburban Tokyo. He had a vague sense
of wanting to accomplish something but no clue what that something should b
e. But that spring he met a man who would become his mentor, and this relati
onship set the course of his entire career.
Takeshi Matsuyama was an elementary-school teacher, but like a small number
of instructors in Japan, he taught no... 阅读全帖 |
|
a*****g 发帖数: 19398 | 16 长篇文章:Why Do Americans Stink at Math?
When Akihiko Takahashi was a junior in college in 1978, he was like most of
the other students at his university in suburban Tokyo. He had a vague sense
of wanting to accomplish something but no clue what that something should b
e. But that spring he met a man who would become his mentor, and this relati
onship set the course of his entire career.
Takeshi Matsuyama was an elementary-school teacher, but like a small number
of instructors in Japan, he taught no... 阅读全帖 |
|
j***e 发帖数: 20 | 17 我去了几次LA的领事馆,觉得他们的服务态度也很好,有一次我老公少复印了几页,女
的officer等着我们复印回来, 还嘱咐我们应该在家里也留复印件,哪个最重要, 觉
得很亲切.
官
领
两 |
|
c********g 发帖数: 449 | 18 The officers at LA consulate are very nice.
I extend my visa etc.
女
觉
事
,
有 |
|
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p***y 发帖数: 18037 | 20 揪感心!联航延飞 载他见母最后一面
2013-03-08 01:31 中国时报 【刘屏╱华盛顿七日电】
航空公司的班机一向不等人,但是也有例外,尤其是旅客赶著见至亲最后一面时
。这样的刻意延误可能让航空公司获奖。
德瑞克(Kerry Drake)住在美国东岸旧金山,在联邦政府上班。这天一大早,
他的兄弟来电「母亲病危,速回」。他立刻登上最近一班飞机,准备经由休士顿转往德
州小城鲁波克(Lubbock)。转机时间只有四十分钟,但这是当天最后一班飞往鲁波克
的飞机,他别无选择,只能一试。
联合航空这班飞机从旧金山起飞时就迟了,令他格外心神不宁,担心赶不及见母
亲最后一面。一位空服员雷尔斯(Sofia Lares)看出他有心事,告诉他,「我们会尽
一切努力帮忙,也会为你多准备一些面纸擦眼泪」。另一位空服员钟兰(Lan Chung)
要了德瑞克转机的班机号码,转告机长。班机赶回了一些时间,但不够。降落休士顿时
,德瑞克看表,往鲁洛克班机应该已离站。
他还是决定试试看。当他跑到登机门时,远远看到登机门竟然还开著。门口有人
朝著他大喊∶「德瑞克先生吗?我们正... 阅读全帖 |
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p***y 发帖数: 18037 | 21 United Airlines Holds Flight So Kerry Drake Could Say Goodbye To Dying
Mother
By Ashley Davis, Thu, March 07, 2013
Though airlines are usually known for being quite unaccommodating to their
passenger’s schedules, one airline went above and beyond to make sure one
man could make it to say goodbye to his mother before she passed away.
United saw Kerry Drake on January 24 in tears as he thought about the
possibility of not making it to his mother in time.
He was flying from San Francisco and his fl... 阅读全帖 |
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a*****g 发帖数: 19398 | 22 长篇文章:Why Do Americans Stink at Math?
When Akihiko Takahashi was a junior in college in 1978, he was like most of
the other students at his university in suburban Tokyo. He had a vague sense
of wanting to accomplish something but no clue what that something should b
e. But that spring he met a man who would become his mentor, and this relati
onship set the course of his entire career.
Takeshi Matsuyama was an elementary-school teacher, but like a small number
of instructors in Japan, he taught no... 阅读全帖 |
|
|
b**j 发帖数: 20742 | 24 请注意opportunity to possess
POSTSEASON – MODIFIED SUDDEN DEATH
The modified sudden death system of determining the winner shall prevail whe
n the score is tied at the end of regulation playing time of postseason NFL
games. The system guarantees each team a possession or the opportunity to po
ssess, unless the team that receives the opening kickoff scores a touchdown
on its initial possession.
· At the end of regulation time, the Referee will immediately toss
a coin at the center of the fie... 阅读全帖 |
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C********o 发帖数: 5368 | 25 赞.
LARED名声很响啊, 偶一直不敢去试试...怕啊怕啊
的。
年努力。结果就
是 |
|
M**********e 发帖数: 4237 | 26 笨猪笨猪你始终不敢说你自己是谁,山水有相逢,咱们那天场上见。LA RED队为何始终
没有夺的北美华
人赛冠军,你们自己太高估你们自己,还真以为你们那帮人有多强。你可以说我技术糙
个子矮,但你说
我身体弱速度慢那咱们有机会撞撞试试。我不认为技术分析是装B,我从建立一支业余
球队从D2打到D1
到拿CITY联赛杯亚军只用了两个赛季,你们LARED现在还是你们LEAGUE的垫底队.笨猪笨
猪你还有脸说
我装B.
这就是你们2010年的成绩
http://arcadiasoccer.org/standings.php |
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i******e 发帖数: 219 | 27 当年,野球出身。我堂哥,不是那麦鹰,是江西省
足球专项第一,啥概念,就是如果他高考能考三百五,他就能去清华的,
高考他考了二百八。
当然,读书改变命运,他短暂的踢了乙级后,就经商,有钱了。
我从小跟他踢球,父母告诫,只踢着玩。于是混迹野球界为主。
高中我们校队是江西省冠军,有几个去了北京三高,校队让我去
我都没去,不需要加分啥的。
大学后才是踢足球的正式开始。毫无悬念的进了科大校队。
由于科大无特招,在安徽从98踢到2003年才夺冠军,一直都是
亚军。 2003以后,开始接触到真正的职业球队。安徽乐普生
二队一直跟我们对踢,第一次踢得时候被打了8:1
,后来一直踢。 慢慢的明白了职业的踢法是啥样的,职业和
业余的最大区别是大场地意识,其实单兵野球王和职业差别不大。
我个人巅峰的比赛因该就是大学生运动会前跟他们的比赛3:3.
我千里单计一个,远射一个,助攻一个。那时候我是科大十号。
meanwhile,2003年我们校队几个人夺了安徽省四人制足球比赛冠军。
去北京被一帮人给菜了。据说对手有四人制国足的。。。反正极其牛逼,没法比
2003年,女足大运会在科大踢。河北女足要跟我们热身。我们踢... 阅读全帖 |
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C***r 发帖数: 759 | 28 CHAP. 11.--OF THE OPINION OF THE PLATONISTS, THAT THE SOULS
OF MEN BECOME DEMONS WHEN DISEMBODIED.
He(4) says, indeed, that the souls of men are demons, and
that men become Lares if they are good, Lemures or Larvae if
they are bad, and Manes if it is
uncertain whether they de serve well or ill. Who does not
see at a glance that this is a mere whirlpool sucking men to
moral destruction? For, however wicked
men have been, if they suppose they shall become Larvae or
divine Manes, they will become t |
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R*o 发帖数: 3781 | 29 There is not a verse in the Bible, however, which presents Calvinism's radic
al idea that the sinner is incapable of believing the very gospel which offe
rs him forgiveness and salvation and yet he is condemned by God for failing
to believe. In fact, as we shall see, the Bible declares otherwise. "All men
everywhere" (Acts 17:30) are repeatedly called upon to repent and to believ
e on Christ. One would never derive from Scripture the idea that the unregen
erate are unable to believe. Dave Breese... 阅读全帖 |
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G*******s 发帖数: 4956 | 30 Blinded By Tradition:
An Open Letter to Dave Hunt
Regarding His Newly Published Attack Upon the Reformation, What Love Is This
? Calvinism's Misrepresentation of God
James White
Updated 5/16/02, see bottom of file
Dear Dave,
In the period of time since I finally received my own copy of your book (you
may recall I scanned through it while standing at your table in St. Louis a
t the PFO Conference) I have gone through a number of different emotions. A
t first I was just going to do one Dividing ... 阅读全帖 |
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a*****g 发帖数: 19398 | 31 长篇文章:Why Do Americans Stink at Math?
When Akihiko Takahashi was a junior in college in 1978, he was like most of
the other students at his university in suburban Tokyo. He had a vague sense
of wanting to accomplish something but no clue what that something should b
e. But that spring he met a man who would become his mentor, and this relati
onship set the course of his entire career.
Takeshi Matsuyama was an elementary-school teacher, but like a small number
of instructors in Japan, he taught no... 阅读全帖 |
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m*****i 发帖数: 1205 | 32 转载自miya日本近代文学网站
(二)今户烧招财猫
今户烧是十五世纪中旬,于东京台东区今户地区起源的素陶瓷器名
称。一八五二年,浅草有位养了一只老猫的老太婆,因为老伴过
世,经济拮据,只好投靠亲戚家。老太婆撒泪与老猫诀别后,当天
夜晚做了一个梦。梦中,老猫告诉主人说,如果制作一座它的偶
像,必定会福德自来。老太婆听从老猫的托梦,将猫偶像供奉在神
龛上,朝晚合掌叩拜。之后,果然如老猫所说,喜报接二连三,老
太婆也不用再寄人篱下了。
http://www.lares.dti.ne.jp/~t-ogi/japan/maneki-3.jpg
(风铃招财猫)
回到旧居后,老太婆因猫偶像而致富的传言,马上遍及左邻右舍,
每天都有人来向她借猫偶像。于是老太婆便托窑户制作陶器招 |
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