登陆注册
5200500000056

第56章

The shape of bodies will not account for their moving upward or downward in general, though it will account for their moving faster or slower.The reasons for this are not difficult to see.For the problem thus raised is why a flat piece of iron or lead floats upon water, while smaller and less heavy things, so long as they are round or long-a needle, for instance-sink down; and sometimes a thing floats because it is small, as with gold dust and the various earthy and dusty materials which throng the air.With regard to these questions, it is wrong to accept the explanation offered by Democritus.He says that the warm bodies moving up out of the water hold up heavy bodies which are broad, while the narrow ones fall through, because the bodies which offer this resistance are not numerous.But this would be even more likely to happen in air-an objection which he himself raises.His reply to the objection is feeble.In the air, he says, the 'drive' (meaning by drive the movement of the upward moving bodies) is not uniform in direction.But since some continua are easily divided and others less easily, and things which produce division differ similarly in the case with which they produce it, the explanation must be found in this fact.

It is the easily bounded, in proportion as it is easily bounded, which is easily divided; and air is more so than water, water than earth.

Further, the smaller the quantity in each kind, the more easily it is divided and disrupted.Thus the reason why broad things keep their place is because they cover so wide a surface and the greater quantity is less easily disrupted.Bodies of the opposite shape sink down because they occupy so little of the surface, which is therefore easily parted.And these considerations apply with far greater force to air, since it is so much more easily divided than water.But since there are two factors, the force responsible for the downward motion of the heavy body and the disruption-resisting force of the continuous surface, there must be some ratio between the two.For in proportion as the force applied by the heavy thing towards disruption and division exceeds that which resides in the continuum, the quicker will it force its way down; only if the force of the heavy thing is the weaker, will it ride upon the surface.

We have now finished our examination of the heavy and the light and of the phenomena connected with them.

THE END

同类推荐
  • 申鉴

    申鉴

    本书为公版书,为不受著作权法限制的作家、艺术家及其它人士发布的作品,供广大读者阅读交流。汇聚授权电子版权。
  • 耳门

    耳门

    本书为公版书,为不受著作权法限制的作家、艺术家及其它人士发布的作品,供广大读者阅读交流。汇聚授权电子版权。
  • 发史

    发史

    本书为公版书,为不受著作权法限制的作家、艺术家及其它人士发布的作品,供广大读者阅读交流。汇聚授权电子版权。
  • 上清洞真解过诀

    上清洞真解过诀

    本书为公版书,为不受著作权法限制的作家、艺术家及其它人士发布的作品,供广大读者阅读交流。汇聚授权电子版权。
  • 疏香阁词

    疏香阁词

    本书为公版书,为不受著作权法限制的作家、艺术家及其它人士发布的作品,供广大读者阅读交流。汇聚授权电子版权。
热门推荐
  • 不负卿城时光

    不负卿城时光

    再相遇,她已经不记得他了,而他,步步为营,让她再次为他沦陷,从幼儿到少年,从少年到老年,从校服到婚纱,他偏执又毫无保留的爱一直都在,他们不负卿城时光
  • 行星与恒星(自然瞭望书坊)

    行星与恒星(自然瞭望书坊)

    人类是宇宙演化的杰作,宇宙是神秘莫测的存在。当宇宙的精灵与莫测的神秘结合在一起时,便碰撞出无数精彩的篇章。人类对宇宙的解读和探秘跨越了千年,宇宙的面貌也越来越清晰地展现在人类面前。
  • 趣谈语言文学

    趣谈语言文学

    近年来,越来越多的人学习汉语,人们也希望更多地了解中国和中国文化。中国是一个历史悠久的国家,其语言文学亦有深厚的功底,诸多名著让人目不暇接。《趣谈语言文学》以细腻的文笔,带领我们慢慢品读诸多经典之作,让我们在文学的殿堂寻找到那份已远去的宁静与淡然。
  • 梦入红楼

    梦入红楼

    “新书《红楼大贵族》已发布,重启红楼路,这一次,不一样的梦,更美的梦。” 不意踏入红楼,走一段红楼路。 (新书已发布,快来围观)VIP群:一一零,八一六,一六一
  • 浩瀚天都

    浩瀚天都

    十年压抑,意可凌天,一朝爆发,功成跨龙腾九天。武道艰难,凝聚浩瀚气运,朕要登顶武道之颠,做那万界帝王。挡道者,杀!逆朕者,杀!……一切皆可杀!
  • 降妖伏魔本纪

    降妖伏魔本纪

    我虽年少,有三尺青锋可除妖。我虽年少,有七寸在腰伏女妖。我虽年少,把刀拿开,什么都可以商量着来……什么叫能屈能伸?本少告诉诸位,可软可硬就叫能屈能伸。妖魔仙佛神来者不拒叫能屈能伸。多想想许仙同志,闭上眼睛,有什么不同么?
  • 超时空微信

    超时空微信

    别人微信附近的人是美女,李大成微信附近的人是慈禧、李莲英、和珅等等一些历史大人物......这可把李大成忙坏了,今天给慈禧祝寿,明天恭喜李莲英升官,后天吧货卖给和珅,要不要随份子钱呢?郑板桥、唐伯虎,苏东坡、王羲之,谁的字画不是价值连城?三国的枭雄英豪,春秋战国的诸子百家......李大成:请把我的话费充满,我要将现代的东西发到古代去,当然,也要把古代的东西带到现代来..
  • 年少时的心上人

    年少时的心上人

    某一天一个小男孩转到了小女孩的班,于是这个小男孩便走进了小女孩的心里。
  • 大唐魂

    大唐魂

    盛极而衰的中唐,安史之乱已经结束,饱经战火荼毒的中原大地仍然暗流涌动,各种割据势力与朝廷各派系明争暗斗,一时群雄并起,战乱频仍,民生凋敝。丑书生陆羽浪迹天涯,在江南歌会上巧遇儿时知己李季兰,季兰已成为名噪天下的青楼诗妓。二人相认,再续前缘。此时江南怪事迭出,事涉民族团结,引起北方义士的注意,并派出剑道高手公孙玉娘一路追查。陆羽一心钻研茶道,却身不由己卷入江湖纷争,多次犯险均为公孙玉娘所救。玉娘对丑书生一见倾心,引起季兰猜忌。世俗的压力使季兰被迫出家为冠。
  • 阿阇梨大曼荼攞灌顶仪轨

    阿阇梨大曼荼攞灌顶仪轨

    本书为公版书,为不受著作权法限制的作家、艺术家及其它人士发布的作品,供广大读者阅读交流。汇聚授权电子版权。