第4章 万物的尺度 The Measure of Things · 第8讲S2

1. 老师，讲稿里说 noble gases 的 noble 不是指‘高尚’而是‘惰性’，为啥英语里会用 noble 这个词来形容这种不爱反应的气体呀？
2. 这里反复提到 elusive，除了形容气体难发现，讲稿里还举了 elusive thief 的例子，这两个用法在语境上到底有啥细微差别？
3. 卡文迪许那个实验用的仪器长得像‘鹦鹉螺牌举重机’，这比喻太形象了，那这台‘18世纪版举重机’和现代健身房里的器械在结构上最核心的区别是啥？
4. 讲稿最后说重力在个体层面其实很弱（not really powerful），只有在大质量物体（如太阳和地球）之间才显得强大，这是为啥呢？
5. 既然有了引力常量就能推算出地球质量，那如果当时卡文迪许没测准这个 elusive force，会对后来的人类航天探索产生多大影响？

1. Why is the word 'noble' used to describe inert gases that don't react easily, instead of just calling them 'inactive' or 'lazy'?
2. The transcript uses 'elusive' for both hard-to-find gases and a sneaky thief; what's the subtle difference in how it's applied in these two contexts?
3. The apparatus is compared to a 'Nautilus weight training machine'; what is the core structural difference between this 18th-century torsion balance and modern gym equipment?
4. Why does the text say gravity is actually weak on an individual level but becomes powerful only when massive objects like the Sun and Earth are involved?
5. If Cavendish hadn't successfully measured this elusive force, how significantly would that have impacted later human space exploration?

1 00:00:19,580 --> 00:00:20,060 他 2 00:00:20,820 --> 00:00:25,870 还留下了一些线索根据这些线索呢人们最终发现了一 3 00:00:25,870 --> 00:00:30,980 些惰性气体这个 noble gases 这 noble 并不是高尚的或 4 00:00:30,980 --> 00:00:33,380 者说贵族的意思而是 inactive 5 00:00:33,640 --> 00:00:39,320 惰性的不容易跟其他的元素产生反应的惰性的气体 6 00:00:40,120 --> 00:00:41,140 some of which, 7 00:00:41,340 --> 00:00:46,480 这个 which 指的就是 gases 这些惰性气体中有一些是非 8 00:00:46,480 --> 00:00:50,420 常难以发现的 so elusive, 9 00:00:50,720 --> 00:00:54,660 something that is elusive is difficult to find or not 10 00:00:54,660 --> 00:00:57,700 often seen you can say an elusive thief, 11 00:00:57,980 --> 00:01:01,500 一个神出鬼没的小偷 or elusive leopard, 12 00:01:02,000 --> 00:01:07,200 踪迹不定的豹这里边最难找到的一些多性气体一直到 13 00:01:07,200 --> 00:01:10,700 了 1962 年才被人发现 But 14 00:01:11,700 --> 00:01:15,380 our interest here is in Cavendish's last known 15 00:01:15,380 --> 00:01:21,180 experiment when in the late summer of 1797 at the age of 16 00:01:21,180 --> 00:01:24,740 67 he turned his attention to the crates of equipment 17 00:01:24,740 --> 00:01:28,640 that had been left to himevidently out of simple 18 00:01:28,640 --> 00:01:31,180 scientific respect by Jean Michel 19 00:01:32,250 --> 00:01:36,150 但是我们现在的兴趣呢是 Kavendish 最后一项为人所 20 00:01:36,150 --> 00:01:40,120 知的 experiment 为什么这里加个 known experiment 因 21 00:01:40,120 --> 00:01:43,890 为他的很多 experiment 别人都不知道所以这是最后一 22 00:01:43,890 --> 00:01:48,100 项我们所能知道的一个 experiment 可能在此之后他还 23 00:01:48,100 --> 00:01:49,290 有别的 experiment 24 00:01:50,080 --> 00:01:53,860 In the late summer of 1797 at the age of 67 25 00:01:54,620 --> 00:01:58,580 he turned his attention to the crates of equipment 他就 26 00:01:58,580 --> 00:02:05,400 把注意力转向了那一箱的仪器我们之前学过的箱子这 27 00:02:05,400 --> 00:02:08,800 项仪器呢是 had been left to him by John Mischel 28 00:02:09,360 --> 00:02:13,660 这是 John Mischel 自己设计并且建造但是他没有能够 29 00:02:13,660 --> 00:02:17,900 自己亲手进行这个实验就去世了然后出于 30 00:02:18,440 --> 00:02:22,120 evidently out of simple scientific respectevidently 31 00:02:22,120 --> 00:02:26,910 means obviously 显然呢是出于对 Kevindish 在科学方 32 00:02:26,910 --> 00:02:31,520 面的尊敬就把这项仪器留给了 Kevindish When 33 00:02:31,520 --> 00:02:32,340 assembled, 34 00:02:32,720 --> 00:02:36,220 Michel's apparatus looked like nothing so much as an 35 00:02:36,220 --> 00:02:39,720 18th century version of a Nautil us weight training 36 00:02:39,720 --> 00:02:43,800 machine.Assembled means to put together, 37 00:02:44,560 --> 00:02:47,080 组装,组装起来以后呢, 38 00:02:47,160 --> 00:02:50,260 Michel 的这个 apparat us means equipment, 39 00:02:50,660 --> 00:02:53,820 他的这台仪器看起来就非常像, 40 00:02:53,940 --> 00:02:57,000 nothing so much as 是其一个强调的作用, 41 00:02:57,060 --> 00:03:00,480 看起来特别像 18th century version of a Nautil us 42 00:03:00,480 --> 00:03:01,660 weight training machine, 43 00:03:01,940 --> 00:03:06,380 Weight Training Machine is like this 这是在健身馆里 44 00:03:06,380 --> 00:03:12,300 面可以看到的举重机而这个 Nautil us 是鹦鹉螺这是举 45 00:03:12,300 --> 00:03:18,040 重机的著名品牌看起来就像是 18 世纪版的鹦鹉螺牌举 46 00:03:18,040 --> 00:03:18,460 重机 47 00:03:19,010 --> 00:03:23,310 那实际上它的这个 operators 是这个样子的我是看不 48 00:03:23,310 --> 00:03:26,510 出来它像举重机 It incorporated weights, 49 00:03:26,810 --> 00:03:28,650 counter weights,pendulums, 50 00:03:28,810 --> 00:03:33,570 shafts and torsion wires Incorporated means included 51 00:03:33,570 --> 00:03:38,250 包括这些东西 weights 本来这个 weights 指的是举重机 52 00:03:38,250 --> 00:03:42,290 这两边这个重量这种砝码叫 weights Counter weights 53 00:03:42,290 --> 00:03:46,550 是指配重用的砝码配重使得两边可以平衡的 54 00:03:47,050 --> 00:03:51,290 还有 pendulumspendulums 我们在之前的课程里面学过 55 00:03:51,290 --> 00:03:54,850 是钟摆不过我也不知道这里哪个像钟摆 56 00:03:55,630 --> 00:03:56,650 也许是这个 57 00:03:57,640 --> 00:04:04,340 其实这是一面镜子 shafts 就是杆一根杆子就这根叫 58 00:04:04,340 --> 00:04:05,060 shafts 59 00:04:05,340 --> 00:04:11,160 and torsion wireswires 是指金属丝不过这里呢它用的 60 00:04:11,160 --> 00:04:15,700 是石英丝石英纤维并不一定是金属的但也可以叫 61 00:04:15,700 --> 00:04:21,320 wires 一根悬在这里的一根丝 torsion 指的是扭转 62 00:04:21,320 --> 00:04:27,120 torsion wires 指的就是这个可以扭转的悬丝这个实验 63 00:04:27,120 --> 00:04:29,900 的名称就叫 Torsion Balance Experiment, 64 00:04:30,440 --> 00:04:34,660 叫扭秤实验,因为看起来像是一个天秤那样, 65 00:04:34,680 --> 00:04:37,120 像是一个秤,所以叫 Balance, 66 00:04:37,340 --> 00:04:41,840 Torsion Balance,测量的是这个悬丝的旋转的程度, 67 00:04:41,880 --> 00:04:43,200 就叫扭秤实验。 68 00:04:44,500 --> 00:04:49,900 At the heart of the machine were two 350 pound lead 69 00:04:49,900 --> 00:04:50,240 balls, 70 00:04:50,580 --> 00:04:55,320 which were suspended beside two smaller spheres.这个 71 00:04:55,320 --> 00:05:03,740 仪器的核心是两个 350 磅重的铅球 350 磅也大概就是 72 00:05:03,740 --> 00:05:08,880 300 多斤,因为一磅是 9 两多这里是 lead balls, 73 00:05:09,160 --> 00:05:11,920 不是 lead balls,应该读作 lead, 74 00:05:11,940 --> 00:05:13,580 是铅这种金属 75 00:05:14,200 --> 00:05:17,240 which was suspended beside two smaller 76 00:05:17,240 --> 00:05:20,140 spheresspheres also means balls, 77 00:05:20,580 --> 00:05:27,500 就这两个小一点的球 suspended 是悬挂的意思悬挂在 78 00:05:27,500 --> 00:05:33,400 两个小球的旁边不过实际上并不是悬挂在旁边的基本 79 00:05:33,400 --> 00:05:36,180 上就是像我们这个图上看的这个样子 80 00:05:36,660 --> 00:05:41,520 好了这个扭称实验的原理大家可以看一则视频地 81 00:05:44,720 --> 00:05:49,360 球上的物体受到地球的引力而不能脱离地面 82 00:05:50,710 --> 00:05:54,890 牛顿通过研究发表了万有引力定律英 83 00:05:56,140 --> 00:06:01,360 国科学家卡文迪许通过实验第一个精确地测得了万有 84 00:06:01,360 --> 00:06:07,820 引力常量的大小现在我们就来看看它是如何测量的把 85 00:06:09,580 --> 00:06:15,680 两个质量为 M1 的小球固定在一根青杆的两端用 86 00:06:16,740 --> 00:06:21,040 一根石英丝将青杆水平地悬挂起来 87 00:06:22,190 --> 00:06:29,530 测量时把两个质量为 M2 的大球放在小球附近根 88 00:06:30,520 --> 00:06:36,720 据万有引力定律由于小球受到大球的吸引力使固定小 89 00:06:36,720 --> 00:06:41,520 球的轻干撞动从而使石英丝扭转根 90 00:06:41,680 --> 00:06:47,100 据扭转角度就可以计算出万有引力常量 The 91 00:06:52,380 --> 00:06:55,540 idea was to measure the gravitational deflection of 92 00:06:55,540 --> 00:06:59,320 the smaller spheres by the larger oneswhich would 93 00:06:59,320 --> 00:07:02,600 allow the first measurement of the elusive forceknown 94 00:07:02,600 --> 00:07:04,320 as the gravitational c ……（后略，完整文稿见视频页字幕）