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TED演讲稿 生物科普动画b站，生物学家解读习以为常的表象“现实”

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关于，人的主观性到底有多大，我们从根本上只是动物的一种，认识能力是多么有限——不去停止自我怀疑是多么重要 。
出处：Why the universe seems so strange?
生物学家理查德·道金斯（Richard Dawkins），观察人类使用的思维参照框架，如何限制我们理解世界，提出“思考不可能” 。（后附英语原文）我所演讲的题目是：“超乎想象的奇妙：科学的奇异之处 。” “超乎想象的的奇妙”这一概念来自于J.B.S.霍尔丹 。他作为一个著名的生物学家，说过：“我现在察觉到 宇宙不仅仅比我们想象的更为奇妙， 甚至比我们所能够想象的更为奇妙 。我怀疑天地间有更多的东西 是任何哲学观点都没有料想到过，甚至是能够料想到的 。” 理查德.费曼曾经这样描述量子理论的精确性 —基于实验预测—量子理论的精确性就如同使用一根头发丝去 厘定整个北美洲的宽度 。这说明了量子理论只是一定程度上的准确 。然而量子理论为了实现这些预言所做出的假设 看起来是如此的不可思议， 以至于费曼本人都不得不这样评论， “如果你认为你理解量子理论了， 那你就没有理解它 。”
物理学家们求诸于或这或那相悖的解释 是多么奇怪啊 。大卫.多依奇在《真实世界的脉络》一书中 采纳了量子理论中对于“多重世界”的解释 因为你能够对“多重世界”理论最差的评价也只能是 毫无根据的废话而已 。它假设了存在着数目巨大并且在不断增加的平行宇宙， 并且它们之间是无法互相探测的， 除非通过精妙的量子力学实验 。这就是理查德.费曼 。
生物学家，刘易斯.沃尔普特 认为现代物理学的奇妙之处 只不过是一个极端的例子 。相比于技术而言， 科学往往会对常识造成破坏 。他指出，每当你喝下一杯水的时候， 你就很可能喝到了至少一个分子 是当年曾经过克伦威尔膀胱的 。（笑声） 这仅仅是最基础的概率论 。每杯水中的水分子数目远远超过 世界上所有杯子或膀胱的数量 。当然，这里的克伦威尔或者膀胱并没有什么特别之处 。你刚才或许已经吸入了一个氮分子 曾经穿过那颗高大的铁树左边的 第三只禽龙的右肺 。
“超乎想象的奇妙” 有没有什么能够使我们有能力想象到一切 并且能够告诉我们与这些能够想到的东西有关的一切的玩艺？ 宇宙中是否存在着某些东西永远超越我们的理解力 但是却又无法超越一些 高等智慧的玩艺呢？是否还存在着 原则上不能被任何人所理解的宇宙呢？ 不管多么高等的的智慧都无法理解 。科学史长期伴随着猛烈的头脑风暴， 背后是随着一代又一代人 对不断增长的 宇宙奇妙级别做出的妥协 。我们现在对于地球在自转 而不是太阳绕着地球转这一常识习以为常——以至于我们很难想象 这曾是一次多么重大的思想革命 。毕竟，地球显然看起来是大而且静止的， 太阳却是小而且移动着的 。但是，这值得我们回忆起 维特根斯坦对于此事的看法 。“告诉我，”他问一个朋友，“为什么人们总是会自然而然地认为 太阳是在绕着地球转 而不是地球自己在自转呢？” 他的朋友回答道:"很显然，因为身边的一切看起来更像是 太阳在绕着地球转 。” 维特根斯坦反问道，“难道说如果地球是自转的话， 身边的一切看上去就会不同了吗？”（笑声）
科学告诉我们，要抵制直觉， 那些看起来显然是固体的东西，例如水晶和岩石 其实是充满了虚无的空间 。我们熟悉例子是：原子核对于一个原子而言就相当于一只苍蝇 在一个体育场的中间，并且另一个原子核位于 另一个体育场当中 。因此，看起来最坚硬、最坚固、最致密的岩石其实 也是完全空洞的，这空洞被微小的粒子分开， 而这些粒子又如此分散地遍布在这广大的空间内，以至于可以被忽略 。为什么岩石看上去，摸上去是固质、坚硬而又无法穿透的呢？ 作为一名进化生物学家，我会这样解释：“我们的大脑不断进化 以帮助我们在所处的这个数量级的尺寸和速度的环境中生存下来 。” 我们从不会在 原子级别的世界中进化 。假如那样的话，我们的大脑很有可能会感觉到岩石是空洞的 。岩石在我们的手中感觉是坚硬且不可穿透的 是因为岩石和手这类物体 并不能互相穿透 。因此，这对于我们的大脑而言， 将此类概念定义为“固体”和“不可穿透”是有用的 。因为此类概念可以帮助我们在这种中等尺寸的世界中 操纵我们的身体，并且我们不得不这样做 。
再谈一谈尺度的另一端，我们的祖先 从来不需要在一个接近光速的宇宙中操纵自己的身体 。如果它们那样做了，我们的大脑将会比现在更好地理解爱因斯坦 。我想把我们进化出生存能力的这个中等规模的环境 命名为中观世界 。和中土世界（《魔戒》发生地）没有关系哦 。中观世界 。（笑声） 我们是在中观世界中得到进化的居民，这限制了我们 所能够想象到的东西 。我们在直觉上很容易明白这样的事实： 当一只兔子以中等的速率在移动的时候， （这种速率是兔子和其他中观世界中物体移动的速度） 撞上了另一个中观世界中的物体，比如说一块岩石，然后兔子就晕了 。
请让我介绍一下陆军少将Albert Stubblebine三世， 他曾是美国军情部门的指挥官 。1983年，当他盯着位于弗吉尼亚阿灵顿的办公室内的一堵墙的时候， 他做出了一个令人惊讶的决定，他试图穿墙进入挨着的办公室 。他先是站了起来，然后从他背后的桌子处动身 。他心里想：“原子到底是由啥构成的？应该是空间吧 。” 他开始朝着墙走去，“我到底是什么构成的呢？应该是原子吧 。” 他加快了自己的步伐，几乎像是在慢跑 。“墙又是什么构成的呢？应该还是原子 。我要做的一切就是让自己融进原子里的空间 。” 接着，少将的鼻子猛的撞到了他办公室里的那堵墙上 。这位指挥16000名士兵的将军 被接二连三的穿墙失败搞得狼狈不堪 。他丝毫不怀疑终究有一天这种能力会成为 军队中的常规武器 。那样的话谁还会招惹一支拥有此种能力的军队呢？ 这个故事来是我前几天 在看《花花公子》时读到的 。（笑声）
我有很多理由认为这是真实的 。我读《花花公子》是因为 我本人在上面登了文章哦 。（笑声） 在中观世界中得以调教的人类直觉，在没有受到协助的情况下， 会很难相信当年伽利略告诉我们 一个重物和一个轻物在不考虑空气阻力的情况下 会同时落到地面这一事实 。这是因为在中观世界里，空气阻力总是存在的 。但假设我们是在真空的环境中进化的话，我们可以预料 到它们会同时落地 。如果我们是细菌的话， 是会持续不断地受到分子间的热作用的冲击的 那将会和我们现在的情况大不相同 。但是中观世界的规模对于布朗运动而言太大了 。同样的，我们生命体以地心引力作用为主导 以至于表面张力可以被忽略 。而一个小虫子对于上述两种力的感知肯定是相反的 。
史蒂夫.格兰德在图中的左侧 道格拉斯.亚当斯在右侧 。斯蒂夫.格兰德在他 名为《万物：生命及如何制造生命》一书中，强烈地抨击了 我们对日常生活中对于物质这一概念的偏见 。我们倾向于认为只有固体的、具体的东西才是 真正的东西 。而真空中的电磁波 是不真实的 。维多利亚时代的人们认为波只能在以物质作为介质的环境下存在， 我们管这种介质叫以太 。但是真实的物质能够让我们宽慰 是因为在我们生存的中观世界中， 物质是一个有用的虚构概念 。对于史蒂夫.格兰德而言，一个漩涡的真实性和 一块岩石差不多 。
在坦桑尼亚的沙漠平原上， 有一个由火山灰形成的沙丘，位于伦盖火山的阴影下 。它是一个美妙的流动沙丘 。这在地理学上被称为新月形沙丘，它整体上 大约以每年17米的速度 向沙漠的西面移动 。这个沙丘在向月牙角方向移动的同时一直能够保持新月形 。风先是将沙子 从坡度较缓的方向吹向另一侧， 沙子会不断机打沙丘脊的顶部， 然后沙子会从沙丘脊部连续不断地落入月牙型的沙丘内部 并且整个号角状的沙丘会随之移动 。斯蒂夫.格兰德指出我们大家都 更像是处于变化中的波而不是一件永恒的物品 。他邀请读者们去回忆 “童年经历中能够清楚的记得的一些能够 看到、感觉到甚至是闻到的东西， 让自己仿佛身如其境 。” 然后，你会发现自己真的好像在那里，是吧？ 否则，你又如何会记着这些东西呢？ 但令人惊奇的是，你根本没有到过那里 。在这一切发生的时候，你身上一个分子都没有到过那 。物质从四面八方汇聚过来， 并且暂时地形成了你 。不管你是什么，你都不是那个 由你身上的物质组成的家伙 。如果这没有让你颈后的汗毛竖起来的话， 那就继续读下去直到你颈后的汗毛竖起来为止，因为这很重要 。"
因此，“真实“并不是一个我们在没有足够信心的情况下就能随意使用的单词 。如果中微子拥有大脑， 并且是从中微子级别的祖先中进化而来的， 那么中微子就会说岩石当然是由空洞组成的 。我们的大脑是在中等级别的祖先中进化的， 所以我们无法穿透岩石 。对于动物而言，“真实”只不过是大脑为了更好地 协助其生存的概念 。并且不同的物种生活在不同的世界当中， 正因此，世上存在着各式让人感到疑惑不快的真实 。我们所见到的真实世界并不是一个没有被修饰过的世界 而是一个被我们的感官数据所控制、调谐的模型， 但是这个模型被建构是为了让我们更好地处理与真实世界之间的关系 。
这个模型的特性取决于我们是何种动物 。会飞的动物需要一个与行走、攀爬或游泳的动物 完全不同的模型 。猴子的大脑必须拥有一套软件使其能够模拟 枝条与树干的三维世界 。鼹鼠也需要一套能够建构模型的软件， 这套软件将专门为地下世界定做 。水黾的大脑则完全不需要三维软件， 因为它们生活在埃德温.阿伯特笔下平面世界中 池塘的表面 。
我推测蝙蝠也许可以通过耳朵识别色彩 。蝙蝠所需的世界模型是为了 在三维世界中穿梭捕食， 这个模型一定与其他任何飞鸟的模型是相似的， 例如像燕子这种在日间飞行的鸟类， 需要执行同样的任务 。蝙蝠在漆黑的环境中通过使用回声来 输入变量的模型这一事实， 对于燕子而言，所使用的就是光线 。两者是随机产生的 。我甚至猜测蝙蝠使用察觉到的色调，如红色和蓝色，作为标签 来对回声中一些有用的方面进行标注， 例如表面的声学质地是平滑的还是粗糙的等等， 同样的，燕子及我们人类使用 红色、蓝色等察觉出的色调 来对光线波长的长短进行标识 。红色与其波长较长这一属性之间并没有什么固有的联系 。
关键点是这个模型的特征是由它如何被使用决定的， 而不是被其感官特性决定的 。J.B.S.霍尔丹自己就曾经说过动物的世界 是被气味支配的 。狗可以区分两种非常相似并且被高度稀释的脂肪酸： 羊油酸（辛酸）和羊脂酸（己酸） 。它们唯一的区别在于它们其中一个的化学链上 多了一对碳原子而已 。霍尔丹猜测狗狗能够根据嗅觉将两种酸的 分子量进行排序， 就好像人可以根据音符将钢琴线的长度 进行排序 。现在，还有另一种脂肪酸叫做羊蜡酸（发酸）， 与前面提到的两者非常相似， 它只不过又多了两个碳原子而已 。一条从没有问过羊蜡酸的小狗，很有可能 轻而易举的识别出它的味道就如同我们 就算我们从来没有听过小号的声音， 也可以轻而易举地识别出小号所发出更高一个音符的声音 。或许像狗狗、犀牛及其他一些以嗅觉为导向的动物可以通过 气味来识别颜色 。理由就和刚才提到的 蝙蝠的例子一样 。
中观世界中有关大小和速度的范围 在我们的进化过程中都会让人在直觉上感到是舒适的 。这有点像是我们在肉眼能够观察到的各种颜色 都属于电磁频谱中的一段小范围之内 。除非我们借助仪器， 否则我们无法观察到那范围之外的颜色 。中观世界同样也只是现实中窄小的一部分， 在这部分世界中，这样我们对它的感知和判断才是正常的， 对于超出这部分的世界，我们会认为是太小、太大、或是太快的 。我们可以对不可能的事物也作出一个类似的界定， 没有什么是完全不可能的 。奇迹只不过是极其不容易发生的事而已 。一座大理石雕像可能会朝我们挥手，它们构成晶状结构的原子 总一直在来来回回的振动 。但因为这些原子的数量太多了， 并且它们之间并没有 在运动方向达成什么默契，所以， 雕像在中观世界中看起来是静止稳定的 。但是如果这些原子刚好在 同一时间往同样的方向不停的移动， 我们就可以看见手向我们挥动 。但是，在中观世界中，概率遏制了这种情况的发生， 以至于如果你从宇宙诞生之时 开始写0直到今天， 或许你都还没写够 。
在中观世界中的进化并不会让我们练就一手 处理小概率事件的本领，因为我们不会活的太长 。在广阔无垠的宇宙空间与漫长的地质年代中， 那些在中观世界中看似不可能的事件 或许就会成为一种必然 。统计行星的数量或许有助于我们理解这一点 。我们不知道宇宙中到底有多少行星， 但是目前比较理想的估计大约是2000亿亿或10000亿亿颗 。这就为展示我们对于生命不可思议的估计提供了 一个不错的视角 。如果我们可以将生命不可思议的范围在频谱上作一些标注的话， 那么它看上去就会和 我们能够看到的电磁频谱的范围差不多 。
如果生命能够在 每颗行星上，每颗恒星甚至 每个星系都起源一次的话，那生命体将会变得非常普遍 但生命只在整个宇宙中起源一次的话， 那这只会是我们所处的这个宇宙了 。而其他的地方将很有可能会出现 诸如青蛙变王子之类的把戏了 。如果生命的起源只发生在宇宙中的一个行星上， 那这颗行星只能是我们地球了，因为我们现在正在谈论这个问题 。这还意味着如果我们接受这种观点的话， 我们就假定了生命的起源作为化学事件 其概率可能低到10000亿亿分之一 。我本人并不认为我们必须接受这种观点， 因为我怀疑生命体在宇宙当中是非常普遍的 。但这依然意味着来自于不同方位的生命要彼此相见 的可能性是微乎其微的， 这看来是一种让人悲伤的观点 。
我应该如何诠释“超乎想象的奇妙”呢？ 这种奇妙是原则上就无法被想象的呢？ 还是说这种奇妙超出了我们想象的能力，而这种限制 是由于我们大脑受到的训练和进化都发生在中观世界中？ 我们是否可以通过训练、实践、从而使我们 从中观世界中解放出来从而以某种新的带有直觉性的 而且精确的方式来理解中观世界之外的事物呢？ 老实说，我也没有答案 。我很好奇我们是否可以通过训练来帮助我们理解量子理论 。例如在孩子的幼年时期，我们带着孩子玩一种电脑游戏， 这种电脑游戏模拟了粒子 在屏幕上的两条裂缝之间穿梭， 这些奇怪的量子力学现象 因被电脑模拟而更加形象， 因此这些现象看起来像是中观世界中的溪流 。同样的，一个模拟相对论的电脑游戏在屏幕上 展示洛伦兹收缩现象等等， 这有助于帮助我们及孩子们理解 这些现象 。
最后我想把有关中观世界的观点应用到我们对于 彼此的认知上来， 当今大多数科学家都会采取一种机械论的观点来看待我们的心智： 我们之所以以这种方式存在，是因为我们的大脑让我们这样存在， 是因为我们的荷尔蒙让我们这样存在 。如果我们在神经解剖学和生理化学层面上不同， 那我们将会显得不同，我们的性格将会不一样 。但是我们科学家的观点往往是不一致的 。否则， 我们对于一个犯错误的人，例如一个谋杀儿童的罪犯， 我们会认为这个家伙有个零件坏了， 他需要修理一下 。而现实中，我们并不会这么说， 包括我在内这些最严肃的机械论者 都会说 “变态佬！监狱是便宜你了！” 甚至，我们还有可能会采取一些报复行为 。如果那样的话 很有可能会引起一系列的反报复行为 。显然，这就是我们今日的世界 。简而言之，当我们像学者一样思考问题的时候， 我们把人看作是精妙复杂的机器, 就像电脑和小车一样 。但是当我们回到现实的时候， 我们的表现却又像是喜剧《弗尔蒂旅馆》中的Basil Fawlty， 我记得他在名为"gourmet night" 的一集中因为汽车无法发动 而狠狠的教训了一顿汽车 。
我们之所以会拟人化地看待汽车和电脑的原因 可以类比于猴子生活在树上， 鼹鼠生活在地底， 水黾生活在由张力主导的平面世界中 。我们生活在一个社会化的世界当中 。我们穿梭在人海当中—— 这是一个社会化的中观世界版本 。我们在进化过程中不断的预测别人的行为， 从而变成了才华横溢，具有超强直觉的心理学家 。把人当作机器来看待 或许在科学和哲学层面上都是准确的 。但如果你要猜测人们下一步会去干什么的话， 这就会是浪费时间 。经济有效地对一个人建模的方法是 把他当做一个有目的的人， 这个人有着愉悦和痛苦、欲望和企图、 内疚、自责这些人格特性 。人格化以及求诸于个人意图 是明智且有效的对人类进行建模的方法 。丝毫不让人惊奇的是，这种建模软件 在当我们去剖析那些不太靠谱的对象的时候会显得很有效 。例如，Basil Fawlty和他的小车以及其它 不计其数想要天人合一的家伙 。
如果宇宙比我们能够想象的还要奇妙的话， 是否是因为我们是被遴选的物种而天生需要承担 想象那些我们需要想象的事物，从而能够 从远古非洲中幸存下来？ 或者是否我们的大脑足够多才多艺并具有无穷的潜力以至于 我们可以通过训练自己从而打破进化的盒子？ 或者还是说，宇宙中存在着一些无比奇妙的事物 以至于没有任何一个物种，甚至是神，都无法想象到的？ 非常感谢！
My title: "Queerer than we can suppose: the strangeness of science." "Queerer than we can suppose" comes from J.B.S. Haldane, the famous biologist, who said, "Now, my own suspicion is that the universe is not only queerer than we suppose, but queerer than we can suppose. I suspect that there are more things in heaven and earth than are dreamed of, or can be dreamed of, in any philosophy." Richard Feynman compared the accuracy of quantum theories -- experimental predictions -- to specifying the width of North America to within one hairs breadth of accuracy. This means that quantum theory has got to be, in some sense, true. Yet the assumptions that quantum theory needs to make in order to deliver those predictions are so mysterious that even Feynman himself was moved to remark, "If you think you understand quantum theory, you dont understand quantum theory."
01:13
Its so queer that physicists resort to one or another paradoxical interpretation of it. David Deutsch, whos talking here, in "The Fabric of Reality," embraces the many-worlds interpretation of quantum theory, because the worst that you can say about it is that its preposterously wasteful. It postulates a vast and rapidly growing number of universes existing in parallel, mutually undetectable, except through the narrow porthole of quantum mechanical experiments. And thats Richard Feynman.
01:52
The biologist Lewis Wolpert believes that the queerness of modern physics is just an extreme example. Science, as opposed to technology, does violence to common sense. Every time you drink a glass of water, he points out, the odds are that you will imbibe at least one molecule that passed through the bladder of Oliver Cromwell. (Laughter) Its just elementary probability theory.
02:18
(Laughter)
02:19
The number of molecules per glassful is hugely greater than the number of glassfuls, or bladdersful, in the world. And of course, theres nothing special about Cromwell or bladders -- you have just breathed in a nitrogen atom that passed through the right lung of the third iguanodon to the left of the tall cycad tree.
02:41
"Queerer than we can suppose." What is it that makes us capable of supposing anything, and does this tell us anything about what we can suppose? Are there things about the universe that will be forever beyond our grasp, but not beyond the grasp of some superior intelligence? Are there things about the universe that are, in principle, ungraspable by any mind, however superior? The history of science has been one long series of violent brainstorms, as successive generations have come to terms with increasing levels of queerness in the universe. Were now so used to the idea that the Earth spins, rather than the Sun moves across the sky, its hard for us to realize what a shattering mental revolution that must have been. After all, it seems obvious that the Earth is large and motionless, the Sun, small and mobile. But its worth recalling Wittgensteins remark on the subject: "Tell me," he asked a friend, "why do people always say it was natural for man to assume that the Sun went round the Earth, rather than that the Earth was rotating?" And his friend replied, "Well, obviously, because it just looks as though the Sun is going round the Earth." Wittgenstein replied, "Well, what would it have looked like if it had looked as though the Earth was rotating?"
04:06
(Laughter)
04:11
Science has taught us, against all intuition, that apparently solid things, like crystals and rocks, are really almost entirely composed of empty space. And the familiar illustration is the nucleus of an atom is a fly in the middle of a sports stadium, and the next atom is in the next sports stadium. So it would seem the hardest, solidest, densest rock is really almost entirely empty space, broken only by tiny particles so widely spaced they shouldnt count. Why, then, do rocks look and feel solid and hard and impenetrable? As an evolutionary biologist, Id say this: our brains have evolved to help us survive within the orders of magnitude, of size and speed which our bodies operate at. We never evolved to navigate in the world of atoms. If we had, our brains probably would perceive rocks as full of empty space. Rocks feel hard and impenetrable to our hands, precisely because objects like rocks and hands cannot penetrate each other. Its therefore useful for our brains to construct notions like "solidity" and "impenetrability," because such notions help us to navigate our bodies through the middle-sized world in which we have to navigate.
05:37
Moving to the other end of the scale, our ancestors never had to navigate through the cosmos at speeds close to the speed of light. If they had, our brains would be much better at understanding Einstein. I want to give the name "Middle World" to the medium-scaled environment in which weve evolved the ability to take act -- nothing to do with "Middle Earth" -- Middle World.
06:00
(Laughter)
06:01
We are evolved denizens of Middle World, and that limits what we are capable of imagining. We find it intuitively easy to grasp ideas like, when a rabbit moves at the sort of medium velocity at which rabbits and other Middle World objects move, and hits another Middle World object like a rock, it knocks itself out.
06:22
May I introduce Major General Albert Stubblebine III, commander of military intelligence in 1983.
06:33
"...[He] stared at his wall in Arlington, Virginia, and decided to do it. As frightening as the prospect was, he was going into the next office. He stood up and moved out from behind his desk. What is the atom mostly made of? he thought, Space. He started walking. What am I mostly made of? Atoms. He quickened his pace, almost to a jog now. What is the wall mostly made of?
07:05
(Laughter)
07:06
Atoms! All I have to do is merge the spaces. Then, General Stubblebine banged his nose hard on the wall of his office. Stubblebine, who commanded 16,000 soldiers, was confounded by his continual failure to walk through the wall. He has no doubt that this ability will one day be a common tool in the military arsenal. Who would screw around with an army that could do that?"
07:35
Thats from an article in Playboy, which I was reading the other day.
07:39
(Laughter)
07:40
I have every reason to think its true; I was reading Playboy because I, myself, had an article in it.
07:46
(Laughter)
07:52
Unaided human intuition, schooled in Middle World, finds it hard to believe Galileo when he tells us a heavy object and a light object, air friction aside, would hit the ground at the same instant. And thats because in Middle World, air friction is always there. If wed evolved in a vacuum, we would expect them to hit the ground simultaneously. If we were bacteria, constantly buffeted by thermal movements of molecules, it would be different. But we Middle-Worlders are too big to notice Brownian motion. In the same way, our lives are dominated by gravity, but are almost oblivious to the force of surface tension. A small insect would reverse these priorities.
08:34
Steve Grand -- hes the one on the left, Douglas Adams is on the right. Steve Grand, in his book, "Creation: Life and How to Make It," is positively scathing about our preoccupation with matter itself. We have this tendency to think that only solid, material things are really things at all. Waves of electromagnetic fluctuation in a vacuum seem unreal. Victorians thought the waves had to be waves in some material medium: the ether. But we find real matter comforting only because weve evolved to survive in Middle World, where matter is a useful fiction. A whirlpool, for Steve Grand, is a thing with just as much reality as a rock.
09:22
In a desert plain in Tanzania, in the shadow of the volcano Ol Doinyo Lengai, theres a dune made of volcanic ash. The beautiful thing is that it moves bodily. Its whats technically known as a "barchan," and the entire dune walks across the desert in a westerly direction at a speed of about 17 meters per year. It retains its crescent shape and moves in the direction of the horns. What happens is that the wind blows the sand up the shallow slope on the other side, and then, as each sand grain hits the top of the ridge, it cascades down on the inside of the crescent, and so the whole horn-shaped dune moves. Steve Grand points out that you and I are, ourselves, more like a wave than a permanent thing. He invites us, the reader, to think of an experience from your childhood, something you remember clearly, something you can see, feel, maybe even smell, as if you were really there. After all, you really were there at the time, werent you? How else would you remember it? But here is the bombshell: You werent there. Not a single atom that is in your body today was there when that event took place. Matter flows from place to place and momentarily comes together to be you. Whatever you are, therefore, you are not the stuff of which you are made. If that doesnt make the hair stand up on the back of your neck, read it again until it does, because it is important.
10:53
So "really" isnt a word that we should use with simple confidence. If a neutrino had a brain, which it evolved in neutrino-sized ancestors, it would say that rocks really do consist of empty space. We have brains that evolved in medium-sized ancestors which couldnt walk through rocks. "Really," for an animal, is whatever its brain needs it to be in order to assist its survival. And because different species live in different worlds, there will be a discomforting variety of "reallys." What we see of the real world is not the unvarnished world, but a model of the world, regulated and adjusted by sense data, but constructed so its useful for dealing with the real world.
11:43
The nature of the model depends on the kind of animal we are. A flying animal needs a different kind of model from a walking, climbing or swimming animal. A monkeys brain must have software capable of simulating a three-dimensional world of branches and trunks. A moles software for constructing models of its world will be customized for underground use. A water striders brain doesnt need 3D software at all, since it lives on the surface of the pond, in an Edwin Abbott flatland.
12:17
Ive speculated that bats may see color with their ears. The world model that a bat needs in order to navigate through three dimensions catching insects must be pretty similar to the world model that any flying bird -- a day-flying bird like a swallow -- needs to perform the same kind of tasks. The fact that the bat uses echoes in pitch darkness to input the current variables to its model, while the swallow uses light, is incidental. Bats, Ive even suggested, use perceived hues, such as red and blue, as labels, internal labels, for some useful aspect of echoes -- perhaps the acoustic texture of surfaces, furry or smooth and so on -- in the same way as swallows or indeed, we, use those perceived hues -- redness and blueness, etc. -- to label long and short wavelengths of light. Theres nothing inherent about red that makes it long wavelength.
13:13
The point is that the nature of the model is governed by how it is to be used, rather than by the sensory modality involved. J.B.S. Haldane himself had something to say about animals whose world is dominated by smell. Dogs can distinguish two very similar fatty acids, extremely diluted: caprylic acid and caproic acid. The only difference, you see, is that one has an extra pair of carbon atoms in the chain. Haldane guesses that a dog would probably be able to place the acids in the order of their molecular weights by their smells, just as a man could place a number of piano wires in the order of their lengths by means of their notes. Now, theres another fatty acid, capric acid, which is just like the other two, except that it has two more carbon atoms. A dog that had never met capric acid would, perhaps, have no more trouble imagining its smell than we would have trouble imagining a trumpet, say, playing one note higher than weve heard a trumpet play before. Perhaps dogs and rhinos and other smell-oriented animals smell in color. And the argument would be exactly the same as for the bats.
14:32
Middle World -- the range of sizes and speeds which we have evolved to feel intuitively comfortable with -- is a bit like the narrow range of the electromagnetic spectrum that we see as light of various colors. Were blind to all frequencies outside that, unless we use instruments to help us. Middle World is the narrow range of reality which we judge to be normal, as opposed to the queerness of the very small, the very large and the very fast. We could make a similar scale of improbabilities; nothing is totally impossible. Miracles are just events that are extremely improbable. A marble statue could wave its hand at us; the atoms that make up its crystalline structure are all vibrating back and forth anyway. Because there are so many of them, and because theres no agreement among them in their preferred direction of movement, the marble, as we see it in Middle World, stays rock steady. But the atoms in the hand could all just happen to move the same way at the same time, and again and again. In this case, the hand would move, and wed see it waving at us in Middle World. The odds against it, of course, are so great that if you set out writing zeros at the time of the origin of the universe, you still would not have written enough zeros to this day.
15:53
Evolution in Middle World has not equipped us to handle very improbable events; we dont live long enough. In the vastness of astronomical space and geological time, that which seems impossible in Middle World might turn out to be inevitable. One way to think about that is by counting planets. We dont know how many planets there are in the universe, but a good estimate is about 10 to the 20, or 100 billion billion. And that gives us a nice way to express our estimate of lifes improbability. We could make some sort of landmark points along a spectrum of improbability, which might look like the electromagnetic spectrum we just looked at.
16:38
If life has arisen only once on any -- life could originate once per planet, could be extremely common or it could originate once per star or once per galaxy or maybe only once in the entire universe, in which case it would have to be here. And somewhere up there would be the chance that a frog would turn into a prince, and similar magical things like that. If life has arisen on only one planet in the entire universe, that planet has to be our planet, because here we are talking about it. And that means that if we want to avail ourselves of it, were allowed to postulate chemical events in the origin of life which have a probability as low as one in 100 billion billion. I dont think we shall have to avail ourselves of that, because I suspect that life is quite common in the universe. And when I say quite common, it could still be so rare that no one island of life ever encounters another, which is a sad thought.
17:39
How shall we interpret "queerer than we can suppose?" Queerer than can in principle be supposed, or just queerer than we can suppose, given the limitations of our brains evolutionary apprenticeship in Middle World? Could we, by training and practice, emancipate ourselves from Middle World and achieve some sort of intuitive as well as mathematical understanding of the very small and the very large? I genuinely dont know the answer. I wonder whether we might help ourselves to understand, say, quantum theory, if we brought up children to play computer games beginning in early childhood, which had a make-believe world of balls going through two slits on a screen, a world in which the strange goings-on of quantum mechanics were enlarged by the computers make-believe, so that they became familiar on the Middle-World scale of the stream. And similarly, a relativistic computer game, in which objects on the screen manifest the Lorentz contraction, and so on, to try to get ourselves -- to get children into the way of thinking about it.
18:41
I want to end by applying the idea of Middle World to our perceptions of each other. Most scientists today subscribe to a mechanistic view of the mind: were the way we are because our brains are wired up as they are, our hormones are the way they are. Wed be different, our characters would be different, if our neuro-anatomy and our physiological chemistry were different. But we scientists are inconsistent. If we were consistent, our response to a misbehaving person, like a child-murderer, should be something like: this unit has a faulty component; it needs repairing. Thats not what we say. What we say -- and I include the most austerely mechanistic among us, which is probably me -- what we say is, "Vile monster, prison is too good for you." Or worse, we seek revenge, in all probability thereby triggering the next phase in an escalating cycle of counter-revenge, which we see, of course, all over the world today. In short, when were thinking like academics, we regard people as elaborate and complicated machines, like computers or cars. But when we revert to being human, we behave more like Basil Fawlty, who, we remember, thrashed his car to teach it a lesson, when it wouldnt start on "Gourmet Night."
19:55
【TED演讲稿 生物科普动画b站，生物学家解读习以为常的表象“现实”】(Laughter)
19:56
The reason we personify things like cars and computers is that just as monkeys live in an arboreal world and moles live in an underground world and water striders live in a surface tension-dominated flatland, we live in a social world. We swim through a sea of people -- a social version of Middle World. We are evolved to second-guess the behavior of others by becoming brilliant, intuitive psychologists. Treating people as machines may be scientifically and philosophically accurate, but its a cumbersome waste of time if you want to guess what this person is going to do next. The economically useful way to model a person is to treat him as a purposeful, goal-seeking agent with pleasures and pains, desires and intentions, guilt, blame-worthiness. Personification and the imputing of intentional purpose is such a brilliantly successful way to model humans, its hardly surprising the same modeling software often seizes control when were trying to think about entities for which its not appropriate, like Basil Fawlty with his car or like millions of deluded people, with the universe as a whole.
21:11
(Laughter)
21:13
If the universe is queerer than we can suppose, is it just because weve been naturally selected to suppose only what we needed to suppose in order to survive in the Pleistocene of Africa? Or are our brains so versatile and expandable that we can train ourselves to break out of the box of our evolution? Or finally, are there some things in the universe so queer that no philosophy of beings, however godlike, could dream them?
21:45
Thank you very much.

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