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MarcusduSautoy_GodelsIncompletenessTheorems_2020E-
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Consider the following sentence: “This statement is false.” |
观察以下句子: “这句话是错误的。” |
Is that true? |
这句话是正确的吗? |
If so, that would make this statement false. |
如果是的话, 那么这句话就是错误的。 |
But if it’s false, then the statement is true. |
如果不是的话, 那么这句话就是正确的。 |
By referring to itself directly , this statement creates an unresolvable paradox . |
通过引用本身, 这句话创造了一个无法解决的悖论。[00:16] |
statement:n.声明;陈述,叙述;报表,清单; referring:v.引用;提到;将…归因于…;把…提交;(refer的现在分词) directly:adv.直接地;立即;马上;正好地;坦率地;conj.一…就; paradox:n.悖论,反论;似非而是的论点;自相矛盾的人或事;
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This question might seem like a silly thought experiment. |
这个问题看起来像一个愚蠢的思维实验 |
But in the early 20th century, it led Austrian logician Kurt G?del to a discovery that would change mathematics forever. |
但在 20 世纪早期, 它使得澳大利亚逻辑学家库尔特·哥德尔 作出了一个永远改变数学界的发现。 |
G?del’s discovery had to do with the limitations of mathematical proofs . |
哥德尔的发现与数学证明的局限性有关。 |
A proof is a logical argument that demonstrates why a statement about numbers is true. |
证明是一种逻辑论证,被用来展示 何以一句对于数字的表述成立。 |
logician:n.逻辑学家;论理学者; mathematics:n.数学;数学运算; limitations:n.局限性;(限制)因素;边界(limitation的复数形式); mathematical:adj.数学的,数学上的;精确的; proofs:n.证明;证据(proof的复数);校稿; logical:adj.合逻辑的,合理的;逻辑学的; demonstrates:v.证明;证实;论证;说明;演示;(demonstrate的第三人称单数)
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The building blocks of these arguments are called axioms— undeniable statements about the numbers involved . |
建立起这些论证的组成部分 被称为公理—— 有关这些提及到的数字 不证自明的论述。 |
Every system built on mathematics, from the most complex proof to basic arithmetic , is constructed from axioms . |
每一个建立在数学基础上的系统, 从最复杂的证明到基础运算, 都由公理推算而来。 |
And if a statement about numbers is true, mathematicians should be able to confirm it with an axiomatic proof. |
如果一个关于数字的论述是正确的, 数学家就应该能够用公理证明它。 |
building blocks:(儿童玩的)积木;建筑砌块;堆积木;建筑砖块;基石; undeniable:adj.不可否认的;公认优秀的;无可争辩的; statements:n.说明; v.(英国)对儿童进行特殊教育评估认定; (statement的第三人称单数和复数) involved:adj.有关的; v.涉及; (involve的过去式和过去分词) complex:adj.复杂的;合成的;n.复合体;综合设施; arithmetic:n.算术,算法; constructed:v.修建;建造;组成;编制,绘制;(construct的过去分词和过去式) axioms:n.[数]公理;公设;原理(axiom的复数); mathematicians:n.[数]数学家(mathematician的复数形式); axiomatic:adj.公理的;自明的;
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Since ancient Greece, mathematicians used this system to prove or disprove mathematical claims with total certainty . |
从古希腊起, 数学家用这个系统 来充分证明或证伪数学陈述。 |
But when G?del entered the field, some newly uncovered logical paradoxes were threatening that certainty. |
但当哥德尔进入了这个领域后, 一些新发现的逻辑悖论 挑战了先前的充分性。 |
Prominent mathematicians were eager to prove that mathematics had no contradictions . |
杰出的数学家们迫切地想证明 数学是没有矛盾性的。 |
disprove:vt.反驳,证明…是虚假的; claims:v.宣称; n.声明; (claim的第三人称单数和复数) certainty:n.必然;确实;确实的事情; uncovered:adj.裸露的; v.揭开盖子; (uncover的过去式和过去分词) paradoxes:n.[数]悖论(paradox的复数); Prominent:adj.突出的,显著的;杰出的;卓越的; contradictions:n.不一致,矛盾,对立;反驳;驳斥;(contradiction的复数)
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G?del himself wasn’t so sure. |
哥德尔自己却没有那么确定。 |
And he was even less confident that mathematics was the right tool to investigate this problem. |
而且他甚至对于数学是否是 解决这个问题正确的工具 更加没有信心。 |
While it’s relatively easy to create a self-referential paradox with words, numbers don't typically talk about themselves. |
尽管用一个文字来形成一个 自我引用的悖论相对简单, 数字通常不会引用自身。 |
A mathematical statement is simply true or false. |
一个数学论述就是简单的对或错。 |
confident:adj.自信的;确信的; investigate:v.调查;研究;审查; relatively:adv.相当程度上;相当地;相对地; self-referential:n.自我指涉;自我指示;adj.自我指认的; typically:adv.代表性地;作为特色地;
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But G?del had an idea. |
但哥德尔有了一个想法。 |
First, he translated mathematical statements and equations into code numbers so that a complex mathematical idea could be expressed in a single number. |
首先,他把数学论述和等式 转化成了代码, 从而使得复杂的数学概念 可以用一数字进行表述。 |
This meant that mathematical statements written with those numbers were also expressing something about the encoded statements of mathematics. |
这意味着用这些数字写成的数学语句 也表达了一些关于数学编码语句的内容。 |
In this way, the coding allowed mathematics to talk about itself. |
以这种方式, 代码能让数学表述自身。 |
equations:n.方程式;等式;均等;均势(equation的复数形式); expressed:v.表示;表达;显而易见;不言自明;(express的过去分词和过去式) expressing:v.表示;表达;表露;显而易见;(express的现在分词) encoded:adj.[计]编码的;v.把…编码(encode的过去分词); coding:n.译码;v.把…编码;(code的现在分词)
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Through this method, he was able to write: “This statement cannot be proved” as an equation, creating the first self-referential mathematical statement. |
通过这个方式,他能够将: “这个论述无法被证明” 写作一个等式, 创造了第一个自我引用的数学论述。 |
However, unlike the ambiguous sentence that inspired him, mathematical statements must be true or false. |
然而,并不像那些启发他的 模棱两可的句子, 数学论述必须是正确或者错误。 |
So which is it? |
因此它是哪个呢? |
If it’s false, that means the statement does have a proof. |
如果它是错误的, 那就意味着论述可以被证明。 |
But if a mathematical statement has a proof, then it must be true. |
但如果一个数学论述可以被证明, 那它一定是正确的。 |
This contradiction means that G?del’s statement can’t be false, and therefore it must be true that “this statement cannot be proved.” |
这个矛盾意味着哥德尔的论述不能是错误的, 因此,“这个论述不能被证明” 是正确的。[02:44] |
ambiguous:adj.模糊不清的;引起歧义的; inspired:adj.受到启发的; v.鼓舞; (inspire的过去分词和过去式)
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Yet this result is even more surprising, because it means we now have a true equation of mathematics that asserts it cannot be proved. |
然而这个结论其实更加令人讶异, 因为它意味着存在一个正确的数学等式 却无法被证明。 |
This revelation is at the heart of G?del’s Incompleteness Theorem , which introduces an entirely new class of mathematical statement. |
这个出乎意料的事实 正是“哥德尔不完备定理”的核心, 开启了一个全新的数学论述的阶段。 |
In G?del’s paradigm , statements still are either true or false, but true statements can either be provable or unprovable within a given set of axioms. |
在哥德尔的范例中, 论述依旧是正确或者错误, 但正确的论述在给定的公理下 可证或不可证。 |
asserts:维护; revelation:n.披露; adj.暴露的; Theorem:n.[数]定理;原理; paradigm:n.范例;词形变化表; unprovable:adj.无法证明的,无法证实的;
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Furthermore , G?del argues these unprovable true statements exist in every axiomatic system. |
此外,哥德尔提出 这些不可证的正确论述 存在于每一个公理系统中。 |
This makes it impossible to create a perfectly complete system using mathematics, because there will always be true statements we cannot prove. |
如此一来就无法 用数学建立一个完美完满的系统, 因为永远会存在 无法被证明的正确论述。 |
Even if you account for these unprovable statements by adding them as new axioms to an enlarged mathematical system, that very process introduces new unprovably true statements. |
即使你可以将这些无法被证明的论述 作为新的公理, 添加进已经很庞大的数学系统, 这个过程依旧会引入新的 无法被证明的正确论述。 |
Furthermore:adv.此外;而且; account for:对…负有责任;对…做出解释;说明…的原因;导致;(比例)占; process:v.处理;加工;列队行进;n.过程,进行;方法,adj.经过特殊加工(或处理)的;
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No matter how many axioms you add, there will always be unprovably true statements in your system. |
无论你添加多少新的公理, 你的系统中永远会存在 无法被证明的正确论述。 |
It’s G?dels all the way down! |
哥德尔的理论永远成立! |
This revelation rocked the foundations of the field, crushing those who dreamed that every mathematical claim would one day be proven or disproven. |
这一发现震撼了数学领域的基础, 粉碎那些梦想总有一天 所有的数学论述 都会被证明或证伪的人。 |
While most mathematicians accepted this new reality, some fervently debated it. |
尽管大部分数学家接受了这个全新的现实, 一些人满怀期待的想推翻它, |
Others still tried to ignore the newly uncovered a hole in the heart of their field. |
而剩下的则打心底里努力地去忽略 这个他们领域中全新的 无法被填补的窟窿。 |
foundations:n.基础;地基;基金会;粉底;(foundations是foundation的复数) crushing:adj.惨重的,毁坏性的;v.压碎;压坏;压伤;挤压变形;(crush的现在分词) fervently:adv.热心地;热诚地; debated:v.讨论,辩论;思考;盘算;(debate的过去分词和过去式) ignore:v.驳回诉讼;忽视;不理睬; hole in the heart:n.先天性心室间隔穿孔;
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But as more classical problems were proven to be unprovably true, some began to worry their life's work would be impossible to complete. |
不过当越来越多的经典问题被证明 它们是无法被证明的正确论述, 一些人开始担心 他们无法完成毕生的事业。 |
Still, G?del’s theorem opened as many doors as a closed. |
即便如此,哥德尔定理 打开的门和关闭的门一样多。 |
Knowledge of unprovably true statements inspired key innovations in early computers. |
有关无法被证明的正确论述的知识 成为了早期电脑的关键创新启发。 |
And today, some mathematicians dedicate their careers to identifying provably unprovable statements. |
而如今,一些数学家穷尽他们的职业生涯 试图去证明那些无法被证明的论述。 |
classical:adj.古典的;经典的;传统的;第一流的;n.古典音乐; innovations:n.创新(innovation的复数);改革; dedicate:vt.致力;献身;题献; careers:n.职业(career的复数);事业;职业生涯;v.全速前进(career的三单形式); identifying:n.识别,标识;标识关系;v.识别;(identify的现在分词) provably:adv.证明地;可查验地;试验得出地;
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So while mathematicians may have lost some certainty, thanks to G?del they can embrace the unknown at the heart of any quest for truth. |
因此即使数学家可能丢失了一些必然性, 多亏了哥德尔, 他们得以以满心的期待 去拥抱未知。 |
embrace:n.拥抱,怀抱;v.拥抱;乐意采纳(思想、建议等);信奉;包括; quest:n.追求;寻找;vi.追求;寻找;vt.探索;
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