第 380 期·中文精讀

尼爾·格申菲爾德:自我複製機器人與製造業的未來

Neil Gershenfeld: Self-Replicating Robots and the Future of Fabrication

物理學家談數字製造、可自我複製的機器人,以及個人化製造將如何改變生產與教育。

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中文精讀由 AI 基於原始訪談改寫,非官方翻譯,可能存在偏差或錯誤;表述以原音訊與官方文稿為準。說明

麻省理工學院有一個叫 CBA 的實驗室,全稱是 Center for Bits and Atoms(位元與原子研究中心)。它的主任尼爾·格申菲爾德在這期播客裡說了一句聽起來很狂的話:他搞明白了馮·諾依曼和圖靈當年犯下的根本性錯誤,也搞明白了生命的秘密。

這話擱別人嘴裡,多半是標題黨。但格申菲爾德在這個領域已經工作了幾十年,他的實驗室做出了世界上第一臺比經典計算機更快的量子計算機的參與工作,參與了最小合成生物體的創造,還做出過能自我複製的機器人。這些成果都在同一個地方完成,那就是數字世界和物理世界的交界處。

圖靈和馮·諾依曼到底錯在哪

圖靈被公認為現代計算架構的奠基人之一,馮·諾依曼也是。格申菲爾德說他們犯了一個物理學上的錯誤,這個錯誤從根上定義了整個電腦科學。

圖靈機的結構是這樣的:一個讀寫頭,一條紙帶,讀寫頭在紙帶上移動、讀取、寫入。問題在於,讀寫頭和紙帶是分離的。這種分離意味著,資訊的儲存和資訊的處理是兩回事。

馮·諾依曼後來寫了一份被格申菲爾德稱為“糟糕的備忘錄”的東西,叫《EDVAC 報告初稿》,把圖靈的這個架構直接搬進了機器裡。這份備忘錄後來引發了一堆專利官司,但它成了現代計算機架構的基礎。你今天用的電腦,大部分精力都花在把資訊從儲存電晶體搬到處理電晶體,儘管這兩類電晶體的計算複雜度其實是一樣的。

格申菲爾德在電腦科學課上看到過一個荒謬的分類表,列了大約一百種計算模型。他說這些全是虛構的。物理學裡只有一種計算模型是真實的:一塊空間佔據空間,它儲存狀態,資訊在空間中傳遞需要時間,你可以和它互動。其他所有模型都是虛構的。

在物理學裡,一塊空間佔據空間,它儲存狀態,資訊穿過它需要時間,你可以和它互動。這是唯一一種物理的計算模型。其他一切都是虛構的。(尼爾·格申菲爾德)

格申菲爾德說,他真正意識到這一點,是有一年去給超級計算機行業年會做主題演講,然後走進展廳和那些造超算的人聊天。他想到電影《大都會》裡的場景:樓上的花園裡人們在嬉戲,樓下的地下室裡人們在扳動操縱桿。今天的計算就是這樣運轉的。我們假裝軟體不是物理的,假裝它和硬體是分開的,整個電腦科學的經典體系都建立在“位元不受原子約束”這個虛構之上。

但計算領域所有的規模化問題,都來自這個邊界。所有的機會,也都來自這個邊界。

有意思的是,圖靈和馮·諾依曼自己都知道這件事。格申菲爾德說,這兩個人在生命最後階段研究的,恰恰就是軟體如何變成硬體。馮·諾依曼研究自複製自動機,也就是一臺機器如何把自己的構造方式傳遞出去。圖靈研究形態發生學,也就是基因如何產生形態。他們晚年研究的都是計算的具身化,但這件事被電腦科學的經典體系遺忘了,只在一些很有意思的支線上發展著。

格申菲爾德說,他一直搞不懂電腦科學和物理科學到底有什麼區別。在那個邊界上工作,讓他參與了兩件大事:一是和合作者一起做出了最早的超越經典計算的量子計算,二是參與了最小合成生物體的創造,在計算機裡設計生命。這兩件事都涉及一個共同點:你沒法把硬體和軟體分開。計算的具身化,是以非常深刻的方式被具身化的。

一個想去職業學校的高中生

格申菲爾德高中時特別想去職業學校,學焊接、修車、蓋房子。他被告知不行,你很聰明,你得坐在教室裡。沒有人能給他解釋為什麼他不能去職業學校。

後來他去了貝爾實驗室,那個在反壟斷拆分之前傳奇一樣的地方。他想進車間動手做點東西,結果收到了工會的申訴。他們說,不行,你很聰明,你得告訴別人怎麼做。

直到他去了 MIT,他才慢慢理解,這個錯誤可以追溯到文藝復興時期。

文藝復興時期出現了“自由技藝”(liberal arts)這個概念。這裡的 liberal 不是政治上的自由派,它指的是通向解放的道路,是人本主義的誕生。自由技藝包括三藝和四藝,大致是語言和自然科學。就在那個時候,冒出來一個糟糕的概念,叫“非自由技藝”。凡是不屬於自由技藝的,都是為了商業利益,都只是做東西,都不配被嚴肅地研究。這就是為什麼學焊接不被當作嚴肅的學科。

但表達的方式從文藝復興到現在已經變了。微加工或者嵌入式程式設計,和畫一幅畫、寫一首十四行詩一樣,都是表達。格申菲爾德說,這就是他後來建立 CBA 的路徑。

他先是在哈佛做初級研究員,透過馬文·明斯基的介紹訪問 MIT,因為他感興趣的是樂器的物理學。他在康奈爾學物理,然後穿過馬路去音樂系吹巴松管,修剪簧片。簧片吹起來很美,但會受潮變軟。後來他發現康奈爾音樂系的地下室裡有個叫大衛·博登的人。博登你可能沒聽過,但他在電子音樂界是傳奇,因為他可以說是第一個電子音樂家。發明 Moog 合成器的鮑勃·穆格也是康奈爾物理系的學生,和格申菲爾德一樣穿過馬路,後來被學校開除,發明了電子音樂。

這件事讓格申菲爾德開始思考一個問題:一件樂器的計算能力是多少?

他透過明斯基認識了媒體實驗室的託德·馬喬弗,當時馬喬弗正要和馬友友開始一個專案,後來促成了一個合作:給一把大提琴裝上感測器,提取馬友友的演奏資料,把它帶進計算環境。

從純粹的物理模擬角度看,如果你取物理相關的最高時間解析度和空間解析度,一個不錯的 GPU 今天就能做到,這在以前是需要國家級超級計算機才能做的事。但真正驅動這個專案的,是馬友友對大提琴的一種非常不感情用事的看法。他不覺得斯特拉迪瓦里琴有什麼神奇的振動在聲波里,他看重的是它作為控制器的表現,作為介面裝置他能怎麼操縱它。

格申菲爾德一開始想的是每秒運算次數,但馬友友關心的是解析度和頻寬:能多快地測量他的動作,以及把這些控制對映到聲音裡的頻寬和解析度。他們最後發現,如果你把他所有的動作都儀器化,連線到幾乎任何東西上,聽起來都像馬友友。神奇之處在於控制,不在於木頭振動的那些不可言說的細節。

專案快結束時,格申菲爾德問馬友友,要讓他放棄斯特拉迪瓦里琴改用他們的裝置,需要什麼條件。馬友友的回答是:只是後勤問題。當時他們的裝置是一堆電子器件、一堆線纜,還得有幾個研究生在旁邊讓它運轉。一旦技術變得像斯特拉迪瓦里琴一樣隱形,那當然可以。

這個專案還有個腳註。在給馬友友的大提琴做感測時出了個意外,後來催生了一個年收入一億美元的車用安全氣囊業務。

事情的經過是這樣的。格申菲爾德要給琴弓裝感測器,又不能干擾演奏,所以他在區域性設定了電磁場,檢測這些場和琴弓的相互作用。但有個問題:每當馬友友的手靠近這些感測場,感測器就開始感應他的手,而不是琴弓上的材料。他不太理解這種干擾是怎麼回事。他招的第一個研究生喬什·史密斯,論文做的就是電場層析成像,如何用電場做三維成像。然後透過託德和實驗室的研究科學家喬·帕拉迪索,促成了一次和魔術師組合潘恩與泰勒的合作。他們在拉斯維加斯表演了一個魔術,用來“聯絡胡迪尼”,這些電磁場就像是在聯絡亡靈。

魔術之後,菲爾·裡特穆勒跑進了格申菲爾德的實驗室。他當時在本田和 NEC 工作。安全氣囊當時正在殺死坐在後向式兒童座椅裡的嬰兒。汽車需要區分幾種情況:面朝前的成年人,氣囊該彈出救命;一袋雜貨,不該彈;後向式嬰兒座椅,彈了會殺死嬰兒。座椅需要能“看見”三維空間,理解座位上是什麼。他們把從潘恩與泰勒魔術、從喬什的論文、從馬友友的大提琴裡來的技術帶到一個車展上,所有汽車公司都說,太好了,什麼時候能買?這就成了 Elisa 公司,一個年收入一億美元的感測器業務。沒什麼宣傳,因為它裝在車裡,車沒殺死你。你不會看到廣告說“我們有很好的感測器所以車不會殺死你”,但它成了領先的汽車安全感測器。

這一切都始於大提琴,始於樂器計算能力這個問題。

一個叫“以上皆非”的系

格申菲爾德在 IBM 研究院花了很多業餘時間,那裡有計算基礎領域的大神。他一直以為自己會去 IBM 接管一個實驗室,但最後一刻轉向,來了 MIT,進了媒體實驗室,開始了 CBA 的前身。

媒體實驗室以尼古拉斯·尼葛洛龐帝聞名。但格申菲爾德說,沒那麼有名的是傑裡·威斯納的角色。威斯納是 MIT 的校長,後來當了肯尼迪的科學顧問,科學界的老前輩。他在生命最後階段,對知識的割裂感到沮喪,所以他想建立一個“以上皆非”的系,一個容納那些不屬於任何系的系。

媒體實驗室在某種意義上是他藏這個系的幌子。作為 MIT 校長,如果他在任期快結束時說,我要建一個容納不屬於任何系的東西的系,各系會尖叫。但所有人都在關注尼葛洛龐帝建立媒體實驗室,傑裡就藏在裡面,建了一個叫“媒體藝術與科學”的系,它其實就是那個“以上皆非”的系。傑裡解釋了這件事,尼葛洛龐帝后來也確認了,這就是格申菲爾德轉向來 MIT 的原因。

他的學生,那些參與創造量子計算或合成生命的學生,拿的就是媒體藝術與科學這個“以上皆非”系的學位。

來了 MIT 之後,他和託德、喬·帕拉迪索、邁克·科利一起啟動了一個叫 Things That Think 的聯盟。那正是物聯網和 RFID 誕生的時候。然後他們開始做一些後來成為量子計算、密碼學、材料、邏輯、微流控開端的工作。這些工作需要大得多的基礎設施,研究週期也長得多。所以他們和一個大約二十人的更大團隊,給 NSF 寫了一份提案,大意是:組裝一套每種工具各一個的設施,用來製造任何尺寸的任何東西。

通常奈米、微米、毫米、米是分開的,輸入和輸出也是分開的。他們想非常字面地研究數字如何變成物理,物理如何變成數字。幸運的是,NSF 那天心情好,資助了這個“每種工具幾乎各一個”的設施。格申菲爾德和包括喬·雅各布森、艾克·崔、斯科特·馬納利斯在內的核心同事一起,啟動了 CBA。

這個實驗室裡有什麼?奈米結構的電子顯微鏡和聚焦離子束探針,微結構的鐳射微加工和 X 射線微斷層掃描,宏觀結構的多軸加工和 3D 列印。一個裝置齊全的研究實驗室也有這些工具,但它們分散在不同地方,通常由技術員操作,你得開個賬戶、立個專案、按時間計費。這些工具本質上是在你不知道自己在做什麼的時候用的,而不是你知道自己在做什麼的時候用的。而 CBA 是在你需要跨尺度工作的時候用的。

專案一旦在這個設施裡跑起來,就不按時間收費,不需要正式提案來排期,使用者自己操作工具。它是為那些還不成形、需要跨越這些學科和尺度的工作準備的。今天 CBA 的專案範圍很廣,從開發最低功耗計算的拉鍊式雙電子器件,到微加工金剛石做百萬、千萬轉每分的軸承用於分子光譜研究,一直到探索在太空中建造百米結構的機器人。

夏農那個最好的碩士論文

要看最大的東西,格申菲爾德說,得把夏農也請進來。

數字是什麼?最隨意的回答是 0 和 1,但這是錯的。更深層的答案來自克勞德·夏農在 MIT 寫的碩士論文,格申菲爾德說那是史上最好的碩士論文。夏農在那篇論文裡發明了現代數字邏輯的概念。

它從萬尼瓦爾·布什那裡來。布什是 MIT 的老前輩,建立了戰後研究體系,催生了 NSF。他也犯了一個重要的錯誤,後面會講。他做了微分分析儀,那是最後一臺大型模擬計算機,一屋子齒輪和滑輪,執行得越久答案越糟。夏農作為學生參與了這個專案,被它煩透了,在碩士論文裡發明了數字邏輯。

然後夏農去了貝爾實驗室。當時通訊開始擴張,電話線路的需求在增加,問題是一根線上能傳多少電話訊息。你可以試著讓它越來越好,夏農問了一個沒人問過的問題:與其讓它越來越好,它的極限在哪裡?他證明了幾件事,其中主要的一件是通道容量的閾值定理。

他的意思是這樣的:我現在對你說話,聲音作為波透過空氣傳播,你離得越遠聽得越差。但看這個影片的人是透過網路資料包收到的。當電腦收到資料包,它能檢測並糾正錯誤。夏農證明的是,如果電纜裡的噪聲在某個閾值之上,看影片的人就完了;但如果噪聲在閾值之下,能量每線性增加一點,錯誤率就指數下降。指數增長在工程裡很少見。這種在閾值之下、透過恢復狀態實現的錯誤指數下降,就叫閾值定理。它催生了數字技術,意味著不可靠的東西可以可靠地工作。

夏農為通訊做了這件事,然後馮·諾依曼受到啟發,把它應用到計算上,證明了一臺不可靠的計算機可以透過同樣的恢復狀態閾值特性可靠地執行。這件事後來被遺忘了很多年,在量子計算時代我們不得不重新發現它,因為那時候東西又變得非常不可靠了。

現在回到最大的東西。

在製造領域,MIT 在 1952 年發明了計算機控制的加工。當時噴氣式飛機剛出現,在銑床上轉搖柄來製造噴氣飛機零件有個極限。這裡有個不太光彩的故事:MIT 實際上是從一個發明家手裡偷來了計算機控制加工,那人帶著它來找 MIT,想和空軍做聯合專案,MIT 基本上把它偷走了。所以歷史有點亂,但那聽起來像是計算機控制加工的誕生。

3D 列印有好幾個發明者,其中一家從格申菲爾德實驗室分拆出來的公司是馬克斯·洛博夫斯基的 Formlabs,現在是一家十億美元級的 3D 列印公司。

但所有這些都還是模擬的。意思是資訊在控制計算機裡,材料裡沒有資訊。這又回到了萬尼瓦爾·布什的模擬計算機:如果你在列印或加工時犯了個錯誤,錯誤只會累積。

真正意義上的計算機化數字製造的誕生,是在四十億年前。那是核糖體的演化年齡。

你的製造方式是這樣的:有一段描述你的程式碼,遺傳密碼,它去到一個微型機器,核糖體,這個分子工廠建造構成你的分子。關於它關鍵要知道的是,大約二十種氨基酸被組裝起來,而在這套機器裡,夏農和馮·諾依曼教給我們的一切都在執行:你檢測並糾正錯誤。如果你混合化學物質,錯誤率大約是百分之一。當你在核糖體裡製造延長的蛋白質,大約是萬分之一。當你複製 DNA,有額外一層錯誤糾正,是億分之一。所以構成你的分子裡,你可以檢測並糾正錯誤,你不需要一把尺子來製造你,幾何來自你的零件。

現在比較一個玩樂高的孩子和一臺最先進的 3D 印表機或計算機化銑床。孩子搭的塔比他的運動控制更精確,因為把積木扣在一起這個動作本身給了關節約束。你可以用不同材料做的積木連線。樂高不需要尺子,因為區域性的幾何給了你全域性的零件。而且沒有樂高垃圾,零件裡有足夠的資訊把它們拆開。這些恰恰是數字程式碼的性質。

不可靠的被變得可靠了。(尼爾·格申菲爾德)

核糖體在四十億年前搞明白的,就是如何具身化這些數字性質。它不服務於通訊或計算,它服務於建造。

格申菲爾德實驗室有一系列專案在研究“數字材料”這個概念。把數字材料想象成樂高積木就行。精確的定義是:一組離散的零件,可逆地連線,全域性幾何由區域性約束決定。這就是把材料數字化。

碳纖維樂高和會走路的機器人

回到最大的東西。格申菲爾德的實驗室和航空航天業合作。Spirit Aero 是波音的工廠,他們來問怎麼連線複合材料。製造複合材料飛機時,你要造出巨大的機翼和機身部件,他們想要更好的方式把它們粘在一起,因為接縫是容易失效的地方。

他們發現的是:與其造幾個大部件,不如造小的碳纖維環,把它們可逆地連線在關節裡,用一種特殊的幾何來平衡欠約束和過約束,恰好合適的自由度。他們就這樣創下了最高模量超輕材料的世界紀錄,本質上就是用碳纖維做樂高。輕質材料對能效至關重要,這讓他們做出了最輕的高模量材料。然後他們證明,只用幾種零件型別,就能調節材料屬性。然後你可以造出非常瘋狂的機器人:不需要一個和巨型噴氣機一樣大的工具來造噴氣機,而是讓小機器人在這些蜂窩結構上行走,來建造結構,在結構上糾錯定位,在結構上導航。

用這些,他們和 NASA 做了變形飛機,一個前學生肯尼·張和本·傑奈特做了一個和 NASA 蘭利最大風洞一樣大的變形飛機。和豐田合作,他們做了超高效賽車。現在他們正在和 NASA 談專案,要做太空望遠鏡和太空棲息地這類東西。

前面提到的核糖體,可以一個分子一個分子地造出一頭大象。核糖體很慢,大約每秒一個分子,但核糖體制造核糖體,所以你有成千上萬個,上萬億個,這就是為什麼能造出一頭大象。同樣,格申菲爾德描述的那些小裝配機器人,本質上也能造出巨型結構,因為機器人能製造機器人。更近一些,他的學生薩米拉和米安娜在《自然·通訊》上發表了一篇論文,展示了這個機器人如何能用它正在製造的零件來製造自己。機器人能製造機器人,所以你能建立起機器人裝配的能力,它能自我複製。

這個機器人長什麼樣?格申菲爾德說,答案在不同尺度上不同。為了解釋這個,他借用了生物學的層級。

在生物學裡,初級結構是信使 RNA 裡的程式碼,告訴核糖體該造什麼。次級結構是幾何基序,比如螺旋或片層。三級結構是功能元件,比如電子供體或受體。四級結構是分子馬達,驅動他的嘴巴說話,或者讓大腦裡的突觸工作。有這個初級、次級、三級、四級的層級。

有意思的是,如果你今天要從供應商那裡買電子元件,有幾十萬種電阻、電容、電晶體,巨大的庫存。而整個生物學只用二十種零件,氨基酸,透過組合它們,你能創造出所有生命。作為材料數字化的一部分,他們實際上在嘗試為工程創造類似氨基酸的東西,用二十種零件創造所有技術。

格申菲爾德還提到他幫好萊塢創立了一個科學辦公室,為電影《火星救援》做過一件有趣的事,他和比爾·奈等人做了一個專案,講如何在火星上真正建立文明,他喜歡這樣描述:如何不帶行李去火星。本質上就是如何在非生命材料中創造生命。

在實驗室裡,他們在不同尺度上為不同目的做這個初級、次級、三級、四級結構。他們在用奈米磚做微型機器人,用來製造太空中的大型結構,機器人的元件現在是釐米級而不是微米級。大型結構的裝配機器人就是構成結構的那些細胞,但也有功能細胞,能處理和執行動作,每個細胞能移動一個自由度,或者連線、斷開、處理。這些元件又可以用更小的零件製造。最終會有一個層級:小零件製造小機器人,小機器人制造更大的零件,更大的零件製造更大的機器人,一路往上。這樣你就能爬升尺度。

格申菲爾德說,早期他試圖從最底層直線走到最頂層,結果發現是個壞主意。現在他們並行地做所有這些,然後它們一起生長。為了造更大的結構,現在有很多關於 3D 列印房子的炒作,印表機和房子一樣大。他們現在正在研究用一群桌面尺度的機器人在結構上行走,來更高效地放置零件。

不能從極小直接走到極大,格申菲爾德說,那會分階段到來。

馮·諾依曼的自複製自動機

這一切的核心,是馮·諾依曼的自複製自動機。

一個學生威爾·蘭福德用小零件做了微型機器人,然後米安娜把它們用於更大的機器人,一路往上,這實際上是在實現自複製自動機這個想法。

格申菲爾德抱怨馮·諾依曼架構時說過,這對馮·諾依曼不公平,因為他從沒聲稱這是他的架構。他真正寫的是那份相當糟糕的備忘錄,那份備忘錄導致了早期計算領域各種官司和爭鬥。他做了關於可靠計算和不可靠裝置的漂亮工作。在生命最後階段,他研究的是,格申菲爾德說必須精確地這樣說:一次計算如何傳達它自己的構造。這很優美。

一次計算可以儲存一段關於如何建造它自己的描述。但有個非常難的問題:如果你腦子裡有這個東西,你怎麼把它傳遞出去,喚醒一個能包含它的東西?你怎麼生出一個知道自己如何製造自己的東西?

他和斯坦·烏拉姆發明了元胞自動機來模擬這些,但那只是理論。格申菲爾德實驗室現在做的,本質上就是如何實現它,如何實現自複製自動機。

自複製自動機在智識上如此重要,因為它是生命的基礎,本質上就是理解生命的本質。他們實際上是在嘗試在非生命材料中創造生命。它在技術上如此重要,因為這是擴充套件能力的途徑。這就是如何從核糖體造出一頭大象,因為裝配者製造裝配者,用簡單的積木,積木內部包含如何製造更多積木的資訊,它們互相建造出任意複雜的物體。

格申菲爾德給了一組數字,把這件事和當下的 AI 熱潮聯絡起來。

一臺百萬億次浮點運算的計算機,也就是當前一代超級計算機,還沒到最大的那些,每秒做十的十七次方次運算。你的大腦每秒也做十的十七次方次運算。它大約有十的十五次方個突觸,以大約一百赫茲執行。所以一兩年前,大型計算機的效能追上了大腦。你可以把 AI 看作突破,但真正的故事是:一兩年前,超級計算機處理器裡大約有十的十五次方個電晶體,儲存器裡也有十的十五次方個電晶體,那就是你大腦裡的突觸。真正的突破是計算機在計算能力上追上了大腦,所以如果它們做不到大致相同的事,那才叫失職。

但格申菲爾德提這件事的原因是:製造超級計算機的晶片工廠每秒放置大約十的十次方個電晶體。而你此刻消化午餐時,每秒放置大約十的十八次方個零件。差了八個數量級。計算能力那一項追上了,真正差出來的是速度:生物建造的速度和最新制造能建造的速度之間,差了八個數量級。這個差距關乎數字製造在建造中具身化程式碼的深層意義,與模擬無關。

一段描述不是描述一個東西,描述變成了那個東西。(尼爾·格申菲爾德)

數字製造的兩種含義

格申菲爾德說,數字製造這個說法有隨意的含義,也有深層的含義。

隨意的含義是,計算機控制工具來製造東西,那是 1952 年 MIT 偷來發明的東西。

深層的含義是核糖體做的事:一段數字描述變成了那個東西。那才是通往《星際迷航》複製器的路。而那件事還不存在。

要理解這個路線圖,格申菲爾德說要引入 fab lab,看它們如何和這一切關聯。

fab lab 是什麼?

這裡有個序列。格申菲爾德和同事無意中啟動了一個網路,現在有一千二百五十個國家裡的兩千五百個數字製造社群實驗室,叫 fab lab。它們每一年半翻一倍。這被稱作“拉塞特定律”,以謝里·拉塞特命名,格申菲爾德說後面會解釋。

序列是這樣的。他們啟動 CBA 做前面講的那種研究。他們有所有這些機器,然後遇到一個問題:要學會使用所有這些機器,得上一輩子的課。所以格申菲爾德和幫助啟動 CBA 的同事開了一門課,謙虛地叫“如何製造幾乎任何東西”。沒有什麼大計劃,它只是面向幾個研究學生,教他們用這些機器。他們完全沒準備好第一次教這門課,結果被淹沒。從那以後每年都有幾百個學生想上這門課,它是 MIT 最超額認購的課程之一。

學生會說,你能在 MIT 教這個嗎?它看起來太有用了。它就是怎麼操作這些機器。

格申菲爾德在課上教學生使用所有這些工具的技能,然後他們做專案,把它們整合起來,成果驚人。

凱莉是個雕塑家,沒有工程背景。她的專案是做了一個裝置,能在你生氣時把尖叫存起來,之後播放出來。你對著這個裝置尖叫,它減弱聲音、錄下來,然後在方便的時候釋放你的尖叫。

另一個叫米金的人,做了一個裝感測器的裙子,上面有刺,當有令人不適的人靠近,它會捍衛你的個人空間。

早期還有一個專案是給鸚鵡做的網頁瀏覽器,鸚鵡有幼兒的認知能力,讓鸚鵡上網衝浪。

還有一個是鬧鐘,你得和它摔跤,證明你醒了。

把這些連起來的是什麼?

MIT 做了第一臺真正的實時計算機,Whirlwind。它被電晶體化後成了 TX。TX 從 MIT 分拆出去成了 PDP,也就是創造了網際網路的小型計算機。MIT 外面是 DEC、Prime、王安、Data General,整個小型計算機產業,整個計算產業都在那裡,當計算變得個人化時它們全都失敗了。數字裝置公司的老闆肯·奧爾森說過一句名言:你不需要在家裡放一臺計算機。DEC 完全錯過了計算變得個人化這件事。

格申菲爾德提到這些,是因為他當時在問如何做數字製造,但不太明白為什麼這門課上的學生向他展示的東西。答案是:數字製造的殺手級應用是個人制造。

凱莉做尖叫裝置,不是因為它是為論文做的。她沒在寫研究論文,也沒打算做成商業模式,她想要一個,因為這是個人表達。這又回到了格申菲爾德在職業學校時的那種個人表達,用這些新的表達方式。

從那以後每年都是這樣。這門課的字面名字就叫“如何製造幾乎任何東西”,是 MIT 的傳奇課程。每年都在擴,MIT 有多個實驗室,參與教學的人和上課的人一樣多。甚至有一個哈佛的實驗室是為 MIT 這門課服務的。

格申菲爾德在訪談快結束時被問到,從人身上學到了什麼。

從他的敘述裡能看到一條線索:他在貝爾實驗室想動手做東西被工會攔下,在 MIT 終於能建立 CBA 做想做的事,然後他開了這門課,發現每年都有幾百個學生想來學怎麼動手做東西。這個需求一直都在,只是被文藝復興時期那個“非自由技藝”的觀念壓了幾百年。

數字製造這件事,往深裡說,是讓描述變成東西,往淺裡說,是讓每個人都能把腦子裡的想法變成手裡的物件。格申菲爾德實驗室那些能自我複製、在結構上行走、糾錯定位的機器人,和凱莉那個存尖叫的盒子,是同一個思路的兩端。一端在挑戰製造業的物理極限,一端在回答一個更樸素的問題:一個人想做個東西,為什麼這麼難?

他在訪談裡說,自己在那個邊界上學到的東西,聽起來都很狂妄,但他都學到了:為什麼圖靈和馮·諾依曼犯了根本性錯誤,生命的秘密,以及如何解決世界上許多最重要的問題。把這三個說法放在一起看,其實是一件事。計算的具身化,就是軟體變成硬體的過程,就是核糖體做的事情,就是自複製自動機要做的事情,也就是他想讓每個普通人都能做到的事情。

如果你對這件事感興趣,下面幾件事可以從今天開始做。

  • 找一個離你最近的 fab lab。全球有兩千五百個,分佈在兩百五十個國家,大多數對公眾開放,有 3D 印表機、鐳射切割機、數控機床這些裝置,你可以去用,不需要工程背景。
  • 去搜 MIT 那門“如何製造幾乎任何東西”(How to Make Almost Anything)的課程資料。它全部公開在網上,從 CAD 到嵌入式程式設計到數控加工,是一套完整的動手製造入門路徑。
  • 下次你想做個小東西時,先別想著外包或買成品。找一個 fab lab 或者本地的創客空間,自己動手做一遍,從想法到實物的這個過程本身會改變你對製造的理解。
  • 如果你是做軟體的,找一個硬體專案參與一下。格申菲爾德整條論證線都在說,位元和原子本來不該分開,理解物理約束會讓你的軟體直覺變得更紮實。
  • 關注 CBA 和 fab lab 網路的公開研究。他們的論文和專案更新大多開源,尤其是數字材料、自複製機器人、微尺度裝配這幾個方向,值得長期跟蹤。
文稿由本站用語音識別模型(基於官方釋出音訊)機器轉寫,可能有識別錯誤,人名與數字請以音訊為準。
Lex Fridman Podcast #380 – Neil Gershenfeld: Self-Replicating Robots and the Future of Fabrication Machine transcription by Qwen3-ASR 0.6B (MLX, local, Apache-2.0). May contain recognition errors. The following is a conversation with Neil Gershenfeld, the director of MIT's Center for Bits and Atoms, an amazing laboratory that is breaking down boundaries between the digital and physical worlds, fabricating objects and machines at all scales of reality, including robots and automata that can build copies of themselves and self assemble into complex structures. His work inspires millions across the world as part of the maker movement to build cool stuff, to create, the very act that makes life so beautiful and fun. And now a quick second mention of each sponsor. Check them out in the description is the best way to support this podcast. We got Element for zero sugar hydration, NetSuite for business management software and BetterHelp for mental health. Choose wisely, my friends. 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And now dear friends, here is Neil Gershenfeld. You have spent your life working at the boundary between bits and atoms, so the digital and the physical. What have you learned about engineering and about nature reality from working at this divide trying to bridge this divide? I learned why von Neumann and Turing made fundamental mistakes. I learned the secret of life. Yeah, I learned how to solve many of the world's most important problems, which all sound presumptuous, but all of those are things I learned at that boundary. Okay, so Turing and von Neumann, let's start there. Some of the most impactful important humans who have ever lived in computing. Why were they wrong? So I worked with Andy Gleason who is Turing's counterpart. So just just for background if anybody doesn't know Turing is credited with the modern architecture of computing, among many other things. Andy Gleason was his US counterpart and you might not have heard of Andy Gleason but you might have heard of the Hilbert problems and Andy Gleason solved the fifth one. So he was a really notable mathematician. During the war, he was Turing's counterpart. Then von Neumann is credited with the modern architecture of computing and one of his students was Marvin Minsky. So I could ask Marvin what Johnny was thinking and I could ask Andy what Alan was thinking. And what came out from that what I came to appreciate as background I never understood the difference between computer science and physical science but Turing's machine that's the foundation of modern computing has a simple physics mistake. Which is the head is distinct from the tape. So in the Turing machine there is a head that programmatically moves and reads and writes a tape. The head is distinct from the tape, which means persistence of information is separate from interaction with information. Then von Neumann wrote deeply and beautifully about many things but not computing. He wrote a horrible memo called the first draft of a report on the edvac, which is how you program a very early computer. In it, he essentially roughly took Turing's architecture and built it into a machine. So the legacy of that is the computer somebody is using to watch this is spending much of its effort moving information from storage transistors to processing transistors even though they have the same computational complexity. So in computer science when you learn about computing, there is a ridiculous taxonomy of about a hundred different models of computation. But they're all fictions. In physics, a patch of space occupies space. It stores state. It takes time to transit and you can interact. That is the only model of computation that's physical. Everything else is a fiction. So I really came to appreciate that a few years back when I did a keynote for the annual meeting of the supercomputer industry and then went into the halls and spent time with the supercomputer builders and came to appreciate. Oh, see if you are familiar with the movie The Metropolis. People would frolic upstairs in the gardens and down in the basement people would move levers and that's how computing exists today that we pretend software is not physical it's separate from hardware and the whole canon of computer science is based on this fiction that bits aren't constrained by atoms. But all sorts of scaling issues in computing come from that boundary but all sorts of opportunities come from that boundary. And so you can trace it all the way back to Turing's machine making this mistake between the head and the tape. Von Neumann in in um he never called it von Neumann's architecture he wrote about it in this dreadful memo and then he wrote beautifully about other things we'll talk about. Now to end a long answer Turing and von Neumann both knew this so all of the canon of computer scientists credits them for what was never meant to be a computer architecture. Both Turing and von Neumann ended their life studying exactly how software becomes hardware. So von Neumann studied self reproducing automata how a machine communicates its own construction. A Turing studied morphogenesis how genes give rise to form. They ended their life studying the embodiment of computation something that's been forgotten by the canon of computing but developed sort of off to the sides by a really interesting lineage. So there is no distinction between the head and the tape between the computer and the computation it is all computation. Right, so I never understood the difference between computer science and physical science and working at that boundary helped lead to things like my lab was part of doing with a number of interesting collaborators the first faster than classical quantum computations. We were part of a collaboration creating the minimal synthetic organism where you design life in a computer. Those both involve domains where you just can't separate hardware from software. The embodiment of computation is embodied in these really profound ways. So the first quantum computation synthetic life so in the space of biology, so the space of physics at the lowest level in the space of biology at the lowest level. So let's talk about CBA Center for Bits and Atoms. What's the origin story of this MIT legendary MIT center that you are a part of creating? In high school, I really wanted to go to vocational school where you learn to weld and fix cars and build houses, and I was told no you are smart you have to sit in a room, and nobody could explain to me why I couldn't go to vocational school. I then worked at Bell Labs, this wonderful place before deregulation legendary place and I would get union grievances because I would go into the workshop and try to make something and they would say no you are smart you have to tell somebody what to do. And it wasn't until MIT and I'll explain how CBA started but I could create CBA that I came to understand this is a mistake that dates back to the Renaissance. So in the Renaissance the liberal arts emerged and liberal doesn't mean politically liberal. This was the path to liberation birth of humanism. And so the liberal arts were the trivium quadrivium roughly language natural science and at that moment what emerged was this dreadful concept of the illiberal arts. So anything that wasn't the liberal arts was for commercial gain and was just making stuff and wasn't valid for serious study and so that's why we're left with learning to weld wasn't a subject for serious study. But the means of expression have changed since the Renaissance. So micro machining or or embedded coding is every bit as expressive as painting a painting or writing a sonnet. So never understanding this difference between computer science and physical science. The path that led me to create CBA with colleagues was I was what's called a junior fellow at Harvard. I was visiting MIT through Marvin because I was interested in the physics of musical instruments. I this will be another slight digression I and Cornell I would study physics and and then I would cross the street and go to the music department where I played the bassoon and I would trim reeds and play the reeds and they'd be beautiful but then they'd get soggy and then I discovered in the basement of the music department at Cornell was David Borden. Who you might not have heard of but is legendary electronic music because he was really the first electronic musician. So Bob Mogue who invented Mogue synthesizers was a physics student at Cornell like me crossing the street and eventually he was kicked out and invented electronic music. David Borden was the first musician who created electronic music. So he's legendary for people like Phil Glass and Steve Reich. And so that got me thinking about I would behave as a scientist in the music department but not in in the physics department but not in the music department got me thinking about what's the computational capacity of a musical instrument. And through Marvin he introduced me to Todd MacOver at the Media Lab who is just about to start a project with YoYo Ma that led to a collaboration to instrument a cello to to extract YoYo's data and bring it out into computational environments. What is the computational capacity of a musical instrument? As we continue on this tangent and we shall return to CBA. Yeah, so one part of that is to understand the computing and if you look at like the finest timescale and length scale you need to model the physics it it's not heroic you a good GPU can do terraflaps today that that used to be a national class supercomputer now it's just a GPU and that's about. If you take the timescales and length scales relevant for the physics that's about the scale of the physics computing for YoYo what was really driving it was he's completely unsentimental about the Strad. It's not that it makes some magical wiggles in the sound wave. It's its performance as a controller how he can manipulate it as an interface device. Interface between what and what exactly him and sound and so so what it led to was I had started by thinking about ops per second but YoYo's question was really. Um resolution and bandwidth it's how fast can you measure what he does and um the the the bandwidth and the resolution of detecting his controls and then mapping them into sounds and what what we found what he found was if you instrument everything he does and connected to almost anything. It sounds like YoYo that that that the magic is in the control not in ineffable details in how the wood wiggles and so with YoYo and Todd that led to a piece and towards the end I asked YoYo what what it would take for him to get rid of his Strad and use our stuff and his answer was just logistics it was at that time. Our stuff was like a rack of electronics and lots of cables and some grad students to to make it work once the technology becomes as invisible as the Strad that then sure absolutely he would take it and by the way as a footnote on the footnote an accident in the sensing of YoYo's cello led to a hundred million dollar year auto safety business to control airbags in cars. How did that work? I had to instrument the bow without interfering with it so I set up local electromagnetic fields where I would detect how those fields interact with the bow he's playing but we had a problem that his hand whenever his hand got near these sensing fields I would start sensing his hand rather than the materials on the bow. And I didn't quite understand what was going on with those that that interference so my very first grad student ever Josh Smith. Did a thesis on tomography with electric fields how to see in three D with electric fields then through Todd and at that point research scientist my lab Joe Paradiso it led to a collaboration with Penn and Teller who. Um, where we did a magic trick in Las Vegas to contact Toudini and sort of these fields are sort of like you know contacting spirits. So we did a magic trick in Las Vegas and then the the crazy thing that happened after that was Phil Rittmuller came running into my lab. He worked with this became with Honda and NEC airbags were killing infants in rear facing child seats. Cars need to distinguish. A front facing adult where you'd save the life versus a bag of groceries where you don't need to fire the airbag versus a rear facing infant where you would kill it and so the the seat need to in effect see in three D to understand the occupants and so. We took the Penn and Teller magic trick derived from Josh's thesis from YoYo's cello to an auto show and all the car companies said great when can we buy it and so that became Elisa and it was a hundred million dollar year business making sensors there wasn't a lot of publicity because it was in the car so the car didn't kill you. So they didn't sort of advertise we have nice sensors so the car doesn't kill you but it became a leading auto safety sensor. And that started from the cello and the question of the computational capacity musical instrument. Right. So now to get back to MIT, I was spending a lot of outside time at IBM research that had gods of the foundations of computing. Um, there is amazing people there and I had always expected to go to IBM to take over a lab but at the last minute pivoted and came to MIT to take a position. In the Media Lab and start what became the predecessor to CBA Media Lab is well known for Nicholas Negroponte. What's less well known is the role of Jerry Weisner. So Jerry was MIT's president before that Kennedy Science Advisor grand old man of science. At the end of his life, he was frustrated by how knowledge was segregated, and so he wanted to create a department of none of the above, a department for work that didn't fit in departments. And the Media Lab in a sense was a cover story for him to hide a department. It as MIT's president towards the end of his tenure if he said I am going to make a department for things that don't fit in departments the departments would have screamed. But everybody was sort of paying attention to Nicholas creating the Media Lab and Jerry kind of hid in it. In it a department called Media Arts and Sciences it's really the department of none of the above, and Jerry explaining that and Nicholas then confirming it is really why I pivoted and went to MIT, um because my students who help create quantum computing or synthetic life get degrees from Media Arts and Sciences this department of none of the above, so that led to coming to MIT, yeah with um ah Todd and Joe Paradiso and Mike Colly we started a consortium called Things That Think and this was around the birth of Internet of Things and RFID but then we started doing things like work we can discuss that became the beginnings of quantum computing and cryptography and materials and logic and microfluidics and those needed much more significant infrastructure and were much longer research arcs so with a bigger team of about 20 people we wrote a proposal to the NSF to assemble one of every tool to make anything of any size was roughly the proposal one of any tool to make anything of any size yeah so they're usually nanometers micrometers millimeters meters are segregated input and output is segregated we wanted to look just very literally how digital becomes physical and physical becomes digital and fortunately we got NSF on a good day and they funded this facility of one of almost every tool to make anything and so with a group of core colleagues that included Joe Jacobson Ike trying Scott Menalas we launched CBA and so you're talking about nanoscale microscale nanostructures microstructures macrostructures electron microscopes and focused ion beam probes for nanostructures laser micro machining and X-ray microtomography for microstructures multi-axis machining and 3D printing for macrostructures just some examples what are we talking about in terms of scale how can we build tiny things and big things all in one place yeah so a well equipped research lab has the sort of tools we're talking about but they're segregated in different places they're typically also run by technicians where you then have an account and a project and you charge all of these tools are essentially when you don't know what you're doing not when you do know what you're doing in that there when you need to work across length scales where we don't once projects are running in this facility we don't charge for time you don't make a formal proposal to schedule and the users really run the tools and it's for work that's kind of incoate that needs to span these disciplines and length scales and so you work in the project today work in CBA today ranges from developing zipped dual electronics for the lowest power computing to micro machining diamond to take million ten million RPM bearings for molecular spectroscopy studies up to exploring robots to build hundred meter structures in space okay can we the three things you just mentioned let's start with the biggest what are some of the biggest stuff you attempted to explore how to build in a lab sure so viewed from one direction what we're talking about is a crazy random seeming of almost unrelated projects but if you rotate 90 degrees it's really just a core thought over and over again just very literally how bits and atoms relate how digital and just going from digital to physical in many different domains but it's really just the same idea over and over again so to understand the biggest things let me go back to bring in now Shannon as well as von Neumann Claude Shannon yeah so what is digital the casual obvious answer is digital in one and zero but that's wrong there's a much deeper answer which is Claude Shannon at MIT wrote the best master thesis ever in his master thesis he invented our modern notion of digital logic where it came from was Vannever Bush was a grand old man at MIT he created the post war research establishment that led to the National Science Foundation and he made an important mistake which we can talk about but he also made the the differential analyzer which was the last grade analog computer so it was a room full of gears and pulleys and the longer it ran the worse the answer was and Shannon worked on it as a student and he got so annoyed in his master thesis he invented digital logic but he then went on to Bell Labs and what he did there was communication was beginning to expand there was more demand for phone lines and so there's a question about how how many phone lines you could phone messages you could send down a wire and you could try to just make it better and better he asked a question nobody had asked which is rather than make it better and better what's the limit to how good it can be and he proved a couple things but one of the main things he proved was a threshold theorem for channel capacity and so what he showed was my voice to you right now is coming as a wave through sound and the further you get the worse it sounds but people watching this are getting it as as in from packets of data in a network when they get when the computer they're watching this gets the packet of information it it can detect and correct an error and what Shannon showed is if the noise in in the cable to the people watching this is above a threshold they're doomed but if the noise is below a threshold for a linear increase in the energy representing our conversation the error rate goes down exponentially exponents are fast there's very few of them in engineering and the exponential reduction of error below a threshold if you restore state is called a threshold theorem that's what led to digital that that means unreliable things can work reliably so Shannon did that for communication then von Neumann was inspired by that and applied it to computation and he showed how an unreliable computer can operate reliably by using the same threshold property of restoring state it was then forgotten many years we had to rediscover it in effect in the quantum computing era when things are very unreliable again but now to go back to how does this relate to the biggest things I've made so in fabrication MIT invented computer controlled manufacturing in 1952 jet aircraft were just emerging there is a limit to turning cranks on a machine on a milling machine to make parts for jet aircraft now this is a messy story MIT actually stole computer controlled machining from an inventor who brought it to MIT wanted to do a joint project with the Air Force and MIT effectively stole it from him so it's kind of a messy history but that sounds like the birth of computer controlled machining 1952 there are a number of inventors of 3D printing one of the companies spun off from my lab by Max Labovsky's Form Labs which is now a billion dollar 3D printing company that's the modern version but all of that's analog meaning the information is in the control computer there's no information in the materials and so it goes back to Vannever Bush's analog computer if you mistake make a mistake in printing or machining just the mistake accumulates the real birth of computerized digital manufacturing is 4 billion years ago that's the evolutionary age of the ribosome so the way you're manufactured is there's a code that describes you the genetic code it goes to a a micro machine the ribosome which is this molecular factory that builds the molecules that that are you the key thing to know about that is it there are about 20 amino acids that get assembled and in that machinery it does everything Shannon and von Neumann taught us you detect and correct errors so if you mix chemicals the error rate is about a part in a hundred when you make elongated protein in the ribosome it's about a part in ten to the four when you replicate DNA there's an extra level of error correction it's a part in ten to the eight and so in the molecules that make you you can detect and correct errors and you don't need a ruler to make you the geometry comes from your parts so now compare a child playing with Lego and a state of the art 3D printer or computerized milling machine the tower made by a child is more accurate than their motor control because the act of snapping the bricks together gives you a constraint on the joints you can join bricks made out of dissimilar materials you don't need a ruler for Lego because the geometry locally gives you the global parts and there's no Lego trash the parts have enough information to disassemble them those are exactly the properties of a digital code the unreliable is made reliable yes absolutely so what the ribosome figured out 4 billion years ago is how to embody these problem these digital properties but not for communication or computation in effect but for construction so a number of projects in my lab have been studying the idea of digital materials and think of a digital material just as Lego bricks the precise meaning is a discrete set of parts reversibly joined with global geometry determined from local constraints and so it's digitizing the materials and so I'm coming back to what are the biggest things I've made my lab was working with the aerospace industry so Spirit Aero was Boeing's factories they asked us for how to join composites when you make a composite airplane you make these giant wing and fuselage parts and they asked us for a better way to stick them together because the joints were a place of failure and what we discovered was instead of making a few big parts if you make little loops of carbon fiber and you reversibly link them in joints and you do it in a special geometry that balances being under constrained and over constrained with just the right degrees of freedom we set the world record for the highest modulus ultralight material just by in effect making carbon fiber Lego so the so lightweight materials are crucial for energy efficiency this let us make make that the lightest weight high modulus material we then showed that with just just a few part types we can tune the material properties and then you can create really wild robots that instead of having a tool the size of a jumbo jet to make a jumbo jet you can make little robots that walk on these cellular structures to build the structures where they error correct their position on the structure and they navigate on the structure and so using all of that with NASA we made morphing airplanes a former student Kenny Chang and Benjinet made a morphing airplane the size of NASA Langley's biggest wind tunnel with Toyota we've made super efficiency race cars we're right now looking at projects with NASA to build these for things like space telescopes and space habitats where the ribosome who I mentioned a little while back can make an elephant one molecule at a time ribosomes are slow they run at about one molecule a second but ribosomes make ribosomes so you have thousands of them trillions of them and that makes an elephant in the same way these little assembly robots I'm describing can make giant structures at heart because the robot can make the robot so more recently to my students Samira and Mianna had a Nature communication paper showing how this robot can be made out of the parts it's making so the robots can make the robots so you build up the capacity of robotic assembly it can self replicate can you linger on what that robot looks like what is a robot that can walk along and do error correction and what is a robot that can self replicate from the materials that is given what does that look like what are we talking so this is fascinating yeah the answer is different at different length scales so to explain that in biology primary structure is the code in the messenger RNA that says what the ribosome should build secondary structure are geometrical motifs are things like helices or sheets tertiary structures are functional elements like electron donors or acceptors quaternary structure is things like molecular motors that are moving my mouth or making the synapses work in my brain so there's that hierarchy primary secondary tertiary quaternary now what's interesting is if you want to buy electronics today from a vendor there are hundreds of thousands of types of resistors or capacitors or transistors huge inventory all of biology is just made from this inventory of 20 parts the amino acids and by composing them you can create all of life and so as part of this digitization of materials we're in effect trying to create something like amino acids for engineering creating all of technology from 20 parts I see as another discretion I helped start an office for science in Hollywood and there was a fun thing for the movie The Martian where I did a program with Bill Nye and a few others on how to actually build a civilization on Mars that they described in a way that I like as I was talking about how to go to Mars without luggage and the at heart it's sort of how to create life in nonliving materials so if if you think about this primary secondary tertiary quaternary structure in my lab we're doing that but on different length scales for different purposes so we're making micro robots out of like nano bricks and to make the robots to build large scale structures in space the elements of the robots now are centimeters rather than micrometers and so the assembly robots for the bigger structures are there are the cells that make up the structure but then we have functional cells and so cells that can process and actuate each cell can like move one degree of freedom or attach or disdetach or process now those elements I just describe we can make out of the still smaller parts so eventually there's a hierarchy of the little parts make little robots that make bigger parts of bigger robots that up through that hierarchy in that way you can move up the length scale right early on I tried to go in a straight line from the bottom to the top and that ended up being a bad idea instead we're kind of doing all of these in parallel and then they're growing together and so to make the larger scale structures we like there's a lot of hype right now about 3D printing houses where you have a printer the size of the house we're right now working on using swarms of these you know table scale robots that walk on the structures to place the parts much more efficiently that's amazing but you're saying you can't for now go from the very small to the very large that'll come that that'll come in stages can we just linger on this idea starting from von Neumann's self replicating automata that you mentioned it's just a beautiful idea so that's at the heart of all of this in the stack I described so one student Will Langford made these micro robots out of little parts that then we're using for Mianna's bigger robots up through this hierarchy and it's really realizing this idea of the self reproducing automata so von Neumann when I complained about the von Neumann architecture it's not fair to von Neumann because he never claimed it as this architecture he really wrote about it in this one fairly dreadful memo that led to all sorts of lawsuits and fights and about the early days of computing he did beautiful work on reliable computation and unreliable devices and towards the end of his life what he studied was how and I have to say this precisely how a computation communicates its own construction so beautiful so a computation can store a description of how to build itself but now there's a really hard problem which is how if you have that in your mind how do you transfer it and wake up a thing that then can contain it so how do you give birth to a thing that knows how to make itself and so with Stan Ulam he invented cellular automata as a way to simulate these but that was theoretical now the work I'm describing in my lab is is fundamentally how to realize it how to realize self reproducing automata and so you know this is something von Neumann thought very deeply and very beautiful of beautifully about theoretically and it's right at this intersection it it's not communication or computation or fabrication it's right at this intersection where communication and computation meets fabrication now the reason self reproducing automata intellectually is so important because this is the foundation of life this is really just understanding the essence of how to life and in effect we're trying to create life in nonliving material the reason it's so important technologically is because that's how you scale capacity that's how you can make an elephant from a ribosome because the assemblers make assemblers with simple building blocks that inside themselves contain the information how to build more building blocks and so between each other construct arbitrarily complex objects right now let me give you the numbers so let me relate this to right now we're living in AI mania explosion time let me relate that to what we're talking about a hundred petaflop computer which is a current generation supercomputer not quite the biggest ones does 10 to the 17 ops per second your brain does 10 to the 17 ops per second it has about 10 to the 15 synapses and they run at about 100 Hertz so as of a year or two ago the compute the performance of a big computer matched a brain so you could view AI as a breakthrough but the real story is um Within about a year or two ago, and let's see that the supercomputer has about ten to the fifteen transistors in the processors, ten to the fifteen transistors in the memory, which is the synapses in your brain. So the real breakthrough was the computers match the computational capacity of a brain, and so we'd be sort of derelict if they couldn't do about the same thing. But now the reason I am mentioning that is the chip fab making the supercomputer is placing about ten to the ten transistors a second. While you are digesting your lunch right now, you are placing about ten to the eighteen parts per second. There is an eight order of magnitude difference. Not so in computational capacity, it's done. We've caught up, but there is eight orders of magnitude difference in the rate at which biology can build versus state of the art manufacturing can build. And that distinction is what we're talking about. That distinction is not analog, but this deep sense of digital fabrication of embodying codes in construction. So a description doesn't describe a thing, but the description becomes the thing. So you are saying, I mean, this is one of the cases you are making in that this is this third revolution. We've seen the Moore's law communication, we've seen the Moore's law like type of growth in computation. And you are anticipating we're going to see that in digital fabrication. Can you actually first of all describe what you mean by this term digital fabrication? So the casual meaning is a computer controls the tool to make something, and that was invented when MIT stole it in nineteen fifty two. Yeah, there is the deep meaning of what the ribosome does of a compute of a digital description doesn't describe a thing, a digital description becomes the thing. That's where the that's that's the path to the Star Trek replicator. And that's the thing that doesn't exist yet. Now I think the the best way to understand what this roadmap looks like is to now bring in fab labs and how they relate to all of this. What are fab labs? So here here is a sequence. With colleagues, I accidentally started a network of what's now twenty five hundred digital fabrication community labs called fab labs right now in one hundred twenty five countries. And they double every year and a half. That's called Lass's law after Sherry Lasseter who I'll explain. So here is the sequence. We started Center for Bits and Adams to do the kind of research we're talking about. We had all of these machines and then had a problem. It would take a lifetime of classes to learn to use all the machines. So with colleagues who helped start CBA, we began a class modestly called how to make almost anything. And there is no big agenda. It was just it was aimed at a few research students to use the machines and we were completely unprepared for the first time we taught it. We were swamped by every year since hundreds of students try to take the class. It's one of the most over subscribed classes at MIT. Students would say things like, "Can you teach this at MIT? It seems too useful. It's just how to work these machines. " And the students in the class, I would teach them all the skills to use all these tools, and then they would do projects integrating them, and they were amazing. So Kelly was a sculptor, no engineering background. Her project was she made a device that saves up screams when you are mad and plays them back later. And saves up screams when you are mad and plays them back later. You scream into this device and it it it deadens the sound, records it, and then when it's convenient releases your scream. Can we just just like pause on the brilliance of that invention, creation, the art. I don't know the brilliance. Who is this that created? Kelly Dobson. Kelly Dobson. Gone on to do a number of interesting things. Meijin, who's gone on to do a number of interesting things, made a dress instrumented with sensors and spines, and when somebody creepy comes close, it would defend your personal space. They're also very. Another project early on was a web browser for parrots, which have the cognitive ability of a young child. Let's parrots surf the internet. You know another another was an alarm clock. An alarm clock you wrestle with and prove you are awake. And what connects all of these is so MIT made the first real time computer, the whirlwind. That was transistorized as the TX. The TX was spun off from MIT as the PDPs. Where the mini computers that created the internet. So outside MIT was Deck Prime Wang Data General the whole mini computer industry, the whole computing industry was there and it all failed when computing became personal. Ken Olsen, the head of Digital, famously said, "You don't need a computer at home." There is a little background to that, but but Deck you know completely missed computing became personal. So I mentioned all of that because I was asking how to do digital fabrication, but not really why the students in this how to make class were showing me. That the killer app of digital fabrication is personal fabrication. Yeah, how do you jump to the personal fabrication? So Kelly didn't make the screen body because it was for a thesis. She wasn't writing a research paper. It wasn't a business model. She wanted it was because she wanted one. It was personal expression going back to me in vocational school is personal expression in these new means of expression. So that's happened every year since. They literally is called the course is literally called how to make almost anything. A legendary course at MIT. Every year, and it's grown to multiple labs at MIT with as many people involved in teaching as taking it. There is even a Harvard lab for the MIT class. What have you learned about humans? Colliding

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