第 195 期·中文精讀

克拉拉·索薩-席爾瓦:在金星及其他行星上尋找生命跡象

Clara Sousa-Silva: Searching for Signs of Life on Venus and Other Planets

天體物理學家討論磷化氫等生物標誌物的爭議,以及在金星大氣中尋找生命的可能。

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2020 年 9 月,全世界媒體都在報道:金星大氣中可能存在磷化氫,而磷化氫可能是生命存在的跡象。論文的共同作者、哈佛大學量子天體化學家克拉拉·索薩-席爾瓦(Clara Sousa-Silva)後來在播客裡說了一句讓人清醒的話:老實說,我們不知道。她說這話沒有客套成分,連那個訊號到底是不是真的,科學界到今天還有分歧。

這篇論文用兩臺望遠鏡、相隔幾個月的獨立觀測,在金星大氣裡找到一個吸收特徵。訊號很弱,噪聲很大,處在儀器靈敏度的邊緣。論文發表之後,有友好的反駁,有再次確認,也有到現在還沒解決的爭論。索薩-席爾瓦把這件事講得很平靜:science 出醜?恰恰相反,這是科學在正常工作。

她給自己起名叫“磷化氫博士”

訪談一開始,主持人問她能不能叫“磷化氫女王”。她笑著說,女王是繼承來的頭銜,我叫“磷化氫博士”(Dr. Phosphine)。她的推特賬號就是 @DrPhosphine,註冊的時候居然還沒被佔用。

在金星論文之前,她研究磷化氫已經超過十年。用她自己的話說,早在磷化氫“變酷”之前,早到別人連這個詞都拼不出來的時候。當時同行對磷化氫的印象只有兩種:不知道它是什麼,或者知道它是地球上最可怕的分子之一。

她對磷化氫談不上什麼一見鍾情,更像長期關係加斯德哥爾摩綜合徵。

磷化氫的分子結構很簡單,一個磷原子在頂端,三個氫原子在下面,是個小金字塔。它屬於宇宙裡最常見的幾種元素組合之一。碳加氫是甲烷,氮加氫是氨,氧加氫是水,這些都是家喻戶曉的分子。磷加氫就是磷化氫,但幾乎沒人聽說過它,因為在地球上你根本不該找到它。

它對需氧生命有劇毒。它干擾氧代謝,而且是以好幾種非常有想象力、非常陰森的方式殺死你。第一次世界大戰中它被用作化學戰劑,最近 ISIS 也用過。絕大多數生命都會避開它,連不靠氧代謝的厭氧生命,製造它也要付出巨大的能量代價。從熱力學角度說,讓磷心甘情願地和氫待在一起,極其困難。

如果你排除萬難把它造出來了,它在大氣裡又會很快被自由基反應掉。所以結論很清楚:哪兒都不該有磷化氫。可我們偏偏在宇宙裡到處都能找到它,而且看起來是生命在製造它。至於生命為什麼製造它、怎麼製造它,沒有人知道。

它的氣味,有文獻描述為“大蒜、魚腥和死亡”的混合。還有一位同行形容得更生動:撒旦後代的尿布。索薩-席爾瓦說這話不是她講的,但她很喜歡這個說法。

它是一種絕對神秘、絕對致命、氣味極其恐怖的分子。生命明明要付出巨大代價才能造出它,宇宙從不犧牲,只有生命會犧牲。這就是它的矛盾之處:我們都該躲著它,它卻幾乎是岩石行星上生命存在的明確標誌。(克拉拉·索薩-席爾瓦)

它憑什麼能當生命訊號

2015 年,她的博士論文全部圍繞磷化氫,還順帶寫了一章氨。博士畢業前後,她發表了一篇題為《磷化氫作為系外行星大氣生物標誌氣體》的論文。論文裡有一個大膽的論斷:在任何岩石行星上發現磷化氫,只能是生命。她說當時大家聽了都點頭,覺得有道理,然後就沒有然後了,沒人關心。

等到金星真的出現訊號,輪到她開始懷疑自己了。她原話是:“在它離我很遠的時候我很確定,現在它就在眼前,我的論斷正在被檢驗,我反而沒那麼確定了。”

這種態度值得停下來想一想。一個科學家花了十幾年建立一套理論,當理論第一次被現實檢驗時,她的第一反應是懷疑自己的理論,而不是捍衛它。這跟她後來反覆提到的“假說生成”和“假說檢驗”的區分是同一件事的兩面。

為什麼磷化氫是這麼好的生命訊號?邏輯其實很樸素:它極難非生物產生,一旦出現又極易被銷燬,所以只要在某個大氣裡穩定存在,就必然有一個持續的、源源不斷的來源。雷電和火山能產生極微量的磷化氫,但量級差得太遠。生命是唯一願意持續付出能量代價製造某樣東西的機制。

問題在於,生命為什麼要造它?酶促路徑至今未知。索薩-席爾瓦說這其實沒那麼令人意外:人類已知的天然產物裡,大約 80% 我們知道生命能造,但不知道怎麼造。知道“生命會造”很容易,把細菌放進培養皿,看它釋放什麼氣體就行。要知道具體是哪條代謝通路在起作用,是另一個量級的問題。磷化氫在實驗室裡被確認由生命產生過,但背後的酶促機制還是空白。

她順帶講了一個讓人印象深刻的類比:松露的香氣是一個幾十億美元產業,直到不久之前,人們也不知道那種氣味的分子到底是怎麼產生的。而這個產業沒有“磷化氫遊說集團”,沒有商業壓力推著研究往前走,所以她只能希望有人願意接手。

168 億個指紋,我們只找到了一個

要理解金星那個訊號有多單薄,得先理解光譜學在幹什麼。

一束光穿過稜鏡或者水滴,展開成彩虹。這道彩虹包含所有顏色,包括看不見的紫外和紅外。如果這束光在到達你之前穿過某種氣體,那些氣體分子會吸收掉彩虹裡非常特定的幾種顏色,其他的不動。每種分子吸收的顏色組合是獨一無二的。

索薩-席爾瓦算過,磷化氫有 168 億種可能的轉動和振動方式。也就是說,如果一束光穿過磷化氫氣體,光譜上應該留下 168 億個微小的凹痕。而金星的資料裡,我們只找到了其中一個。

她原話是:“168 億分之一。現在的遊戲是,我們能不能找到其他任何一個。”

很難。其他的凹痕都落在電磁波譜裡非常糟糕的位置,現有儀器基本夠不著。理論上還有第二個可以找,但需要連續觀測很多很多天,目前排不進日程。

那金星這一個訊號是怎麼被識別出來的?先看資料的形狀:它像一條波浪線,大部分是噪聲和基線。如果能算出這條波浪線的精確形狀,把它減掉,理論上應該剩下一條直線;如果線上有東西,那就是一個吸收訊號。她們做的就是這件事:擬合基線,減掉,剩下的位置上出現了一個訊號,在 8.904 波數。

問題也在這裡:這個方法做錯了,你自己就能造出一個訊號。

所以她們做了交叉驗證。在那個頻率上,已知只有兩種分子會吸收:磷化氫和二氧化硫。她們在同一個觀測波段裡找了另一塊區域,那裡磷化氫不吸收,但二氧化硫吸收。去看,沒有訊號。於是推斷:那應該是磷化氫。論文投出去,剩下的就是歷史了。

這裡有一個細節值得記住:ALMA 和 JCMT 兩臺望遠鏡,相隔幾個月,獨立觀測。兩臺的用意很明確:排除單臺儀器系統性誤差的可能。

兩種科學:生成假說和檢驗假說

索薩-席爾瓦在訪談裡做了一次很清晰的方法論區分,值得單獨拎出來。

假說檢驗(hypothesis testing)是科學方法的骨幹。但當你在一堆噪聲極大的資料裡檢驗一個假說時,你有可能會誤造出一個虛假訊號。你自己都不知道。

假說生成(hypothesis generation)是更保守的路子。你看到一堆資料,不帶偏見地問:裡面有什麼?資料量大的時候這很好。資料量小的時候,你清理噪聲的動作可能把訊號也一起清掉了,連洗澡水和孩子一起倒掉。

金星這件事恰好落在這個模糊地帶。資料處理有完全合法的方式,經過多位專家核查,訊號出現了;也有同樣合法的方式,訊號消失了。兩種結果都成立,分歧在於這個訊號意味著什麼。

她的結論是:如果訊號是真的,而且確實是磷化氫,那非常令人興奮,因為我們不知道除了生命還能怎麼解釋它。但從這裡跳到“金星人”,還有巨大的一步。

主持人問她,那金星上的居民是不是叫“金星人”(Venusians)?她說,在知道他們自稱什麼之前,就先這麼叫吧。

如果金星有生命,我們該不該去

訪談裡有一段討論,語氣平靜,但結論很硬。

索薩-席爾瓦說她不怕外星生命。她認為害怕這件事本身有點傻。但她非常明確地反對現在就去金星取樣。

如果金星上有生命,那很可能是最後一撥倖存者,是一個曾經可能宜居的世界的遺骸。我不想我們與外星生命的第一次接觸,以一場屠殺告終。(克拉拉·索薩-席爾瓦)

她提到一個詞:銀河倫理。她經常想象外星天文學家在看著我們,如果我們把這件事搞砸了,他們會多麼失望。

這個立場背後有科學理由,情感只佔一部分。觀測者會影響被觀測者。如果我們在另一個星球上發現生命,然後發現那是我們自己帶過去的,那會是科學史上最令人心碎的時刻之一。火星已經面臨這個問題:我們訪問過太多次,如果那裡有生命,永遠說不清是不是我們種下的。金星反而好一點,因為探測器去那裡很快就熔化了,金星很擅長銷燬外來物。

她也提到,極端微生物確實頑強,但那是相對於地球上的極端環境而言。金星雲層是另一回事。在地球上能扛住極端條件的生物,放到金星大氣裡大機率也活不下來。

所以她的方案是:先派軌道器。她說自己很失望,人類至今沒有在每個太陽系天體周圍放一個軌道器。一個小衛星就行,長期盯著看:雲怎麼動,裡面有什麼,閃電和火山活動頻率如何,地形有沒有變化,有沒有一個生物圈正在活動。先把遠距離能知道的都知道了,再談別的。

太陽系裡另外幾個值得看的地方

訪談裡聊到幾個候選地點。土衛二(Enceladus)有從地下海洋噴出來的間歇泉羽流,你不用鑽到冰層下面,直接分析噴出來的物質就行。土衛六(Titan)有甲烷海洋,蜻蜓號(Dragonfly)探測器正在準備過去。

索薩-席爾瓦說,這幾種環境和地球上有生命的地方完全不同,連地球上的極端環境都算不上。如果生命能在這麼多種完全不同的棲息地各自起源,那說明生命的資源利用能力比我們想象的強得多,那它在宇宙中到處都是。

她對太陽系內生命的態度,比對銀河系內智慧生命的態度樂觀得多。

如果太陽系裡任何一個地方有生命,哪怕只是火星,我願意賭上我擁有的一切,每一個行星系統都有宜居潛力。就算沒有宜居行星,也會有衛星,繞著巨行星轉,生命會很多。(克拉拉·索薩-席爾瓦)

至於智慧生命,她的判斷是:極不可能,甚至不確定這件事在機率上是否說得通。地球歷史上出現過大約 50 億個物種,只有一個搞出了智慧,而且只持續了極短的一瞬。她原本小時候想找能交朋友的外星人,後來不得不放棄這個夢想。

這裡有個很有意思的觀點反轉。主持人說,如果生命在宇宙中普遍存在,那智慧文明可能也很多,只是都活不長,彼此錯過。索薩-席爾瓦接過來:是啊,就像夜航的船,在黑暗裡擦肩而過。然後她說,這很悲傷嗎?地球並沒有因為有了我們而變得更好,它不欠我們任何東西。

她還補了一句:地球上的生命在我們之前就很好,在我們之後也會很好。樹、海豚、蟑螂、真菌,它們都會沒事的。真正短暫的是我們。

62000 年的工作,和一個叫 RASCAL 的作弊器

磷化氫只是 16000 個候選生物標誌分子中的一個。

這 16000 個分子,是我們在尋找另一個地球、或者尋找外星生物標誌時會關心的物件。要能從遠處探測到它們,前提是知道它們的光譜指紋。目前人類大概只搞清楚了 4%,水、甲烷、氨、二氧化碳,再加上乙炔、氰化氫這類,勉勉強強。剩下 96%,我們幾乎完全不知道它們在光譜上會留下什麼痕跡。

如果索薩-席爾瓦用做磷化氫的方法,為這 16000 個分子逐個計算,需要 62000 年。她算過這個數。她說時間過得真快啊,如果你樂在其中的話。

所以她的思路是:如果我做得差一點呢?差很多呢?速度能快多少?差到什麼程度之前還算有用?

她原話是:“我能差到什麼程度才變得沒用?在被人發現之前。”

答案是很差也沒關係。因為這些分子根本沒人知道長什麼樣,任何一點資訊都比零好。

於是有了 RASCAL:Rapid Approximate Spectral Calculations for All,快速近似全譜計算。她用了有機化學和量子化學兩邊的捷徑。

捷徑的來源很有意思。幾十年前,有機化學家想知道一個化合物是什麼,會看光譜,看到一個特徵,說:這個我見過,通常是碳碳三鍵。而且他們大多是對的。幾乎每個含碳碳三鍵的分子都在那個位置有特徵,區別只在其他部分。這類東西叫官能團。

後來質譜和核磁共振出來了,這套方法被淘汰了,但這些老教科書還在。索薩-席爾瓦把它們儘可能都收集起來。書裡有幾百條描述:當你有一個碘原子接在這個位置,總是有一個特徵出現在那裡,通常很尖銳,很強;另一些組合,特徵很寬。

她把所有這些碎片編成一本巨大的字典,寫程式碼把它們拼起來,像樂高積木,或者弗蘭肯斯坦的怪物。你給它任何一個分子,它告訴你:這個鍵、這個原子、這個團簇,光譜應該長這樣。粗糙,但能用。

目前 RASCAL 能給出一個初步答案:你看到這個特徵,它可能是這 816 個分子之一,祝你好運。她正在做的下一步是讓答案更有用:這 816 個裡面,只有 12% 在這個區域也有特徵,去那裡看。如果那裡什麼都沒有,就排除這 12%,繼續縮小。它還能告訴你,要區分這 816 個分子,你需要多高的解析度。

機器學習在這裡有空間嗎?有,但訓練集很糟糕。很多資料是幾十年前的,有些檔案是 1970 年代某個疲憊的人手繪的。拿這些訓練,等於把舊錯誤穩定地複製下去,而且沒有辦法驗證。她的計劃是先把訓練集手工改善,再試機器學習,但最終需要實驗資料來檢驗,也就是要有實驗室願意花錢,把危險氣體放進腔體,在極端溫度下測光譜。這是另一個難題。

從量子到天體:她為什麼覺得自己越來越不特別

主持人在訪談裡問了一個很寬的問題:你覺得科學裡最美妙的觀念是什麼?

索薩-席爾瓦的回答,是她個人經歷的一條線索。

小時候她想了解太空,理由有點自私:能預測天體執行讓她覺得自己很有力量,能控制比自己大得多的東西。後來學天文,不再只想知道恆星怎麼動,而是想知道周圍行星怎麼動。再深入下去,行星本身又不夠了,她想知道行星的大氣,然後想知道大氣裡的分子,最後一路縮小到量子尺度。

現在她大部分工作都在量子層面:用極小的工具,去回答人類能提出的最大的問題。這個跨越本身,就是她覺得科學最酷的地方。

而她在這條路上得到的東西,和最初想要的相反。她說自己越做研究,越覺得自己不特別,人類和地球在宇宙中的位置越來越不例外。但她同時覺得越來越不孤獨。

我失去了力量感,但我得到了陪伴。這是一筆很好的交易。(克拉拉·索薩-席爾瓦)

她講碩士論文時,講了一個畫面。小時候有人告訴她,太陽最終會膨脹成紅巨星,水星會掉進去,金星也會掉進去,太陽根本不在乎。她覺得很渺小,覺得太陽應該對自己的行星負點責任,結果它像個暴力的、疏忽的家長,甚至吃掉了自己的孩子。

她的碩士論文研究的就是這件事。她用計算機模擬了成千上萬次恆星死亡過程,看行星系統會怎樣。她原話是:基本上是在殺死幾十顆行星,重複幾千次。模擬裡,恆星失去質量,行星軌道隨之改變,類木行星撞上別的行星,或者被甩進恆星。她說看著這些模擬非常恐怖,是徹底的屠殺。

但跑上千次之後,總有一些系統能找到新的平衡。恆星死亡之後,一些行星系統會重新穩定下來,穩定幾十億年,足夠生命重新起源。白矮星非常穩定,在宇宙時間尺度上幾乎不動。她的想法是:如果生命是必然的,那它四億年前來過一次沒什麼關係,四十億年後還可以再來一次。

這個視角後來變成了她面對宇宙的基本姿態:太陽不欠我們任何東西,它不是壞父母,它根本不是父母。

“我是個糟糕的程式設計師”

作為一個量子天體化學家,她的工作幾乎全靠計算。訪談裡她講了實話:她是個糟糕的程式設計師。

原因她解釋得很清楚。大部分科學家沒受過正式程式設計訓練,先學的是物理、化學,然後被告知要建模、跑模擬,於是去學一點程式碼,夠跑就行,不會再深入。結果是程式碼很少最佳化,非常笨重,半年後自己都讀不懂。她的變數名非常丟人。她編譯報錯資訊裡會寫“至少你爸爸還愛你,克拉拉”這種話,完全不解決問題。

她學過 MATLAB、Java,大學時學的,基本沒用上。Fortran 很有用,雖然不好玩,因為太多遺留程式碼是 Fortran,你要用退休前輩的程式碼就得學。視覺化用 IDL。現在她像正常人一樣用 Python,好多了。

但她對“糟糕的程式設計師”定義很特別:我能完成任務,所以我是程式設計師;但沒人能看懂我的程式碼、沒人知道我怎麼完成的任務,所以我是糟糕的程式設計師。包括六個月後的她自己。

主持人在這裡補了一段很到位的觀察:軟體工程教育有一個陷阱,就是過度追求“正確的做法”。Stack Overflow 上那種對最優解的執念,會讓人把時間花在最佳化上,而不是完成任務。這跟一些生產力愛好者一樣,90% 的時間花在研究如何高效,然後什麼也沒做。

索薩-席爾瓦承認這一點,但她也提出了另一面的問題:她的程式碼開源放在 GitHub 上,任何人都能下載。但如果程式碼寫得足夠晦澀,沒人真正能用起來,那算真的開源嗎?她把自己的工作發表了嗎?她說這件事讓她有負罪感。

她給年輕人的建議,方向可能和很多人的直覺相反:教一個程式設計師科學概念,比教一個科學家程式設計容易得多。她寧願招一個會程式設計但幾乎不知道太空在哪的人,也不願教一個天文學家寫程式碼。

不要當混蛋,就能做出好科學

訪談裡有一段關於合作者的討論,可能是整期節目裡最實用的一段。

索薩-席爾瓦說,科學家很難在不高效的時候感到快樂,這是個陷阱。她自己也沒完全跳出來。但她發現了一件事:當她的學生高效工作時,她也能感到快樂,這種間接滿足感救了她。

她還提到學術界一個很常見的現象:資深科學家帽子太多,行政、服務、教學佔滿時間,自己的科研時間被擠壓,於是潛意識裡把學生的科研當成自己的,對實驗室裡的年輕人產生所有權感。她說這很令人心碎,她見過太多次,慶幸自己沒掉進去。

她的建議很簡單:

不要當混蛋,就能做出很多好科學。在你的領域裡找那些好人,跟他們合作。哪怕他們不是最強的科學家,你們做出來的科學會更好。(克拉拉·索薩-席爾瓦)

理由是,一個讓你痛苦的合作者會毀掉你的整個生活。它會讓你不想做科研,讓你做得粗糙,因為你不專注,不想反覆檢查,只想趕緊結束。

她還批評了科學界“孤狼”的神話:那個看到別人看不到的東西的科學家。她說這個形象很吸引人,很多人要麼真的在扮演它,要麼在假裝扮演它。首先它多半是謊言。現代科學,尤其是天文學,高度跨學科,任何單打獨鬥的現代科學家大機率做得不怎麼樣,因為你需要獨立的眼睛幫你檢查,需要子領域的專家核查你的工作。其次,這個夢會讓你痛苦,讓你的科學變差。

她舉了一個自己的例子。她有一項工作一直在拖延,因為不在乎結果,又很費勁,預計未來十年大概只有十個人會引用。後來她跟一位合作者傑森·迪特曼(Jason Dittman)花了一個下午,時間飛快過去,她覺得自己變高了,呼吸更順暢了,做完之後是個更好的人。她說秘訣就是找到讓你對科學產生這種感覺的人。

她順帶提到丹尼爾·卡尼曼(Daniel Kahneman)。主持人說他跟卡尼曼對談過,真正讓他震撼的東西在思想之外:那種孩子式的好奇心、觀點的推拉、幾乎沒有自我、但又在某個想法上保留一點固執的分寸感,還有真正傾聽別人的能力。索薩-席爾瓦同意:合作是可以訓練的技藝,並非天生的稟賦。她這些年確實比從前更會合作了。

她不覺得宇宙有意義,而且為此開心

訪談快結束時,主持人問了一個很大、幾乎無法回答的問題:這一切的意義是什麼?地球上的生命有什麼意義?你在金星和系外行星上尋找的那種生命,又有什麼意義?

她的回答可能是整期節目裡最需要停下來讀兩遍的部分。

我認為沒有意義。我在意義的缺席裡感到巨大的解脫。追問意義是人類的一種慾望,而宇宙對此毫不在乎。(克拉拉·索薩-席爾瓦)

但她馬上做了一次區分,這個區分很關鍵:她仍然在生活裡尋找意義,享受道德判斷的複雜性,覺得這些慾望深具人性。她只是不認為這種意義是普適的、絕對的。意義是我們用頭腦召喚出來的東西,它在我們之中真實,但拿不到宇宙層面去用。

就像太陽不該為吞噬自己的行星負責。宇宙不欠我們任何東西,也不回答我們的問題。她說,向宇宙要求意義,是一種僭越:我們算什麼東西,憑什麼要求宇宙交出答案。

而她從這件事裡得到的是自由。一旦沒有預設的意義,你就不必再去找到它。

主持人提醒她,這聽起來像薩姆·哈里斯(Sam Harris)關於自由意志的立場:無論決定論還是隨機性,都不能讓你成為自己行動的主宰,而哈里斯對此很坦然。索薩-席爾瓦說,她對生命的看法不一樣。她認為生命確實有意義,在生命範圍內尋找意義值得讚賞。她只是不認為這套東西能推廣到生命之外,更不能推廣到地球之外。意義是人類的建構,只在我們之中有效,也只對其他會受我們行為影響、或因我們的互動而感到喜悅的生命形式有效。

她把話收得很緊:我們有很多責任,但那是道德責任。在這些責任裡找到意義,會讓它們更容易被履行。所以意義有價值,無論它是否“真實”。但試圖把整個宇宙擬人化,什麼也得不到,而且是最高階別的傲慢。

讓她走進科學的那些東西

主持人問她關於書和電影。她說自己堅持留出時間,儘量不努力工作,雖然經常失敗。她的判斷標準是:一天能有四個高質量的科研小時就夠了,之後就是遞減回報,八個小時裡全是郵件、會議、爛程式碼和資料處理。

她小時候的科學生命,很大一部分來自卡爾·薩根(Carl Sagan)的《接觸》(Contact)。她覺得自己就是書裡的艾莉(Ellie),會變成艾莉,那個角色和關於生命、太空、宇宙的想法深深打動了她。後來電影上映,換成朱迪·福斯特來演,她說這也挺好。

書裡那句話她一直記著:如果宇宙裡只有我們,那真是浪費了巨大的空間。她說這個想法非常好用:也許我們是特別的,但那樣會很糟。找不到同伴、必須承認自己特別,這不如有同伴來得好。她從薩根那裡學到的就是這個。

外星人來過嗎

訪談裡有一段關於 UFO 和外星人造訪的討論,態度很有意思:她既極其開放,又極其懷疑。

她相信宇宙裡可能有我們想象不到的智慧形式。物理定律是普適的,化學定律是普適的,元素週期表對所有生命都只有那麼多選項,能量有多少是能算出來的。所以哪怕智慧遠超我們想象,它仍然在同一個宇宙裡,受同一批規則約束。我們並非完全瞎摸。

但她對“外星人訪問過地球”這件事下了一個近乎嘲諷的判斷。她說自己相信地心說 conspiracy 的可能性都比外星人造訪高。她給出的理由與星際旅行難度相關:星際距離太大,跨越它必須是有意為之,必須是一件極大的事,一件代價高到不划算的事。

她還有一個更狠的論證。如果真有能跨越星際的文明來了,而且被任何人看到了、被任何人探測到了,那麼沒有任何政府、任何軍隊能把它藏住。我們在登月上都很勉強,這些存在比我們高出太多太多。全球軍隊聯合起來都關不住。這個想法本身就可笑。

再加上科學家根本不會保密。她說自己見過太多科學家,保密能力極差。金星磷化氫這件事算是保得比較好的了,但她還是告訴了她爸爸。

我敢拿一切打賭,我們沒被造訪過,因為我們太無能,守不住這個真相。(克拉拉·索薩-席爾瓦)

主持人提出了一個不同的角度:也許外星文明來過,只是我們和他們都無法識別彼此。我們對生命的定義太窄,困在哺乳動物、叢林、人類時間尺度這個層面上。索薩-席爾瓦部分同意,但堅持一個邊界:不能因為開放就什麼都信。她被人當面吼過,因為不信地球是空心的。她說那個 conspiracy 至少概念上很可愛,南極洲進去,裡面養著猛獁象和納粹。

為什麼“不特別”是好訊息

回到金星。她說的話裡有一句值得單獨拎出來:如果金星雲層裡真的有生命,那是曾經可能宜居的世界的最後倖存者。這句話改變了整個問題的性質。我們找到的可能是一個災難倖存者,尋找鄰居這件事要往後放。

這也是她反對現在去取樣的核心。她想先把能遠端知道的都知道了,再決定要不要干涉。她自己承認,想伸手去抓一勺是人的本能,但她有工程上的理由,也有倫理上的理由。

工程上:我們對金星雲層瞭解得不夠,不知道該怎麼規劃取樣。那地方很惡劣,要造出能可靠完成任務、測量結果可信、還能把資訊傳回來的東西,不容易。

倫理上:如果那是生命,我們不該是第一個動手的。

她還提了一件事,語氣半開玩笑,但底下是認真的:如果有外星天文學家一直在看我們,他們大概會先注意到 CFCs。氯氟烴是毫無疑問的工業標誌,一旦探測到,就是確鑿的智慧生命證據。她說那段時間,外星人大概在寫論文,題目叫《地球的終結》,然後人類居然聯合起來把它禁了,臭氧層空洞開始縮小。她願意相信他們為我們感到驕傲。

主持人說,他們可能更擔心核武器。她說,是啊,如果我是外星人,我會在活體第一次找到毀滅整個群落的方法時開始出現。然後自己補了一句:當然,也可能只是因為現在人人都有攝像頭了。

開放心態的副產品

訪談最後,主持人說了一段挺動人的話。他說自己支援對 UFO 保持開放,他支援的理由跟信不信無關,開放本身會產生無法預測的連帶效應。如果你不立刻笑掉大牙,這種思維方式可能會在別的領域帶來突破。太多科學家一聽到外星人就翻白眼,而這是最大的、最激動人心的問題之一。翻白眼預設了你已經瞭解了這個世界,實際上你只知道 0.0001%。

索薩-席爾瓦沒有反駁。她自己就是一個把整個職業生涯押在一個“聽起來不太嚴肅”的分子上的人。磷化氫在十年前是個沒人願意拼寫的詞,現在它是金星論文的主角。

她的立場可以概括成兩句話:對宇宙保持謙卑,對自己保持懷疑。前者讓你願意去看那些沒人看的地方,後者讓你在看的時候不敢太快下結論。

如果你也想做點類似的事

這期訪談資訊量很大,但落到行動上,有幾條是可以直接拿去用的。

  • 想進入計算型科研領域,先學程式設計再補科學,比反過來容易得多。索薩-席爾瓦明確說,她寧願招一個會寫程式碼但不知道太空在哪的人,也不願教天文學家寫程式碼。
  • 別陷入“正確做法”的執念。程式碼的第一目標是完成任務,能跑、結果可信、別人能看懂,就夠好了。過度最佳化和生產力崇拜一樣,會讓你把 90% 的時間花在準備工作上,永遠不開始。
  • 開源不只是把程式碼放到 GitHub。如果沒人能讀懂、用不起來,那等於沒發表。變數名和結構是科學傳播的一部分。
  • 選合作者時,優先選讓你做完工作後感覺更好的人,而不是簡歷更漂亮的人。痛苦的合作會降低科研質量,因為你不願意反覆檢查,只想趕緊結束。
  • 評估一個訊號時,先問自己是在生成假說還是在檢驗假說。資料量小的時候,後者的風險是把噪聲做成訊號,而且你自己不會發覺。
  • 如果你在做跨學科的事,接受“我能差到什麼程度才算沒用”這個問題。在沒人知道答案的領域,粗糙的估計比精確的空白有用得多。
  • 對“我們是特別的”
  • 對“我們是特別的”這個假設保持警惕。索薩-席爾瓦說她越做研究越覺得自己不特別,這在她看來是好訊息。如果生命是必然的,它就在到處都是;如果它稀有,那這一個就更值得好好照顧。
  • 把“不知道”說出口。金星論文最有價值的部分,是作者們在公開場合反覆承認訊號很弱、處理方式可以不同、結論可能翻轉。這種坦誠不會削弱科學,反而讓人相信其餘的部分。

訪談裡她說過一句話,可以當作整期的註腳。她說地球上的生命在我們之前就很好,在我們之後也會很好。樹、海豚、蟑螂、真菌,它們都會沒事的。

這句話聽起來像是在貶低人類,其實不是。它把人類從宇宙的中心挪開,然後給了我們一件更值得做的事:在還在這裡的這段時間裡,把能看懂的東西儘量看懂。

磷化氫是一個很具體的例子。它是一個有毒的、氣味恐怖的、沒人願意研究的分子,十年裡只有一個人認真給它算光譜。然後它出現在金星的大氣裡,讓全世界重新討論一個幾千年的問題。索薩-席爾瓦沒有說那就是外星人,她說的是:如果訊號是真的,我們不知道除了生命還能怎麼解釋它。這句話的分寸感,值得每個做判斷的人學一學。

她還有一句更樸素的話,講合作者的。她說不要當混蛋,就能做出很多好科學。這句話沒有引用價值,但它可能是整期節目裡最容易落地的一條。

文稿來自公開 Kaggle 資料集(rajneesh231/lex-fridman-podcast-transcript),為早期自動轉錄存檔,可能存在識別錯誤。
The following is a conversation with Clara Souza Silva, a quantum astrochemist at Harvard specializing in spectroscopy of gases that serve as possible signs of life on other planets, most especially the gas phosphine. She was a coauthor of the paper that in 2020 found that there is phosphine in the atmosphere of Venus and, thus, possible extraterrestrial life that lives in its atmosphere. The detection of phosphine was challenged, reaffirmed, and is now still under active research. Quick mention of our sponsors, Onnit, Grammarly, Blinkist, and Indeed. Check them out in the description to support this podcast. As a side note, let me say that I think the search for life on other planets is one of the most important endeavors in science. If we find extraterrestrial life and study it, we may find insights into the mechanisms that originated life here on Earth, and more than life, the mechanisms that originated intelligence and consciousness. If we understand these mechanisms, we can build them. But more than this, the discovery of life on other planets means that our galaxy and our universe is teeming with life. This is humbling and terrifying, but it is also exciting. We humans are natural explorers. For most of our history, we explored the surface of the Earth and the contents of our minds. But now, with spacefaring vessels, we have a chance to explore life beyond Earth, their physics, their biology, and perhaps the contents of their minds. This is the Lux Friedman Podcast, and here is my conversation with Clara Souza Silva. Since you're the world expert in, well, in many things, but one of them is phosphine, would it technically be correct to call you the queen of phosphine? I go for Dr. Phosphine. Queen is an inherited title, I feel. But you still rule by love and power, so, but while having the doctor title, I got it. Kindness. Kindness. Kindness. In September 2020, you coauthored a paper announcing possible presence of phosphine in the atmosphere of Venus, and that it may be a signature of extraterrestrial life. Big maybe. Big maybe. There was some pushback, of course, from the scientific community that followed, friendly, loving pushback. Then in January, another paper from University of Wisconsin, I believe, confirmed the finding. So where do we stand in this saga, in this mystery of what the heck is going on, on Venus in terms of phosphine and in terms of aliens? Let's try to break it down. The short answer is we don't know. I think you and the rest of the public are now witnessing a pretty exciting discovery, but as it evolves, as it unfolds, we did not wait until we had, you know, years of data from 10 different instruments across several layers of the atmosphere. We waited until we had two telescopes with independent data months apart, but still, the data is weak. It's noisy. It's delicate. It's very much at the edge of instrument sensitivity, sensitivity, and so we still don't even know if it is phosphine. We don't even really know if the signal is real. People still disagree about that. I think at the more philosophical end of how this happened, I think it is a distinction, and myself and other coauthors were talking about this, it's a distinction between hypothesis generation and hypothesis testing. Now hypothesis testing is something that I think is the backbone of the scientific method, but it has a problem, which is if you're looking through very noisy data and you want to test the hypothesis, you may by mistake create a spurious signal. The safest, more conservative approach is hypothesis generation. You see some data and you go, what's in there? With no bias. Now this is much safer, much more conservative, and when there's a lot of data, that's great. When there isn't, you can clean the noise and take out the signal with it. The signal with a bath water, whatever the equivalent of the analogy would be. And so I think the healthy discourse that you described is exactly this. There are ways of processing the data, completely legitimate ways, checked by multiple people and experts where the signal shows up and then phosphine is in the atmosphere of Venus, and some where it doesn't, and then we disagree what that signal means. If it's real and it is an ambiguously phosphine, it is very exciting because we don't know how to explain it without life, but going from there to Venusians is still a huge jump. And so... Venusians. So that would be the title for the civilization, if it is a living and thriving on Venus's Venusians. Until we know what they call themselves and that's the name, yes. So this is the early analysis of data or analysis of early data. It was nevertheless, you waited until the actual peer reviewed publication to know? Of course. And analysis of the two different instruments months apart. So that's ALMA and JCMT, the two telescopes. I mean, it's still, I mean, it's really exciting. What did it feel like sort of sitting on this data? Like kind of anticipating the publication and wondering and still wondering, is it true? Like how does it make you feel that a planet in our solar system might have phosphine in the atmosphere? It's nuts. It's absolutely nuts. I mean... In the best possible way? I've been working on phosphine for over a decade. Before it was cool. Way before it was cool. Before anyone could spell it or heard of it. And at the time people either didn't know what phosphine was or only knew it for being just possibly the most horrendous molecule that ever graced the earth. And so no one was a fan. And I had been considering looking for it because I did think it was an unusual and disgusting but very promising sign of life. I've been looking for it everywhere. I really didn't think to look in the solar system. I thought it was all pretty rough around here for life. And so I wasn't even considering the solar system at all, never mind next door Venus. It was only the lead author of the study, Jane Greaves, who thought to look in the clouds of Venus and then reached out to me to say, I don't know phosphine but I know it's weird. How weird is it? And the answer is very weird. And so the telescopes we're looking at, this is visual data. That's what I mean by visual. You wouldn't see the phosphine. Well, but I mean it's a telescope. It's remote. It's remote. You're observing, you're what zooming in on this particular planet and what does the sensor actually look like? How many pixels are there? What does the data kind of look like? It'd be nice to kind of build up intuition of how little data we have based on which, I mean, if you look at like, I've just been reading a lot about gravitational waves and it's kind of incredible how from just very little, like probably the world's most precise instrument, we can derive some very foundational ideas about our early universe. And in that same way, it's kind of incredible how much data, how much information you can get from just a few pixels. So what are we talking about here in terms of based on which this paper saw possible signs of phosphine in the atmosphere? So phosphine, like every other molecule has a unique spectroscopic fingerprint, meaning it rotates and it vibrates in special ways. I calculated how many of those ways it can rotate and vibrate, 16.8 billion ways. What this means is that if you look at the spectrum of light and that light has gone through phosphine gas on the other end, there should be 16.8 billion tiny marks left, indentations left in that spectrum. We found one of those on Venus, one of those 16.8 billion. So now the game is, can we find any of the other ones? But they're really hard to spot. They're all in terrible places in the electromagnetic spectrum. And the instruments we use to find this one can't really find any other one. There's another one of the 16.8 billion we could find, but it would take many, many days of continuous observations and that's not really in the cards right now. There's all kinds of noise, first of all. There's all kinds of other signal. So how do you separate all of that out to pull out just this particular signature that's associated with phosphine? So the data kind of looks somewhat like a wave and a lot of that is noise and it's a baseline. And so if you can figure out the exact shape of the wave, you can cancel that shape out and you should be left with a straight line and if there's something there, an absorption, so a signal. So that's what we did. We tried to find out what was this baseline shape, cleaned it out and got the signal. That's part of the problem. If you do this wrong, you can create a signal. But that signal is at 8.904 wave numbers and we actually have more digits than that, but I don't remember by heart. And ALMA in particular is a very, very good telescope, array of telescopes and it can focus on exactly that frequency. And in that frequency, there are only two known molecules that absorb it all. So that's how we do it. We look at that exact spot where we know phosphine absorbs the other molecules SO2. If there is extraterrestrial life, whether it's on Venus or on exoplanets where you looked before, how does that make you feel? How should it make us feel? Should we be scared? Should we be excited? Let's say it's not intelligent life. Let's say it's microbial life. Is it a threat to us? Are we a threat to it? Or is it only, not only, but mostly a possibility to understand something fundamental, something beautiful about life in the universe? Hard to know. You would have to bring on a poet or a philosopher on the show. I feel those things. I just don't know if those are the right things to feel. I certainly don't feel scared. I think it's rather silly to feel scared. Definitely don't touch them. Sometimes in movies, don't go near it. Don't interfere. I think one of the things with Venus is because of phosphine, now there is a chance that Venus is inhabited. And in that case, we shouldn't go there. We should be very careful with messing with them, bringing our own stuff there that contaminates it. And Venus has suffered enough. If there's life there, it's probably the remains of a living planet, the very last survivors of what once was potentially a thriving world. And so I don't want our first interaction with alien life to be a massacre. So I definitely wouldn't want to go near out of a, let's say, galactic responsibility, galactic ethics. And I often think of alien astronomers watching us and how disappointed they would be if we messed this up. So I really want to be very careful with anything that could be life. But certainly I wouldn't be scared. Humans are plenty capable of killing one another. We don't need extraterrestrial help to destroy ourselves. Scared mostly of other humans. Exactly. But these, this life, if there is life there, it does seem just like you said, it would be pretty rugged. It's like the cockroaches or Chuck Norris, I don't know. It's the, some kind of, it's something that survived through some very difficult conditions. That doesn't mean it would handle us, you know, it could be like war of the worlds. You come, just because you're resilient in your own planet doesn't mean you can survive another. The extremophiles, which are very impressive, we should all be very proud of our extremophiles. They wouldn't really make it in the Venusian clouds. So I wouldn't expect, because you're tough, even Chuck Norris tough, that you would survive on an alien planet. And then from the scientific perspective, you don't want to pollute the data gathering process by showing up there. The observer can affect the observed. How heartbreaking would it be if we found life on another planet and then we're like, oh, we brought it with us. It was my sandwich. But that's always the problem, right? And it's certainly a problem with Mars because we've visited the, if there is life on Mars or like remains of life on Mars, it's always going to be a question of like, well, maybe we planted it there. Let's not do the same with Venus. It's harder because when we try to go to Venus, things melt very quickly. So it's a little harder to pollute Venus. It's very good at destroying foreigners. Yeah. Well, in terms of Elon Musk and terraforming planets, Mars is stop number one, then Venus maybe after that. So can we talk about phosphine a little bit? So you mentioned it's a pretty... Love talking about phosphine. Love phosphine. What's your Twitter handle? It's like Dr. Phosphine. It's Dr. Phosphine. Yes. You will be surprised here. It wasn't taken already. I just grabbed it. I didn't have to buy it off anyone. Yeah. So what is it? What's phosphine? You already mentioned it's pretty toxic and troublesome and outside, troublesome, sorry. No, I love it. I'm going to stop calling it troublesome. So maybe what are some things that make it interesting chemically and why is it a good sign of life when it's present in the atmosphere? Like you've described in your paper, aptly titled the phosphine as a biosignature gas in exoplanet atmospheres. I suppose you wrote that paper before Venus. I did. Yes. I did. And no one cared. In that paper, I said something like, if we find phosphine on any terrestrial planet can only mean life. And everyone's like, yeah, that sounds about right. Let's go. And then Venus shows up and I was like, are you sure? I'm like, I was sure before I was sure. Now that it's right here, I'm less sure now that my claims are being tested. So phosphine, phosphine is a fascinating molecule. So it's shaped like a pyramid with a phosphorus up top and then three hydrogens. It's actually quite a simple molecule in many ways and you know, it's the most popular elements in the universe, carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur. When you add hydrogen to them, it makes quite simple, quite famous molecules. You do it to oxygen, you get water, you do it to carbon, you get methane, you do it to nitrogen, you get ammonia. These are all molecules people have heard of, but you do it to phosphorus, you get phosphine. People haven't heard of phosphine because it's not really popular on earth. You really shouldn't find it anywhere on earth because it is extremely toxic to life. It interacts with oxygen metabolism and everything you know and love uses oxygen metabolism and it interacts fatally. So it kills in several very imaginative and very macabre ways. So it was used as a chemical warfare agent in the first world war and most recently by ISIS. So really bad. Most life avoids it. Even life that might not avoid it, so life that doesn't use oxygen metabolism, anaerobic life still has to put crazy amounts of effort into making it. It's a really difficult molecule to make, thermodynamically speaking. It's really difficult to make that phosphorus want to be together with that hydrogen. So it's horrible. Everyone avoids it. When they're not avoiding it, it's extremely difficult to make. You would have to put energy in, sacrifice energy to make it. And if you did go through all that trouble and made it, it gets reacted with the radicals in the atmosphere and gets destroyed. So we shouldn't find it anywhere and yet we do. This is kind of weird molecule that seems to be made by life and we don't even know why. Life clearly finds a use for it. It's not the only molecule that life is willing to sacrifice energy to make, but we don't know how or why life is even making it. So absolutely mysterious, absolutely deadly, smells horrifically. When it's made, it produces other kind of diphosphenes and it's been reported as smelling like garlicky, fishy death. Once someone referred to it as smelling like the, let me see if I remember, the rancid diapers of the spawn of Satan. Oh, very nice. Yeah, very vivid. And so... You're a poet after all. I didn't call it that, someone else did. And so it's just this horrific molecule, but it is produced by life. We don't know why. And when it is produced by life, it's done with enormous sacrifice and the universe does not sacrifice, life sacrifices. And so it's this strange, contradictory molecule that we should all be avoiding and yet seems to be an almost an ambiguous sign of life on rocky planets. Okay. Can we dig into that a little bit? So on rocky planets, is there biological mechanisms that can produce it? You said that why is unclear, why life might produce it, but is there an understanding of what kind of mechanisms might be able to produce it, this very difficult to produce molecule? We don't know yet. The enzymatic pathways of phosphine production by life are not yet known. This is not actually as surprising as it might sound. I think something like 80% of all the natural products that we know of, so we know biology makes them. We don't know how. It is much easier to know life produces something because you can put bacteria in a Petri dish and then watch and then that gas is produced, you go, oh, life made it. That actually happened with phosphine. But that's much easier to do of course, than figuring out what is the exact metabolic pathway within that life form that created this molecule. So we don't know yet. Phosphine is really understudied. No one had really heard of it until nowish. What you were presenting is the fact that life produces phosphine, not the process by which it produces phosphine. Is there an urgency now? Like if you were to try to understand the mechanisms, the, what did you call them, enzymatic pathways that produce phosphine, how difficult is that of a problem to crack? all of human civilization. So to roll your eyes is not the right answer. To roll your eyes presumes that you know anything about this world as opposed to just knowing point zero zero zero one percent of this world. And so being humble in the face of that, being open to the possibility of aliens visiting Earth is a good idea. Not everything, though. I'm not so open minded to the flat Earth hypothesis as there's a growing number of people believing in. But even then. Or the inner Earth, I've got shouted at in a public talk about it. So like the Earth is hollow? Yeah. My understanding is that there's this conspiracy theory that as far as I can tell has no grounding in reality is that there's a slightly smaller Earth inside this one, which is just too cute as a concept. That's awesome. And you can access it, I think, from Antarctica. And that's where we keep, and I quote, the mammoths and the Nazis. Yeah, I mean, that one is ridiculous. But like I do like. Hey, I thought you were keeping an open mind. I genuinely think that's more likely than aliens visiting the Earth. And I say this as someone who has dedicated her life to finding like alien life. And so that's how improbable, I think, the visitations are. Because interstellar distances are so huge that it's just not really worth it. See, I have a different view on this whole thing. I think the aliens that look like little green men are like extremely low probability event. Like mammoths and Nazis under that level. But other kind of ideas, like the sad thing to me, and I think in my view, if there's other alien civilizations out there and they visited Earth, neither them or perhaps just us would be even able to detect them. Like we wouldn't be open minded enough to see it. Like if, because our understanding of what is life, and I just talked to Sarah Walker, who's. You know Sarah. Yeah, we talked for three hours about the question of what is life. Sarah's a good person to talk to about what is life. But like the whole point is we don't really, we have a very narrow minded view of what is life. And when it shows up, and it might be already here, trees and dolphins and so on, or mountains or I don't know, or the molecules in the atmosphere, or like people make fun of me. But I do think that ideas are kind of aliens themselves, or consciousness could be the aliens, or it could be the method by which they communicate. We don't know shit about the way our human mind works. And the fact that this thing is a quantum process, please don't I understand this. It's not woo woo. I'm not I, we could, but it very well could be there could be something at the at the physics level, right? It could be at the chemical or the biological level, things that are happening that we're just close to close minded, because our conception of life is at the level of like us, like at the jungle level of mammals. And on the time scale, that's the human time scale, we may not be able to perceive what alien life is actually like what the scale at which their intelligence realizes itself when we're not able to perceive. And the other thing that's really important about alien visitations, whether it happened or not, is especially after COVID in 2020, I'm losing a little bit of faith of our government being able to handle that that well, not our government, but us as a society, as a collective, being able to deal with new things in an effective way that's inspiring, that's efficient, that like, whether it's if it's a dangerous thing to deal with it to alleviate the danger, whether it's the possibility of new discoveries and something inspiring to ride that wave and make it inspiring all those kinds of things. I honestly think if aliens showed up, they would look around, everybody would ignore them and the government might like hide it, try to like see to keep it from the Chinese and the Russians if it's the United States, call it a military secret in a very close minded way. And then the bureaucracy would drown it away to where through paperwork, the poor aliens would just like waste away and sell somewhere like there's a certain That would not happen, that would never happen, part of the reason that I feel so confident that aliens have not visited because they would have had to visit just to have a look remotely, from Neptune or something, which makes no sense because interstellar travel is so difficult that it would be quite a ridiculous proposition, but that's the bit that I think is technically possible. If they did come here and they were visible by anyone, detectable by anyone, the thought that any government, no matter, or any military could just contain them, these beings are capable of traveling interstellar distances when we can barely go to the moon, like barely go to the moon. These things would be way, way, way, way out there. Way. And the fact that we think our puny military, even if all the military in the world got together and the fact that they could somehow contain it, that's the bit that's laughable. Ants trying to contain a human that visited them. Exactly. And scientists, you would have to bring scientists on board. You've met a lot of scientists. How good are they at keeping secrets? Because in my experience, they're absolutely appalling at keeping secrets. Yeah, that's terrible. Even the Phosphine on Venus thing, which was a pretty well kept secret. This is true. You had a bunch of people that were. I told my dad. Yeah. You know, my dad knew and hopefully didn't tell anyone, but if it had been an alien visiting, he probably would have told a mate, you know? And so these secrets could not be kept by any scientist that I know and certainly not collaborative scientists, which would be needed. You would need all sorts of scientific teams. So between the pathetic power of any world's military compared to any civilization capable of traveling and our absolute inability to keep secrets, absolutely not. I will bet everything that we have not been visited because we are too pathetic to hold that truth. If we're just making like a $10 bet, the possibility here that the main alien, say there exists one alien civil, other intelligent alien civilization in the galaxy. To me, if they visit Earth, what's going to visit Earth is like the crappy, like the really crappy, short straw, like, like this, this like really dumb thing that's, I don't know, like the early game boys or something like, there's a cartoon about this. There's an alien that gets sent to Earth, Commander Spiff or something, and it's kind of a punishment or something, but that's not possible. That's the thing because interstellar distances are so hard to, to cross. You have to do it on purpose. You have to do on purpose. It has to be a big, big deal, and we know this because yes, you're right. We don't know enough about galactic biology. We don't know what the universal rules of biology or biochemistry are because we only have the Earth, but we do know that the laws of physics are universal. We can predict behavior in the universe and then see it happen based on these laws of physics. We know that the laws of chemistry are universal. We know the periodic table is all they have to choose from. So yes, they may be some sort of unimaginable intelligence, but they still have to use the same periodic table that we have access to. They still have a finite number of molecules they can do things with. So they still have to use the resources around them, the stars around them, the universe around them, and we know how much energy is in these places. And so yes, they may be very capable, capable beyond our wildest dreams, but they're still in the same universe, and we know a lot of those rules. We're not completely blind. But there's a colleague of yours at Harvard, Kamran Vafa, he's a theoretical physicist. I don't know if you know him. I've only joined Harvard about six months ago. Okay. It's time to meet all the theoretical physicists. So he's a string theorist, but his idea is that aliens that are sophisticated enough to travel interstellar like those kinds of distances will figure out actually ways to hack the fabric of the universe enough to have fun in other ways, like this universe is too boring. Like you would figure out ways to create other universes, like you go outside the physics as we know it. So the reason we don't see aliens visiting us all over the place is they're having fun elsewhere. This is like way too boring. We humans think this is fun, but it's actually mostly empty space that no fun is happening. There's no fun in visiting Earth for a super advanced civilization. So he thinks like if alien civilizations are out there, they found outside of our current standard models of physics ways of having fun that don't involve us. That's probably true, but even the notion of visiting, that's so literally pedestrian. Of course we want to go there because going there is the only thing we know. We see a thing we want, we want to go there and get it. But that is probably something they've no longer gotten need for. I specifically don't particularly want to go to space. Sounds awful. None of the things I like are going to be there. My whole work is my whole career is finding life and understanding the universe. So I care a lot, but I care about knowing about it and I feel no need to go there to learn about it. And I think as we develop better tools, hopefully people will feel less and less a need to go everywhere that we know about. And I would expect any alien civilization worth the salt have developed observation tools and tools that allow them to understand the universe around them and beyond without having to go there. This going is so wasteful. Yeah. So more focused on the knowledge and learning versus the colonization, like the conquering and all those kinds of things. That's beneath them. That's beneath them. I mean, that said, do you think there's in your hopeful search for life through phosphine and other gases, do you think there's other alien civilizations out there? First do you think there's other life out there? First do you think there's life in the solar system? Second do you think there's life in the galaxy? And a third, do you think there's intelligent life in the solar system or the galaxy outside of earth? So intelligent life, I have no idea. It seems deeply unlikely possible, but I'm not even sure if it's plausible. So that's the special thing to you about earth is somehow intelligent life came to me. Yes. And it's only, you know, very briefly, probably extremely briefly. Oh, you mean like it's always going to be like, we're going to destroy ourselves. Exactly. Oh boy. We're going to continue on earth happily, probably more happily. So the trees and the dolphins will be here, I'm telling you. And the cockroaches and the incredible fungi, you know, they'll be fine. So life on earth will be fine, was fine before us and will be fine after us. So I'm not that worried about intelligent life, but I think it is unlikely, even on earth is unlikely out of, what is it, five billion species across the history of the earth. Yes. For an intelligent one and for a blink of an eye, possibly not much longer than that. So I wouldn't bet on that at all, though I would love it, of course, you know, I wanted to find aliens since I was a little girl. And so of course I initially wanted to find ones that I could be friends with and I've had to let go of that dream because it's so deeply implausible. But see the nice, and sorry to interrupt, but the nice thing about intelligent alien civilizations, they may have more biosignatures than nonintelligent ones. So they might be easier to detect, that would be the hope. On earth that's not the case, but it could be the case elsewhere. Oh, it's not the case on earth. Most of the biosignatures we have on earth are created by quite simple life. If you don't count pollution, pollution is all, all us baby. So you don't see polluting gases as a possible, like. I look for polluting gases. I would love to find polluting gases. Well, you know, I'd be worried for them, of course, the same way I, I think about my alien colleagues all the time looking at us and I'm sure they worry about our pollutions, but it would be a really good, robust, unambiguous sign of life if we found complex pollutants. So I look for those too. I just don't have any hope of finding them. I think intelligent life in the galaxy at the same time that we're looking is deeply implausible, but life I think is inevitable and if it is inevitable, it is common. So I think there'll be life everywhere in the galaxy. Now how common that life is, I think will depend a lot on whether there's life in the solar system beyond earth. So I'll adjust my expectations very much based on there being life in the solar system. If there's life in the Venusian clouds, if there's life in the, if there are biosignals coming out of the plumes of Enceladus, if there's life on Titan. Yeah, that's right. Yeah, yeah. Plumes of Enceladus. That's the, that's the Saturn one. It's the moon that has the geysers that come out. And so you can't see the, under the subterranean oceans, but. It's supposed, so it would be in the atmosphere. I was going to ask you about that one. Have you looked at that? Have you, is that a hope for you to use the tools you're using with RASCAL and other ways for detecting the 16,000 molecules that might be biosignatures to look at Enceladus? Yes, that's absolutely the plan. What's the limiting factor currently? Is it the quality of the telescopes, what's the quality of the data? Yeah, the quality of the data, the observational data, and also the quality of RASCAL and other associated things. So we're missing a lot of fundamental data to interpret the data that we get and we don't have good enough data. But hopefully we will, in the coming decades, we'll get some information on Titan. We have Dragonfly going over. We'll get the plumes of Enceladus. We will look at the clouds of Venus and there's other places. And so if we find any life or any sign of life ever, like on Mars, then I'll adjust my calculations and I'll say life is not just inevitable and common, but extremely common. Because all of these places we've mentioned, the subterranean oceans on Enceladus, the methane oceans of Titan, the clouds of Venus, the acidic clouds of Venus, these are places that are very different from the places where we find life on Earth. Even the most extreme places. And so if life can originate in all of these completely different habitats, then life is even more resourceful than we thought, which means it's everywhere. That's really exciting if it's everywhere. If there's life on just one of the moons, if it's on Mars. Anywhere. Anywhere in the solar system and I will bet everything I own that every solar system, every planetary system has a potential for habitability. Because even if they don't have a habitable planet, they'll have moons around other giant planets and there'll be so much life. So for me, that's the only thing to figure out now, whether life is inevitable and quite common throughout the galaxy or everywhere, but it's somewhere between those two. In life, I make no bets and if I had to bet, I would be against. To me, like two discoveries in the 21st century would change everything. One is, and maybe I'm biased, but one is a discovery of life in the solar system. I feel like that would change our whole conception of how unique we are in the universe. I think I'm much more eager than you are to jump from basic life to intelligent life. I feel like if there's life everywhere, like the odds are, there has, like we cannot, like you have, oh, I see. You're saying there could have been many intelligent civilizations out there, but they just keep dying out. It's like little. Yeah. I was detecting them, you know, ships in the night. Ships in the night. No, that's ultra sad. Just like. Is it sad? The earth is not better for having us. Is it, we, it doesn't owe us anything. Would you be sad to find alien giraffes? Would you be disappointed if you found alien giraffes? Because I would not. No, well, giraffes, first of all, they look goofy with their necks and everything, but. We do not shit on giraffes. Okay. Giraffes are wondrous animals, are deeply understudied. We still know so little about them because no one does PhDs in giraffes. I am disappointed I made a PhD in phosphine when people aren't doing PhDs in giraffes. We do not know enough about giraffes. I think it was like Ricky Gervais that did a whole, like a long thing. You can't trust Ricky Gervais to talk about giraffes. That is not his expertise. Yeah. But it's a stupid necks, it doesn't make any sense. I mean, that's fine. Giraffes are very resourceful animals who do incredible things and can kick a lion in the face. Why don't you climb the tree? Why don't you climb the tree? You don't need to grow through the lengthy evolutionary process. You're shitting on giraffes. Okay. Giraffes are wondrous animals. Fine. I would very appreciate it. Take it back. I take it back. I apologize. I trust your expertise on this. The thing that makes humans really fascinating, and I think the earth, but I'm a human, is we create things that are, yes, there's all the ugliness in the world. There's all the, on the biological, on the chemical level, there's the pollution, but we create beauty. If you even from a physics perspective, look at symmetry as somehow capturing beauty, the breaking of symmetries, stuff grounded in all the different definitions of symmetry, we're good at creating things. So are spiders. But not giraffes. Okay. But yes, this is a... Spiders. Spiders that create little bubbles of air so they can breathe underwater, they can literally scuba dive. There are spiders that can create parachutes so they can glide. And talk about symmetry, look what spiders can do. And I just thought of spiders, but if I was an alien species coming to earth, there'll be plenty to wonder, and we would just be one of the things, clunky, naked monkey. The ants might be even more fascinating. The ants. The ants can figure out exactly through some emergent consciousness what the maximum distance between their trash, their babies, and their food is just from without any of them knowing how to do this. And collectively they've learned how to do this. If I was an alien species, I'll be looking at that. Well, so that was the other thing I was going to mention. The second thing is I tend to believe we can engineer consciousness, but at the basic level, in the source of consciousness, because if consciousness is unique to humans, and if we can engineer it, that gives me hope that it could be present elsewhere in the universe. That's the other thing that makes, it's an open question, that makes humans perhaps special is not maybe the presence of consciousness, but somehow a presence of elevated consciousness. It does, again, maybe human centric, but it feels like we're more conscious than giraffes, for example, and spiders. Yes, I won't deny that. There is something special about humans. They're my favorite species. They are. They are. Some of my best friends are humans. I think highly of humans. It's great. I just don't have great hope for our longevity, and specifically I don't have great hope given that we're the only species that are five billion that did this cool consciousness trick. I just, I don't want to bet on finding a kinship elsewhere. That's quite interesting to think about. I don't think I've even considered that possibility that there would be life in the solar system, so that indicates that very possibly life is literally everywhere. Everywhere it can happen, it does. And especially what we're discovering with the exoplanets now, how numerous they are, or earthlike habitable, quote unquote, planets, they're everywhere. The most common type of planet is rocky, it seems. But I didn't consider the possibility that life is literally everywhere, and yet intelligent life is nowhere long enough to communicate with each other, to form little clusters of civilizations that expand beyond the solar system and so on. Man, maybe becoming a multi planetary species is a less likely pursuit than we imagine. I agree. But one of the things that makes humans beautiful is we hope. What I hope for humanity, and one of the things I hope for is that we become less obsessed with conquering, and we become less obsessed with spreading ourselves. I hope that we transcend that, that we're happy with the universe without having to go and take it. So you can hope for the species without hoping for a multi planetary existence. That is only, I think, the drive of our most primitive instincts to go and take, to go and plant a flag somewhere. We love planting a flag somewhere. And maybe we could overcome that minor drive. And once we do, the AI systems we build will destroy us because we're too peaceful, and they will go and conquer and plant the flags. Best of luck to them. Rock roaches will be happy to keep to the business as they always have. I tend to believe that robots can have the same elegance and consciousness and all the qualities of kindness and love and hope and fear that humans have. In principle, they could, yes. I don't really trust the people who make them. This is about the giraffe comment, isn't it? I haven't forgiven you for shitting on giraffes, whatever they've done to you. Just as a small tangent, your master's thesis is also fascinating. Maybe we could talk about it for just a little bit. It's titled Influence of a Star's Evolution on its Planetary System. So this interplay between a star and a planet, is there something interesting you could say about what you've learned about this journey that a star takes and the planets around it? Well, when I was younger and I was told what would happen ultimately to the Earth as the sun expands towards a red giant and mercury would just like fall in and then Venus fall in and the sun doesn't care. And it just seemed so, I felt so small. I felt like the Earth and everything on it, it's just the universe doesn't care. Even our sun doesn't care. And I think I felt like our sun should feel some sort of responsibility for its planets. And it just felt like such a violent and neglectful parent. It's like a parent eating its own children. It's horrible. It's just a horrible notion, but it made me think, what if there's some sort of generation? And so at the time when I was doing my master's, there was a notion of the white dwarf cemetery, which is this idea that when stars become white dwarfs, that death is so horrible that planets, potentially habitable planets that could have been habitable before, they're now gone. There's no chance for life. But then I thought, what if life returns? Now it's a white dwarf, it's calmed down, it's not going to go anywhere. White dwarfs are very stable across like universal timescales. And so could you have planets around the white dwarf that could themselves get life again? No, life doesn't care. And so my work was basically killing dozens of planets, thousands of times. I just ran thousands and thousands of end body simulations. Oh, you simulated this? Yeah. So I simulated the star growing and just eating all these planets up and just absolute chaos. The orbits of the planets would change as the star loses mass. So you would have like Jupiter planets just crashing into the other planets, throwing them into the sun early. It was terrifying to watch these simulations. It was absolute carnage. But if you run thousands of these simulations, some systems find new balance ways of staying alive. Some systems post star death find stable orbits again for billions of years, more than enough for life to originate again. And so that was my idea during that time that Thesis was trying to explore this notion of life coming back. And this idea of the universe doesn't care if you're here or not, and it will go about its business. Andromeda will crash into us and doesn't care. No one cares if you're alive in the universe. And so letting go of that preciousness of life, I found very useful at that stage of my career. And instead, I just thought, if life is inevitable, it doesn't matter that it came by four billion years ago. It can start again four billion years later. And maybe that is nice. Maybe that's where hope lies, the Phoenix rising everywhere. Planets being destroyed and created and we're here now and others will be more or less hereish billions of years later. So accepting the cycle of death and life and yeah. Not taking it personally. Not taking it personally. The sun doesn't owe us anything. It's not a bad parent. It's not a parent at all. Yeah. I was looking at the work of Freeman Dyson and seeing how this universe eventually will just be a bunch of supermassive black holes before they also evaporate. A bunch of tiny black holes too. Yeah. Absolute quiet. Everyone, all the black holes a little too far away from one another to even interact until it's just silence forever. But until then, many, many cycles of death and destruction and rebirth. And rebirth. You kept bringing up sort of coding stuff up. I wanted to ask two things. First of all, what programming language do you like? And also what, because you're as a computational quantum astrochemist, no, yes, that's right. You're kind of, you could say you're actually understanding some exceptionally complicated things with one of the things you're using is the tools of computation of programming. Is there a device you can give to people, because I know quite a few that have not practiced that tool and have fallen in love with a particular science, whatever it's biology and chemistry and physics and so on. And if they were interested in learning to program and learning to use computation as a tool in their particular science, is there advice you can give on programming and also just maybe a comment on your own journey and the use of programming in your own life? Well, I'm a terrible programmer. A lot of scientists, their programming is bad because we never learned formal programming. We learned science, physics, chemistry. And then we were told, oh, you can, you have to get these equations modeled and run through a simulation. And you're like, oh, okay, so I'm going to learn how to code to do this. And you learn just as much as you need to run these simulations and no more. So they're rarely optimized and they're really clunky. Six months later, you can't read your own code. My variable names are extremely embarrassing. I still have error messages for different compilation errors that say things like, at least your dad loves you, Clara. You know, it doesn't help me at all. Just like you suck at coding, but there's other things in your life. So I'm a bad programmer. And so, you know, if that will give hope to anyone else who's a bad programmer, I can still do pretty impressive science. But I learned, I think I started learning MATLAB and Java when I was in college. It did me no good at all. It has not been particularly useful. I learned some Fortran that was very useful, even though it's really not a fun language because so much of legacy code is in Fortran. And so if you want to use other people's code who have now retired, Fortran will be nice. And then I used IDL to visualize. So that simulation and body simulation, those all Fortran and IDL. But thankfully, since I've left college, I've just learned Python like a normal person and that has been much nicer. So most of my code now is in Python. I should also make a few quick comments as well. So one is, you say you're sort of bad at programming. I've worked with a lot of excellent scientists that are quote unquote bad at programming. They're not. It gets the job done. In fact, there's a downside to sort of, especially getting a software engineering education. If I were to give advice, especially if you're doing a computer science degree and you're doing software engineering, is not to get lost in the optimization of the correct, there's an obsession, you could see it in like Stack Overflow, of the correct way to do things. And I think you can too easily get lost in constantly trying to optimize and do things the correct way when you actually never get done. The same thing happens, you have like communities of people obsessed with productivity and they keep researching productivity hacks and then they spend like 90% plus of their time figuring out how to do things productively and then never actually do anything. So there's a certain sense if you focus on the task that needs to be done, that's what programming is for. So not over optimizing, not thinking about variable names in the following sense. Sometimes you think, okay, I'm going to write code that's going to last for decades. In reality, your code, if it's well written or poorly written, will be very likely obsolete very quickly. The point is to get the job done really well. So there's a trade off there that you have to make sure to strike. I should also comment as a public service announcement or a request, if there's any world class Fortran or Cobalt programmers out there, I'm looking for them, I want to talk to you. That will not be me, I'm a terrible Fortran programmer. But it's fascinating because so much of the world in the past and still runs programming languages and there's no experts on it. They're all retiring. I disagree slightly in that I think because I can get the job done, I'm a programmer. But because no one else can look at my code and know how I got my job done, I'm a bad programmer. That's how I'm defining it. Including yourself. Including myself six months later, I'm working with a new student right now and she sent me some messages on Slack being like, what is this file that you've got with some functions that run? And I was like, this was from 2018, it wasn't that long ago and I can no longer remember what that code does. I'm going to spend now two days reading through my own code and trying to improve it. And I do think that's frustrating. And so I think my advice to any young people who want to get into astronomy or astrobiology or quantum chemistry is that I certainly find it much easier to teach the science concepts to a programmer than the programming to a scientist. And so I would much, much faster hire someone who knows programming but barely knows where space is than teach programming to an astronomer. Oh, that's fascinating. Yeah. Okay. This is true. I mean, yeah, there's some basics. I'm focusing too much on the silver lining because the people that write MATLAB code, yeah, single variable, single letter variable names, those kinds of things. And it's accessibility, right? It's I want my code to be open source and it is, it's on GitHub, anyone can download it. But is it really open source if it's written so cryptically, so poorly that no one can really use it to its full functionality? Have I really published my work and that weighs on me? I feel guilty for my own inadequacies as a programmer. But you can only do so much. I've already learned quantum chemistry and astrophysics. So yeah, I mean, there's all kinds of ways to contribute to the world. One of them is publication, but publishing code is a fascinating way to contribute to the world, even if it's very small, very basic element, great code. I guess I was also kind of criticizing the software engineering process versus like, which is a good thing to do is code that's readable, almost like without documentation, it's readable, it's understandable. The variable names, the structure, all those kinds of things. That's the dream. That's the dream. This is a dumb question. What do you, all right. No, no, tell me a dumb question. I want to hear it. Okay. I mean, okay, this is the question about beauty. It's way too general. It's very impossible. It's like asking, what's your favorite band? What's your favorite music band? Oh, I thought you meant wavelength band. I was like, I definitely have favorite wavelength bands. Absolutely. Well, it's hard to narrow it down, huh? Okay. What do you use the most beautiful idea in science? It's not a dumb question. Do you want to try the question again proudly? Okay. I have a really good question to ask you. Okay. Don't oversell it. I've got an okay question to ask you, you know? What do you use the most beautiful idea in science, something you just find inspiring or just maybe the reason you got into science or the reason you think science is cool? My favorite thing about science is kind of the connection between the scales. So when I was little and I wanted to know about space, I really felt that it would make me feel powerful to be able to predict the heavens. Something so much larger than myself that felt really powerful. It was almost a selfish desire and that's what I wanted. There was some control to being able to know exactly what the sky would do. And then as I got older and I got more into astronomy and I didn't just want to know how the stars moved. I wanted to know how the planets around them moved. And then as I got deeper into that field, I really didn't care that much about the planets. I wanted to know about the atmospheres around the planets and then the molecules within those atmospheres and what that might mean. So I ended up shrinking my scale until it was literally the quantum scale. And now all my work, the majority of my work is on this insane quantum scale. And yet I'm using these literal tiny, tiny tools to try and answer the greatest questions that we've ever been able to ask. And this crossing of scales from the quantum to the astronomical, that's so cool, isn't it? Yeah. It spans the entirety, the tiny and the huge. That's the cool thing about, I guess, being a quantum astrochemist is you're using the tools of the tiny to look at the heavenly bodies, the giant stuff. And the potential life out there that this is the thing that connects us, that you can't escape the rules of the quantum world and how universal they themselves are despite being probabilistic. And that makes me feel really pleased to be in science, but in a really humbling way. It's no longer this thirst for power. I feel less special the more work I do, less exceptional the more work I do. I feel like humans and the earth and our place in the universe is less and less exceptional. And yet I feel so much less lonely. And so it's been a really good trade off that I've lost power, but I've gained company. Wow. That's a beautiful answer. I don't think there's a better way to actually end it. You're right. I asked a mediocre question and you came through. You made the question good by a brilliant answer. You're the Michael Jordan and I'll be the Dennis Rodman. I don't know enough about basketball. I mean, literally you've reached the peak of my basketball knowledge because I know that those people are basketball pros, I believe, but only because I watch Space Jam, I think. Are there books or movies in your life? Long ago or recently, do you have any time for books and movies had an impact on you? What ideas did you take away? I absolutely have time for books and movies. I try as best I can to not work very hard. I mostly fail. I should point out. But I think I'm a better scientist when I don't work evenings and weekends. If I get four good hours in a day, I often don't. I often get eight crappy hours, emails, meetings, bad code, data processing. But if I can get four high quality scientific hours, I just stop working for the day because I know it's diminishing returns after that. So I have a lot of time. I try to make as much time as I can. Can you kind of dig into what it takes to be, one, productive, two, to be happy as a researcher? Because I think it's too easy in that world because you have so many hats, you have to wear so many jobs, you have to be a mentor, a teacher, a head of a research group to research yourself. You have to do service, all the kinds of stuff you're doing now with education and interviews. So as a public science, like being a public communicator, that's a job. The whole thing. Pays very poorly. I'll pay you in Bitcoin. Okay. I'll take Bitcoin. So is there some advice you can give to the process of being productive and happy as a researcher? I think, sadly, it's very hard to feel happy as a scientist if you're not productive. It's a bit of a trap, but I certainly find it very difficult to feel happy when I'm not being productive. It's become slightly better. If I know my students are being productive, I can be happy. But I think a lot of senior scientists, once they get into that mindset, they start thinking that their student science is theirs. And I think this happens a lot with senior scientists. They have so many hats, as you mentioned, they have to do so much service and so much admin, that they have very little time for their own science. And so they end up feeling ownership over the junior people in their labs and their groups. And that's really heartbreaking. I see it all the time. And that, I think I've escaped that trap. I feel so happy, even when I'm not productive, when my students are productive. I think that sensation I was describing earlier of they only need to be half as productive as me for me to feel like I've done my job for humanity. So that has been the dynamic I've had to worry about. But to be productive is not clear to me what you have to do. You have to not be miserable otherwise. I find it extremely hard when I'm having conflicts with collaborators, for example, kind of very hard to enjoy the work we do. Even if the work is this fantastical phosphine or things that I know I love, still very difficult. So I think choosing your collaborators based on how well you get along with them is a really sound scientific choice. Being a miserable collaborator ruins your whole life. It's horrible. It makes you not want to do the science. It probably makes you do clumsy science because you don't focus on it. You don't go over it several times. You just want it to be over. And so I think in general, just not being a douchebag can get so much good science done. Just find the good people in your community and collaborate with them. Even if they're not as good scientists as others, you'll get better science out. Yeah, don't be a douchebag yourself and surround yourself by other cool people. Exactly. And then you'll get better science than if you would try to work with three geniuses who are just hell to be around. Yeah. I mean, there's parallel things like that. I'm very fortunate now. I was very fortunate at MIT to have friends and colleagues there that were incredible to work with. But I'm currently sort of, I'm doing a lot of fun stuff on the side, like this little podcast thing and I mentioned to you, I think, robotics related stuff. I was just at Boston Dynamics yesterday checking out their robots. And I'm currently, I guess, hiring people to help me with a very fun little project around those robots. Want to put an ad in? No. I have more applications I can possibly deal with, there's thousands. So it's not an ad, it's the opposite. We need to put an ad out for someone to help you go through the applications. Well, that too is already there. Over 10,000 people apply for that. An infinite Master Yoshika doll of application management. But the point is, it's not exactly, the point is, like what I'm very distinctly aware of is life is short and productivity is not the right goal to optimize for, at least for me. The right goal to optimize for is how happy you are to wake up in the day and to work with the people that you do. Because the productivity will take care of itself. Agreed. And so like, it's so important to select the people well. And I think one of the challenges with academia, as opposed to sort of the thing I'm currently doing is, like, saying goodbye is sometimes a little bit tougher. Because your colleagues are there, I mean, their goodbye hurts. And then if you have to spend the rest, you know, for many years to come, still surrounded by them in the community, it's tougher. It kind of adds, puts extra pressure to stay in that relationship, in that collaboration. And in some sense, that makes it much more difficult, but it's still worth it. It's still worth it to break ties if you don't, if you're not happy, if there's not that magic, that dance. I talked to this guy named Daniel Kahneman. Oh, I know. Danny Kahneman. Danny, yeah. Boy, did that guy make me realize, like, what a great collaborator is. Well, he had Tversky, right? Yeah. So they had, obviously, they had a really deep collaboration there, but, like, I collaborated with him on a conversation, like, just, like, talking about, I don't know what we're talking about. I think cars, autonomous vehicles, but the brainstorming session, I'm like a nobody. And the fact that he would, with that childlike curiosity and that dance of thoughts and ideas and the push and pull and the, like, and the lack of ego, but then enough ego to have a little bit of a stubbornness over an idea and a little bit of humor and all those things, it's like, holy shit, that person, also the ability to truly listen to another human, it's like, okay, that's what it takes to be a good collaborator. It made me realize that I haven't been, I've been very fortunate to have cool people in my life, but there's, like, levels even to the cool. Yeah, I don't think you can compete with Danny Kahneman on cool. He's just incredible. Everybody was like, okay, I guess what I'm trying to say is that collaboration is an art form, but perhaps it's actually a skill, is allowing yourself to develop that skill because that's one of the fruitful skills. And praise it in students, you know, and I think it is something you can really improve on. I've become a better collaborator as the years have gone on. I don't have some innate collaborative skills. I think they're skills I've developed, and I think in science there's this really destructive notion of the lone wolf, the scientist who sees things where others don't, you know, then that's really appealing and people really like either fulfilling that or pretending to be fulfilling that. And first of all, it's mostly a lie. Any modern scientist, particularly in astronomy, which is so interdisciplinary, any modern scientist that's doing it on their own is doing a crappy job most likely because you need an independent set of eyes to help you do things. You need experts in the sub fields that you're working on to check your work. But most importantly, it's just a bad idea. It doesn't lead to good science and it leaves you miserable. I was recently, I had some work that I was avoiding and I thought maybe I should pursue the scientific project because I don't care enough about the outcome and it's going to be a lot of hard work. And I was trying to balance these two things to be really difficult. And the outcome is that maybe 10 people will cite me in the next decade because it's not, no one's asking for this question to be answered. And then I found myself working with this collaborator, Jason Dittman. And I spent a whole afternoon hours with him working on this and time flew by and I just felt taller and like I could breathe better. I was happier, I was a better person when it was done. And that's because he's a great collaborator. He's just a wonderful person that brings out joy out of science that you're doing with him. And that's really the trick. You find the people that make you feel that way about the science you're doing and you stop worrying about being the lone wolf. That's just a terrible dream that will leave you miserable and your science will be shit. And since I'm Russian, just murder anybody who doesn't fall into that beautiful collaborative relationship. We were talking about books. Books, yes. Is there books, movies? Why was I talking about my productivity? Oh, you said you maybe don't have time for books and movies. And you said you must make time for books and movies. Make time to not work. Make time to not work whatever that looks like to you. But there's plenty. When I was younger, I found a lot of my scientific fulfillment in books and movies. Now as I got older, I have plenty of that in my work and I try to read outside my field. I read about Danny Kahneman's work instead. But when I was little, it was Contact, the Carl Sagan book. I really thought I was just like Ellie and I was going to become Ellie. I really resonated with me, that character and the notions of life and space and the universe. Even the idea of then the movie came out and I got to put Jodie Foster in that, which helped. But even the notion of if it is just us, what an awful waste of space, I find extremely useful as a concept to think maybe we are special, but that would suck is a really nice way of thinking of the search for life, that it's much better to not be special and have company. I got that from Carl Sagan. So that's where I always recommend. Let me ask one other ridiculous question. We talked about the death and life cycle that is ever present in the universe until it's not, until it's supermassive and little black holes too at the end of the universe. What do you think is the why, the meaning of it all? What do you think is the meaning of life here on Earth and the meaning of that life that you look for, whether it's on Venus or other exoplanets? I think there's none. I find enormous relief in the absence of meaning. I think chasing for meaning is a human desire that the universe doesn't give two shits about. But you still enjoy... I enjoy finding meaning in my life. I enjoy finding where the morality lies. I enjoy the complication of that desire and I feel that is deeply human, but I don't feel that it's universal. It's somehow absolute. Like we conjure it up. We bring it to life through our own minds, but it's not any kind of fundamental way real. No. And the same way the sun is not to be blamed for destroying its own planets. The universe doesn't care because it has no meaning. It owes us nothing. And looking for meaning in the universe is demanding answers. Who are we? We're nothing. We don't get to demand anything and that includes meaning. And I find it very reassuring because once there is no meaning, I don't have to find it. Yeah. Once there's no meaning, it's a kind of freedom in a way. You sound a bit like... I'm happy about it. This isn't a depressing outlook as far as I'm concerned. It's happiness. Yeah. Yeah. So, I mean, there's a... I don't know if you know who Sam Harris is, but he, despite the pushbacks from the entirety of the world, really argues hard that free will is an illusion, that the deterministic universe and it's all already been predetermined and he's okay with it. And he's happy with it, that he's distinctly aware of it. And that's okay. The quantum world will disagree with him on the deterministic nature of nature. Well, he's not saying it's deterministic, but he's saying that the randomness doesn't help either. Randomness does not help in the experience of feeling like you're the decider of your own actions. That he kind of is okay with being a leaf flowing on the river, or being the river, as opposed to having or being like a fish or something that can decide its swimming direction. He's okay just embracing the flow of life. I mean, in that same way, it kind of sounds like your conception of meaning. I mean, it just is. The universe doesn't care. It just is what it is and we experience certain things and some feel good and some don't. And that's life. But I don't feel like that about life. I think life does have meaning and it's laudable to look for that meaning in life. I just don't think you can apply that beyond life and certainly not beyond earth. That this notion of meaning is a human construct and so it only applies within us and the other life forms and planet types that suffer from our intrusions or rejoice from our interactions. But this meaning is ours to do as we please. We created it, we've created a need for it, and so that's our problem to solve. I don't apply it beyond us. I think we as humans have a lot of responsibilities, but they're moral responsibilities. And a lot of those responsibilities are much more easily fulfilled if you find meaning in them. So I think there's value to meaning, whether it's real or not. I just think we gain nothing from trying to anthropomorphize the entire universe. And also that's the height of hubris. That's not for us to do. Yeah. It also could be just like duality and quantum mechanics. It could be both that there is meaning and that there isn't. And we're somehow depending on the observer, depending on the perspective you take on the thing. I mean, even on earth that's true, but whether things have meaning or not depends a lot on who's looking. Whether it's us humans, the aliens or the giraffes. Clara, this was an incredible conversation. I mean, I learned so much, but I also am just inspired by the passion you have in not finding meaning in the universe. I'm very passionate about not finding meaning in the universe. You're the most inspiring nihilist I've ever met. I'm just kidding. You are truly an inspiring communicator of everything from phosphine to life to quantum astrochemistry. I can't wait to see what other cool things you do in your career, in your scientific life. Thank you so much for wasting your valuable time with me today. I really appreciate it. It was my pleasure. I'd already got my four hours of productivity before I got here. And so it's not a waste. It's all downhill from there. Thank you. Thanks for listening to this conversation with Clara Sousa Silva. And thank you to Onnit, Grammarly, Blinkist, and Indeed. Check them out in the description to support this podcast. And now let me leave you with some words from Konstantin Tsiolkovsky. The earth is the cradle of humanity, but mankind cannot stay in the cradle forever. Thank you for listening and hope to see you next time. It's really difficult. If I'm not mistaken, even the scent of truffles, obviously a billion dollar industry, huge deal. Until quite recently, it wasn't known exactly how those scents, those molecules that create this incredible smell were produced. This is a billion dollar industry. As you can imagine, there is no such pressure. There's no phosphine lobby or anything that would push for this research, but I hope someone picks it up and does it. And it isn't crazy because we know that phosphine is really hard to make. We know it's really hard for it to happen accidentally. Even lightning and volcanoes that can produce small amounts of phosphine, it's extremely difficult for even these extreme processes to make it. So it's not really surprising that only life can do it because life is willing to make things at a cost. So maybe on the topic of phosphine, what, again, you've gotten yourself into trouble. I'm going to ask you all these high level poetic questions. I apologize. No, I would love it. Okay. When did you first fall in love with phosphine? It wasn't love at first sight. It was somewhere between a long relationship and Stockholm syndrome. When I first started my PhD, I knew I wanted to learn about molecular spectra and how to simulate it. I thought it was really outrageous that we as a species couldn't detect molecules remotely. We didn't have this perfect catalog ready of the molecular fingerprint of every molecule we may want to find in the universe. And something as basic as phosphine, the fact that we didn't really know how it interacted with light and so we couldn't detect it properly in the galaxy, I was so indignant. And so initially I just started working on phosphine because people hadn't before. And I thought we should know what phosphine looks like and that was it. And then I read every paper that's ever been published about phosphine. It was quite easy because there aren't that many. And that's when I started learning about where we had already found it in the universe and what it meant. I started finding out quite how little we know about it and why. And it was only when I joined MIT and I started talking to biochemists that it became clear that phosphine wasn't just weird and special and understudied and disgusting. It was all these things for oxygen loving life. And it was the anaerobic world that would welcome phosphine and that's when the idea of looking for it on other planets became crystallized. Because oxygen is very powerful and very important on Earth but that's not necessarily going to be the case on other exoplanets. Most planets are oxygen poor, overwhelmingly most planets are oxygen poor. And so finding the sign of life that would be welcomed by everything that would live without oxygen on Earth seemed so cool. But ultimately the project at first was born out of the idea that you want to find that molecular fingerprint of a molecule. And this is just one example. And that's connected to then looking for that fingerprint elsewhere in a remote way. And obviously that then at that time where exoplanets already, when you were doing your PhD, and by the way you should say your PhD thesis was on phosphine. It was all on phosphine, 100% on phosphine with a little bit of ammonia. I have a chapter that I did where I talked about phosphine and ammonia. But no, phosphine was very much my thesis. But at that time when you're writing it there's already a sense that exoplanets are out there and we might be able to be looking for biosignatures on those exoplanets? Pretty much. I did my PhD in 2015. We found the first exoplanets in the kind of mid to late 90s. So exoplanets were known. It was known that some had atmospheres and from there it's not a big jump to think, well, if some have atmospheres, some of those might be habitable and some of those may be inhabited. So how do you detect, you started to talk about it, but can we linger on it? How do you detect phosphine on a faraway thing, rocky thing, rocky planet? What is spectroscopy? What is this molecular fingerprint? What does it look like? You've kind of mentioned the wave, but what are we supposed to think about? What are the tools? What are the uncertainties? All those kinds of things. So the path can go this way. You've got light, kind of pure light. You can crack that light open with a prism or a spectroscope or water and make a rainbow. That rainbow is all the colors and all the invisible colors, the ultraviolet, the infrared. And if that light was truly pure, you could consider that rainbow to just cover continuously all of these colors. But if that light goes through a gas, we may not see that gas. We certainly cannot see the molecules within that gas, but those molecules will steal, absorb some of that light, some, but not all. Each molecule absorbs only very specific colors of that rainbow. And so if you know, for example, that shade of green can only be absorbed by methane, then you can watch. As a planet passes in front of a star, the planet's too far away, you can't see it. And it has an atmosphere. That atmosphere is far too small, you definitely can't see it. But the sunlight will go through that atmosphere. And if that atmosphere is methane, then on the other side, that shade of blue, I can't remember if I said blue or green, that color will be missing because methane took it. And so with phosphine, it's the same thing. It has specific colors, 16.8 billion colors that it absorbs it and nothing else does. And so if you can find them and notice them missing from the light of a star that went through a planet's atmosphere, then you'll know that atmosphere contains the molecule. How cool is that? That's incredible. So you can have this fingerprint within the space of colors and there's a lot of molecules. And I mean, I wonder, that's a question of like how much overlap there is. How close can you get to the actual fingerprint? Like can phosphine unlock the iPhone with its lights on? You said 16.8 billion, so presumably this rainbow is discretized into little segments somehow. Exactly. How many total are there? How a lot is 16.8 billion? It's a lot. We don't have the instruments to break these, break any light into this many tiny segments. And so with the instruments we do have, there's huge amounts of overlap. As an example, a lot of the ways it's detectable is because the carbon and the hydrogens, they vibrate with one another, they move, they interact. But every other hydrocarbon, acetylene, isoprene has carbon and hydrogens also vibrating and rotating. And so it's actually very hard to tell them apart at low resolutions and our instruments can't really cope with distinguishing between molecules particularly well. But in an ideal world, if we had infinite resolution, then yes, every molecule's spectral features will be unique. Yeah, like almost too unique, like it would be too trivial. At the quantum level, they're unique. At our level, there's huge overlap. Yeah. So you can start to then try to disambiguate the fact that certain colors are missing, what does that mean? And hopefully they're missing in a certain kind of pattern where you can say with some kind of probability, there's this gas, not this gas. So you're solving that gaseous puzzle. I got it. Okay. We can go back to Venus actually and show that. So with this, I mentioned those two molecules that could be responsible for that signal, the resolution that we have. It was phosphine and SO2, sulfur dioxide. And that resolution could really be one of the other, but in the same bandwidth, so in the kind of the same observations, there was another region where phosphine does not absorb, we know that, but SO2 does. So we just went and checked and there was no signal. So we thought, oh, then it must be phosphine. And then we submitted the paper. The rest is history. I got it. Well, yeah, that's beautifully told. Is there, so the telescopes we're talking about are sitting on earth. What can it help solving this fingerprint, molecular fingerprint problem if we do a flyby? Does it help if you get closer and closer or are telescopes pretty damn good for this kind of puzzle solving? Telescopes are pretty good, but the earth's atmosphere is a pain. I mean, I'm very thankful for it, but it does interrupt a lot of measurements and a lot of regions where phosphine would be active, they are not available. The earth is not transparent in those wavelengths. So being above the atmosphere would make a huge difference. Then proximity matters a lot less, but just escaping the earth's atmosphere would be wonderful. But then it's really hard to stay very stable and if there is phosphine on Venus, there's very little of it in the clouds. And so the signal is very weak and the telescopes we can use on earth are much bigger and much more stable. So it's a bit of a trade off. So is it, are you comfortable with this kind of remote observation? Is it at all helpful to strive for going over to Venus and like grabbing a scoop of the atmosphere or is remote observation really a powerful tool for this kind of job? Like the scoop is not necessary. Well a lot of people want to scoop, I get it. I get it completely. That's my natural inclination, yeah. I don't want to scoop specifically because if it is life, I want to know everything I can remotely before I interfere. So that's my, I've got ethical reasons against the scoop more than engineering reasons against the scoop. But I have some engineering reasons against the scoop. Scoop is not a technical term, but I feel like now it's too late to take it back. We don't understand the clouds well enough to plan the scoop very well. Because it's not that saturated, like there's not that much of it present. No, and the place is nasty. You know, it's not going to be easy to build something that can do the task reliably and can be trusted, the measurements can be trusted and then pass that message on. So actually I'm for an orbiter. I think we should have orbiters around every solar system body whose job is just to learn about these places. I'm disappointed we haven't already got an orbiter around every single one of them. A small, it can be a small satellite. Getting data, figuring out, you know, how do the clouds move? What's in them? How often is there lightning and volcanic activity? Where's the topography? Is it changing? Is there a biosphere actively doing things? We should be monitoring this from afar. And so I'm for over the atmosphere, hopefully around Venus, that would be, that would be my choice. Okay. So now recently Venus is all exciting about a phosphine and everything. Is there other stuff maybe before we were looking at Venus or now looking out into other solar systems? Is there other promising exoplanets or other planets within the solar system that might have phosphine or might have other strong biosignatures that we should be looking for like phosphine? There's a few, but outside the solar system, all are kind of promising candidates. We know so little about them. For most of them, we barely know their density. Most of them, we don't even know if they have an atmosphere, nevermind what that atmosphere might contain. So we're still very much at the stage where we have detected promising planets, but they're promising in that they're about the right size, about the right density. They could have an atmosphere and they're about the right distance from their host star. But that's really all we know. Near future telescopes will tell us much more, but for now we're just guessing. So you said near future, so there's hope that there'll be telescopes that can see that far enough to determine if there's an atmosphere and perhaps even the contents of that atmosphere? Absolutely. JWST, launching later this year, will be able to get a very rough sense of the main atmospheric constituents of planets that could potentially be habitable. And that's this year. What's the name? JWST, the James Webb Space Telescope. Okay. And that's going to be out in space, past the atmosphere. Yes. Is there something interesting to be said about the engineering aspect of the telescope? I mean, it's an incredible beast, but it's a beast of many burdens. So it's going to do, it's going to. See, you are a poet. You are, yeah. I love it. This is very eloquent. You're speaking to the audience, which I appreciate. So yeah, so it's a giant engineering project and is it orbiting something, do you know? So it's going to be above the atmosphere and it will be doing lots of different astrophysics. And so some of its time will be dedicated to exoplanets, but there's an entire astronomy field fighting for time before the cryogenic lifetime of the instrument. And so when I was looking for the possibility of finding phosphine on distant exoplanets, I used JWST as a way of checking with this instrument that we will launch later this year, could we detect phosphine on an oxygen poor planet? And there I put very much a hard stop where some of my simulation said, yes, you can totally do it, but it will take a little under the cryogenic lifetime of this machine. So then I had to go, well, that's not going to, no one's going to dedicate all of JWST to look for my molecule that no one cared about. So we're very much at that edge, but there'll be many other telescopes in the coming decades that will be able to tell us quite a lot about the atmospheres of potentially habitable planets. So you mentioned simulation. This is super interesting to me. And this perhaps could be a super dumb question, but I think I haven't been able to, I haven't been able to prove you wrong on that one. You simulate molecules to understand how they look from a distance is what I understand. Like what does that simulation look like? So it's talking about which colors that the rainbow will be missing. Is that the goal of the simulation? That's the goal, but it's really just a very, very nasty Schrodinger's equation. So it's a quantum simulation. Oh, so it's simulating at the quantum level. Yes. So I'm a quantum astrochemist. Hi, I'm Clara. I'm a quantum astrochemist. That's how we should have started this conversation. Can you describe the three components of that quantum astro and chemist and how they interplay together? So I study the quantum behavior of molecules, hence the quantum and the chemist specifically so I can detect them in space, hence the astro. So what I do is I figure out the probability of a molecule being in a particular state. There's no deterministic nature to the work I do, so it's every transition is just a likelihood. But if you get a population of that molecule, it will always happen. And so this is all at the quantum level. It's a Schrodinger equation on, I think, 27 dimensions. I don't remember it by heart. And what this means is I'm solving these giant quantum matrices. And that's why you need a lot of computer power, giant computers, to diagonalize these enormous matrices, each of whom describes a single vibrational behavior of a molecule. So I think phosphine has 17.5 million possible states it can exist in. And transitions can occur between pairs of these states, and there's a certain likelihood that they'll happen. This is the quantum world. Nothing is deterministic. There's just a likelihood that it will jump from one state to another. And these jumps, they're transitions, and there's 16.8 billion of them. When energy is absorbed, that corresponds to this transition, we see it in the spectrum. This is more quantum chemistry than you had asked for. I'm sorry. No, no. I'm sorry. Brain's broken. So when the transitions happen between the different states, somehow the energy maps the spectrum. Exactly. Energy corresponds to a frequency, and a frequency corresponds to a wavelength, which corresponds to a color. So there's some probability assigned to each color then? Exactly. And that probability determines how intense that transition will be, how strong. And so you run this kind of simulation for particular, so that's 17.5 squared or something like that. So 15.5 million energies, each one of whom involves diagonalizing a giant matrix with a supercomputer. I wonder what the most efficient algorithm for diagonalization is, but there's some kind of... There's many. Depends on kind of the shape of the matrix. So they're not random matrices. So some are more diagonal than others, and so some need more treatment than others. Most of the work ends up going in describing the system, this quantum system in different ways until you have a matrix that is close to being diagonal, and then it's much easier to clean it up. So how hard is this puzzle? So you're solving this puzzle for phosphine, right? Is this... Are we supposed to solve this puzzle for every single molecule? Exactly. Oh boy. Yes, I calculated if I did the work I did for phosphine, again, for all the molecules for which we don't have spectra, for which we don't have a fingerprint, it would take me 62,000 years, a little over. 62,000 years. What time flies when you're having fun? Okay. But you write that there are about 16,000 molecules we care about when looking for a new Earth or when we try to detect alien biosignatures. If we want to detect any molecules from here, we need to know their spectra, and we currently don't. So to solve this particular problem, that's my job. What was that? I mean, that's absolutely correct. I could have not said it better myself. Did you take that from my website? Yeah, I think I stole it. And your website is excellent, so it's a worthy place to steal stuff from. Thank you. How do you solve this problem for the 16,000 molecules we care about, of which phosphine is one? Yes. So, taking a step a little bit out of phosphine, is there... Well, we were having so much fun. We were having so much fun. No, no, we're not saying bye. No, no, no. It's sticking around. I'm just saying we're joining, more friends coming to the party. How do you choose other friends to come to the party that are interesting to study as we solve one puzzle at a time through the space of 16,000? So we've already started. Out of those 16,000, we understand water quite well, methane quite well, ammonia quite well, carbon dioxide. I could keep going. And then we understand molecules like acetylene, hydrogen cyanide, more or less. And that takes us to about 4% of those 16,000. We understand about 4% of them, more or less. Phosphine is one of them. But the other 96%, we just really have barely any idea at all of where in the spectrum of light they would leave a mark. I can't spend the next 62,000 years doing this work. And I don't want to, even if somehow I was able, that wouldn't feel good. So one of the things that I try to do now is move away from how I did phosphine. So I did phosphine really the best that I could, the best that could be done with the computer power that we have, trying to get each one of those 16.8 billion transitions mapped accurately, calculated. And then I thought, what if I do a worse job? What if I just do a much worse job? Can I just make it much faster and then it's still worth it? How bad can I get before it's worthless? And then could I do this for all the other molecules? So I created exactly this terrible, terrible system. So how, what's the answer to that question, that fundamental question I ask myself all the time in other domains. How crappy can I be before I'm useless? Before somebody notices. Turns out pretty crappy because no one has any idea what these molecules look like. Anything is better than nothing. And so I thought, how long will it take me to create better than nothing spectra for all of these molecules? And so I created RASCAL, Rapid Approximate Spectral Calculations for All. And what I do is I use organic chemistry and quantum chemistry and kind of cheat them both. I just try to figure out what is the fastest way I could run this. And I simulate rough spectra for all of those 16,000. So I've managed to get it to work. It's really shocking how well it works considering how bad it is. Is there insights you could give to like the tricks involved in making it fast? Like what are the maybe some insightful shortcuts taken that still result in some useful information about the spectra? The insights came from organic chemistry from decades ago. When organic chemists wanted to know what a compound might be, they will look at a spectrum and see a feature and they would go, I've seen that feature before. That's usually what happens when you have a carbon triple bonded to another carbon. And they were mostly right. Almost every molecule that has a carbon triple bonded to another one looks like that. Has other features different that distinguish them from one another, but they have that feature in common. We call these functional groups. And so most of that work ended up being abandoned because now we have mass spectrometry. We got nuclear magnetic resin spectroscopy, so people don't really need to do that anymore. But these ancient textbooks still exist and I've collected them all as many as I could. And there are hundreds of these descriptions where people have said, oh, whenever you have a iodine atom connected to this one, there's always a feature here and it's usually quite sharp and it's quite strong. And some people go, oh yeah, that's really broad feature. Every time that combination of atoms and bonds. So I've collected them all and I've created this giant dictionary of all these kind of puzzle pieces, these Lego parts of molecules. And I've written a code that then puts them all together in some kind of like Frankenstein's monster of molecules. So you asked me for any molecule and I go, well, it has these bonds and this atom dangling off this atom and this cluster here, and I tell you what it should look like and it kind of works. So this creates a whole portfolio of just kind of signatures that we could look for. Rough, very rough signatures. But still useful enough to analyze the atmospheres, the telescope generated images of other planets? Close. Right now it is so complete. So it has all of these molecules that it can tell you, say you look at an alien atmosphere and there's a feature there. It can tell you, oh, that feature, that's familiar. It could be one of these 816 molecules, best of luck. So I think the next step, which is what I'm working on is telling you something more useful than it could be one of those 816 molecules. That's still true. I wouldn't say it's useful. So it can tell you, but only 12% of them also have a feature in this region. So go look there. And if there's nothing there, it can't be those and so on. It can also tell you things like you will need this much accuracy to distinguish between those 816. So that's what I'm working on. But it's a lot of work. So this is really interesting, the role of computing in this whole picture. You mentioned code. So like you as a quantum astrochemist, there is some role for programming in your life, in your past life, in your current life, in your group? Oh yeah, almost entirely. I'm a computational quantum astrochemist, but that doesn't roll off the tongue very easily. So this is fundamentally computational. Like if you want to be successful in the 21st century in doing quantum astrochemistry, you want to be computational? Absolutely. All quantum chemistry is computational at this point. Okay. So does machine learning play a role at all? Is there some extra shortcuts that could be discovered through, like you see all that success with protein folding, right? A problem that thought to be extremely difficult to apply machine learning to because it's, I mean mostly because there's not a lot of already solved puzzles to train on. I suppose the same exact thing is true with this particular problem, but is there hope for machine learning to help out? Absolutely. Currently you've laid out exactly the problem. The training set is awful and because there's so, a lot of this data that I'm basing it on is literally many decades old. The people who worked on it and data that I get, often they're dead and the files that I've used, some of them were hand drawn by someone tired in the seventies. Yes. So I can of course have a program training on these, but I would just be perpetuating these mistakes without hope of actually verifying them. So my next step is to improve this training set by hand and then try to see if I can apply machine learning on the full code of the full 16,000 molecules and improve them all. But really I need to be able to test the outcomes with experimental data, which means convincing someone in a lab to spend a lot of money putting very dangerous gases in chambers and measuring them at outrageous temperatures. So it's a work in progress. And so collecting huge amounts of data about the actual gases. So you are up for doing that kind of thing too. So actually like doing the full end to end thing, which is like having a gas, collecting data about it, and then doing the kind of analysis that creates the fingerprint and then also analyzing using that library, the data that comes from other planets. So you do the full. Full from birth to death. Interesting. Yes. I worked in an industrial chemistry laboratory when I was much younger in Slovenia and there I worked in the lab actually collecting spectrum and predicting spectrum. What's it like to work with a bunch of gases that are like not so human friendly? It's terrifying. It's horrific. It's so scary. And I love my job. I'm willing to clearly sacrifice a lot for it, you know, job, stability, money, sanity. But I only worked there for a few months and it was really terrifying. There's just so many ways to die. You know, usually you only have a handful of ways to die every day, you know. And if you work in a lab, there's so many more, orders of magnitude more. And I was very bad at it. I'm not a good hands on scientist. I want a laptop connected to a remote super computer or a laptop connected to a telescope. I don't need to be there to believe it. And I am not good in the lab. Yeah. When there's a bunch of things that can poison you, a bunch of things that could explode and they're gaseous and they're often, maybe they might not even have a smell or they might not be visible. It's like... So many of them give you cancer. It's just so cruel. And some people love this work, but I've never enjoyed experimental work. It's so ungrateful. So lonely. Well, most, I mean, so much work is lonely if you find the joy in it, but you enjoy the results of it. Yes. So I'm very thankful for all the experimentalists in my life, but I'll do the theory. They do the experiment and then we talk to one another and make sure it matches. Okay. Beautiful. What are spectroscopic networks? Those look super cool. Are they related to what we were talking about? The picture look pretty. Oh, yes, slightly. So remember when I mentioned the 17.5 million energy levels? Yes. There are rules for each molecule on which energy levels they can jump from and to and how likely it is to make that jump. And so if you plot all the routes it can take, you get this energy network, which is like a ball. So these are the constraints of the transitions that could be taken. Exactly for each molecule. Interesting. And they're not, so it's not a fully connected, it's like it's sparse somehow. Yes, you get islands sometimes. You get a molecule can only jump from one set of states to another and it's trapped now in this network. It can never go to another network that could have been available to other siblings. Is there some insights to be drawn from these networks? Like something cool that you can understand about a particular molecule because of it? Yes. Some molecules have what we call forbidden transitions, which aren't really forbidden because it's quantum. There are no rules. No, I'm not joking. One of the rules is just the rules are very often broken in the quantum world. And so forbidden transitions doesn't actually mean they're forbidden. Low probability. Exactly. They just become deeply unlikely. Yeah. Cool. And so you could do all the same, like I'm coming from a computer science world, I love graph theory. So you can do all the same graph theoretic kind of analysis of clusters or something like that. Exactly. All those kinds of things. And draw insights from it. Cool. And they're unique for each molecule. And the networks that you mentioned, that's actually not too difficult a layer of quantum physics. By then, all the energies are mapped. So we've had high school children work on those networks. And the trick is to not tell them they're doing quantum physics until like three months in when it's too late for them to back out. And then you're like, you're a quantum physicist now. And it's really nice. Yeah. Okay. But like the promise of this, even though it's 16,000, even just a subset of them, that's really exciting because then you can do as the telescope data get better and better, especially for exoplanets, but also for Venus. You can then start like getting your full, like, you know how you get like blood work done or like you get your genetic testing to see what your ancestors are. You can get the same kind of like high resolution information about interesting things going on on a particular planet based on the atmosphere. Right? Exactly. How cool would that be if we could, you know, scan an alien planet and go, oh, this is what the clouds are made of. This is what's in the surface. These are the molecules that are mixing. Here are probably oceans because you can see these types of molecules above it. And here are the Hadley cells. Here are how the biosphere works. We could map this whole thing. Wouldn't it be cool if the aliens like are aware of these techniques and like would spoof like the wrong gases, just to like pretend that's how they can be, it's like an invisibility cloak. They can generate gases that would throw you off or like, or do the opposite. They pretend they will artificially generate phosphine. So like, like the dumb, the dumb apes on earth again, like go out, like flying in different places because it's just fun. It's like some teenager alien somewhere, just pranking. Yeah. I was asked that exact question this Saturday by, by a 70 year old boy in Canada, but it was the first time I'd been asked that question, the second in a week. We're kindred spirits, him and I. We can, they can prank us to some extent, but the, this work of interpreting an alien atmosphere means you're reading the atmosphere as a message and it's very hard to hide signs of life in an atmosphere because you can try to prank us, but you're still going to fart and breathe and somehow metabolize the environment around you and call that whatever you call that and release molecules. And so that's really hard to hide. You know, you can go very quiet. You can throw out some weird molecule to confuse us further, but we can still see all your other metabolites. Yeah. It's hard to fake. Is there, so you kind of mentioned like water that what, what other gases are there that we know about that are like high likelihood as biosignatures in terms of life? I mean, what are your other favorites in terms of, so, so we've got phosphine, but like what, what else is a damn good signal to be a, that you think about that we should be looking for if we look at another atmosphere, is there gases that come to mind or are there all sort of possible biosignatures that we should love equally? There's many, so there's water. We know that's important for life as we know it. There's molecular oxygen on earth. That's probably the most robust sign of life, particularly combined with small amounts of methane. And it's true that the majority of the oxygen in our atmosphere is a product of life. And so if I was an alien astronomer and I saw earth's atmosphere, I'm, I would get a Nobel I think on, you know, What would you notice? I mean, this is a really, I would be very excited about this. About the oxygen. I'm not finding 20%, 21% of oxygen atmosphere. That's very unusual. So would that be the most exciting thing to you from an alien perspective about earth in terms of the tech, like analyzing the atmosphere, like what are the biosignatures of life on earth? Would you say in terms of the contents of the atmosphere is oxygen, high amount of oxygen, pretty damn good sign. I mean, it's not as good as the TV signals we've been sending out. Those are slightly more robust than oxygen. Oxygen on its own has false positives for life. So there's still ways of making it, but it's, it's a pretty robust sign of life in the context or atmosphere with the radiation that the sun produces, our position in relation to the sun, the other components of our atmosphere, the volcanic activity we have, all of that together makes the 20% of oxygen extremely robust sign of life. But outside that context, you could still produce oxygen without life. But phosphine, although better in the sense of it is much harder to make, it has lower false positives, still has some. So I'm actually against looking for specific molecules unless we're looking for like CFCs. If we find CFCs, that's definitely aliens, I feel confident, chlorofluorocarbons. And so, you know, if aliens had been watching us, they would have been going, oh no, CFCs. I mean, they're not going to last long. Let's, you know, everyone's writing their thesis on the end of, the end of the earth. And then we got together, we stopped using them. I like to think they're really proud of us. You know, they literally saw our ozone hole shrinking. They've been watching it and they saw it happen. I think to be honest, they're more paying attention to the whole nuclear thing. I don't think they care. It's not going to bother them. Oh, I mean, worried about us. Oh yes. Oh no, worried about us. They, I mean, this is why the aliens have been showing up recently. It's like, if you, if you look at, I mean, there is, I mean, it's probably, there's a correlation with a lot of things, but what the ufologists quote unquote often talk about is that there seems to be a much higher level of UFO sightings since like in the nuclear age. So like if aliens were indeed worried about us, like if you were aliens, you would start showing up when the living organisms first discovered a way to destroy the entire, the entire colony. Can the increase in sightings not have to do with the fact that people now have more cameras? It's an interesting thing about science, like with UFO sightings, it's like either 99.9% of them are false or 100% of them are false. The interesting thing to me is that in that 0.01%, there's a lot of things in science that are like these weird outliers that are difficult to replicate. You have like, there's even physical phenomena, ball lightning. There's difficult things to artificially create in large amounts or observe in nature in large amounts in such a way that you can do it to apply the scientific method that could be just things that like what happened like a few times or once and you're like, what the hell is that? And that's very difficult for science to know what to do with. I'm a huge proponent of just being open minded because when you're open minded about aliens, for example, it allows you to think outside of the box in other domains as well. And somehow that will result, like if you're open minded about aliens and you don't laugh it off immediately, what happens is somehow that's going to lead to a solution to a P equals NP or P not equals NP. Like in ways that you can't predict, the open mindedness has tertiary effects that will result in progress, I believe, which is why I'm a huge fan of aliens because it's like because too many scientists roll their eyes at the idea of aliens, alien life. And to me, it's one of the most exciting possibilities in the biggest, most exciting questions before

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