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Popular Physics, The physics of entropy and the origin of life | Sean Carroll

The physics of entropy and the origin of life | Sean Carroll

- I think that once you learn about the second law of thermodynamics, it can be a little depressing.

You've been told that there's a fundamental feature of reality: that disorder increases, that things just wind down, right?

That batteries run out, that cream and coffee mix together, that ice cubes melt.

It's kind of a depressing view of the future.

How did all of this interestingness come about in the first place?

If the whole thing that reality does is just move closer and closer to complete disorder, then how did something as exquisitely organized as a human being come about?

This idea that there's this tension between the organization of things in the Universe and the natural evolution of things became a little bit sharper over the course of the 1800s because that's when we put together this idea that entropy increases all the time.

Things tend to go from orderly to disorderly just because there are many more ways to be disorderly.

This is a deep down law of nature.

It implies what we call the 'Heat death of the Universe': That all the stuff you see, the engines, the burning stars, the living beings, these all represent systems that are increasing the overall entropy of the Universe.

And if you think, which is probably true, that there's a maximum entropy you can reach, a maximum level of disorderliness and chaos, eventually we will get there, and all the interestingness in the Universe will be gone.

The Universe will reach what we call an 'equilibrium' — a state of maximum chaos, and nothing interesting happening anymore.

One of the issues with really feeling through the implications of the second law of thermodynamics is that people tend to mix up simple versus complex and orderly versus disorderly.

The truth is these are two different axes, two different ways of thinking about something.

The increase of entropy says that we go from orderly to disorderly, but it says nothing about simple versus complex.

This is a new scientific question that we are facing right now:

"What is the journey from low entropy to high entropy like and how is it affected by the laws of physics so that the actual path it takes leads to complex structures?"

One of the difficulties in figuring out, specifically, how life here on Earth came into being is that it's not just a random sort of complex system, it's a very specific thing.

And life as we know it now involves different aspects, all of which are important.

You need replication, right? You need Darwinian evolution.

We have DNA. We have a genome that gets replicated, not perfectly, but pretty well.

You need compartmentalization.

Every cell has a cell wall so you can separate the living cell from the rest of the world.

And also you need metabolism, right?

You need that fuel, you need that low-entropy energy that we can use to keep ourselves going and then expel to the world in a higher-entropy form.

So, which came first?

This is why explaining the beginning of complex structures is always hard, because they all seem to depend on each other.

There is a replication-first camp in the origin of life studies literature that says, "Look, clearly the genetic information is necessary to call it life, that must have come first and it must have hooked up to an energy source."

But there's also a metabolism-first camp that says, "Look, it doesn't matter if you have information sitting there, if it's not going someplace, if it's not doing anything, if it's not moving around and metabolizing, you can't call it life."

And the nice thing to me about the metabolism-first point of view is that you can kind of see how it might arise out of purely physical, non-biological processes because remember, to maintain its orderliness and its complexity, living beings need to increase the entropy of the Universe, they need to feed off of low-entropy energy.

So this was an idea that a number of biologists and geologists had.

And on the basis of it, they made predictions.

They said, you know, "Life is not gonna form in some warm pond."

This was Darwin's idea, that maybe you just put all the stuff together, all the ingredients, and eventually a little bug crawls out, okay? Or a little bacterium.

And they said, "Look, that's never gonna happen, because there's no increasing entropy.

What you need is just the right biochemical, geological arrangement of things to have these long, sophisticated, complex reactions happen that can then be captured into the first living organism."

And they thought about what kind of conditions would they be, and they thought that it might be a warm, hydrothermal vent under the oceans, right? With certain chemical balances.

And I'm a physicist, I don't know the details and I shouldn't say anything, but the point is these kinds of hydrothermal vents were not known at the time, they had not yet been discovered, but a prediction was made — these must exist in order for life to have come into existence.

And after the prediction was made, we found them.

Famously, the 'Lost City' formation at the bottom of the Atlantic Ocean was found by submersibles going down near the bottom of the ocean floor.

They found exactly the kind of geochemical conditions that had been hypothesized as possible places where life could have formed.

Does that mean it's right?

No, but it's a little bit of evidence that it could be on the right track.

The origin of life, I think, personally, is one of the most important unanswered scientific questions but it's one that we're absolutely making progress on right now.

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The physics of entropy and the origin of life | Sean Carroll |||||||||Sean Carroll|Carroll Die Physik der Entropie und der Ursprung des Lebens | Sean Carroll La física de la entropía y el origen de la vida | Sean Carroll La physique de l'entropie et l'origine de la vie | Sean Carroll La fisica dell'entropia e l'origine della vita | Sean Carroll エントロピーの物理学と生命の起源|ショーン・キャロル A física da entropia e a origem da vida | Sean Carroll Физика энтропии и происхождение жизни | Шон Кэрролл Entropins fysik och livets ursprung | Sean Carroll Entropi Fiziği ve Yaşamın Kökeni | Sean Carroll Фізика ентропії та походження життя | Шон Керролл 熵物理学与生命起源 |肖恩·卡罗尔 熵物理學與生命起源 |肖恩·卡羅爾

- I think that once you learn about the second law of thermodynamics, it can be a little depressing.

You've been told that there's a fundamental feature of reality: that disorder increases, that things just wind down, right? ||||||||||||||||se desintegram|| Disseram a você que existe uma característica fundamental da realidade: que a desordem aumenta, que as coisas simplesmente diminuem, certo?

That batteries run out, that cream and coffee mix together, that ice cubes melt. |as pilhas|||||||||||cubos de gelo| Que as pilhas acabem, que as natas e o café se misturem, que os cubos de gelo derretam.

It's kind of a depressing view of the future. É uma visão deprimente do futuro.

How did all of this interestingness come about in the first place? |||||fascinating events|||||| |||||interessância|||||| Como todo esse interesse surgiu em primeiro lugar?

If the whole thing that reality does is just move closer and closer to complete disorder, then how did something as exquisitely organized as a human being come about? |||||||||||||||||||||perfectly||||||| |||||||||||||||||||||exquisitamente||||||| Se tudo o que a realidade faz é apenas se aproximar cada vez mais da desordem completa, então como surgiu algo tão primorosamente organizado como um ser humano?

This idea that there's this tension between the organization of things in the Universe and the natural evolution of things became a little bit sharper over the course of the 1800s because that's when we put together this idea that entropy increases all the time. ||||||||||as coisas|||||||||||||||||||||||||||||||||| Essa ideia de que existe essa tensão entre a organização das coisas no Universo e a evolução natural das coisas tornou-se um pouco mais nítida ao longo dos anos 1800 porque foi quando reunimos essa ideia de que a entropia aumenta o tempo todo.

Things tend to go from orderly to disorderly just because there are many more ways to be disorderly. |||||ordenado||desordenado|||||||||| As coisas tendem a passar de ordenadas a desordenadas pelo simples facto de haver muitas mais formas de ser desordenado.

This is a deep down law of nature.

It implies what we call the 'Heat death of the Universe': That all the stuff you see, the engines, the burning stars, the living beings, these all represent systems that are increasing the overall entropy of the Universe. Implica o que chamamos de 'morte térmica do universo': todas as coisas que você vê, os motores, as estrelas em chamas, os seres vivos, todos representam sistemas que estão aumentando a entropia geral do universo.

And if you think, which is probably true, that there's a maximum entropy you can reach, a maximum level of disorderliness and chaos, eventually we will get there, and all the interestingness in the Universe will be gone. ||||||||||||||||||||desordem e caos||||||||||||||||| E se você pensa, o que provavelmente é verdade, que existe uma entropia máxima que pode alcançar, um nível máximo de desordem e caos, eventualmente chegaremos lá, e todo o interesse do Universo desaparecerá.

The Universe will reach what we call an 'equilibrium' — a state of maximum chaos, and nothing interesting happening anymore. O Universo atingirá aquilo a que chamamos um "equilíbrio" - um estado de caos máximo, em que já nada de interessante acontece.

One of the issues with really feeling through the implications of the second law of thermodynamics is that people tend to mix up simple versus complex and orderly versus disorderly. Um dos problemas de realmente sentir as implicações da segunda lei da termodinâmica é que as pessoas tendem a misturar simples versus complexo e ordenado versus desordenado.

The truth is these are two different axes, two different ways of thinking about something. |||||||eixos|||||||

The increase of entropy says that we go from orderly to disorderly, but it says nothing about simple versus complex.

This is a new scientific question that we are facing right now:

"What is the journey from low entropy to high entropy like and how is it affected by the laws of physics so that the actual path it takes leads to complex structures?" "Como é a jornada de baixa entropia para alta entropia e como ela é afetada pelas leis da física, de modo que o caminho real que leva a estruturas complexas?"

One of the difficulties in figuring out, specifically, how life here on Earth came into being is that it's not just a random sort of complex system, it's a very specific thing. Uma das dificuldades em descobrir, especificamente, como a vida aqui na Terra surgiu é que não é apenas um tipo aleatório de sistema complexo, é uma coisa muito específica.

And life as we know it now involves different aspects, all of which are important. E a vida, tal como a conhecemos atualmente, envolve diferentes aspectos, todos eles importantes.

You need replication, right? You need Darwinian evolution. ||replicação||||darwiniana| É preciso replicação, certo? Precisas da evolução darwiniana.

We have DNA. We have a genome that gets replicated, not perfectly, but pretty well. |||||||||replicado||||| Nós temos ADN. Temos um genoma que é replicado, não na perfeição, mas bastante bem.

You need compartmentalization. ||compartimentalização

Every cell has a cell wall so you can separate the living cell from the rest of the world. Todas as células têm uma parede celular para que se possa separar a célula viva do resto do mundo.

And also you need metabolism, right? E também é preciso metabolismo, certo?

You need that fuel, you need that low-entropy energy that we can use to keep ourselves going and then expel to the world in a higher-entropy form. ||||||||||||||||||||release to environment|||||||| ||||||||||||||||||||expelir|||||||| Você precisa desse combustível, precisa dessa energia de baixa entropia que podemos usar para nos manter funcionando e depois expelir para o mundo em uma forma de alta entropia.

So, which came first?

This is why explaining the beginning of complex structures is always hard, because they all seem to depend on each other.

There is a replication-first camp in the origin of life studies literature that says, "Look, clearly the genetic information is necessary to call it life, that must have come first and it must have hooked up to an energy source." |||||||||||||||||||||||||||||||||||connected to||||| Há um primeiro campo de replicação na origem da literatura de estudos da vida que diz: "Olha, claramente a informação genética é necessária para chamá-la de vida, que deve ter vindo primeiro e deve ter se ligado a uma fonte de energia."

But there's also a metabolism-first camp that says, "Look, it doesn't matter if you have information sitting there, if it's not going someplace, if it's not doing anything, if it's not moving around and metabolizing, you can't call it life." |||||||||||||||||||||||||||||||||||metabolizando||||| Mas também há um campo de metabolismo que diz: "Olha, não importa se você tem informações aí, se não está indo a algum lugar, se não está fazendo nada, se não está se movendo e metabolizando, você não pode chame de vida."

And the nice thing to me about the metabolism-first point of view is that you can kind of see how it might arise out of purely physical, non-biological processes because remember, to maintain its orderliness and its complexity, living beings need to increase the entropy of the Universe, they need to feed off of low-entropy energy. ||||||||||||||||||||||||||puramente||||||||||ordem e complexidade|||||||||||||||||||||| E o bom para mim sobre o primeiro ponto de vista do metabolismo é que você pode ver como ele pode surgir de processos puramente físicos e não biológicos porque, lembre-se, para manter sua ordem e complexidade, os seres vivos precisam aumentar a entropia do Universo, eles precisam se alimentar de energia de baixa entropia.

So this was an idea that a number of biologists and geologists had. |||||||||os biólogos||geólogos|

And on the basis of it, they made predictions.

They said, you know, "Life is not gonna form in some warm pond." Eles disseram, você sabe, "A vida não vai se formar em algum lago quente."

This was Darwin's idea, that maybe you just put all the stuff together, all the ingredients, and eventually a little bug crawls out, okay? Or a little bacterium. ||||||||||||||||||||microorganism||||||| ||de Darwin||||||||||||||||||um bichinho|se arrasta||||||um pequeno bacilo Isso foi ideia de Darwin, que talvez você apenas junte todas as coisas, todos os ingredientes e, eventualmente, um pequeno inseto apareça, ok? Ou uma pequena bactéria.

And they said, "Look, that's never gonna happen, because there's no increasing entropy.

What you need is just the right biochemical, geological arrangement of things to have these long, sophisticated, complex reactions happen that can then be captured into the first living organism."

And they thought about what kind of conditions would they be, and they thought that it might be a warm, hydrothermal vent under the oceans, right? ||||||||||||||||||||hidrotermal||||| E eles pensaram sobre que tipo de condições seriam, e pensaram que poderia ser uma fonte hidrotermais quente sob os oceanos, certo? With certain chemical balances.

And I'm a physicist, I don't know the details and I shouldn't say anything, but the point is these kinds of hydrothermal vents were not known at the time, they had not yet been discovered, but a prediction was made — these must exist in order for life to have come into existence. ||||||||||||||||||||||fontes hidrotermais||||||||||||||||||||||||||||| E eu sou um físico, não sei os detalhes e não devo dizer nada, mas a questão é que esses tipos de fontes hidrotermais não eram conhecidas na época, ainda não haviam sido descobertas, mas uma previsão foi feita — estes devem existir para que a vida tenha surgido.

And after the prediction was made, we found them.

Famously, the 'Lost City' formation at the bottom of the Atlantic Ocean was found by submersibles going down near the bottom of the ocean floor. |||||||||||||||submersíveis||||||||| Notoriamente, a formação da 'Cidade Perdida' no fundo do Oceano Atlântico foi encontrada por submersíveis descendo perto do fundo do oceano.

They found exactly the kind of geochemical conditions that had been hypothesized as possible places where life could have formed. ||||||geoquímica|||||hipotetizadas|||||||| Eles encontraram exatamente o tipo de condições geoquímicas que foram hipotetizadas como possíveis lugares onde a vida poderia ter se formado.

Does that mean it's right?

No, but it's a little bit of evidence that it could be on the right track.

The origin of life, I think, personally, is one of the most important unanswered scientific questions but it's one that we're absolutely making progress on right now.

— Get smarter, faster with videos from the world's biggest thinkers. |||||||||intelligent minds — Fique mais inteligente e rápido com vídeos dos maiores pensadores do mundo.