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The Naval Podcast Hosted by Naval Ravikant: Season 3 – Science Is the Engine That Pulls Humanity Forward

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This is a master post featuring the Key Takeaways from Season 3 of Naval Ravikant’s (@naval) podcast series with Brett Hall (@ToKTeacher)

Science Is the Engine That Pulls Humanity Forward | Episode 1

  • Naval is first and foremost a student of science
    • All of his heroes are scientists
    • In our age, scientific and technological progress seem inevitable
    • Life is continuously getting better thanks to science and we take it for granted
  • Science is also the study of truth
    • “How do we know something to be true”?
  • Most of us have a vague idea of science or the scientific method
    • The idea of science is getting hijacked
    • We are told to “believe” in science (an oxymoron)

The Beginning of Infinity | Episode 2

  • Sometimes a book impacts you the second time you read it
    • This was the case for Naval reading David Deutsch’s The Beginning of Infinity
    • This book transformed Naval’s thinking
      • It not only expanded his knowledge but also his reasoning
      • In the past decade, only Nassim Taleb’s books did the same
  • Naval finds most “Mental Models” people talk about not worth paying attention to
    • The mental models in “The Beginning of Infinity” are transformational
      • They completely change the way you look at what is true and what isn’t
  • The book expands on Karl Popper’s theory of what is scientific
    • It also covers a wide variety of philosophical ideas
      • Including epistemology, quantum mechanics, multiverse theory, infinity, mathematics

Nullius in Verba | Episode 3

  • The Beginning of Infinity is not easy to read
  • Naval wanted to understand its principles so that he could confirm or refute them
  • As a young science student, Brett remembers Deutsch’s book The Fabric of Reality putting into words his outlook on life

Explanations That Reach the Entire Universe | Episode 4

  • You don’t need to know every single fact to understand everything that can be understood
  • Certain fundamental theories allow you to form a lens through which you can understand anything that can be understood
    • Quantum theory
      • Regarded deeper, more foundational, than the theory of relativity
      • Some physicists expect a unification of the two in the future
    • The theory of computation
    • Evolution by natural selection
    • Epistemology (Theory of Knowledge)

Read the Best 100 Books Over and Over Again | Episode 5

  • The Beginning of Infinity reminds Naval of Gödel, Escher, Bach by Douglas R Hofstadter
    • They both bring together ideas from different disciplines
    • They’re difficult to understand and follow completely
    • Everyone claims to have read them, but few people understand them
  • Naval finds himself going back to the idea of only reading the best 100 books over and over
  • Currently, Naval is reading The Beginning of Infinity and The Fabric of Reality again and again
    • He wants to understand them fully
    • If he understood those books 20 years ago he would know a lot more
      • Reading those early would have led him to choose the right books to read afterward
    • He recommends getting the books in all possible versions (hardcover, audio, electronic)

We’re at The Beginning of an Infinity of Knowledge | Episode 6

  • In The Beginning of an Infinity, you’re not getting the standard take on physics, philosophy, or mathematics
    • Instead, you get David Deutsch’s worldview
    • He’s an expert in all these areas
  • Deutsch’s worldview is deeply optimistic
    • Reality is comprehensible and problems are solvable
      • Anything not forbidden by the laws of physics is possible
    • Progress is inevitable as long as we have good explanations
    • Humans are universal explainers
      • Anything that can be known, can be known by humans
      • Humans are the beginning of an infinite knowledge
      • We can constantly replace old theories with improved ones
      • There’s no endpoint
    • The universe is our resource to learn about and transform
  • These ideas are explained in more detail in Chapter 3 Notes of TokCast with Brett Hall

People Are a Force of Nature | Episode 7

  • Through knowledge, people transform the world
    • We  took raw materials that sat doing nothing for ages and created a civilization
  • Knowledge of the laws of physics is sufficient to explain what we see in the universe
    • But it is not sufficient to explain the appearance of Manhattan
  • To explain the rise of civilizations you have to consider human’s capacity to explain the world scientifically, philosophically, and politically
    • Many scientists only seek to explain natural phenomena and take humans out of the picture
  • If we really want to understand how the universe is going to evolve, we have to account for people
    • The knowledge we create
    • The choices we will make

It’s Impossible to Predict the Growth of Knowledge | Episode 8

  • Stephen Hawking saw humans as insignificant
    • He famously said that humanity is just a chemical scum on a moderate-sized planet, orbiting around an average planet
    • While true in a sense, Hawking’s view misses a bigger point
  • Humans are, as far as we know, the only creature in the Universe capable of creating knowledge that could transform reality
    • In the future, human knowledge could shape the course of our solar system and even our galaxy
  • It’s impossible to predict the future growth of knowledge
    • By its nature, knowledge creation brings something into existence that did not exist before and thus, that could not be predicted
    • “If you could predict it, you would have invented it already” Naval
  • Doomsayers make predictions extrapolating negative trends and ignoring positive ones
    • Positive trends get ignored because they depend on knowledge creation and are unpredictable

Humans Are Unique in Our Ability to Understand Things | Episode 9

  • “Information is useless unless there’s a brain there to receive it” Naval
    • The value of knowledge depends on the human who can make use of it
  • Much of science has become very reductive
    • It breaks things down into smaller and smaller pieces to come up with explanations
  • Complexity Theory represents a counter-trend
    • It studies higher-level systems that have unpredictable emergent properties at a micro-level
    • At a macro-level it allows us to come up with some good explanations

Good Explanations Are Acts of Creativity | Episode 10

  • The concept of “good explanations” is Deutsch’s improvement upon the scientific method
  • Good explanations are
    • Testable and falsifiable
      • You should be able to run experiments and test if they are true or not
    • Creative
      • They may not be obvious to find and involve some creative thinking
  • Looking at the sun setting we may think that the sun is moving
    • But there is a more creative explanation that also fits the facts, the Earth is rotating
    • It is something that can be tested and verified
  • The idea of good explanations is explored in more detail in the TokCast notes on Chapter 1 of David Deutsch’s book The Beginning of Infinity

Good Explanations Are Hard to Vary | Episode 11

  • Just because a theory is falsifiable, it doesn’t mean that it’s a good explanation
    • I can tell you that eating 1kg of grass will cure your cold
      • This is testable and falsifiable
      • It doesn’t have any valid explanation behind it
  • Good explanations are hard to vary
    • They need to be precise, and there need to be reasons for their precision
    • They make narrow and risky predictions
  • The ancient Greek explanation for seasons was testable but easy to vary
    • Ancient Greeks correctly predicted winter through the myth of the Goddess Persephone, going to the Underworld every six months
      • But a totally different myth about another God could have also explained the beginning of winter
  • In the axis tilt theory, if you tilt the axis by more or less than what they are, the seasons would be different
    • The facts are hard to vary

There Is No End of Science | Episode 12

  • If your test is inconsistent with a theory, it doesn’t mean that it refutes the theory
    • If the only theory you had gets refuted, where do you jump to?
      • What is more likely to be flawed; your test or the theory?
    • Some experiments in the past were inconsistent with general relativity
      • Eventually, they all turned out to be flawed
  • The Eddington experiment was consistent with Einstein’s general relativity but inconsistent with Newton’s theory of universal gravitation
    • It doesn’t mean that general relativity is a final, perfect theory
  • “We never have the final word—and that’s a good thing” Brett Hall
    • We can always continue to improve and make new discoveries
    • Humans are fallible and so are our theories, there is no perfection to be reached
  • “We are at the beginning of infinity, and we will always be at the beginning of infinity  precisely because we can improve our ideas” Brett Hall

There Is No Settled Mathematics | Episode 13

  • You can never establish a final truth
    • No number of white swans can disprove the existence of a black swan
    • “There is no settled science, there is no settled mathematics. There are good explanations that will be replaced over time with more good explanations that explain more of the world” Naval
  • Gödel’s incompleteness theorem says that no formal system, including mathematics, can be both complete and correct
    • Mathematician Gregory Chaitin argued that this theorem opens up for creativity in mathematics
    • If a better explanation is always possible, humans need to use creativity to continuously inquire and innovate
  • The hierarchy of knowledge we inherit from school
    • Mathematics can prove things to be certainly true
    • Science doesn’t give certain truths but we can be confident in our discoveries
    • Philosophy is just a matter of opinion
  • David Deutsch’s calls this idea that mathematics gives us certain, final truths the mathematician’s misconception

The Methods of Mathematics Are Fallible | Episode 14

  • “Ultimately, even mathematics is a creative act and can have error within it” Naval
  • Comparing math to fundamental particle physics
  • The subject matter of particle physics is fundamental particles while for math it is “necessary truth”
    • Just because fundamental particles are the subject matter of particle physics it doesn’t mean that we found them
      • We only found the smallest particles detectable by our particle accelerators
      • We used to think that atoms were fundamental, then we found nuclei and electrons
      • Now we say that quarks are fundamental, but we can continue to inquire to discover what might be inside them
    • Similarly, just because mathematicians create knowledge about necessary truth, doesn’t mean that they found it
      • Mathematicians are just as fallible as anyone else
      • What they prove can be found to be an error

All Knowledge Is Conjectural | Episode 15

  • All knowledge is always our best understanding at a given time
  • How do we know an axiom to be true?
    • The usual answer is: “because it’s obviously the case”
    • We should always be skeptical of the feeling of certainty
    • “When people have been absolutely certain, even in a domain as apparently full of certainty as mathematics, they’ve been shown to be wrong” Brett Hall 
  • Even apparently obvious things like Euclid’s Elements may be false
    • How many straight lines can you draw through two points?
    • The obvious answer may seem one
      • But that is if you only assume 2 dimensions to be there
    • If you think in three dimensions:
      • You can bend the piece of paper and punch a hole through both points
      • You have another straight line
  • Even in Math, where we try to be as precise as possible, it is easy to make errors or rely on false assumptions
    • “It is impossible to speak in such a way that you cannot be misunderstood” Karl Popper
  • Questioning the assumptions of 2 dimensions in geometry led to geometry in a curved space which led to Einstein’s General Relativity
    • Questioning our deepest assumptions is what leads to true progress

Is the Universe Discrete or Continuous? | Episode 16

  • There is a contradiction in our most foundational explanations in physics
    • What is the fundamental nature of reality?
  • Quantum theory suggests that things are discrete
    • There is the smallest possible thing from which everything else is built
    • E.g. the photon can be seen as the smallest possible particle of light
  • General relativity holds the opposite
    • Things, including time and space, are continuous and infinitely divisible
  • Physicists are trying to unify quantum theory and General relativity to resolve this contradiction

Every Theory Is Held Inside a Physical Substrate | Episode 17

  • “You’re always bound by the laws of physics” Naval
    • Abstract mathematical theories may have no mapping to reality
  • The example of Zeno’s Paradox
    • If space is infinitely divisible, you can never get all the way to your destination
    • You can’t go through infinite points in a finite amount of time
    • It’s easy to refute Zeno’s paradox by a simple experiment
  • “We don’t live in a world of pure mathematics; we live in a world of physics” Brett Hall

We Can’t Prove Most Theorems with Known Physics | Episode 18

  • We can’t prove the majority of theorems in mathematics (Godel’s incompleteness theorem)
  • “The things that are not computable vastly outnumber the things that are computable” Brett Hall 
  • What’s computable depends on our computers, which we make obeying the laws of physics
    • Mathematicians think they can get outside of the laws of physics
      • But even their brains are constrained by physics
    • If we could step outside the laws of physics we could prove different theorems
      • Problems outside of the laws of physics cannot be proved
  • Problems that can be proven as true or false are the most interesting ones
    • They apply to our physical universe and have the power to affect it

Probability Is Subjective | Episode 19

  • Uncertainty, randomness, and probability are all subjective
  • There is no uncertainty in the universe
    • When you roll a die, you, as an individual, are uncertain about the outcome
    • This doesn’t mean that there is uncertainty in the universe
  • According to quantum theory, every single possible thing that can happen does happen
    • “There is no inherent uncertainty in the universe because everything that can happen actually will happen” Brett Hall
  • This is connected to the concept of the multiverse
    • “You occupy a single universe, and in that universe, when you roll the die, it comes up a two” Brett Hall
    • In other universes, the die will show different results

Is Light a Particle or a Wave? | Episode 20

  • The Double-slit experiment is a famous experiment about particle-wave duality
    • When you shine light through two slits, you don’t simply get two beams of light
      • You get an “interference pattern” because light waves interfere with each other
    • This experiment led Einstein to say, “God does not play dice with the universe”
    • David Deutsch explains the experiment in this video
  • Quantum theory claims that all particles sometimes behave like particles and sometimes like waves 
    • Particles bounce off each other
    • Waves pass through each other (like ocean waves)

The Multiverse | Episode 21

  • How can we explain what goes on in the Double-slit experiment?
  • The only explanation
    • When we fire a photon, there are also photons in other universes that we can’t see 
    • The photons that we can’t see can interact and interfere with those that we see, creating an interference pattern
  • “We are forced to acknowledge the existence of these other particles, and not only these other particles but other universes in which these particles exist” Brett Hall

We Explain the Seen in Terms of the Unseen | Episode 22

  • People might object if we talk about things that can’t be observed in science
  • “Almost everything of interest that you know about science is about the unobserved” Brett Hall
    • Dinosaurs are unobserved
      • We’ve only observed fossils, ossified bones transformed into rocks
      • We interpreted those fossils to be part of dinosaurs’ skeletons and made up a story about what dinosaurs were
    • No one has ever observed the core of the sun and no one will ever be able to
  • “Even many of the things that we say we have seen, we’ve actually just seen instruments detect those things” Naval

Science Expands Our Vision of Reality | Episode 23

  • The history of ideas and science is a history of us broadening our vision of exactly how large physical reality is” Brett Hall
    • We used to think that the Earth was the center of the Universe
    • Then we thought that the Sun was the center
    • Then we realized that our star system is only one among billions of stars
    • And then that our galaxy is one of the hundreds of billions of galaxies
  • The multiverse is another step in this trend of broadening our vision
    • We still haven’t figured out many aspects of the multiverse

Science Is an Error-Correcting Mechanism | Episode 24

  • We are obsessessed with using induction to explain the world around us 
    • The idea that we can predict the future based on the past
  •  Black swans are a great example of how induction fails
    • “Repeatedly observing the same phenomena over and over again should not make you confident that it will continue in the future” Brett Hall
    • If a biologist in Europe only observes white swans, he might be tempted to predict that all swans are white, but he would be wrong
      • In Western Australia, there are swans that are identical to those in Europe, but black
  • Another example of (failed) induction
    • If you see the sun rise every day since the beginning of your life, should you scientifically conclude that the sun will rise tomorrow?
    • No! That would not be using the scientific method
    • If you move to Antarctica you won’t see the sun rise for several months
  • “Science is not about cataloging a history of events that have occurred in the past and presuming they’re going to occur again in the future” Brett Hall

Theories Are Explanations, Not Predictions | Episode 25

  • How induction fails – a practical experiment
    • Heat up some water and keep its temperature with a thermometer
    • You’ll observe the temperature rising linearly
    • If you use induction, you could assume that the temperature will continue rising to infinity as long as it’s being heated
    • In reality, the water reaches a plateau at its boiling point and starts evaporating
      • With heat, the velocity of water particles increases
      • At 100°C, they reach escape velocity and start evaporating
      • This process requires energy, and this explains why you can have heating without increasing temperature
  • Science is about explanations, not predictions
    • Once we have an explanation, we can make the prediction

Make Bold Guesses and Weed Out Failures | Episode 26

  • Science is not the only field proceeding by trial and error
    • Innovation and technology come from the same process
      • Making creative guesses, trying them out, and selecting the ones that work
      • This is what inventors like Edison and Tesla have done
    • Even evolution and natural selection work this way
  • All knowledge creation is ultimately an act of creativity
    • “Your best theories are going to be creative guesses, not simple extrapolations” Naval
  • Another example of how induction fails
    • A turkey, fed every single day of his life, may predict that its owner will always feed him
    • Then Thanksgiving comes…
  • Good, scientific explanations:
    • Are testable, falsifiable, and hard to vary
    • Make bold and narrow predictions
    • Rely on creativity
  • Einstein said he wasn’t necessarily brighter than most people
    • His curiosity and imagination were key for him
    • He needed to imagine what could possibly explain what he was observing

Science Advances One Funeral at a Time | Episode 27

  • Even geniuses make mistakes
    • Brett considers Feynman the second greatest physicist of the 20th century, after Einstein
    • Feynman once said: “If you think you understand quantum theory, you don’t understand quantum theory”
    • This is nonsense, indeed David Deutsch understands quantum theory
  • Planck’s principle says that science advances one funeral at a time
  • Even in the investing world, geniuses such as Warren Buffet and Charlie Munger can’t wrap their heads around cryptocurrencies
    • The nature of people is to get stuck in their usual ways of seeing things

It’s Rare to Have Competing, Viable, Scientific Theories | Episode 28

  • Bayesianism and Solomonoff’s theory of inductive inference assume that you can list all the possible theories
    • Then, the correct theory will be a probability-weighted one that takes into account all possible theories
  • “It’s very rare in science to have more than one viable theory” Brett Hall
    • A rare exception is that of the Newtonian theory of gravity and the theory of general relativity
  • Bayesianism may work well in finite spaces that are already known, but not to come up with new explanations
    • New explanations require creativity
  • A good application of Bayesianism is the Monty Hall problem
    • If you’re given the choice to pick one of three doors, knowing that behind a door stands a prize
    • You pick the first door randomly, and later you find that one of the doors you didn’t pick doesn’t contain the prize
    • You get offered to change your choice to the other closed door, do you switch?
    • Yes, because when you first picked the door you had a 33% chance of winning the prize
      • The other two doors constituted a 66% chance of winning
    • It may be easier to understand this thinking about picking 1 door out of 100 hundred, and then 98 empty doors being revealed

We’re All Equal in Our Infinite Ignorance | Episode 29

  • “Induction says that prediction is the main reason science exists, but it’s really explanation” Brett Hall
    • The aim of science is to explain things, even if it can’t predict what will happen with absolute certainty
    • The unknown can be much more fun than the known
  • Science is never settled” Naval
    • We should always stay open to new ideas and explanations
  • “In our infinite ignorance, we are all equal” Karl Popper
    • Even those who claim to be experts in a field are ignorant about infinite things
      • Their ignorance will affect the things they know
  • You can never know where the next great idea will come from
    • A student may come in and challenge the foundations of the greatest expert

It’s Easy to Extrapolate How Things Will Get Worse | Episode 30

  • The theories predicting that we are going to imminently create Artificial General Intelligence rely on induction
    • They extrapolate the progress made in AI and assume that it will start thinking soon
  • A similar extrapolation is that humans are destroying the Earth and that the growing population will make the issue worse
    • “If you believe that knowledge comes through creativity, then any child born tomorrow could be the next Einstein or Feynman” Naval
    • They could change the world for the better in unpredictable, nonlinear ways
    • Our concern for the environment is slowing down development in many countries
    • This also prevents many people to access education and resources to come up with better solutions to the problems we face
  • Why we tend to be pessimists even when we’re living in a world of such innovation?
    • The risk of ruin is so large that we’re hardwired to be pessimists
      • Evolutionarily, as an optimist, if you were right you would get a small gain, but if you were wrong (and get eaten by a tiger) you’d be done
    • It’s also easier to extrapolate how things can go badly than how they can improve

Pessimism Seems Like an Intellectually Serious Position | Episode 31

  • There is an incentive bias to be either pessimists or optimists
  • Intellectuals tend to get rewarded for being pessimistic
    • Explaining all the issues that are going on and how dangerous they are, seems like an intellectually serious position
    • Instead, claiming that those problems can be solved often sounds “kumbaya”
  • Entrepreneurs, instead get rewarded for being optimistic
    • While pessimists get their feedback from other people, entrepreneurs get theirs from nature and free markets
  • So far, most pessimistic predictions about catastrophe have been wrong
  • Naval himself has been guilty of recording a doomsayer podcast (check out the episode notes)
    • Today, he doesn’t agree with the conclusion that we should slow down to avoid catastrophe
  • “Pessimism doesn’t acknowledge all the ways that we have innovated our way out of previous traps” Naval
    • Pessimists imply that humans are not creative
    • “The only way out is through progress” Naval

Rational Optimism Is the Way Out | Episode 32

  • “Professions in which you get your feedback from other members of that profession tend to get corrupted” Naval
    • Journalists writing for other journalists, or restaurant owners trying to impress other restaurant owners are examples of this
    • Scientists getting feedback from Nature or entrepreneurs getting their from free markets tend to produce much better results
  • Pessimism is self-fulfilling
  • Adopting a pessimistic outlook on the world affects your psychology and personal life
    • You start seeing your family, friends, and society through the same lens
    • That will also affect how you show up in the world
  • The way out is rational optimism
    • Issues arise due to our lack of knowledge
    • “Through creativity, we can always come up with good explanations to improve our lives and everybody else’s lives” Naval
    • The natural conclusion is to stay optimistic
Naval's Podcast and Periscope Sessions : , ,
Notes By Giorgio Parlato

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