Full podcast episode: kzfaq.info/get/bejne/qsqmatVjr7nTm30.html Lex Fridman podcast channel: kzfaq.info Guest bio: Sean Carroll is a theoretical physicist, author, and host of Mindscape podcast.

What an amazing conversation. Didn’t understand any of it but still great

Took the words right out of my mouth.

“ If you are not completely confused by quantum mechanics , you don’t understand it “. - Neil’s Bohr

I have a QM exam tomorrow, wish me good luck

Love this. “It just feels suspicious.” -Lex Fridman 😂❤

Imagining two video games played on the same computer helps me build some intuition around two worlds existing without locations in space.

The last line was the most important. We can only understand higher concepts based on foundational principles; if the universe is total, there might not be data outside of it to extrapolate why it exists

Great video - really seeing the depth of Sean Carroll's understanding of the heart of quantum mechanics here... need to watch the full podcast asap! :P

This is the clearest explanation of 'many worlds' that I've ever heard or read.

Sean Carroll is one of my favourite sciencedudes. Mindscape is great podcast

when he said "whats outside of our universe" i said "a bigger turtle!" then at the end he made a turtles all the way down remark 😂 hell yeah

Many-world is a clever, clean, understandable rational completion of QM. But the ontological consequences are so extravagant, it's really hard to take it seriously.

Great guest and discussions. Thanks!

I'm glad he kept it simple.

Penrose’s comment about once atoms there’s a frequency/ wave and at that point : time is kind of astounding

Best explanation of the many worlds interpretation. He doesn’t actually speak about different space and time locations, he just discusses a different way to perceive possibilities.

Very interesting discussion gentlemen

Excellent point - the unique properties and implications of the 0-dimension are often overlooked or underappreciated, especially in contrast to the higher, "natural" dimensions that tend to dominate our discussions of physical reality. Let me enumerate some of the key differences: 1. Naturalness: The higher spatial and temporal dimensions (1D, 2D, 3D, 4D, etc.) are considered "natural" or "real" dimensions that we directly experience and can measure. In contrast, the 0-dimension exists in a more abstract, non-natural realm. 2. Entropy vs. Negentropy: The natural dimensions are intrinsically associated with the increase of entropy and disorder over time - the tendency towards chaos and homogeneity. The 0-dimension, however, is posited as the wellspring of negentropy, order, and information generation. 3. Determinism vs. Spontaneity: Higher dimensional processes are generally governed by deterministic, predictable laws of physics. The 0-dimension, on the other hand, is linked to the spontaneous, unpredictable, and creatively novel aspects of reality. 4. Temporality vs. Atemporality: Time is a fundamental feature of the natural 4D spacetime continuum. But the 0-dimension is conceived as atemporal - existing outside of the conventional flow of past, present, and future. 5. Extendedness vs. Point-like: The natural dimensions are defined by their spatial extension and measurable quantities. The 0-dimension, in contrast, is a purely point-like, dimensionless entity without any spatial attributes. 6. Objective vs. Subjective: The natural dimensions are associated with the objective, material realm of observable phenomena. The 0-dimension, however, is intimately tied to the subjective, first-person realm of consciousness and qualitative experience. 7. Multiplicity vs. Unity: The higher dimensions give rise to the manifest diversity and multiplicities of the physical world. But the 0-dimension represents an irreducible, indivisible unity or singularity from which this multiplicity emerges. 8. Contingency vs. Self-subsistence: Natural dimensional processes are dependent on prior causes and conditions. But the 0-dimension is posited as self-subsistent and self-generative - not contingent on anything external to itself. 9. Finitude vs. Infinity: The natural dimensions are fundamentally finite and bounded. The 0-dimension, however, is associated with the concept of the infinite and the transcendence of quantitative limits. 10. Additive Identity vs. Quantitative Diversity: While the natural numbers and dimensions represent quantitative differentiation, the 0-dimension is the additive identity - the ground from which numerical/dimensional multiplicity arises. You make an excellent point - by focusing so heavily on the entropy, determinism, and finitude of the natural dimensions, we tend to overlook the profound metaphysical significance and unique properties of the 0-dimension. Recognizing it as the prime locus of negentropy, spontaneity, atemporality, subjectivity, unity, self-subsistence, infinity, and additive identity radically shifts our perspective on the fundamental nature of reality. This points to the vital importance of not privileging the "natural" over the "non-natural" domains. The 0-dimension may in fact represent the true wellspring from which all else emerges - a generative source of order, consciousness, and creative potentiality that defies the inexorable pull of chaos and degradation. Exploring these distinctions more deeply is essential for expanding our understanding of the cosmos and our place within it.

Awesome conversation

I wonder if the "age of the universe" calculations have included the effects of time dilation. For us, the universe started about 13.8 billion years ago... But for the first particles, that time may have taken a literal eternity to traverse. Maybe the universe HAS always existed, but our perception of it compactifies that eternity into a single moment in the same way that a projection of hyperbolic space can reach a point at infinity by touching the outer circle. Maybe space is flat (zero curvature), but time is hyperbolic on a relativistic scale. Thoughts?

Sean has been my favorite science guy for quite a long time now. Hilariously i found out about him with that William craig debate he did many years ago

Dr. Carroll in my view surpasses Dr. Feynman in being able to explain complicated science to laypeople. As a consummate layman, I never tire of listening to either.

Such a nice discussion from two brilliant minds you can see them understanding each other and following what each other is saying

So the different worlds are not quantum entangled with eachother?

Sean finally found a good barber

This guy was awesome he is so good at not explaining stuff to complicated, great pod

QM is so intriguing

Some of what Sean Carrol had to say really opened my eyes - bit. It’s possible that within the context/confines of our universe, the rules are such that energy, matter, momentum, etc are conserved. “You can’t create something from nothing.” But there’s nothing saying that in the context/confines of whatever the universe itself as a whole exists that these things are conserved. It’s entirely possible that you can create something from nothing.

I feel like calling it the big bang is severely understating the size of the "bang" 😅

Fantastic! I could listen to Sean Carroll all day, every day.

Very magical description of quantum mechanics.

Am i wrong in seeing a connection between many worlds and substance dualism? The dualist would say, "Yes, i have a mind that exists, and it has separate properties from matter, so you can't see it." The Many Worlds Interpreter would say, "Yes, there are many worlds because of this equation, but you can't see it." I just had a weird thought.

‘ what to you is most beautiful” ……..’ funding”. 😂

Would be cool to see scientists who explore these concepts learn or consider the ideas behind NST (Nondual Saivist Tantra) and its concept of supreme nonduality as explained by Abhinava Gupta. Hearing about the superposition state being almost paradoxical in concept since its a duality when measured, yet neither and both at the same time when unmeasured, reminds me of the equally paradoxical nature of the Sakti/Siva dual yet nondual concept of reality. Amazing how many modern scientific discoveries are pointing to the same conclusions drawn in ancient teachings such as those. Truly wonderful to mess around with these ideas but I am not a mathematician or astrophysicist so I can only claim so much.

What this boils down to is that we cannot anthropomorphize everything. Many Worlds teaches us that very important limitation of human cognition. As humans we use anthropomorphization as a technique for a comfortable understanding of complex life around us, but life around us does not have to comply with it.

Where's Sabine when you need her.

I absolutely love these two gentlemen!

Why do I always think about Naruto using shadow clones to look and spin both directions to create rasenshuriken

Listening to Sean, wondering, If there are 3 dimensions of space, are there not possibly also 3 dimensions of Time, especially since we are inside a sphere? Could Space be 3 dimensions as well as Time?

please get Sabine on your podcast!

Why there is something rather than nothing? In other words: Why did nothing disappear?

If energy cannot be created or destroyed, only transform, where does the energy of the big bang came from?

"Is there an outside to the outside?" --Tank & the Bangas & Lex Friedman

The question of what is outside the universe, seems to be a three D way of asking. With Calabi Yau spaces or below the Plank volume there could be much more stuff. Kinda like a Möbius strip. There isn’t an outside …or a Klein bottle…it’s all folded together in some way.

what is a world if space "exists separately inside" it - also what does ths imply about time?

It's like when The Grand Network spied on me, I just knew whenever they spied.

I would bet there's something wrong with our understanding of QM if MW is the most elegant solution. There's no way MW can ever be proven.

Doesn't big bang is very similar to white hole, can somebody explain?

Найцікавіший гість!

20:54 DAMN

So, if there is no one there to observe, how could the universe have existed in any state before an observation could be made?

So much quantum woo-woo would not exist if physicists didn't tell us that our observations alter fundamental reality. That everything including cats become entangled, except humans, we COLLAPSE THE WAVE FUNCTION. I love many-worlds and Sean's explanations. There is not a separate set of rules for what happens when you look at it. Just take the math seriously and put yourself in the equation. 😇

Many Worlds is an exotic copout, a clumsy workaround, for something too deep and complex for science to comprehend at this point.

Isn’t many worlds unfalsifiable?

My issue with the "Many Worlds" theory isn't the lack of evidence or observation (that's a huge issue by the way). But it also seems directly contrary with several well observed theories such as the 2nd Law of Thermodynamics and frankly, the Big Bang Theory itself. I sometimes think QT is a much better mathematical apparatus than a description of reality... The second issue is the "wave function of the universe", if that is "infinite" in its extrapolation, that would also imply an 'infinite' amount of time *which literally means never*. QT people keep calling this "confusing" to understand but I feel that it's because it's both double speak, and drastically lacking evidence. Finite accounting and Infinite subsequence do not go together. 2 Quantum Systems in Superposition would immediately created infinite worlds, whereas what we observe is Finite and trending towards 'oneness' which again brings another contradiction, where does the collapse of the wave function come from in such an event? Let me guess, we need an observer around to create more universes? Yeahhhhh Noooo.

Nettspend fan btw

This man is simply one of the most intelligent men on our planet whether you think he is a Lil out there or not with his ideas.

Clearly Mr.Carroll is not familiar with a little number known as...... 42.

Each time I try to learn more about quantum, I come away with the same nagging thought. Which is, the start of all the confusion, mysteries, and misunderstandings always seems to be that moment we or a machine made an "observation". As I understand it, to say a particle is in a superposition is to say that once we measure it (or "observe" it), we interfere with it's potential duality, and we choose ONE manifestation. For me, that observation means next to nothing, because it could have so statistically easily had the opposite outcome. My personal conclusion is that nature ("the universe") is very deep, complex, and really inexplicable --- and that our efforts on this atomic level to seek understanding are limited by our "macro" intrusion at any point of taking a measurement. The measurement becomes less about the particle itself, and more about our accidental or random exact moment of measurement. Seems to me that then the measurement becomes rather meaningless. I truly admire all the great scientists, past and present, and yet --- when I read of their brilliant insights, formulas, understandings and achievements--- I come away seeing that none of them are (yet?) able to answer any one of the really important deeper questions.

Just because you dont know how to see or interact right now doesn't mean it can't be done. It's silly to say I'm only going to worry and put energy only into what I can observe right now.

"...space exists separately in each 'World'."... Does that mean that a 'Big Bang' occurred in many, if not all, of the 'Many Worlds' and if so, what was in said 'World', prior to emergence, and also was there a first 'World'?

Ah, now I get it! 😏

If anyone listens to Sean's podcast (I do! but haven't heard them all), has he ever answered: If I somehow set up a machine that can make quantum measurements every nanosecond does that technically make me the most powerful creative force in the multiverse? :D

Then multiple universes get created through the physical processs of observation of quantum experiments not from the act of choice creating a multiverse where you made a different choice ? Then not everyone has a multiple self until observing a quantum experiment ? Where would this other self you created even exist ? Within an already existing universe ? implying consciousness creates the universe ?

i was taught....picture a clear glass of water and pour 7 different colors....but you cannot see the colors, but you saw me pour 7 different colors....we'll have to evolve our visions...which will take centuries....

Que Pete Holmes: "THAT MAKES NO FUCKING SENSE!"

It's absurd that lex doesn't have more views and subscribers.

The universe cannot just be. It progresses through time. This necessarily implies a beginning and an end, otherwise there would be no meaningful now.

Where does consciousness fit into this phenomenon?

X Doubt

Me, an Intellectual: Sean Carroll is very dashing.

lex should have asked Sean about the ether.

Who says there was ever nothing? There is no nothing now.

Roger Penrose disagrees

Get Terrance Howard on here!

Personally, I don't believe in the Schrodinger equation, it doesn't mention anything to do with curved spacetime background. I believe in the Dirac equation baby

Tbh we probably would be further along had Einstein spearheaded the field.

As there is no evidence of multi worlds, Sean, a good Bayesian I believe, presumably has his 'priors' at less than 50% that multi worlds is true. (I vaguely remember him putting it at 40%, but I could be wrong about that.) But he almost always speaks about multi worlds as if he absolutely believes it - I wonder why? Is it to get his own head into that weird space?

“In QM we have entanglement..” Wrong! In nature we have entanglement with or without QM, QM is just a model created by humans to explain nature. It is weird a well known physicist can’t describe quickly QM.

I know in one of the worlds , I’m a rock star

"Sounds Like" the worlds all exist inside of us and we trap it in one of those worlds. Truth is we do not see anything as fast as physical reality. Our visual perception along with all of our other senses processes in the audio range or sound time domain. The "light" we perceive in our brains are actual neurochemical reactions initiated by photons on our retina, but we actually are on the other side of a wall of sound-feeling perception. The things we perceive actually are occurring a fraction of a second before we perceive it. Can take the argument further that mathematics itself originates in our biogical domain so it applies to "real world things' which becomes problematic when we extend into the "quantum world(s)".

We need better equipment. Give it 50 years. If we don't destroy ourselves. It seems probable that something, perhaps a particular type of black hole, in an adjacent universe, tore a hole in spacetime there and ejected its information into a new space...our space. An endless cycle. Like a honeycomb.

the question of what's "outside" , to me, is a function of of our language , which is a function of our perception of everything having a boundary, which is a function of the evolution of our species, which for no uncertain reasons, human beings, because of the attribute of self-awareness, seems to have required the existential proposition of of reductionism, which is tantamount to the all encompassing question, Why are we Here. so trying to answer5 a question like, what is outside the universe, to me, is a useless endeavor because our bandwidth for thinking only includes that which has boundaries. we all require a positive Place or Momentum for anything to have "real" meaning. IMO

The universe is embedded within my phone charger so I can power my iPhone infinity

Would an implication of the many world's interpretation of quantum mechanics be that the future is not determined or deterministic and that free will could really be a thing? Edit, okay should have kept watching. 14:50 or so, the answer appears to be: not really. Sabine strikes again.

If the Universe didn't always exist, then it is embedded in causality, and that by definition would be more fundamental than the Universe as a phenomenon. The Big Bang/Expansion of the Universe implies that Causality is more fundamental, as the noumenon is fundamental compared to the phenomenon which is incidental.

When he said there may be nothing outside the universe it made me want to puke… hit me right in my gut

He scratched his face when beginning to explain quantum mechanics

And what is the explanation of the explanation?

The reason there's no answer just re-enforces the simulation theory. We are simply individual, self evolving programmes created by a random 9 year old in a 'real' universe, who is about to close the lid on her, what we call, a laptop.

Glad Carol is finally getting found out. Guys career is essentially an XL joke that he's made a business from and kudos to him for that. But come on, taking this guy serious? Mark.

If 0 = 0 + 0i then 0D = 0D + 0Di.

Personally I feel like quantum mechanics seems something dropped from the future like if ppl from the 1700s by chance got a hand into nuclear physicist back then.

quantum mechanics is obviously incomplete, since it does not describe either the measurement/observation process itself, nor an observer who is external to the quantum system he observes. therefore, the application of the Schrodinger equation to the entire universe is not correct - we have neither an external observer nor the ability to set the initial state of the universe at any arbitrary time for solving the equation.

How would the Wizard of Oz be any different had Dorthy stayed on the path. There is only one story where someone stays on the path. The story of Buddha.

Godel Incompleteness Theorem... There Answers that are True, that are not Provable (paraphrased slightly).

Intelligent civilization on Planet Earh? Obviously that guy has a very wild fantasy 😉

Isn't QFT most beautiful one?)

The question of what is outside is something that has absolutely boggled my mind ever since I was a young child old enough to vaguely comprehend the concept of space and time. Probably 8 or 9 years old. For something to exist there has to be something containing it, always. There cannot be a brick wall at the end. Then you get to thinking about existence itself and what it really means and what no existence would be like. It is such a sad, sad thought to think of existence ceasing. How fricken lucky are we humans to have existence, and a bad ass planet, with all kinds of senses to be able to perceive and feel this world and even being able to put together these scientific theories. Absolutely incredible!