@@briandimattia629 I think I'm a bit like Einstein, slightly autistic, don't commit anything to memory that I can look up. I keep up to date via journals and the internet. I work with computers at a system level.
@@boohoo5419 yeah well. At a certain point he says from now one we’re going to look at the observer in a quantum mechanical state and then like five minutes later he says that we observed the cat in a classical state. I don’t know if you know what I mean, I worded it very poorly but man is it hard to follow… you have any advicr for other videos on this topic?
@@bennozelaar his theory is that we are also quantum mechanical systems bcs we are made of particles as well. the cat is classical later bcs he speaks of it after the measurement. we can only measure classical systems and the quantum state diverges at this point. this doesnt make much sense at all. like i said. multiverse theory isnt science. this is as scientific as a priest talking about god. he can make shit up as he goes. if you wanna understand what he talks about start at string theory. then you understand the problem that hes trying to solve.
I completely agree with Sean about the nature of reality and the possibilities out there. I like his style, in that, he doesn't try to force one particular viewpoint over another, he's just interested in getting at the truth. I get the idea from his mannerisms that he sees all these differing opinions as a dance rather than a battle.
You have to be incredibly intelligent to explain things this simply. Being a great teacher is very difficult and most people don’t have the intelligence to do it well. I would like to be this man’s neighbor.
In the Trivium rhetoric is the last skill you learn to master. Rhetoric is the ability to transmit information simply and concisely to other individuals. You know you really know something when you can explain it to someone else very eloquently and simply that's when you have mastered your own knowledge.
Every time I watch this video, I'm in the world where Sean hops to the right. In the world where he hopped to the left, I actually gave a bulletproof account of the true nature of QM and our universe. I just can't get back there now.
The West has always been at the forefront of science. However , a few problems are inherent or commonly affecting the scientists from knowing the reality : 1. Language. Typically English. Language js ambiguous. A tool invented by ancient people. An art used to describe science. Problem due to its flaws : ambiguity affects communication, info propagation , discussions, debates, etc. 2. Heavily affected by Christianity. Limited minds affect knowing reality. 3. Based on maths : it works because its its system invented by humans. Of course within its rules it must work. This does not mean it can be used to know reality. It can be a limitation preventing knowing reality. The west is too confident they know a lot when no one in the world knows anything absolutely fundamental in the universe. All theories. My point is , due to all these assumptions and thinking constraints, we are guaranteed not to understand the reality. Its just not possible. What is and has been happening is scientists Believing they are right. The west is living in their own bubble. All human race should come together to find the truth. Look at China, overtaking USA. Why? Did USA not know long ago this is gonna happen? They should know. But what's the reality? Both civilisations do not really understand the other. They live in their own bubble , limiting the possibilities. Ego, Racism, xenophobia, culture, religion etc. Human ignorance
When I was an undergrad learning QM, my professor would say “shut up and do the math. It works, and that’s as good as you’re going to get.” I see why now.
Professors that've lost their drive for knowledge and try to inspire the same in their students do society a disservice. This is why we remember Max Planck better than we do Phillip von Jolly.
I am not a scientist, just an interested party. However, listening to this lecture made me think about when I was a child and I thought about when I moved my finger. Whether that changed the entire universe or created a new one or not was a very insightful thought to have for a person from 45 years ago. It's almost like it's intuitively known to us that things are dynamically changing depending on your perspective
My though of this lecture by professor Sean Carroll is that basically Gravity is merely an Entanglement of all as such, I believe..this way of thinking brings the unification and understanding to describe how quantum and classical mechanics unites and works!
You've inadvertently hit on my one reason for not buying many worlds. If true, then it has profound implications for consciousness, because after all, shouldn't we ALWAYS find ourselves in a universe in which we are alive and not one in which we are dead or never existed? That's a given right? So, that means that no matter how many times per second we die in no matter how many worlds, our experience will always be that we are alive, even if we have just narrowly survived death. Here we mix in a little Fermi Paradox just to spice things up; If the above is true, then where are all the great survivors? Where's the person that attempts suicide daily but can never die because we happen to live in a universe where he is still alive? And also if true, doesn't that make us immortal since no matter how unlikely it is that we live to be a 1000 years old, there must be worlds in which technology has allowed us to do so and so we continue to live and have that experience? IOW, many worlds is too messy and leads to too many absurd outcomes. (related to your comment because where are all the people that hit the lottery every time they play, a possibility that is highly unlikely but must happen constantly in a many worlds universe, and also related to Fermi as in "Where are all the tourists?")
I hope every lecturer explain things like this... and yes, we do have resources, we do have our textbooks, but not everything can be covered in our textbooks. Some textbooks only explains the "gist" of the subject, and is not really delving deeper into it. Sometimes I'm feelin' like telling my college professors that if we could learn everything we need from our textbooks, then what's their role in our education? We would ask things, and we will only receive their ramblings, then we would be reminded that we need to finish a couple of lessons within 3 hours including all the mandatory exams. No wonder, I've only gained interest in learning now that I'm working.
Maybe all measurement taking is extended overtime. If you could measure some fundamentally random quantum phenonenon at an instant, you might get a blurry picture (though it's not clear how a measurement device would record a "blurry" number) , but you cannot. Your measurement necessarily coarse-grains reality, averages a quantum state over time.
Once the alternate world you created to decide where to go in front of you does its test, it collapse the incorrect one of maybe even many. It’s exactly what one does when one selects an operational amp for use, you build the test feed back circuit, and that’s where dark matter and energy won’t be found but it’s there, correction was there. So good work, it’s a model that works beyond all the bickering.
I am from India. Hearty congratulations to the new scientist channel! Sean Carroll is my favourite physicist.The way Carroll explains science is commendable. 💐🌹
Well-presented description of why things made of clay can never perceive the course of events taking place in the Planck time. This is perhaps not so mysterious. Otherwise, we might think ourselves to be lost in a sort of fog.
What divides the quantum world from the classical world is that different types of Brownian motion are at work. In quantum mechanics we have tachyonic Brownian motion which is orthogonal to the wavelike behaviour. In the classical world orthogonality breaks down and the wavelike behaviour is obliterated, leaving a residue of classical Brownian motion. This idea is pitched at computer simulation. If we want to simulate something simple like an electron in a potential well, then we need to find a way to add tachyonic Brownian motion to the electron. The well needs to have some classical Brownian motion added because it is a dimple in a massive object. I don't mind hearing a claim that tachyonic Brownian motion can split the Universe in half, but I would then suggest that classical Brownian motion can glue it back together again, restoring the Universe that we actually experience. I just cannot locate the world where I win the National Lottery every week.
@@neharai4927 Unfortunately I cannot. It's my idea as far as I know. The idea is that the Minkowski formalism can be taken as a ready-made formalism which describes something deeper, namely that there is one way to travel faster than light which exchanges spacelike and timelike intervals, and another way which exchanges energy and momentum. These two ways are not the same. We can have an oscillation in the first way which can lead to destructive interference, and random motion in the second way which leads to a broken symmetry when an entity interacts with two or more detectors. This entity is definitely both a wave and a particle. Whether it is the typical entity of quantum mechanics remains to be seen, but I feel that I have my foot in the door when it comes to computer simulation.
This is the first time in hundreds of videos that it has been made clear to me that it's ONLY these special subatomic events that branch the universe and that if some dumb choice of yours doesn't correspond with one, the universe doesn't care. This feels vital and should be in every introduction to the subject. Nice one!
@@fallingintofilm Yeah, I think Prof Sean misspoke, unless his use of "quantum events" means something other than what I think it means. Every mental process involves thousands of quantum events, emitting a lot of protons, recapturing many of them elsewhere in our bodies, and transferring a lot of electrons. Our actions based on our choices involve many, many millions of quantum events over time, probably more. Each choice and each action remove us farther from the world where we first pondered the choice. (I think this is a plausible mechanism for free will when each universe has a fixed future.)
@@beenaplumber8379 The point is that it's not the making of the choice that's branching the universe. In fact, the universe is branching millions of times in the short time you actually make a decision. It's not like before the decision, you were in one branch, and then after the decision, you're in two branches, each with a different outcome to the decision. You're in millions of parallel states. In some you have decided one way, in some the other (and probably many more options outside the binary). The point Sean is making, is that there's no significance to the making of a choice. The branching is happening regardless, and the universe doesn't care. In fact, it might also be possible that you're going to make a decision, and in literally every possible future state that the wave function evolves into, you make the same decision. In which case the wave function can still be branching without even having different outcomes to the choice.
@@TijmenZwaan I understand what you're saying, and it makes sense to me. The millions of branchings that occur anyway make the quantum events associated with my mental process get lost in the chaos. But your last paragraph - I don't agree. Or i need to qualify it. All possible outcomes must exist, in one universe or another. Maybe not as a direct result of a choice, or maybe so, but they must exist.
@@beenaplumber8379 All possible outcomes must exist. However, not all outcomes must be possible. We have no idea whether the wave function contains the possibility for you to have chosen A or B, or that all the possibilities in the wave function all lead to you choosing A. To give an exaggerated example, lets say the choice is to A, walk to the grocery store and B, fly to the grocery store. It's not possible for a human to fly to the grocery store (on their own at least). So even though the wave function exists, and all possibilities therefore must exist, that does not mean that B is actually included in the possibilities.
I dont understand how infinitely minboggling the bifurcation speed of (One) universe is. Sean gives examples of ONE PERSON doing A instead of B, but isn't the wave funktion of that universe bifurcating into different uni AS SOON AS ANY ONE SINGLE PHOTON OR ELECTRON ETC INTERACTING WITH THE ENVIRONMENT?!
The limit to understanding seems to be in the ability of the mind to grasp the uncountably large and uncountably small. If a different system for understanding these proportions is learned though considerable practice (just as learning to add, subtract, multiply and divide took considerable practice). A billion millimeter cubes in a line is 1000km long but can be conceptualized using 3D - so it can be thought of as being a cubic meter. A billion billion billion in a row is 100 million light years, which is a cube with 1000km sides. This is an intellectual tool that allows all things to be conceptualized and realized
I think ultimate understanding has something to do with the making of predictions. Knowing a thing is knowing its behavior. I have the feeling that my question, 'what are fields made of', either cannot be answered outside of mathematics or any material explanation of them must be metaphorical and their 'reality' beyond understanding. But I see now that it must be that way with everything. All our understanding exists only as metaphorical ideas. The way we think has as much influence on what we think as does actuality. Cheers!
You don't violate conservation of energy if you assume that both universes exist as a wave function, but only one of those universes receives the mass-energy content of the universe.
Great lecture! One thing I don’t get... ok, no split when choosing pizza over Chinese. And: yes, there is a split on every quantum experiment. But the latter cannot be the only case. I’m missing the link between seemingly probabilistic results and seemingly classical everyday life. What are the ‘normal’ or ‘natural’ cases the universe splits up? And about how many times does this occur?
after he hoped, people were like should we clap? so like 5 people clapped, thank God its would have been awkward if he just stood there for 5 seconds only to proceed.
yes!!! loved that too! he is all about getting Hugh the credit he deserves. PS I wonder if any of these folks consider it disrespectful when we use their first names...
Everett was a true genius but he was bitterly let down by the scientific establishment of the time. I'm so gald Dr Carroll gives the appropriate credit to his groundbreaking work.
This answers the question of free will (stay with me). I make a choice (a sum of several quantum events), which determines which universal branch I take. It does not affect the universe I left behind. Each and every universe is fixed, but we choose the subsets of universes we experience. I think Prof Sean is mistaken when he says decisions are not quantum events. As far as we know (I'm a retired neuroscientist), decisions are a sum of electrochemical interactions in the brain, all of which emit photons, and all of which involve electron shuffling. Our actions are the same, whether muscular or glandular. If a quantum event is all that's needed, there ya go. Our choices result in many thousands of them, and our corresponding actions result in many millions, and it's all volitional.
I think you got it backwards, this would actually disprove the free will. As such your decision is mere result of probability of quantum event and free will and decision making is thus an illusion. In your interpretation the person making the decision is not the one actually making it, the outcome of quantum event is.
@@sssummmak I have made one or two assumptions here, the most important being that I can create chemical changes in my brain and body by will. I can raise my hand by will, and raising my hand causes quantum events. Some might argue that my hand will rise on its own and be accompanied by the delusion that I caused it to happen. But of what evolutionary advantage would that kind of self-deception be? Absent any empirical evidence to decide that matter, I can't reject your criticism as impossible, so I will say this might put the answer to the question of freewill under the Many Worlds theory, but like everything in science, nothing is certain. I favor my choice as the agent of change in the world around me because it fits all of my subjective observations so far, and if I am correct, that provides a viable pathway for freewill. That's a sorta anthropic principle thing there - if it were different, freewill could not exist - but since freewill is the question right now, I am giving this as a hypothesis that fits under the umbrella Many Worlds theory. Show me that the quantum events result in my perception that I have made a choice, and you will have refuted my hypothesis. Until then, you have pointed out a valid weakness in it, though your criticism shares the identical weakness - lack of empirical evidence.
@@beenaplumber8379 I personally also prefer thinking I have a free will and by self observation I have reached similar conclusion untill disproven. But you brought up interesting idea. If indeed processees in our brains are result of quantum events, even the decision itself may be simple result of such an event. in other words, in one universe you want to do thing a and in universe you want to do b. In both you feel that it is your own free decision.
@@sssummmak It still seems to come down to whether the quantum events precede or follow the thoughts. I guess we could be tossed randomly (or at least unpredictably) from universe to universe, telling ourselves "I meant to do that!" My hypothesis is scarcely better though, as I think you've aptly pointed out. I think what I was really happy about at first is that there is now a framework for freewill. It still may or may not be a truth, but there's a path to getting there now. Before Many Worlds, it was either yes or no, with freewill proponents sometimes needing to add a bit of god power to justify freewill as superior. I think many Worlds gives us the possibility to find something more than a chicken-or-egg type conundrum. But you're absolutely right - the more I think about it, the more I see the equal likelihood of agency vs. riding along. But there's another cool possibility - you lose the grandfather paradox with many worlds. Invent a time machine, go back in time & kill your grandfather, and all you've done is kill him in that timeline, not the one you originated in. You can mess with the past all you want because it's not going to affect the timelines you followed to get there. That's still cool!
@@beenaplumber8379 I'm confused. Where are your thoughts supposed to come from if not from activity in your brain? Regarding the physics of (non existent) free will, I would recommend this video: ua-cam.com/video/zpU_e3jh_FY/v-deo.html
Around 35:10, you say 'Decisions in your head are purely classical processes - most of your thoughts have nothing to do with quantum mechanics.' But surely your head (and its brain!) are themselves quantum objects - as are processes running in them? So your decision for pizza or curry (I'd go for curry) is itself a quantum process. You seem to be indicating a curious dualism - quantum, and non-quantum, processes. But my understanding of what you said earlier is that everything is quantum. All quantum, everywhere, everywhen. If this is not so, what have I misunderstood?
I don't think people don't like the many-worlds interpretation, I think people love this idea. The Hollywood productions reflect that in last two decades. I think Copenhagen interpretation is closer to our experience and more faithful to Occams razor.
There is no such thing as a collapse of the wave function, so no, it does not break the speed of light. It doesn't do anything other than to confuse people who don't understand physics.
Question: Are there a finite number of possible superpositions for a given subatomic particle? If quantum particles are not particles but waves, that would seem to mean that superpositions would not be quantifiable, and not countable. And if this were true, wouldn't a new branch have infinite outcomes? If anyone could speak on this, I would appreciate it!
If you think about it, in a quantum world the number of possible superposed states MUST be finite, because all of the variables that distinguish one state from another are quantised
I remember David Wallace's reply to this in his book The Emergent Multiverse. The "collapse" phenomenology is the point-like intersections of continuous waves, so in the math that's an infinite number. The catch is that two arbitrarily close points in that continuum will have exactly the same phenomenology; there's no observable fact that could distinguish them. So it's not appropriate to call them "separate branches". Once you start thinking like that, you see that the issue of what actually defines a "branching" can be really nuanced and complex; you have to dig into how the actual observation may change from our perspective. Also there's the problem of chaos, the butterfly effect, e.g., where two nearby points won't appear differentiated early on, but after some amount of time they take surprisingly divergent paths. The branching happens later but was already set in motion earlier, so when is it fair to call it a "branching"? It gets complicated! Edit: You also have to keep in mind that we, as classical objects, observe ourselves taking a random walk through the continuum. Countless other versions of us are taking their own random walks through the continuum. What we usually mean by "world" is the path of that random walk, and a branching a divergence in that walk. In that context, what we're talking about is a version of us, our world, that's taking almost exactly the same walk as us through the Hilbert space continuum, arbitrarily close, so close that there's no observational difference. Our consciousnesses and the reality we observe are exactly the same in every way. Does that make us the "same person" in the "same world"? I think yes; but it's more of a philosophical question than a scientific one at that point.
"Why do we see things in location?" Maybe it's the same reason we can watch multiple things at the same time. The U.S. Open TV coverage will split screen and show 2 tennis games at once. Hard as I try, I can't watch both games at the exact same time. Maybe our ability to comprehend what we see is limited to seeing one world at a time.
Maybe the measurement problem is the same than in photography. If you take too long exposure, you will see blurred image. We should just measure faster 10e-33sec or similar. Some have suqqested that there are universal clock in that speed.
in a certain experiment you can see particles fly out of objects that radioactivly decay, if it was a wave it would radiate in a sphere in all directions. the double slit experiment shows a wave? so it collapses under observation. we are all in the same system connected by the fields that atoms get there mass.
If we seriously consider the experiment of "Wigner's Friend", we have to accept a multi-world interpretation. An observer in his world is in his time, and for him a division of his world arises in his time. However, for transcendents outside the universe the universe is stationary.
@@schakiarligonde1736 When the entanglement of quantum superposition extends to include an observer, it evolves into a state of multiple coexisting worlds.
Just a small thing : the universe cannot _be split at the same moment,_ because _"the universe at the same moment"_ does not have any meaning, *and Sean Carroll knows it perfectly.* *Speaking of "many minds" instead does nor require any put-aside of Relativity, Special nor General.*
@@jamescollier3 According to GR there is no such thing as "the universe" (at a given time), but as many different universes as possible observers, with just a coherence contraint. Right ?
hmmm does this relate to the question of free will in some way? that we "have free will" in a quantum way, that is any choice is an infinite choice but free will becomes entangled so our experience is there is no free will? hmmm.
Pilot Wave theory is the most intuitive straight forward interpretation of Quantum Mechanics, but it is clearly incompatible with Special Relativity, but it is compatible with Galilean Relativity, where space and time are absolute and field propagation is not limited by the speed of light. I propose that Relativity is just an optical illusion. Relativity has a simple built in logical fallacy, and no theory based on a logical fallacy can be true, no matter how many experiments seem to prove it, or how many people say it is true. Below is a very simple logical argument highlighting the logical fallacy, using the same terminology Einstein used to derive Relativity. According to Relativity, observers on a moving train and on a stationary train platform will disagree on the size of the ""Train"" and the passage of time on the ""Train"". This is a complete logical contradiction if the size and the passage of time of the train are real. If the size of the train is real, then the ""Train"" can not be both contracted and not contracted. The same goes for the observed passage of time on the ""Train"". If these effects are observed, then the only possible conclusion is that it is an optical illusion. Things that are real must appear to be same from all frames of reference. If not, then by definition it is an illusion. Again the argument is very simple and it is the argument Einstein used to derive Relativity, and no acceleration is used in the argument. A train with length (L) traveling at constant velocity (v) relative a stationary observer on a station platform. According to Relativity, the stationary observer will see the train contracted (L/r, where r is the Relativistic gamma), whereas an observer on the train will see it not contracted (L). So the train is both contracted (L/r) and not contracted (L) depending on the observer. This is a complete contradiction (L not equal L/r) and can not be true if length is real. The same argument applies to passage of time on the Train, where both observers will disagree on the passage of time. If time is real, it can not be both dilated and not dilated (T not equal rT). If space and time are observed to be both large and small simultaneously for one inertial reference frame, such as the ""Train"", then it must be an optical illusion. This argument is only the tip of the iceberg. There is much more evidence including both theoretical and experimental, so please keep reading. Hi my name is Dr William Walker and I am a PhD physicist and have been investigating this topic for 30 years. It has been known since the late 1700s by Simone LaPlace that nearfield Gravity is instantaneous by analyzing the stability of the orbits of the planets about the sun. This is actually predicted by General Relativity by analyzing the propagating fields generated by an oscillating mass. In addition, General Relativity predicts that in the farfield Gravity propagates at the speed of light. The farfield speed of gravity was recently confirmed by LIGO. Recently it has been shown that light behaves in the same way by using Maxwell's equations to analyze the propagating fields generated my an oscillating charge. For more information search: William Walker Superluminal. This was experimentally confirmed by measuring radio waves propagating between 2 antennas and separating the antennas from the nearfield to the farfield, which occurs about 1 wavelength from the source. This behavior of gravity and light occurs not only for the phase and group speed, but also the information speed. This instantaneous nature of light and gravity near the source has been kept from the public and is not commonly known. The reason is that it shows that both Special Relativity and General Relativity are wrong! It can be easily shown that Instantaneous nearfield light yields Galilean Relativity and farfield light yields Einstein Relativity. This is because in the nearfield, gamma=1since c= infinity, and in the farfield, gamma= the Relativistic gamma since c= farfield speed of light. Since time and space are real, they can not depend on the frequency of light used. This is because c=wavelength x frequency, and 1 wavelength = c/frequency defines the nearfield from the farfield. Consequently Relativity is an optical illusion. Objects moving near the speed of light appear to contract in length and time appears to slow down, but it is just what you see using farfield light. Using nearfield light you will see that the object has not contracted and time has not changed. For more information: Search William Walker Relativity. Since General Relativity is based on Special Relativity, General Relativity must also be an optical illusion. Spacetime is flat and gravity must be a propagating field. Researchers have shown that in the weak field limit, which is what we only observe, General Relativity reduces to Gravitoelectromagnetism, which shows gravity can be modeled as 4 Maxwell equations similar in form to those for electromagnetic fields, yielding Electric and Magnetic components of gravity. This theory explains all gravitational effects as well as the instantaneous nearfield and speed of light farfield propagating fields. So gravity is a propagating field that can finally be quantized enabling the unification of gravity and quantum mechanics. The current interpretation of quantum mechanics makes no sense, involving particles that are not real until measured, and in a fuzzy superposition of states. On the other hand, the Pilot Wave interpretation of Quantum Mechanics makes makes much more sense, which says particles are always real with real positions and velocities. The particles also interact with an energetic quantum field that permeates all of space, forming a pilot wave that guides the particle. This simpler deterministic explanation explains all known quantum phenomena. The only problem is that the Pilot Wave is known to interact instantaneously with all other particles, and this is completely incompatible with Relativity, but is compatible with Galilean Relativity. But because of the evidence presented here, this is no longer a problem, and elevates the Pilot Interpretation to our best explanation of Quantum Mechanics. *UA-cam presentation of above argument: ua-cam.com/video/sePdJ7vSQvQ/v-deo.html *Paper it is based on: William D. Walker and Dag Stranneby, A New Interpretation of Relativity, 2023: vixra.org/abs/2309.0145
I have another explanation for the question of Schrodinger cat that is very simple and I am sure that is right: the mechanism that activates the poison, in this case is also a detector of the quantum state, therefore the cat will never be in a superposition of states, but it will be dead or alive not both, and this regardless of the open or closed box, or who observes
So does that mean with black holes there's a quantum particle there and that's actually where it is? Or is it that that's a place of significant entanglement which might be the same thing a point where the many worlds converge and the particle of all the worlds overlapping on each other is actually in that spot. So the degree of entanglement of the many worlds is proportional to the mass and energy of that spot until you get a single concentration and convergence and the "big bang" happens again. So the "probalistic" overlapping position of the other worlds is actually the mass in which I see and interact given I don't know which world I'm actually in. It's like probablistic mass that actually makes up the mass and material of the world I can actually live and breath in and interact with
So how does the entanglement explanation of gravity relate to the hypothetical graviton? Is there a quantum field with bosons that carry the force of gravity, or this would be an alternative explanation where there is no quantum field of gravity?
*SERIOUS opinions only, please:* I'm not smart. So, I have to ask: Must each of these "splits" create its own "big bang" somewhere else with the creation of a new universe? Or does the parallel world just sort of divide off within this universe? (Insults to my person will be ignored.)
Not a serious opinion, simply an explanation: there isn’t another big bang because there isn’t a creation of a new universe. The wave function which describes the one universe simply evolves in such a way that a term with amplitude A becomes a set of i€{1,…,N} new terms with amplitudes Ai such that the sum of (Ai)^2 = A^2. There is only one universal wave function. It is simply a superposition of orthogonal states.
I'm just saying maybe I don't understand something. But I think Marletto believes in this which would technically break the very laws of thermodynamics she considers impossible to break? I don't see how you could believe in that and give up on a perpetual motion machine. Every time you look or measure or make a decision the universe branches off, breaking one of the laws that makes perpetual motion impossible. Wouldn't our universe taken as a complete system be a perpetual motion machine?
Really enjoyed this presentation. I'm already a big fan of Mind Scape. One question: where does the energy come from to create the new branches of the entire universe?
@@Vld45 How does the mass energy of 511keV of an electron split? Where do you get the 1GeV for the proton in a hydrogen from? To be honest, you are just another one of those guys who don't know how quantum mechanics actually works. The result is that folks like Sean Carroll can pull one over you with the stupid MWI interpretation. :-)
Sean Carroll makes it seem like it the coppenhagen interpretation is more weird than the many worlds interpretation. Both are strange. One essentially says that our consciousness manifests reality, the other say that there are an infinite number of universes.
(0:50) But the photon that is "split" to the rt or lt is detected by sensors made by fallible Homo sapiens, and the particle accelerator is made by fallible Homo sapiens too. What I'm getting at is the Homo sapiens, particle accelerator, the sensors, and other variables that includes the electric grid, the iphone, the Universe Splitter app have been corrupted by fallible Homo sapiens and the deterministic Universe. Therefore, "randomness" is an illusion. It would be better if Carroll, instead of doing what the app tells him, does a headstand and simultaneously hops to the lt instead.
Entanglement is not an irreversable process. In fact it is very fragile because it requires specific conditions (very low temperatures etc) Otherwise the whole universe would be entangled since the Big Bang.
@@neharai4927 Of course entanglement can happen anywhere anytime but lasts only for a very short time. If we want to maintain it for a long time, for example in quantum computers, we must keep the temperature close to zero.
What's the difference between an observation & an event? If a photograph is taken then not viewed for 100yrs. Are the silver halide crystals in the emulsion in superposition for all that time? Which is the observation. The photograph or the viewing of the photograph? Or are the states of the photographic crystals events or a stored observation?
And that's the entire point. The idea of observation is simply not well defined. Which is why the many worlds interpretation is much more appealing. "Are the silver halide crystals in the emulsion in superposition for all that time?" Yes. In fact, it will never get out of that superposition. There is no wave function collapse, so superpositions are permanent. What happens is that you as the observer also become entangled with what you're observing, so you also go into a superposition. We are just experiencing one branch of the larger superposition of the universe.
ففردا هم میگویم که چرا نظریه انیشتین در مورد سرعت نور و اینکه چرا ذرات نمیتوانند بالاتر از سرعت نور حرکت کنند ،درست است ولی سرعت ذرات درعین حال خیلی بیشر از سرعت نور هستش و این تناقض رو ایا خودتان میتوانید پیدا گنید ؟؟
But the electron wave function values are essentially zero, except in the shells around the nucleus. So saying the atom is mostly empty space still seems valid.
Quantum mechanics is about possibilty, but usually among so many possibilities only one or few will be realized, the percentage of realization depends on the conditions which favorite the chance to occur ,right?
If we put more than 3 observers at the same time to open the cat box, if they all have the same conclusion, will the thinking of superposition still exists?
Kinda blew my mind! Newtonian physics, general relativity, quantum mechanics, and now this. If it holds up, it really is of that magnitude, right? Pinch me! Because Many Worlds has a correlate, Many Minds, that is like an algebraic transformation of Many Worlds, only IMO it's simpler because it does not assume a universe. The only first principle is the thinking observer. It's almost a solipsism like that, but not quite. Anyway, from that one assumption, "I think, therefore I am," Schrödinger's equation and all of quantum mechanics is emergent, and therefore so is everything else. I hope I live long enough to see this work out! (With my luck, I'll probably kick the bucket when we have another turn-of-the-20th-century moment when we realize that we've barely scratched the surface of a whole new underlying system.)
@blindwillie99 Because, for all you know, consciousness might be the only thing there is. What makes you so sure you need anything of any complexity in order to dream up a world where brains and complexity are required to think? The surest sign that you don't know something is the certainty with which you think you know it. Certainty makes terrible scientists. "How can anyone seriously posit" is another way of saying "I can't think of a basis to posit." Then you give up and give your Nobel to the next in line. That's a crisis of imagination, or lack thereof. "I can't think of how, therefore it's not valid." A scientist from the Mayo Clinic gave a talk at my lab once, and he had spent hundreds of thousands of dollars, maybe millions, on a flawed research program. He couldn't make sense of his data, so he concluded his hypothesis must be correct because he couldn't think of a better explanation - never mind that his data did not support his hypothesis either. When he left, we all had a few chuckles at the poor guy's expense. Narrow thinking and closed minds block learning. Einstein's best work all came directly from his wide-open mind and incredibly fertile imagination. Sadly, his worst work came from just the opposite - things he refused to consider because they seemed preposterous to him. Give yourself a chance to go through the brilliant phase before settling in the humdrum monotony of narrowed expectations.
@@beenaplumber8379 Try thinking without a brain. You want to believe that consciousness is fundamental only because you don't want your personal awareness to come to a permanent end at death. The psychology here is obvious.
@@b.g.5869 There's another example. You have a hypothesis (my motives + the need for a brain led to my conclusion), and you can't think of a better explanation. That is a starting point, not a basis for a conclusion. Your only evidence is reason, but reason can only get us to a hypothesis, not a scientific conclusion. (That is a very common misconception among non-scientists.) The problem, and the strongest challenge to research in psychology, is that no one can know the internal experiences of another person (without ESP). They are not directly subject to scientific study. That is why psychological diagnoses are defined by statistical variation from normal behavior, not internal experiences. (Their lack of correlation of disorders to neural processes has also thrown a real monkey wrench into the field of psychological research, yet even that could not give us access to internal experiences.) I would like to amend my own statement of my first principle: I am aware, therefore I am. Thinking might imply some cognitive process that doesn't require awareness, but it might require a flesh computer (no one can say for sure). Neuroscientists can't even say where different types of memories are stored. (Certain types of task memories might be stored in the motor groups that perform those tasks, for instance.) You can speculate about my motives if you like, but the evidence for that is scant. You can speculate you need a brain to think (or maybe to be aware), but again, the evidence is scant. In any case, the Many Minds theory requires an observer, nothing more. I think the pertinent question for you is how much evidence do you really have that a brain is required first in order to have an observer? Even defining an observer is problematic under quantum theory. I think you might have fallen into that trap where you assume things that are intuitive to you must be true. The whole weirdness of quantum theory is that it is so very counter-intuitive. You don't know more than I do, and I don't know more than you do. (I'm a retired neuroscientist, so you think I might claim to know more than you, but I don't. This is far broader than the study of one organ system.) The difference is that you are *assuming* a lot more than I am. Do you realize how little you know, how little you can know, about all this? I think the basis for your confidence is misplaced. I'm just excited by all this theoretical work because it's beginning to make so much more sense to me now!
@@beenaplumber8379 Interesting debate here. Your position made me think of Donald Hoffman - I wonder if you are familiar with his work? From what I can gather, he is working on developing a mathematical model which posits consciousness is fundamental and matter emergent. I believe his goal is to use the model to attempt to derive general relativity equations, Schrodigners equations etc.
Isn't that specifically what he's saying isn't happening at 35:00? "If you don't know whether to order pizza or curry for dinner tonight and you finally make a decision, that doesn't mean there's another universe in which you ordered another one".
@@dantenotavailable What I am saying 'If you have come to a decision about ordering pizza or curry, your conclusion may have been to stay in for pasta'
@@life42theuniverse It may have been, but it might also not have been one of the possibilities. It could very well be that the wave function had no possible states where he saw left/right on the screen, but jumped in the other direction. The fact that all possible worlds and all possible outcomes exist simultaneously does not mean that everything is possible to exist or happen.
In that case(a crazy amount of "particles" interacting simultaniously) how does that universe wave function even "keep track" of it self? So to speak...
Why would it need to? It simply has to obey the rules. On a much smaller, more digestible scale, the ants in Langtons' Ant sims don't need to "keep track" of anything, they just obey the rules of their universe, and stuff happens
Time is very interesting to say the least... to say the most would take an infinite amount of space. I just said that now... and it is then. Glory be to what was, is, and will be.... thank you 😊 Such an awesome observation obviously observed by observing observers in observatories. More than meets the eye. Just think about how many atoms are in front of you while you read what is on your screen... then think.... how many atoms are in this "I" that's controlling your mind right now? 👁
People today asking "How come we see only one cat?" ~ Diogenes the Cynic walking across the room to refute Zeno. The analogue to limit theory's solution* to Zeno's paradox may emerge, but we don't have it. Positing that the wave function collapses not only into the observed universe but also into all other possible universes is fun but 90%? I guess if you stated anything less than p=0.9 you'd never be published.
what if quantum stuff like the cat alive or dead are entirely dependent on our own consciousness and are not actually existing outside of ourselves or our reasoning
@SeanCarroll, This is an excellent speech as far as public speaking techniques go -- but I think it can be greatly enhanced if you add a few words about how do fields work - that there can be fields that are cross-interacting, self-interacting and non-interacting. AND, non-self-interacting fields are actually fairly easy to visualize - very much like the sound waves in a 1D string, or surface waves in a pond. if you spend a few words on explaining that some events are interacting (and produce a split) and some are non-interacting (waves just travel on their own and move away from each other, maybe even going through each other without distortion) the entire story will be much more believable. You can do it!
@@HawthorneHillNaturePreserve Thank you for entangling me back to this topic a full year later. I enjoyed this lecture today as much as I enjoyed it back then. A year after, I understand more of it. As to yourself -- does spreading hate make you feel smarter? Please let me know.
I'm sure it must be me, but I still simply don't know what QM actually is. When I read comments that say how brilliant this speaker is and how well he explains QM, I can't help but think it's just like the emperor's new clothes. It's all way beyond me and I don't mind saying so. How can I not have a clue about what this speaker has been saying? Surely language is meant to be a tool to aid communication, not make things even more unfathomable than they were at the beginning. 🤷
If there is a 50 % chance that he hops left and 50 % chance he hops right, then if both events occur, then the probability for each event is 100 %, and for both 200 %, which is a contradiction.
I see many people praising this lecture, and for the most part I found it quite informative. However, there is one thing Sean says that doesn't quite sit with me. I don't understand why our thoughts/decisions wouldn't make separate worlds / put our brains in superpositions. Surely, our thoughts exist, are causal, and have a physical presence? We don't have mind reading abilities, but surely we can observe our own thoughts? Even if we can't observe our own thoughts, I think it's reasonable to say someone or something COULD observe our thoughts, with proper tools or technology? Regardless, certainly our thoughts exist, and when we decide things in our mind, it affects the future before we have even acted. It makes zero sense to me, that our thoughts must be committed to action in order to "branch in two." It would make more sense if in fact, the universe DOES branch whenever we have different thoughts. It makes no sense to refer to thoughts as classical processes as a reason for not causing the universe to branch. . . The cat, the box, and the sleeping gas are all classical objects, yet that scenario still causes entanglement with the universe, superpositions, and a branching universe. So why wouldn't our thoughts? I completely disagree here. @New Scientist
Our brains are also quantum mechanical. When he says they act by "classical" rules, I think that's shorthand for saying that (almost) every single branch is going to have the same outcome, i.e., you make the same decision. So every quantum event in your brain making up your thought or decision is branching the universe, but you're making the same decision in all of them. Or even if you make different decisions, the process is spread over a vast number of worlds, so it's not the decision itself that's branching the universe. If you want a little more detail, the leading theory for a large category of human decisions is the Diffuse Drift Model. In that model, in contemplating a decision, the brain tracks the activation-strength of triggering the decision by a very large set of neurons, e.g., "hop left" and "hop right", modeled by two nodes that receive inputs, each one with a threshold, if the activation crosses the threshold, the action is triggered and the alternative is shut off. The nodes are going to receive random inputs so there's a measure of random drift left and right, but some evidence or considerations can give a big push in one direction or another, and when the drift finally crosses a threshold for either left or right, the action is triggered. So the reason why a decision doesn't branch the universe is because it's a classical stochastic system. A decision is going to be composed of quintillians of quantum events gradually drifting to the left or right node. In the vast number of cases, those quintillian events are always going to eventually drift to the same threshold because of who you are as a person, your personality, your history, how you think, etc. All that said, there are cases you can imagine where a decision would split the world, and that's the case where out of these quintillians of quantum events, a SINGLE ONE is the determining event that makes LEFT trigger and not right. (In one world you hop left, then in the alternative worlds, well it wouldn't be hop right, since the right node is still a long drift away, the alternatives are not hopping left at exactly that moment.) That would be a "decision" that branches the universe. But you can see from the way the model is set up that that's vastly unlikely. You'd have to be teetering right on the edge of a decision and really randomly fall to one side or another. But even in most cases of teetering on a decision, it's usually not a single quantum event that pushes you into one decision or another but a set of still a pretty large number. And once it's that large of a number, we're not talking about a single branching per se but a vast number of branches all going in the same direction with slightly different but stochastically equivalent paths. Edit: Oh I should add something. It's usually not a single quantum event that can trigger a behavior, in case you're thinking for any decision there's always that last straw that makes the camel hop. All decisions require multiple different brain areas signing off on the decision before it's triggered; so while there may be a final determining quantum event for one of them; it's not a good description of the "decision", because you have to take into account the activation of other areas too. So even my "you could imagine a single quantum event" example isn't really fair. Behind all of this I think is the theoretical point that classical physics is emergent in MWI. David Wallace wrote a whole book explaining this called The Emergent Multiverse. So I think what he's really saying is that the best description for brain action is under the emergent rules of classical physics, biology, neuroscience, etc., which are emergent rules under MWI. Biology is hot & wet where decoherece is happening every 10^-20 seconds, so quantum effects get washed out, it's just noise, and the signal that describes what's happening is the emergent rules of classical physics. I like the language of topos theory, which would say the "signal" is the rules of classical physics; the topos which "carries" the signal is quantum physics. Well I think this is the right way to think about it. I'm happy if someone has any corrections, elaborations, or comments to that.
I've watched this lecture several times now and each viewing is as engaging as the first. Dr Carroll is a stellar lecturer.
Agreed
Yes, I’m still stuck on how does a wave spin?
@@sbschamp10 I thought I was getting close to having an intuitive understanding of QM, and then you had to go and ask a question like that.
i watched it then i didn't watch it and i understand but don't comprehend. i think i got a better grasp when i wasn't watching it.
He's great. I'd like to watch him and Lawrence kraus have a conversation
An absolute masterpiece. Sean Carrol is a great communicator and surely one of top guys in his field.
EWW44WAqaW3TDW !qaqrydtd
As a non physicist who left school at 16 but with an overwhelming interest in cosmology I think I actually understood that.
Lovely, nice to hear. Its been 4 months since your comment, how has your interest manifested itself in your life up too this point?
@@briandimattia629 I think I'm a bit like Einstein, slightly autistic, don't commit anything to memory that I can look up. I keep up to date via journals and the internet. I work with computers at a system level.
No you don't , quantum mechanics is short is insisting this world is a Matrix a simulation and not real at all. Now tell me you understand it.
Every once in a while I come back to this lecture to try and understand it! Diving in right now, wish me luck!
its pseudo science. so.. dont know what you try to understand. nothing of this is testable..
@@boohoo5419 yeah well. At a certain point he says from now one we’re going to look at the observer in a quantum mechanical state and then like five minutes later he says that we observed the cat in a classical state. I don’t know if you know what I mean, I worded it very poorly but man is it hard to follow… you have any advicr for other videos on this topic?
@@bennozelaar his theory is that we are also quantum mechanical systems bcs we are made of particles as well. the cat is classical later bcs he speaks of it after the measurement. we can only measure classical systems and the quantum state diverges at this point. this doesnt make much sense at all. like i said. multiverse theory isnt science. this is as scientific as a priest talking about god. he can make shit up as he goes. if you wanna understand what he talks about start at string theory. then you understand the problem that hes trying to solve.
I completely agree with Sean about the nature of reality and the possibilities out there. I like his style, in that, he doesn't try to force one particular
viewpoint over another, he's just interested in getting at the truth. I get the idea from his mannerisms that he sees all these differing opinions
as a dance rather than a battle.
You have to be incredibly intelligent to explain things this simply. Being a great teacher is very difficult and most people don’t have the intelligence to do it well. I would like to be this man’s neighbor.
In the Trivium rhetoric is the last skill you learn to master. Rhetoric is the ability to transmit information simply and concisely to other individuals. You know you really know something when you can explain it to someone else very eloquently and simply that's when you have mastered your own knowledge.
Every time I watch this video, I'm in the world where Sean hops to the right. In the world where he hopped to the left, I actually gave a bulletproof account of the true nature of QM and our universe. I just can't get back there now.
From many worlds theory you can also deduct that time travel is analogous to travelling between parallel worlds.
They're actually different 'worlds' in the same universe; Carroll explained this.
Many universes refers to the multiverse of eternal cosmic inflation.
you smokin the indicar sativa? Oh, wait more like shrooms or acid? Let me know please I gotta kno
The West has always been at the forefront of science. However , a few problems are inherent or commonly affecting the scientists from knowing the reality :
1. Language. Typically English. Language js ambiguous. A tool invented by ancient people. An art used to describe science. Problem due to its flaws : ambiguity affects communication, info propagation , discussions, debates, etc.
2. Heavily affected by Christianity. Limited minds affect knowing reality.
3. Based on maths : it works because its its system invented by humans. Of course within its rules it must work. This does not mean it can be used to know reality. It can be a limitation preventing knowing reality.
The west is too confident they know a lot when no one in the world knows anything absolutely fundamental in the universe. All theories.
My point is , due to all these assumptions and thinking constraints, we are guaranteed not to understand the reality. Its just not possible. What is and has been happening is scientists Believing they are right. The west is living in their own bubble. All human race should come together to find the truth. Look at China, overtaking USA. Why? Did USA not know long ago this is gonna happen? They should know. But what's the reality? Both civilisations do not really understand the other. They live in their own bubble , limiting the possibilities. Ego, Racism, xenophobia, culture, religion etc. Human ignorance
I wish I could like this video ten times. Subscribed.
14 year old here, love this stuff!!
Same!
@@poopityscoopity2042 god
My man Sean has mastered his craft
What craft is that?
Ah, but which craft? Or is that, witch craft?
When I was an undergrad learning QM, my professor would say “shut up and do the math. It works, and that’s as good as you’re going to get.” I see why now.
Shut up and calculate. There's nothing to see here.
@@b.g.5869 certainly not the deepest mysteries of the universe
Professors that've lost their drive for knowledge and try to inspire the same in their students do society a disservice.
This is why we remember Max Planck better than we do Phillip von Jolly.
I am not a scientist, just an interested party. However, listening to this lecture made me think about when I was a child and I thought about when I moved my finger. Whether that changed the entire universe or created a new one or not was a very insightful thought to have for a person from 45 years ago. It's almost like it's intuitively known to us that things are dynamically changing depending on your perspective
That was a great lecture!
Outstanding lecture not to mention compelling arguments.
Great Video. Really interesting. I’m learning all the time. 😀👍
My though of this lecture by professor Sean Carroll is that basically Gravity is merely an Entanglement of all as such, I believe..this way of thinking brings the unification and understanding to describe how quantum and classical mechanics unites and works!
Stellar presentation that helped me think about the subject, and actually form my own opinion on the relationship between Gravity and the Many Worlds.
Wow. Wonderfully explained.
I need a quantum lottery ticket generator. That way, I'll always be in a world where I win the jackpot!
Not a bad username or point there dude!
@@benjammin8184 I agree about the username
the chances of other people winning is so low i ought to win every week.
You've inadvertently hit on my one reason for not buying many worlds. If true, then it has profound implications for consciousness, because after all, shouldn't we ALWAYS find ourselves in a universe in which we are alive and not one in which we are dead or never existed? That's a given right? So, that means that no matter how many times per second we die in no matter how many worlds, our experience will always be that we are alive, even if we have just narrowly survived death. Here we mix in a little Fermi Paradox just to spice things up; If the above is true, then where are all the great survivors? Where's the person that attempts suicide daily but can never die because we happen to live in a universe where he is still alive? And also if true, doesn't that make us immortal since no matter how unlikely it is that we live to be a 1000 years old, there must be worlds in which technology has allowed us to do so and so we continue to live and have that experience? IOW, many worlds is too messy and leads to too many absurd outcomes. (related to your comment because where are all the people that hit the lottery every time they play, a possibility that is highly unlikely but must happen constantly in a many worlds universe, and also related to Fermi as in "Where are all the tourists?")
Then you are the only concious human being in this universe. All alone to spend your winning money.
I hope every lecturer explain things like this... and yes, we do have resources, we do have our textbooks, but not everything can be covered in our textbooks. Some textbooks only explains the "gist" of the subject, and is not really delving deeper into it. Sometimes I'm feelin' like telling my college professors that if we could learn everything we need from our textbooks, then what's their role in our education? We would ask things, and we will only receive their ramblings, then we would be reminded that we need to finish a couple of lessons within 3 hours including all the mandatory exams. No wonder, I've only gained interest in learning now that I'm working.
Maybe all measurement taking is extended overtime. If you could measure some fundamentally random quantum phenonenon at an instant, you might get a blurry picture (though it's not clear how a measurement device would record a "blurry" number) , but you cannot. Your measurement necessarily coarse-grains reality, averages a quantum state over time.
Professor Sean Caroll deserves an honorary Nobel Prize for his services in communication of Physics. Check out his podcast "Mindscape"!
What a fantastic and informative video
Absolutely fantastic! Just brilliant!
"Atoms are mostly wave function." Favorite quote from this.
Once the alternate world you created to decide where to go in front of you does its test, it collapse the incorrect one of maybe even many. It’s exactly what one does when one selects an operational amp for use, you build the test feed back circuit, and that’s where dark matter and energy won’t be found but it’s there, correction was there. So good work, it’s a model that works beyond all the bickering.
My idea but other worlds might say otherwise, no difference.
You guys rock.
I am from India. Hearty congratulations to the new scientist channel! Sean Carroll is my favourite physicist.The way Carroll explains science is commendable. 💐🌹
Well-presented description of why things made of clay can never perceive the course of events taking place in the Planck time. This is perhaps not so mysterious. Otherwise, we might think ourselves to be lost in a sort of fog.
Great lecture by Sean Carroll
What divides the quantum world from the classical world is that different types of Brownian motion are at work. In quantum mechanics we have tachyonic Brownian motion which is orthogonal to the wavelike behaviour. In the classical world orthogonality breaks down and the wavelike behaviour is obliterated, leaving a residue of classical Brownian motion.
This idea is pitched at computer simulation. If we want to simulate something simple like an electron in a potential well, then we need to find a way to add tachyonic Brownian motion to the electron. The well needs to have some classical Brownian motion added because it is a dimple in a massive object.
I don't mind hearing a claim that tachyonic Brownian motion can split the Universe in half, but I would then suggest that classical Brownian motion can glue it back together again, restoring the Universe that we actually experience. I just cannot locate the world where I win the National Lottery every week.
Where can I learn about tachyonic browniab motion? Can u suggest some book?
@@neharai4927 Unfortunately I cannot. It's my idea as far as I know. The idea is that the Minkowski formalism can be taken as a ready-made formalism which describes something deeper, namely that there is one way to travel faster than light which exchanges spacelike and timelike intervals, and another way which exchanges energy and momentum. These two ways are not the same.
We can have an oscillation in the first way which can lead to destructive interference, and random motion in the second way which leads to a broken symmetry when an entity interacts with two or more detectors. This entity is definitely both a wave and a particle. Whether it is the typical entity of quantum mechanics remains to be seen, but I feel that I have my foot in the door when it comes to computer simulation.
This is the first time in hundreds of videos that it has been made clear to me that it's ONLY these special subatomic events that branch the universe and that if some dumb choice of yours doesn't correspond with one, the universe doesn't care. This feels vital and should be in every introduction to the subject. Nice one!
I’m not sure that’s true.
@@fallingintofilm Yeah, I think Prof Sean misspoke, unless his use of "quantum events" means something other than what I think it means. Every mental process involves thousands of quantum events, emitting a lot of protons, recapturing many of them elsewhere in our bodies, and transferring a lot of electrons. Our actions based on our choices involve many, many millions of quantum events over time, probably more. Each choice and each action remove us farther from the world where we first pondered the choice. (I think this is a plausible mechanism for free will when each universe has a fixed future.)
@@beenaplumber8379 The point is that it's not the making of the choice that's branching the universe. In fact, the universe is branching millions of times in the short time you actually make a decision. It's not like before the decision, you were in one branch, and then after the decision, you're in two branches, each with a different outcome to the decision. You're in millions of parallel states. In some you have decided one way, in some the other (and probably many more options outside the binary).
The point Sean is making, is that there's no significance to the making of a choice. The branching is happening regardless, and the universe doesn't care.
In fact, it might also be possible that you're going to make a decision, and in literally every possible future state that the wave function evolves into, you make the same decision.
In which case the wave function can still be branching without even having different outcomes to the choice.
@@TijmenZwaan I understand what you're saying, and it makes sense to me. The millions of branchings that occur anyway make the quantum events associated with my mental process get lost in the chaos.
But your last paragraph - I don't agree. Or i need to qualify it. All possible outcomes must exist, in one universe or another. Maybe not as a direct result of a choice, or maybe so, but they must exist.
@@beenaplumber8379 All possible outcomes must exist. However, not all outcomes must be possible.
We have no idea whether the wave function contains the possibility for you to have chosen A or B, or that all the possibilities in the wave function all lead to you choosing A.
To give an exaggerated example, lets say the choice is to A, walk to the grocery store and B, fly to the grocery store.
It's not possible for a human to fly to the grocery store (on their own at least). So even though the wave function exists, and all possibilities therefore must exist, that does not mean that B is actually included in the possibilities.
I dont understand how infinitely minboggling the bifurcation speed of (One) universe is. Sean gives examples of ONE PERSON doing A instead of B, but isn't the wave funktion of that universe bifurcating into different uni AS SOON AS ANY ONE SINGLE PHOTON OR ELECTRON ETC INTERACTING WITH THE ENVIRONMENT?!
The last 5 minutes blew my mind
the audio quality if off...i've seen this lecture before and it was better if i am recalling correctly
Carroll simply detests Bohr lol he almost can't contain it. Anyways, always deeply fascinating to listen to Carroll dissecting QM
Also misspelled his first name😂 Niels- not Neils
with every potential branching energy gets potentially doubled, and conservation is blown into pieces.🤔
But the energy in the universe itself is conserved
The limit to understanding seems to be in the ability of the mind to grasp the uncountably large and uncountably small. If a different system for understanding these proportions is learned though considerable practice (just as learning to add, subtract, multiply and divide took considerable practice). A billion millimeter cubes in a line is 1000km long but can be conceptualized using 3D - so it can be thought of as being a cubic meter. A billion billion billion in a row is 100 million light years, which is a cube with 1000km sides. This is an intellectual tool that allows all things to be conceptualized and realized
I think ultimate understanding has something to do with the making of predictions. Knowing a thing is knowing its behavior. I have the feeling that my question, 'what are fields made of', either cannot be answered outside of mathematics or any material explanation of them must be metaphorical and their 'reality' beyond understanding. But I see now that it must be that way with everything. All our understanding exists only as metaphorical ideas. The way we think has as much influence on what we think as does actuality. Cheers!
Well Explained 👍
You don't violate conservation of energy if you assume that both universes exist as a wave function, but only one of those universes receives the mass-energy content of the universe.
a wonderful teacher
Great lecture! One thing I don’t get... ok, no split when choosing pizza over Chinese. And: yes, there is a split on every quantum experiment. But the latter cannot be the only case. I’m missing the link between seemingly probabilistic results and seemingly classical everyday life. What are the ‘normal’ or ‘natural’ cases the universe splits up? And about how many times does this occur?
after he hoped, people were like should we clap? so like 5 people clapped, thank God its would have been awkward if he just stood there for 5 seconds only to proceed.
I love how the observer is Hugh Everett.
yes!!! loved that too! he is all about getting Hugh the credit he deserves. PS I wonder if any of these folks consider it disrespectful when we use their first names...
@@JoeHynes284a little late, but if they were anything like the physicists of today, I’d say most of them would prefer it.
@@Muongoing.97c I think you are absolutely correct, but I still refer them as doctor or professor or at least I try to
I think Sean is very entangled with the quantum theory.
Everett was a true genius but he was bitterly let down by the scientific establishment of the time. I'm so gald Dr Carroll gives the appropriate credit to his groundbreaking work.
Yes, he was a true genius who made his main mistake in the second sentence of his thesis. ;-)
This answers the question of free will (stay with me). I make a choice (a sum of several quantum events), which determines which universal branch I take. It does not affect the universe I left behind. Each and every universe is fixed, but we choose the subsets of universes we experience. I think Prof Sean is mistaken when he says decisions are not quantum events. As far as we know (I'm a retired neuroscientist), decisions are a sum of electrochemical interactions in the brain, all of which emit photons, and all of which involve electron shuffling. Our actions are the same, whether muscular or glandular. If a quantum event is all that's needed, there ya go. Our choices result in many thousands of them, and our corresponding actions result in many millions, and it's all volitional.
I think you got it backwards, this would actually disprove the free will. As such your decision is mere result of probability of quantum event and free will and decision making is thus an illusion. In your interpretation the person making the decision is not the one actually making it, the outcome of quantum event is.
@@sssummmak I have made one or two assumptions here, the most important being that I can create chemical changes in my brain and body by will. I can raise my hand by will, and raising my hand causes quantum events. Some might argue that my hand will rise on its own and be accompanied by the delusion that I caused it to happen. But of what evolutionary advantage would that kind of self-deception be? Absent any empirical evidence to decide that matter, I can't reject your criticism as impossible, so I will say this might put the answer to the question of freewill under the Many Worlds theory, but like everything in science, nothing is certain.
I favor my choice as the agent of change in the world around me because it fits all of my subjective observations so far, and if I am correct, that provides a viable pathway for freewill. That's a sorta anthropic principle thing there - if it were different, freewill could not exist - but since freewill is the question right now, I am giving this as a hypothesis that fits under the umbrella Many Worlds theory. Show me that the quantum events result in my perception that I have made a choice, and you will have refuted my hypothesis. Until then, you have pointed out a valid weakness in it, though your criticism shares the identical weakness - lack of empirical evidence.
@@beenaplumber8379 I personally also prefer thinking I have a free will and by self observation I have reached similar conclusion untill disproven. But you brought up interesting idea. If indeed processees in our brains are result of quantum events, even the decision itself may be simple result of such an event. in other words, in one universe you want to do thing a and in universe you want to do b. In both you feel that it is your own free decision.
@@sssummmak It still seems to come down to whether the quantum events precede or follow the thoughts. I guess we could be tossed randomly (or at least unpredictably) from universe to universe, telling ourselves "I meant to do that!" My hypothesis is scarcely better though, as I think you've aptly pointed out.
I think what I was really happy about at first is that there is now a framework for freewill. It still may or may not be a truth, but there's a path to getting there now. Before Many Worlds, it was either yes or no, with freewill proponents sometimes needing to add a bit of god power to justify freewill as superior. I think many Worlds gives us the possibility to find something more than a chicken-or-egg type conundrum. But you're absolutely right - the more I think about it, the more I see the equal likelihood of agency vs. riding along.
But there's another cool possibility - you lose the grandfather paradox with many worlds. Invent a time machine, go back in time & kill your grandfather, and all you've done is kill him in that timeline, not the one you originated in. You can mess with the past all you want because it's not going to affect the timelines you followed to get there. That's still cool!
@@beenaplumber8379 I'm confused. Where are your thoughts supposed to come from if not from activity in your brain?
Regarding the physics of (non existent) free will, I would recommend this video: ua-cam.com/video/zpU_e3jh_FY/v-deo.html
Around 35:10, you say 'Decisions in your head are purely classical processes - most of your thoughts have nothing to do with quantum mechanics.' But surely your head (and its brain!) are themselves quantum objects - as are processes running in them? So your decision for pizza or curry (I'd go for curry) is itself a quantum process. You seem to be indicating a curious dualism - quantum, and non-quantum, processes. But my understanding of what you said earlier is that everything is quantum. All quantum, everywhere, everywhen. If this is not so, what have I misunderstood?
The new problem is that cats are always sleeping anyways
I don't think people don't like the many-worlds interpretation, I think people love this idea. The Hollywood productions reflect that in last two decades. I think Copenhagen interpretation is closer to our experience and more faithful to Occams razor.
I hope one day I see Sean Carroll debating Tim Moudlin.
is the wave function collapsing or decoherence breaking the speed of light ?
There is no such thing as a collapse of the wave function, so no, it does not break the speed of light. It doesn't do anything other than to confuse people who don't understand physics.
Still can not figure it out , but some how I can Imagen it , different hand movement in all directions?
Damn I'm dumb.
That is a readily falsifiable hypothesis. Nice one! Now collect your data.
he must have done this kinda of lecture for so thousands of times
Fascinating!
What is the mathematics? Feynman sum of integral path?
Or is just philosophy?
Mathematics of what? Many worlds? It doesn't have any "mathematics" of its own. It's just a (false) reinterpretation of standard quantum mechanics.
ممنونم از شما
My opinion of Carroll has only gone up over the years
Question: Are there a finite number of possible superpositions for a given subatomic particle? If quantum particles are not particles but waves, that would seem to mean that superpositions would not be quantifiable, and not countable. And if this were true, wouldn't a new branch have infinite outcomes? If anyone could speak on this, I would appreciate it!
If you think about it, in a quantum world the number of possible superposed states MUST be finite, because all of the variables that distinguish one state from another are quantised
I remember David Wallace's reply to this in his book The Emergent Multiverse. The "collapse" phenomenology is the point-like intersections of continuous waves, so in the math that's an infinite number. The catch is that two arbitrarily close points in that continuum will have exactly the same phenomenology; there's no observable fact that could distinguish them. So it's not appropriate to call them "separate branches". Once you start thinking like that, you see that the issue of what actually defines a "branching" can be really nuanced and complex; you have to dig into how the actual observation may change from our perspective. Also there's the problem of chaos, the butterfly effect, e.g., where two nearby points won't appear differentiated early on, but after some amount of time they take surprisingly divergent paths. The branching happens later but was already set in motion earlier, so when is it fair to call it a "branching"? It gets complicated!
Edit: You also have to keep in mind that we, as classical objects, observe ourselves taking a random walk through the continuum. Countless other versions of us are taking their own random walks through the continuum. What we usually mean by "world" is the path of that random walk, and a branching a divergence in that walk. In that context, what we're talking about is a version of us, our world, that's taking almost exactly the same walk as us through the Hilbert space continuum, arbitrarily close, so close that there's no observational difference. Our consciousnesses and the reality we observe are exactly the same in every way. Does that make us the "same person" in the "same world"? I think yes; but it's more of a philosophical question than a scientific one at that point.
"Why do we see things in location?" Maybe it's the same reason we can watch multiple things at the same time. The U.S. Open TV coverage will split screen and show 2 tennis games at once. Hard as I try, I can't watch both games at the exact same time. Maybe our ability to comprehend what we see is limited to seeing one world at a time.
Maybe the measurement problem is the same than in photography. If you take too long exposure, you will see blurred image. We should just measure faster 10e-33sec or similar. Some have suqqested that there are universal clock in that speed.
in a certain experiment you can see particles fly out of objects that radioactivly decay, if it was a wave it would radiate in a sphere in all directions. the double slit experiment shows a wave? so it collapses under observation. we are all in the same system connected by the fields that atoms get there mass.
time is relative
What is quantum information conservation law
If we seriously consider the experiment of "Wigner's Friend", we have to accept a multi-world interpretation. An observer in his world is in his time, and for him a division of his world arises in his time. However, for transcendents outside the universe the universe is stationary.
This isn’t true at all
@@schakiarligonde1736 When the entanglement of quantum superposition extends to include an observer, it evolves into a state of multiple coexisting worlds.
Just a small thing : the universe cannot _be split at the same moment,_ because _"the universe at the same moment"_ does not have any meaning, *and Sean Carroll knows it perfectly.*
*Speaking of "many minds" instead does nor require any put-aside of Relativity, Special nor General.*
He's just saying: the math/equation dictates the universe splits. 25:55
@@jamescollier3 According to GR there is no such thing as "the universe" (at a given time), but as many different universes as possible observers, with just a coherence contraint. Right ?
@@Paganel75 sorry. You lost me. Lol
hmmm does this relate to the question of free will in some way? that we "have free will" in a quantum way, that is any choice is an infinite choice but free will becomes entangled so our experience is there is no free will? hmmm.
Very interesting. I hope as we learn more about the mechanisms behind awareness this will become clearer
Decisions don't split up the world.The branching has nothing to do with the brain.
Pilot Wave theory is the most intuitive straight forward interpretation of Quantum Mechanics, but it is clearly incompatible with Special Relativity, but it is compatible with Galilean Relativity, where space and time are absolute and field propagation is not limited by the speed of light. I propose that Relativity is just an optical illusion. Relativity has a simple built in logical fallacy, and no theory based on a logical fallacy can be true, no matter how many experiments seem to prove it, or how many people say it is true. Below is a very simple logical argument highlighting the logical fallacy, using the same terminology Einstein used to derive Relativity.
According to Relativity, observers on a moving train and on a stationary train platform will disagree on the size of the ""Train"" and the passage of time on the ""Train"". This is a complete logical contradiction if the size and the passage of time of the train are real. If the size of the train is real, then the ""Train"" can not be both contracted and not contracted. The same goes for the observed passage of time on the ""Train"". If these effects are observed, then the only possible conclusion is that it is an optical illusion. Things that are real must appear to be same from all frames of reference. If not, then by definition it is an illusion.
Again the argument is very simple and it is the argument Einstein used to derive Relativity, and no acceleration is used in the argument. A train with length (L) traveling at constant velocity (v) relative a stationary observer on a station platform. According to Relativity, the stationary observer will see the train contracted (L/r, where r is the Relativistic gamma), whereas an observer on the train will see it not contracted (L). So the train is both contracted (L/r) and not contracted (L) depending on the observer. This is a complete contradiction (L not equal L/r) and can not be true if length is real. The same argument applies to passage of time on the Train, where both observers will disagree on the passage of time. If time is real, it can not be both dilated and not dilated (T not equal rT). If space and time are observed to be both large and small simultaneously for one inertial reference frame, such as the ""Train"", then it must be an optical illusion.
This argument is only the tip of the iceberg. There is much more evidence including both theoretical and experimental, so please keep reading. Hi my name is Dr William Walker and I am a PhD physicist and have been investigating this topic for 30 years. It has been known since the late 1700s by Simone LaPlace that nearfield Gravity is instantaneous by analyzing the stability of the orbits of the planets about the sun. This is actually predicted by General Relativity by analyzing the propagating fields generated by an oscillating mass. In addition, General Relativity predicts that in the farfield Gravity propagates at the speed of light. The farfield speed of gravity was recently confirmed by LIGO.
Recently it has been shown that light behaves in the same way by using Maxwell's equations to analyze the propagating fields generated my an oscillating charge. For more information search: William Walker Superluminal. This was experimentally confirmed by measuring radio waves propagating between 2 antennas and separating the antennas from the nearfield to the farfield, which occurs about 1 wavelength from the source. This behavior of gravity and light occurs not only for the phase and group speed, but also the information speed. This instantaneous nature of light and gravity near the source has been kept from the public and is not commonly known. The reason is that it shows that both Special Relativity and General Relativity are wrong! It can be easily shown that Instantaneous nearfield light yields Galilean Relativity and farfield light yields Einstein Relativity. This is because in the nearfield, gamma=1since c= infinity, and in the farfield, gamma= the Relativistic gamma since c= farfield speed of light. Since time and space are real, they can not depend on the frequency of light used. This is because c=wavelength x frequency, and 1 wavelength = c/frequency defines the nearfield from the farfield. Consequently Relativity is an optical illusion. Objects moving near the speed of light appear to contract in length and time appears to slow down, but it is just what you see using farfield light. Using nearfield light you will see that the object has not contracted and time has not changed. For more information: Search William Walker Relativity.
Since General Relativity is based on Special Relativity, General Relativity must also be an optical illusion. Spacetime is flat and gravity must be a propagating field. Researchers have shown that in the weak field limit, which is what we only observe, General Relativity reduces to Gravitoelectromagnetism, which shows gravity can be modeled as 4 Maxwell equations similar in form to those for electromagnetic fields, yielding Electric and Magnetic components of gravity. This theory explains all gravitational effects as well as the instantaneous nearfield and speed of light farfield propagating fields. So gravity is a propagating field that can finally be quantized enabling the unification of gravity and quantum mechanics.
The current interpretation of quantum mechanics makes no sense, involving particles that are not real until measured, and in a fuzzy superposition of states. On the other hand, the Pilot Wave interpretation of Quantum Mechanics makes makes much more sense, which says particles are always real with real positions and velocities. The particles also interact with an energetic quantum field that permeates all of space, forming a pilot wave that guides the particle. This simpler deterministic explanation explains all known quantum phenomena. The only problem is that the Pilot Wave is known to interact instantaneously with all other particles, and this is completely incompatible with Relativity, but is compatible with Galilean Relativity. But because of the evidence presented here, this is no longer a problem, and elevates the Pilot Interpretation to our best explanation of Quantum Mechanics.
*UA-cam presentation of above argument:
ua-cam.com/video/sePdJ7vSQvQ/v-deo.html
*Paper it is based on: William D. Walker and Dag Stranneby, A New Interpretation of Relativity, 2023: vixra.org/abs/2309.0145
@4:30 He's name is "Niels bohr" :-)
Awesome Cool Video
I have another explanation for the question of Schrodinger cat that is very simple and I am sure that is right:
the mechanism that activates the poison, in this case is also a detector of the quantum state, therefore the cat will never be in a superposition of states, but it will be dead or alive not both, and this regardless of the open or closed box, or who observes
Nope.
So does that mean with black holes there's a quantum particle there and that's actually where it is? Or is it that that's a place of significant entanglement which might be the same thing a point where the many worlds converge and the particle of all the worlds overlapping on each other is actually in that spot. So the degree of entanglement of the many worlds is proportional to the mass and energy of that spot until you get a single concentration and convergence and the "big bang" happens again. So the "probalistic" overlapping position of the other worlds is actually the mass in which I see and interact given I don't know which world I'm actually in. It's like probablistic mass that actually makes up the mass and material of the world I can actually live and breath in and interact with
So how does the entanglement explanation of gravity relate to the hypothetical graviton? Is there a quantum field with bosons that carry the force of gravity, or this would be an alternative explanation where there is no quantum field of gravity?
*SERIOUS opinions only, please:* I'm not smart. So, I have to ask: Must each of these "splits" create its own "big bang" somewhere else with the creation of a new universe? Or does the parallel world just sort of divide off within this universe? (Insults to my person will be ignored.)
Not a serious opinion, simply an explanation: there isn’t another big bang because there isn’t a creation of a new universe. The wave function which describes the one universe simply evolves in such a way that a term with amplitude A becomes a set of i€{1,…,N} new terms with amplitudes Ai such that the sum of (Ai)^2 = A^2. There is only one universal wave function. It is simply a superposition of orthogonal states.
I'm just saying maybe I don't understand something. But I think Marletto believes in this which would technically break the very laws of thermodynamics she considers impossible to break? I don't see how you could believe in that and give up on a perpetual motion machine. Every time you look or measure or make a decision the universe branches off, breaking one of the laws that makes perpetual motion impossible. Wouldn't our universe taken as a complete system be a perpetual motion machine?
Really enjoyed this presentation. I'm already a big fan of Mind Scape. One question: where does the energy come from to create the new branches of the entire universe?
That's like asking "Where does the energy for Santa Claus come from?"
It doesn't come from anywhere since the universe splits.There is no new energy being created.
@@Vld45 So now you have to prove experimentally that the total mass-energy of the new universe is zero. Good luck with that.
@@lepidoptera9337 How did you infer that the energy is zero? Did you even read my last sentence? The energy that already is, splits.
@@Vld45 How does the mass energy of 511keV of an electron split? Where do you get the 1GeV for the proton in a hydrogen from? To be honest, you are just another one of those guys who don't know how quantum mechanics actually works. The result is that folks like Sean Carroll can pull one over you with the stupid MWI interpretation. :-)
I believe there is a part of me that is a physicist. It is not the choice I made but still connected. I feel this is why I am so attentive to Physics.
Well, that part should be rolling on the floor laughing right now.
Sean Carroll makes it seem like it the coppenhagen interpretation is more weird than the many worlds interpretation. Both are strange. One essentially says that our consciousness manifests reality, the other say that there are an infinite number of universes.
(0:50) But the photon that is "split" to the rt or lt is detected by sensors made by fallible Homo sapiens, and the particle accelerator is made by fallible Homo sapiens too. What I'm getting at is the Homo sapiens, particle accelerator, the sensors, and other variables that includes the electric grid, the iphone, the Universe Splitter app have been corrupted by fallible Homo sapiens and the deterministic Universe. Therefore, "randomness" is an illusion. It would be better if Carroll, instead of doing what the app tells him, does a headstand and simultaneously hops to the lt instead.
Entanglement is not an irreversable process. In fact it is very fragile because it requires specific conditions (very low temperatures etc) Otherwise the whole universe would be entangled since the Big Bang.
But plants n brains are constantly doing quantum entanglement even in room temperature.
@@neharai4927 Of course entanglement can happen anywhere anytime but lasts only for a very short time. If we want to maintain it for a long time, for example in quantum computers, we must keep the temperature close to zero.
What's the difference between an observation & an event?
If a photograph is taken then not viewed for 100yrs. Are the silver halide crystals in the emulsion in superposition for all that time?
Which is the observation. The photograph or the viewing of the photograph?
Or are the states of the photographic crystals events or a stored observation?
And that's the entire point. The idea of observation is simply not well defined. Which is why the many worlds interpretation is much more appealing.
"Are the silver halide crystals in the emulsion in superposition for all that time?"
Yes. In fact, it will never get out of that superposition. There is no wave function collapse, so superpositions are permanent.
What happens is that you as the observer also become entangled with what you're observing, so you also go into a superposition.
We are just experiencing one branch of the larger superposition of the universe.
Sean Carroll, i think maybe we need a 10 billion dollar double slit experiment to figure it out ;) A highly advanced setup -.-
Who said it can't be tested? Please
ففردا هم میگویم که چرا نظریه انیشتین در مورد سرعت نور و اینکه چرا ذرات نمیتوانند بالاتر از سرعت نور حرکت کنند ،درست است ولی سرعت ذرات درعین حال خیلی بیشر از سرعت نور هستش و این تناقض رو ایا خودتان میتوانید پیدا گنید ؟؟
If somebody tells you atoms is mostly empty space; that's not true. Atoms is mostly wave-function!
But the electron wave function values are essentially zero, except in the shells around the nucleus. So saying the atom is mostly empty space still seems valid.
@@raygromer a 'cloud' of probabilities
Quantum mechanics is about possibilty, but usually among so many possibilities only one or few will be realized, the percentage of realization depends on the conditions which favorite the chance to occur ,right?
No, under the Many Worlds interpretation, ALL of them are realised, but as soon as the split occurs, they can no longer exchange information
@@talltroll7092 So there's no free will & we're living each possibility out, individually? What determines the reality we ARE in?
If we put more than 3 observers at the same time to open the cat box, if they all have the same conclusion, will the thinking of superposition still exists?
No. That's the same as 1 cat
Wow, goosebumps around 52m when I realised what he was getting at. Incredible if it holds true.
Kinda blew my mind! Newtonian physics, general relativity, quantum mechanics, and now this. If it holds up, it really is of that magnitude, right? Pinch me! Because Many Worlds has a correlate, Many Minds, that is like an algebraic transformation of Many Worlds, only IMO it's simpler because it does not assume a universe. The only first principle is the thinking observer. It's almost a solipsism like that, but not quite. Anyway, from that one assumption, "I think, therefore I am," Schrödinger's equation and all of quantum mechanics is emergent, and therefore so is everything else. I hope I live long enough to see this work out! (With my luck, I'll probably kick the bucket when we have another turn-of-the-20th-century moment when we realize that we've barely scratched the surface of a whole new underlying system.)
@blindwillie99 Because, for all you know, consciousness might be the only thing there is. What makes you so sure you need anything of any complexity in order to dream up a world where brains and complexity are required to think? The surest sign that you don't know something is the certainty with which you think you know it. Certainty makes terrible scientists. "How can anyone seriously posit" is another way of saying "I can't think of a basis to posit." Then you give up and give your Nobel to the next in line. That's a crisis of imagination, or lack thereof. "I can't think of how, therefore it's not valid."
A scientist from the Mayo Clinic gave a talk at my lab once, and he had spent hundreds of thousands of dollars, maybe millions, on a flawed research program. He couldn't make sense of his data, so he concluded his hypothesis must be correct because he couldn't think of a better explanation - never mind that his data did not support his hypothesis either. When he left, we all had a few chuckles at the poor guy's expense. Narrow thinking and closed minds block learning. Einstein's best work all came directly from his wide-open mind and incredibly fertile imagination. Sadly, his worst work came from just the opposite - things he refused to consider because they seemed preposterous to him. Give yourself a chance to go through the brilliant phase before settling in the humdrum monotony of narrowed expectations.
@@beenaplumber8379 Try thinking without a brain.
You want to believe that consciousness is fundamental only because you don't want your personal awareness to come to a permanent end at death. The psychology here is obvious.
@@b.g.5869 There's another example. You have a hypothesis (my motives + the need for a brain led to my conclusion), and you can't think of a better explanation. That is a starting point, not a basis for a conclusion. Your only evidence is reason, but reason can only get us to a hypothesis, not a scientific conclusion. (That is a very common misconception among non-scientists.) The problem, and the strongest challenge to research in psychology, is that no one can know the internal experiences of another person (without ESP). They are not directly subject to scientific study. That is why psychological diagnoses are defined by statistical variation from normal behavior, not internal experiences. (Their lack of correlation of disorders to neural processes has also thrown a real monkey wrench into the field of psychological research, yet even that could not give us access to internal experiences.)
I would like to amend my own statement of my first principle: I am aware, therefore I am. Thinking might imply some cognitive process that doesn't require awareness, but it might require a flesh computer (no one can say for sure). Neuroscientists can't even say where different types of memories are stored. (Certain types of task memories might be stored in the motor groups that perform those tasks, for instance.)
You can speculate about my motives if you like, but the evidence for that is scant. You can speculate you need a brain to think (or maybe to be aware), but again, the evidence is scant.
In any case, the Many Minds theory requires an observer, nothing more. I think the pertinent question for you is how much evidence do you really have that a brain is required first in order to have an observer? Even defining an observer is problematic under quantum theory. I think you might have fallen into that trap where you assume things that are intuitive to you must be true. The whole weirdness of quantum theory is that it is so very counter-intuitive.
You don't know more than I do, and I don't know more than you do. (I'm a retired neuroscientist, so you think I might claim to know more than you, but I don't. This is far broader than the study of one organ system.) The difference is that you are *assuming* a lot more than I am. Do you realize how little you know, how little you can know, about all this? I think the basis for your confidence is misplaced. I'm just excited by all this theoretical work because it's beginning to make so much more sense to me now!
@@beenaplumber8379 Interesting debate here. Your position made me think of Donald Hoffman - I wonder if you are familiar with his work? From what I can gather, he is working on developing a mathematical model which posits consciousness is fundamental and matter emergent. I believe his goal is to use the model to attempt to derive general relativity equations, Schrodigners equations etc.
1:55 there are also the worlds that you are told to jump right and you jump left and when told to jump left you jump right.
Isn't that specifically what he's saying isn't happening at 35:00?
"If you don't know whether to order pizza or curry for dinner tonight and you finally make a decision, that doesn't mean there's another universe in which you ordered another one".
@@dantenotavailable What I am saying 'If you have come to a decision about ordering pizza or curry, your conclusion may have been to stay in for pasta'
@@life42theuniverse It may have been, but it might also not have been one of the possibilities. It could very well be that the wave function had no possible states where he saw left/right on the screen, but jumped in the other direction.
The fact that all possible worlds and all possible outcomes exist simultaneously does not mean that everything is possible to exist or happen.
Do the branches of the wave function effect the curvature of space in the ‘vicinity’.
In that case(a crazy amount of "particles" interacting simultaniously) how does that universe wave function even "keep track" of it self? So to speak...
Why would it need to? It simply has to obey the rules. On a much smaller, more digestible scale, the ants in Langtons' Ant sims don't need to "keep track" of anything, they just obey the rules of their universe, and stuff happens
Time is very interesting to say the least... to say the most would take an infinite amount of space.
I just said that now... and it is then.
Glory be to what was, is, and will be.... thank you 😊
Such an awesome observation obviously observed by observing observers in observatories.
More than meets the eye.
Just think about how many atoms are in front of you while you read what is on your screen... then think....
how many atoms are in this "I" that's controlling your mind right now? 👁
و ریمان رو اگر بگم اونجا چی میگید ؟؟؟
People today asking "How come we see only one cat?" ~ Diogenes the Cynic walking across the room to refute Zeno. The analogue to limit theory's solution* to Zeno's paradox may emerge, but we don't have it. Positing that the wave function collapses not only into the observed universe but also into all other possible universes is fun but 90%? I guess if you stated anything less than p=0.9 you'd never be published.
what if quantum stuff like the cat alive or dead are entirely dependent on our own consciousness and are not actually existing outside of ourselves or our reasoning
@SeanCarroll, This is an excellent speech as far as public speaking techniques go -- but I think it can be greatly enhanced if you add a few words about how do fields work - that there can be fields that are cross-interacting, self-interacting and non-interacting. AND, non-self-interacting fields are actually fairly easy to visualize - very much like the sound waves in a 1D string, or surface waves in a pond. if you spend a few words on explaining that some events are interacting (and produce a split) and some are non-interacting (waves just travel on their own and move away from each other, maybe even going through each other without distortion) the entire story will be much more believable. You can do it!
Right - because he had unlimited time in which to explicate all elements of QM. Sheesh.
@George Rey, I’ll get right on that! - Sean Carroll
@@HawthorneHillNaturePreserve Thank you for entangling me back to this topic a full year later. I enjoyed this lecture today as much as I enjoyed it back then. A year after, I understand more of it. As to yourself -- does spreading hate make you feel smarter? Please let me know.
I'm sure it must be me, but I still simply don't know what QM actually is.
When I read comments that say how brilliant this speaker is and how well he explains QM, I can't help but think it's just like the emperor's new clothes.
It's all way beyond me and I don't mind saying so. How can I not have a clue about what this speaker has been saying? Surely language is meant to be a tool to aid communication, not make things even more unfathomable than they were at the beginning. 🤷
If there is a 50 % chance that he hops left and 50 % chance he hops right, then if both events occur, then the probability for each event is 100 %, and for both 200 %, which is a contradiction.
If there is any book on this topic many world interpretation plz recommend
Carroll's new book
@@arevogtmoum6224 name
@@physicsstudent3176 I would bet that Are Vogt Moum is refering to "Something Deeply Hidden"!
The Beginning of Infinity has a chapter on it, maybe The Fabric of Reality too, both by David Deutsch
We at least we know the cat is alive and I’m happy about that :)
Anyone who doesn't agree with Many Worlds Interpretation of Quantum mechanics has under developed imagination.
There might be a world out there where I believe in Many Worlds.
I see many people praising this lecture, and for the most part I found it quite informative. However, there is one thing Sean says that doesn't quite sit with me. I don't understand why our thoughts/decisions wouldn't make separate worlds / put our brains in superpositions. Surely, our thoughts exist, are causal, and have a physical presence? We don't have mind reading abilities, but surely we can observe our own thoughts? Even if we can't observe our own thoughts, I think it's reasonable to say someone or something COULD observe our thoughts, with proper tools or technology? Regardless, certainly our thoughts exist, and when we decide things in our mind, it affects the future before we have even acted.
It makes zero sense to me, that our thoughts must be committed to action in order to "branch in two." It would make more sense if in fact, the universe DOES branch whenever we have different thoughts. It makes no sense to refer to thoughts as classical processes as a reason for not causing the universe to branch. . . The cat, the box, and the sleeping gas are all classical objects, yet that scenario still causes entanglement with the universe, superpositions, and a branching universe. So why wouldn't our thoughts? I completely disagree here.
@New Scientist
Our brains are also quantum mechanical. When he says they act by "classical" rules, I think that's shorthand for saying that (almost) every single branch is going to have the same outcome, i.e., you make the same decision. So every quantum event in your brain making up your thought or decision is branching the universe, but you're making the same decision in all of them. Or even if you make different decisions, the process is spread over a vast number of worlds, so it's not the decision itself that's branching the universe.
If you want a little more detail, the leading theory for a large category of human decisions is the Diffuse Drift Model. In that model, in contemplating a decision, the brain tracks the activation-strength of triggering the decision by a very large set of neurons, e.g., "hop left" and "hop right", modeled by two nodes that receive inputs, each one with a threshold, if the activation crosses the threshold, the action is triggered and the alternative is shut off. The nodes are going to receive random inputs so there's a measure of random drift left and right, but some evidence or considerations can give a big push in one direction or another, and when the drift finally crosses a threshold for either left or right, the action is triggered. So the reason why a decision doesn't branch the universe is because it's a classical stochastic system. A decision is going to be composed of quintillians of quantum events gradually drifting to the left or right node. In the vast number of cases, those quintillian events are always going to eventually drift to the same threshold because of who you are as a person, your personality, your history, how you think, etc. All that said, there are cases you can imagine where a decision would split the world, and that's the case where out of these quintillians of quantum events, a SINGLE ONE is the determining event that makes LEFT trigger and not right. (In one world you hop left, then in the alternative worlds, well it wouldn't be hop right, since the right node is still a long drift away, the alternatives are not hopping left at exactly that moment.) That would be a "decision" that branches the universe. But you can see from the way the model is set up that that's vastly unlikely. You'd have to be teetering right on the edge of a decision and really randomly fall to one side or another. But even in most cases of teetering on a decision, it's usually not a single quantum event that pushes you into one decision or another but a set of still a pretty large number. And once it's that large of a number, we're not talking about a single branching per se but a vast number of branches all going in the same direction with slightly different but stochastically equivalent paths. Edit: Oh I should add something. It's usually not a single quantum event that can trigger a behavior, in case you're thinking for any decision there's always that last straw that makes the camel hop. All decisions require multiple different brain areas signing off on the decision before it's triggered; so while there may be a final determining quantum event for one of them; it's not a good description of the "decision", because you have to take into account the activation of other areas too. So even my "you could imagine a single quantum event" example isn't really fair.
Behind all of this I think is the theoretical point that classical physics is emergent in MWI. David Wallace wrote a whole book explaining this called The Emergent Multiverse. So I think what he's really saying is that the best description for brain action is under the emergent rules of classical physics, biology, neuroscience, etc., which are emergent rules under MWI. Biology is hot & wet where decoherece is happening every 10^-20 seconds, so quantum effects get washed out, it's just noise, and the signal that describes what's happening is the emergent rules of classical physics. I like the language of topos theory, which would say the "signal" is the rules of classical physics; the topos which "carries" the signal is quantum physics.
Well I think this is the right way to think about it. I'm happy if someone has any corrections, elaborations, or comments to that.
@@cademosley4886 This is very informative. I appreciate the explanation. Thank you.