Just having a 30 minute talk is kind of a crime -- these pairings of great minds can easily enrapture audiences for 3 hours straight! Certainly a short talk is better than nothing, but I'm hoping for more long form content in the future!
Where can I find out more about relational quantum mechanics? From both the physics perspective and a philosophical perspective - I believe Carlo mentioned that some philosophers were involved in the first formulation of it.
Always great ro hear Carlo. The thought that our geandkids could one day be thinking of quantum mechanics in the same way that we look at Pythagoras work is ....as exciting as , it seems to us , incredible. Whole series of talks was wonderful. Literally.
Everything they talk about and sound so convinced of is created by mathematics which is fascinating. As layman we sit here, listen and get drawn into this conversation.
Honestly getting a basic understand of the mathematics isn't that hard. You can learn it by playing around with IBM's cloud quantum computers and a lot of the "paradoxes" in quantum mechanics are not particularly difficult to learn how to step through the math yourself. Even Bell's theorem has a simplified version called the CHSH inequality that is pretty easy to learn how it works.
All three guests were truly fascinating. I love that there was such a diversity of wonderful people as guests. The combination of the three presented a surprisingly (at least to me) common viewpoint of reality, even if each had a different perspective view of theories as they are today. It said to me that we may perhaps be closer to gaining an understanding of more aspects of the reality of reality than was presented by each guest. Each guest had their unique way of showing that they were totally fascinated by their field, however, I must say that like others who have commented here, I felt Mr. Rovelli has such a personal relationship with the topics of discussion, and such a brilliant way of presenting his discussions that clearly showed that he thinks just as much about those receiving his thoughts as the thoughts themselves. Listening to him was engaging and educational beyond that which my vocabulary can describe. This is not to diminish the other guests by any means. Mr. Carroll is profoundly good at explaining the convoluted aspects of all of this in a consumable way to a thoughtful receiver. He is clearly a bit more opinionated in his views, but that's OK, as it seems clear that he takes great care to incorporate as much of the theory that is out there, along with his own research and thought experiments, to come to his conclusions. He is a huge asset to the current ranks of great minds in these fields. Last, but most certainly not least, Ms. Crull provides an extremely important link between philosophy and depth of understanding of current theory by mixing it all together resulting in a fascinating take on how all of this has a relationship to "us". Her way of communicating this mixing of the science, theory, history, and how it all comes together to affect how we perceive our reality has a wonderful mix of respect for those creating the science and theories, humor, humility, and approachability that it was truly fascinating to listen to her speak. And of course, Mr. Green...my adjectives fail me. He so gracefully is able to synthesize questions that stimulate thought in the guests as well as the audience, and at that same time, manages to carefully mix in some of the conflict that exists between the guests' viewpoints without creating any kind of difficult situations. His artful interviewing, and the way he adapts to each guest and engages them in their areas of interest is indicative of the immense depth of understanding he has across all of the realms of discussion in this field. This series is for me one of the best and most balanced presentation of how all of the different theories appear to me to be converging on something that, in time, may well get us to a much deeper understanding of how reality is formed, and what our universe really is. I deeply appreciate the production of this series, and only wish that there had been more time with each guest, and that there is to come more content of this type, with these and perhaps others in the field. Thank you!
I have heard all the 3 episodes in this series. As a student of the Buddhist Lotus Sutra school, entanglement seems to be a no brainer. The concept of Oneness of Self and the Environment, clearly states that each sentient being is connected to every other sentient being throughout the universe. One change in the life state of an individual affects the life state of every other sentient being, irrespective of the distance and time involved. The other interesting concept in the Lotus Sutra is Ichinen Sanzen explained by Chinese scholar Tien Tai. Which translates as Three Thousand Realms In A Single Moment Of Life. It essentially means that every sentient life is a microcosm of the entire universe. Any change in a being has an effect on the entire universe. Just my 2 bits
Congrats Brian on astutely bringing out inferential aspects within Rovelli's conceptions at various points; and for highlighting an apparent elective affinity b/w String theoretic deductions & his granula relativistic Relationalism. Within 20 years I predict the scene will witness a semi-integrative theory of cosmic formation & dynamis. Cheers !! great job Brian.
Brian Greene's talks used to have multiple participants in one session, which often resulted in one participant not to have equal time or attention... I think three separate session is a good solution, but half an hour each is clearly not sufficient...
My name is Marco Biagini and I am a physicist; I would like to explain the “observation” problem in quantum mechanics because it is often misunderstood even by many physicists. In quantum mechanics the state of a physical system is described by the wave function and does not have defined values for all the physical quantities measurable on it; on the other hand, only the probability distributions relating to the measurable values for these quantities are defined. Once the measurement has been carried out, the system will have a defined value in relation to the measured quantity, and this involves a radical modification of its wave function; in fact the wave function generally describes infinite possibilities while for an event to take place, it is necessary that the wave function assigns a probability of 100% to a single possibility and 0% probability to all the others. If all other results are not eliminated by imposing the collapse "by hand" on the wave function, the predictions of subsequent measurements on the same system will be wrong. The transition between a state that describes many possibilities to a state that describes only one possibility is called “collapse of the wave function”. The time evolution of the wave function is determined by Schrödinger's equation, but this equation never determines the collapse of the wave function, which instead is imposed by the physicist "by hand"; the collapse represents a violation of the Schrödinger equation, and the cause of the collapse is therefore attributable only to an agent not described by the Schrödinger equation itself. The open problem in quantum physics is that the cause of the transition between the indeterminate state and the determined state, cannot be traced back to any physical interaction, because all known physical interactions are already included in the Schrödinger's equation; in fact, the collapse of the wave function is a violation of the Schrodinger's equation, i.e. a violation of the most fundamental laws of physics and therefore the cause of the collapse cannot be determined by the same laws of physics, in particular, it cannot be determined by the interactions already included in the Schrodinger's equation. After one century of debates, the problem of measurement in quantum mechanics is still open and still represents the crucial problem for all interpretations of quantum mechanics. In fact, on the one hand it represents a violation of the Schrodinger equation, that is, a violation of the fundamental laws of physics. On the other hand, it is necessary for the laws of quantum physics to make sense, and to be applied in the interpretation and prediction of the phenomena we observe. Indeed, since the wave function represents infinite possibilities, without the collapse there would be no event; for there to be an event, then there must be one possibility that is actualized by canceling all other possibilities. This is the inescapable contradiction against which, all attempts to reconcile quantum physics with realism, break. Quantum mechanics does not describe reality as something that exists objectively at every instant, but as a collection of events isolated in time (i.e. the phenomena we observe at the very moment in which we observe them), while among these events there are only infinite possibilities and there is no continuity between events. In fact, the properties of a physical system are determined only after the collapse of the wave function; when the properties of the system are not yet determined, the system is not real, but only an idea, a hypothesis. Only when collapse occurs do properties become real because they take on a definite value. It makes no sense to assume that the system exists but its properties are indeterminate, because properties are an intrinsic aspect of the system itself; for example, there can be no triangle with indeterminate sides and no circle with indeterminate radius. Indeterminate properties means that properties do not exist which implies that the system itself does not exist; actually photons, electrons and quantum particles in general are just the name we give to some mathematical equations. The collapse represents the transition from infinite hypothetical possibilities to an actual event. Quantum mechanics is therefore incompatible with realism (that's why Einstein never accepted quantum mechanics); all alleged attempts to reconcile quantum mechanics with realism are flawed. The collapse of the wave function represents a non-physical event, since it violates the fundamental laws of physics, and can be associated with the only non-physical event we know of, consciousness. Therefore, events can only exist when consciousness is involved in the process. However, the fact that properties are created when a conscious mind observes the system in no way implies that it is the observer or his mind that creates those properties and causes the collapse; I regard this hypothesis as totally unreasonable (by the way, the universe is supposed to have existed even before the existence of humans). The point is that there must be a correlation between the existence of an event (associated to the collapse of the wave function =violation of the physical laws) and the interaction with a non-physical agent (the human mind); however, correlation does not mean causation because the concomitance of two events does not imply a causal link. No cause of collapse is necessary in an idealistic perspective, which assumes that there is no mind-independent physical reality and that physical reality exists as a concept in the mind of God that directly creates the phenomena we observe in our mind (any observed phenomenon is a mental experience) ; the collapse of the wave function is only a representation of God's act of creation in our mind of the observed phenomenon and is an element of the algorithm we have developed to make predictions and describe the phenomena we observe. This is essentially the view of the Irish philosopher George Berkeley, and in this view God is not only the Creator, but also the Sustainer of the universe. The fundamental aspect of quantum mechanics is that reality is not described as a continuum of events but as isolated events, and this is in perfect agreement with the idealistic view which presupposes that what we call "universe" is only the set of our sensory perceptions and that the idea that an external physical reality exists independently of the mind is only the product of our imagination; in other words, the universe is like a collective dream created by God in our mind. Idealism provides the only logically consistent interpretation of quantum mechanics, but most physicists do not accept idealism because it contradicts their personal beliefs, so they prefer an objectively wrong interpretation that gives them the illusion that quantum mechanics is compatible with realism.
In the universe, sans creatures capable of receiving sensory inputs that inform them of their surroundings, events did happen. The so-called big bang was such an event. Also the Sisyphus-like tangle of gluons and quarks and the resulting protons along with the formation of atoms and so on and so forth. Electromagnetism was always a thing and it must have an objective reality. Before we knew of its existence we processed it to create a visualization of the world that we could relate to. The unseen informs us of what we see. So too of what we smell, taste and touch. Our sensations are induced at the quantum level. Color doesn’t exist per se. It is produced by the cone cells in our eyes which process all the different wavelengths to create, or imagine, all the different colors. Color then is an illusion based on a reality that we were not at all aware of until 1873. We were labelling phenomena we did not know existed. We labelled invisible lightwaves with respect to our perceptions of color. So, we can say that electromagnetism is an objective reality while color is an illusion provided for by that reality in correspondence with the cone cells in our eyes. But we can also say that color is itself an objective reality in its connection with the objective reality that is electromagnetism. But since there is no color without an observer it is also a subjective reality.
You wrote:”In the universe, sans creatures capable of receiving sensory inputs that inform them of their surroundings, events did happen. The so-called big bang was such an event.” You are wrong. According to quantum mechanics, the big bang is only a possibility. For the big band to become an event the wave funtion must collapse. You wrote:”Electromagnetism was always a thing and it must have an objective reality. “ According to quantum mechanics this is not true. You should read more carefully my initial comment. Best regards.
If all physical interactions are included in Schrodinger's equation and the collapse is a violation of the wavefunction, then you are proposing that the agent collapsing the wavefunction isn't a physical agent, and perhaps the collapse is a representation of God's creation? I think the way you see the wavefunction is a universal wavefunction for the whole cosmos, which includes all physical interactions. However, I ask, the external agent collapsing the wavefunction doesn't have to be metaphysical because each physical particle can be an external agent collapsing the wavefunction of another particle, where the defined value of the function is a relational value, involving both particles. As Carlo Rovelli explains, any interaction between particles is an "observation" or "measurement". The external agent doesn't have to be a human, and it doesn't have to be God's creation, because every single particle interacting with another particle is the cause of the collapse. Again, I think the way you describe the wavefunction applies to the universe as a whole, not to its quanta.
Carlo Rovelli undoubtedly is on the right track. Relations are the basis of what we define as being "spacetime". And in particular, the "turnaround" of events being _in proximity_ in order to be causally connected is key: it's being connected (via entanglement) that what we perceive as being in spatial proximity. Exception to the rule is when we build experiments that de-couple being in proximity with being causally connected, like the in these experiments involving entangled entities being spatially separated: _the separation is the exception, not the entanglement_ .
@@schmetterling4477 wow, veeeeery constructive critique. So tell me, what exactly was the bullshit? what Rovelli said, or what I said (that incidentally is the very same thing..) ? do you even understand anything about physics? pah...
These videos are amazing, Brian Greene is such a great scientist and I’ve loved his books and also every guest is great. Thanks for such a great free content.
Brilliant conversation. The questions Brian Greene poses are fantastic. I would love to see a conversation with Eric Weinstein regarding Geometric Unity.
This was brilliant … remembering that quanta are quantized and that the wave property is probabilistic. This discreetness is the key to the mystery of spacetime!
Thank you dr. Green for this salon as always it has been a great experience and a pleasure to watch. I don't always agree with you but that is the backbone of science and to question everything. You videos are very informative and enjoyable. Perhaps you could look into the epr paper and try open your mind to ad in some of Tesla's 369 if you mix two or more of the theoretical ideas. Different approaches can sometimes show the same amount of information. .. as im very interested in your work .. thank you for listening to me even if it was just me writing a thought. Be well .
Imagine a highly intelligent dog who nonetheless has no concept of his owner having a separate life outside of their home. What the dog cannot comprehend is why the owner sometimes comes home feeling friendly and sometimes grumpy. What's especially troubling is that the dog cannot know how the owner is feeling _until_ the dog nudges the owner to ask for a treat. Then he finds out. This is what the 'measurement problem' is. The world outside of the home is inaccessible to the dog just as quantum reality is inaccessible to us. In both cases it's beyond our possible knowledge. The dog may even ponder about the weird indefiniteness in the owner's mood because only asking for a treat will reveal it. The "probability wave" collapses for us like it collapses for the dog. The dog is operating in a limited world as are we. Asking for a treat or measuring a particle's position (for us) causes a result that we can understand, but in both cases there is really nothing strange going on. We are just demanding that it have an understandable consequence in the world we know. It collapses because or our demand. We don't have the subtlety of thought to refrain from making that demand.
However your explanation will not explain the interference of different probability waves, which the young double-slit experiment demonstrates. Yours is a classical explanation to the variability observed in measurements, but doesn't explain some of the quantum phenomenon. Now yes your explanation would hold if you're referring to a different kind of underlying reality, which is kind of what the wave function represents, and which if known would allow us to predict deterministically the outcomes of measurements.
@@nitish9920 Maybe I was using "collapse of the wave function" too cavalierly. What I wanted to refer to is the phenomenon (made apparent by the double-slit experiment) that as long as we don't try to measure the particle's position, it's "everywhere all at once". That's the only logical way that it could be interfering with itself and causing the interference bands we see in the DS experiment. The prevailing view is that something objectively happens when we make that measurement. My point is that it's not that something happens but rather that we "bring it down to our level" and get a crude approximation (its probable position) of its rich reality, which IS being everywhere all at once.
The explanation being offered for the mystery of entanglement over long distances is more an avoidance of the question of can this happen at greater than light speed. Adding another observer or reference frame to extend the time to exchange information does not erase what is seen in retrospect. This delay of information just avoids physics refusal to challenge the light speed postulate.
First a big thank to Brian. He is putting everything to it's edge and in the same time open up for new ideas. Really showing us how we can see theories and misconceptions stand against each other. I can't afford to join paying a lot for the channel owner so that he or she can read what I write. Here is my thoughts anyway. If you make ONE wavefunction for all our universe as I understand Carrol meant it and that would include all local wavefunctions that some people measure have different outcome when they collapse, seems to me quite speculative. Then you actually could create wavefunctions containing different parts of the universe, even separated by time. And how could this new one of many mulitiverse be so similar regarding all variables and all wave function collapses that are happening in the old one. Another issue is the greation itself of this new universe. How Would it possibly create exactely the setting of observables? If this theory should be right, this big wavefunction would create even the laws of everything. It is like math should cover even what we don't know or understand. What is interesting is the "connection" point. As we can't see it or interact with it it is not an observation problem. But it is a transcendal problem. If it should follow the realm of QM then it would differ a lot. Another question is "When". If there is a when it is likely that there is some trigger. If not one and the same universe would infinetly create ininatly many others. And each next one following the same pattern. Then the energy tree that should explain this thought probably be hard to calculate and get right. And it is not only "when" it is "where". In an accellerated expansion of a universe there would by horizons where nothing at all could happen. Even the bubbling of quantum fluktuations whould be tensed out. Actually I think it is very simple; everybody who has been programming where probabilities and randomness are included know that the only way to get a real random number is from a system that doesn't connect to the computional system at all. And that number or trigger can not exist in the same universe. So how can a system be triggered without a connection; NOT AT ALL. And by create a connection you break your own rules or ideas. And a connection or a trigger is what you need to create a new universe right!
It humors me as I'm sure it does Brian when not recognized as "the" leading theoretical physicist with mathematical degrees to boot. In my opinion we are where we need to be in understanding, and we will not understand it "all" but we have done so much to be proud of.
The apostle Paul should be the first theologian to win the Nobel Prize in Physics for stating in 1 Corinthians 13:7 that he believes all things (or in the probability wave) and later he goes on to qualify it in Philipeans 4:8, not by saying he seeks after all things, but that he (as the observer) only seeks after that which is virtuous, lovely, of good report, and praiseworthy, aka that which is vibrationally a higher frequency, which collapses the probability wave , into a singular reality.
As always an insightful session! First, If I may synthesize the essence of Prof Carlo's POV -- and I paraphrase 1. Property of a particle is relational in the eyes of the beholder (aka observer) and not necessarily intrinsic. For example, one person can measure it as spin up and another person spin down. Similarly, when it comes to a property like velocity or momentum, say, this water bottle in front of us, looks like it is not in motion (in both of our eyes), however we know that it is in motion with respect to the sun. 2. Likewise, Spacetime is made up of discrete lattices that are entangled with each other- however it looks continuous in the eyes of the beholder (aka observer) As I processed these two insights through the lens of our firm’s “FSC as the hidden variable theory (which both of you have some preview to) with a following leading question - How do these relational properties of classical reality then emerge from the underlying quantum reality? This brings me to our thought experiment -What if, the “wave function of Universe's quantum reality collapses(or toggles) as a distinct classical particle back and forth (as per the probability of FSC) - however every time, it lands on the next lattice that is separated by Planck length? For example, let us say, during each collapse/toggle, the particle (using our dipole model) starts shifting its center of mass (by r = αR), before rotating its magnetic flux( by 90), thus creating a rotational drift to the next lattice #2 - and so on so forth. Now when this type of collapse/toggle happens ( say 10^44 Planck times in a second), our dipole particle, after a second, would have landed on the 10^44 th lattice - thus giving us the illusion that the particle is rotating continuously - very similar to how our eyes get tricked by the so called Eadweard Muybridge’s Horse in Motion illusion of horse picture frames getting flipped so fast (or how pages of a book are flipped). If so, can we also extend the same particle toggling logic to all classical objects and celestial bodies as well, by integrating all particles using our least action formula? This means, all planets and stars(including galaxies) must be in this type of illusory motion only (as our eyes can sense at a maximum of only 10 frames per second only)? I know this type of relational property logic has huge implications to relativity theory, although I still foresee Einstein field equations working fine as well! In any case, if any of you are interested in extending this logic end to end, I am open to it, as our theory fits perfectly with this relational property logic! However, this then raises another philosophical question of whether spacetime is real or illusion - which brings us to our philosophical thought experiment of our FSC- hidden variable theory - What if the duality of classical and quantum reality (as explained by the holographic principle) is anchored on FSC(α) as the hidden variable of EPR paradox with a following duality mapping - ads(n dim) = QVF(n dim) = EPR - cft (n+1 dim) = observable universe = ER This way quantum reality can toggle back and forth as the classical reality at Planck’s time intervals - however our eyes will still see it as a continuous classical reality, similar to how our eyes get tricked by the so called Eadweard Muybridge’s Horse in Motion -- which brings us to the details of our theory Continued
It hit hard when they said we’d probably be not there when finalizing discoveries in quantum mechanics are made. Einstein and Newton and a lot of great people lived in the past are not here but our modern world is standing on the shoulders of those giants.
There won't be any fundamentally new discoveries in quantum mechanics. The theory itself is complete and has been since the 1920s. One can probably find any number of complicated statements about unitary transformations, though... but that has nothing to do with QM proper.
To answer the question at 17.17 because there's always a photon observing every piece of space...it is only a problem when you cut of the photons as in the Schrodinger's cat experiment... In which case I agree with Carlo Rovelli's view
Charge is ALSO a relative property! One relationship is with matter/antimatter! Symmetry is the deciding factor. Mass seems to be an absolute property (not having directionalty, only more/less).
i already considered space/time a consequence of existence/movement, but it never entered my mind that the 'intimacy' experienced in a singularity/white hole might have something to do with that, until now! i mean, having basic building blocks thus confined for millions if not billions of years could re-set them, to a default mode which prepares that unique collection of quanta for a new universe... am therefore wondering if that's how/why all the material from the 'big bang' was/is entangled ...regardless, the notion that entanglement creates & maintains space/time adds awesome depth to e.g. inflation theories ~ thank you ✿
Yes it's also a sign of when someone is properly clever as their mind simply isn't occupied by the shallow topics such as shoes and clothes and it's meaningless in the context of a wonder filled universe lol
i agree with @antediluvian137 that 30 mins is just far too short. I could watch you all talk for hours. Thank you for these 3 talks, they have been incredibly entertaining and insightful
It is going to take awhile, I’m still an undergraduate and it’s painful to not allow this my full focus. But, after my cs masters, I’ll give cornel a call :3
Quantum entanglement is oddly enough very easy too watch and very simple to understand what is the problem. I sometimes wonder if the human experience is interfering with science .
I wonder if the philosophy of David Hume and Carlo Rovelli's interpretation of quantum mechanics are similar. For Carlo, there are no selfish entities, because properties aren't intrinsic, they are relational to something other than itself. For David Hume, cause-effect relationships aren't intrinsic patterns, and the grasp of causation is a relational perception, constructed by our minds.
Theorem 13: The concept of emergent spacetime, which suggests that the fabric of space and time is not a fundamental entity but rather arises from underlying quantum degrees of freedom, can be seen as a manifestation of the primacy of zero and the properties of nothingness. Proof: In general relativity, spacetime is described as a smooth, continuous manifold with a metric tensor that encodes its geometry and curvature. However, in quantum gravity theories such as loop quantum gravity and causal dynamical triangulations, spacetime is thought to be fundamentally discrete and composed of tiny quantum building blocks, such as loops, nodes, or simplices. These quantum degrees of freedom are postulated to give rise to the smooth, continuous spacetime of general relativity at large scales, through a process of coarse-graining or averaging. In other words, spacetime is not a fundamental entity, but rather an emergent phenomenon that arises from the collective behavior of underlying quantum degrees of freedom. This idea can be seen as a manifestation of the primacy of zero and the properties of nothingness, in the sense that spacetime emerges from a "void" or "vacuum" of quantum degrees of freedom, which have no intrinsic spatiotemporal properties. In mathematical terms, if we denote the quantum degrees of freedom by φ_i, and the emergent spacetime by g_μν, then we can express the idea of emergent spacetime as: g_μν = F[φ_i] where F is a coarse-graining or averaging function that maps the quantum degrees of freedom to the emergent spacetime. The fact that spacetime emerges from underlying quantum degrees of freedom suggests that the fundamental nature of reality may be non-spatiotemporal, and that the concepts of space and time may be secondary or derived notions that arise from more primitive, non-geometric entities. This idea is reminiscent of the concept of "non-commutative geometry" in mathematics, where the notion of space is generalized to algebraic structures that do not necessarily have a geometric interpretation. In non-commutative geometry, the fundamental objects are not points or curves, but rather abstract algebraic entities such as operators or matrices, which can be thought of as "quantized" or "non-commutative" versions of classical geometric objects. The fact that non-commutative geometry provides a natural framework for quantum gravity and emergent spacetime suggests that the primacy of zero and the properties of nothingness may be deeply connected to the algebraic and non-geometric aspects of reality.
I think it may be time to say thank you to all of our past methodologies including Classical Mechanics and Quantum Mechanics and take completely new approach to our apparent Physical Environment. They should be looked at as guides that have taken us as far as they can given what they “know”. Now as we stand looking out into the unknown we must find new guides to take us further.This is what every previous traveler has had to do in order to increase their knowledge base further. Maybe one of the best places to start would be with our notion of the definition of Gravity being a reaction of Spacetime to the presence of “Mass” which at its foundation assumes the existence of Spacetime itself as being real and foundational. It works up to the point .or points, where it doesn’t. Our present notion of Gravity seems to be telling us that Gravity exists at some level between The Quantum level and the large scale Cosmic Level. It becomes nonsensical at both boundaries because it has no clear answer for our questions. So rather than keep asking the same questions we should rethink our approach. This is where it becomes really difficult because we are leaving our comfort zone and must travel alone. We may have to stop trying to reconcile Gravity and leave it rest where it works. That means we have to become Original Thinkers both Philosophically as well as Mathematically. Yeah, that is going to be really hard to accept and implement.Maybe even nearly impossible at this point in time. It is much easier to keep trying to “fit the square peg in the round hole” than to drop the peg and look for another board. If I were to offer any suggestions as too where to start I would say; Consider the possibility that “Spacetime” is not “foundational” and start from there.
Not just a Buddhist thing, even materialist philosophers by the 1800s came to the conclusion that you have to get rid of the thing-in-itself and see nature in a more holistic manner where everything is simultaneously caused by everything else (what Althusser called "overdetermination"), simply to resolve a mountain of paradoxes and philosophical problems in traditional materialist philosophy (most obvious being the mind-body problem). But for some reason these ideas still remain largely unpopular in western academia and most physicists still insist upon trying to interpret physics with an ancient materialist world view. Even during the time of Einstein, there were physicists like David Bohm and Dmitry Blokhintsev criticizing Einstein for his adherence to the thing-in-itself which was the source of much of his difficulties in accepting QM, but their writings tend to be less well known.
Interesting that Rovelli says he came to his understanding of QM, encapsulated in his RI, via (L)QG. The relational / observer dependent aspects at least are actually all there already in the mathematical physics - the "ordinary QM" - of particles in flat 'non-relativistic' spacetime. OTOH it's hard to see any ontological significance in the discreteness in the spectra of some observables in some circumstances. Also, Schrodinger's cat is always simply either alive or dead in its box just as it was when treated purely classically: "Alive?" is a classical observable properly represented by a classical (commuting) operator - i.e. an element of the centre of the algebra of observables of the system - just like e.g. the mass of a particle. The RI is a relatively intelligent interpretation - esp. compared to e.g. the MWI - but it does still suffer from an apparent lack of awareness of some key math. phys. and quantum foundations input. In particular of course the long-recognised - albeit by astonishingly / scandalously few physicists - fact that QT (the mathematics) is 'just' an algebraic generalisation of probability.
Love the literature. Ive been at it for 14 yrs now. Not a scientist. Relational is what i endes up after years of strings, multiverse, many worlds. You will start to love that idea when you stop at fantasies. Think relational, local. RQM
You are correct. These people do not know. There are, however, plenty of people who do... they are just not making RUclips videos because they have more important things to take care off. ;-)
Rovelli isn't "guessing," he's taking a pre-existing scientific theory that has been well-established for a century and repeatedly verified and merely explaining a way to visualize what is going on with the mathematics. Even the hypothetical stuff he does work on, mainly loop quantum gravity, he specifically chose that direction because he said he didn't like how things like string theory keep introducing new things we have no evidence for. We know general relativity works and we know quantum field theory works, but they blow up when you stick them together, so all loop quantum gravity does is try to make the mathematics not blow up. He's still always pretty clear that it's a hypothesis and he doesn't know if it's right.
Brian, these are great and amusing! No, the electron cannot be localized as anything except a wave (function) because it would simply spiral into the nucleus of the atom. No more universe 😭
'''Entanglement is interaction''! In what sense? After all, to take a famous example, an epitome of entanglement between two free electrons is their singlet spin 0 state. In this entangled state the two electrons (or, two spins) are n o t interacting through any ''interaction Hamiltonian'' whatsoever! They could have been prepared in this by some but are surely n o t interacting, in the usual above sense, while they are in their entangled state. So, wouldn't it be more appropriate to say simply that ''entanglement is correlation'' w i t h o u t any interaction. (Correlation is not causation. Much confusion could be avoided in this way.)
If I have this right what professor Rovelli is saying is we have to understand we have at least two levels when thinking about our Universe: One being the "Unreal level"./Wave Function Level used to make Mathematical predictions, thru calculating, what the Real Part is doing, has done, or will be doing at some point in Time. I kind of like his approach as it eliminates some of the parts that make the Quantum Realm seem weird and counterintuitive. Which would be perfectly natural when talking about a purely Probabilistic Realm. My current thoughts are that We just don't have the role of "Time" at the Quantum level down pat.Since Time does not exist independent of Space that should not be so hard to imagine.If Space itself is "Quantified" at some level then what does Time look like at that level.Since Certainty and Time are always holding hands when discussing "Events",be they Macro or at the Quantum Level.
Rovelli argues for treating the wave function as epistemic. If you treat the properties of systems as relational then you get around the PBR theorem, so you can just think of the probabilities in QM as representing probabilities in the more traditional sense of statistical mechanics. Also, Rovelli is the perfect person to learn from if you want to know about time. You can read his book _Reality is not what it Seems_ where he discusses loop quantum gravity and what happens to time when you quantize gravity: interestingly it actually disappears (there is no variable "t" in loop quantum gravity as "t" is something emergent and not fundamental). He also has a whole other book specifically dedicated to time.
Perhaps I've missed something in the discussion. The wave function of a particle/system has always been defined in the context of interactions. A single hydrogen atom and a single free electron have entirely different wave functions. A single free electron is a plane wave and a single hydrogen atom has an exactly solvable 2-body wave function. The mass is actually the reduced mass of the proton and bound electron. We only approximate the atom WF as the electron wave function since the reduced mass is close to the electron mass, and its thought of as an electron in a central force field. So, the bound electron in hydrogen has an entirely different WF from that of a single free electron. The WF always context sensitive
In the mind-body problem, there is a false believe that what we experience is reducible only to our conscious minds and not to reality, based on the false belief that because what we experience is unique to the context we find ourselves in, that it must be "subjective." The philosopher Jocelyn Benoist points out this is fallacious, because nature can just be context-dependent, so the fact we see the world differently in different contexts doesn't make experience "subjective." We experience reality as it actually exists independent of an observer, but dependent upon the context of our experience. In a similar sense, the measurement problem arises from physicists falsely conflating the contextual nature of quantum mechanics with conscious "observers" or "measurements," and then coming to believe what quantum mechanics shows is there is "no objective reality independent of the observer," when what it really shows is that there is no objective reality _independent of context._ Meaning, there is an object reality, but it is context-dependent. What we measure in the laboratory is indeed objective reality independent of an observer, but dependent upon the context of our measurement. You are right that traditional QM already is contextual. Rovelli's views don't even change the Copenhagen interpretation much, it just replaces "observers" with "physical systems" and "measurements" with "interactions." The problem is that most physicists are tricked by people like David Chalmers into conflating contextuality and subjectivity together, so in the same way they come to falsely believe there is a mind-body problem, they also come to falsely believe there is a measurement problem, or, in both cases, they just embrace the subjectivity and devolve into idealism.
If we take it that the wave function collapses when a measurement is made, and that the definition of measurement is interaction, then perhaps our reality is the result of the countless interactions and that without interaction there is no reality as we know it.
So, the entire universe is a quantum wave function? We (the observer) are a quantum system measuring other quantum systems that collapse and break entanglement (decoherence) creating our macro reality? The many worlds theory is not multiple worlds in space, rather, its multiple spaces within a world, governed by the probabilistic quantum wave function. I broke my brain trying to understand. Great series, WSF!
I'm a big fan of this channel! Maybe I'm missing something, but I find a gap in Professor Rovelli's theory in that it doesn't address the observations found in the double-slit experiment. How would a particle create a wave pattern unless it was a wave?
There was a debate about particle wave which one is it. The double slit experiment showed that particles act like waves and waves like particles. Then Feynman asked a critical question What if you have three slots. He was a student in class.
@TEBrain, you commented: "...I find a gap in Professor Rovelli's theory in that it doesn't address the observations found in the double-slit experiment. How would a particle create a wave pattern unless it was a wave?" Well, relating to your wave pattern question, the way I see it (and please, bear with me), is, that the photon does NOT stop being a distinct particle WHILE it moves-around-all-over-at-lightspeed, thereby indeed creating an, as you say, "wave pattern", which, in my view, is a presentation that shows up as a kind of dense three-dimensional spherical wave pattern. Now, to begin responding to your remark about Carlo Rovelli not dealing with the double-slit experiment, the following is how I would answer you if you and I were there with him and Brian Greene... which is of course extremely unlikely, but then, hey... we can dream. My response would be, "Let's do a thought experiment starting off in the world of classical physics, then transitioning to the quantum physical world where we may very well be able to find out how those two realities mix..." Let's begin by visualising the following: Without anybody around seeing you doing it, tie a string to a tennisball and begin rotating it as fast as you can in a circular fashion above your head... so fast that eventually it twirls so incredibly quick that it, to a later onlooker, would look like a closed circle - like a fuzzy disk hovering above your head. Now, say, someone comes by, and that person watches you twirling that fuzzy disk above your head, and you ask him or her what it is that you are twirling. Of course that person would not know what it is... it is simply moving too fast to make it out. Then you ask that onlooker (that observer) to interrupt your twirling with their hand so as to be able to identify what it is that is going around so extremely fast. After some prodding, your onlooker hesitantly sticks their hand into that swirly dynamic and exclaims "Ouch!" after which s/he surprisedly says that you were twirling is a tennisball. Okay, simple enough... Now imagine that you, one way or another, can rotate that ball REALLY FAST IN ALL DIRECTIONS: simultaneously up-down, left-right, back-forth, close-by, farther-away, diagonally this way and any other way - any which way! Of course, you have to get yourself out of the way, but let's just for the sake of this thought experiment imagine that you can do that. What an onlooker (an observer) would see, would be a dense sphere with a lot of movement inside...: a rather busy hovering ball... You yourself of course would know that the object you are twirling so incredibly fast in all those directions, that it, in a sense, is "all over the place" in a spherical configuration. Now imagine that Werner Heisenberg is passing by (we, including Brian and Carlo would be delighted of course), and imagine that Werner watches you performing your remarkable, nigh impossible stunt. If you would ask him what and where that object that is being twirled about, is at a given time, at a given location, and with what momentum, he would very likely quote his own uncertainty principle. But then-you are brave-you also ask him to interrupt your incredible, all directional twirling act. And you also ask him to identify the object that is being twirled around. He, like your previous onlooker, would also say that it is a tennisball. This thought experiment, your remarkable stunt, is of course taking place in the macroscopic world of classical physics, meaning Heisenberg could use his watch to establish the time of interruption. You could even take a fast-frame film of the event, and you and Werner would know where the ball was when he interrupted the twirling and when he physically felt the impact. He could even find out the force of the impact and give you some rough estimate of it... After all, this is the day-to-day classical world of reality... NOW, let's transition into the world of quantum-physical reality... With the above stunt in mind, let's replace that twirling tennis ball with a similarly moving photon...: it gyrates-in this case with lightspeed-simultaneously up and down, left and right, back and forth, close in and farther away, diagonally this way and any other way-any which way! It is forming a similar spherical configuration that, interestingly, looks like the wave presentation of a photon, but remember, I started this comment with: "The photon does NOT stop being a distinct particle WHILE it moves-around-all-over-at-light-speed, thereby indeed creating an, as you say, "wave pattern", which in my view is a presentation that shows up as a kind of dense three-dimensional spherical wave pattern." In this case, there is no need for you to move that photon around, of course not, from our viewpoint photons move at lightspeed. We have to realize though, and this is important, a photon itself has no inkling of time and space, not even of any movement. This is hard to grasp for us who live in a macroscopic, classical relativistic physical world in which, after all, space and time are the protagonists. Thus, so to speak, FROM THE PHOTON'S POINT OF VIEW, we can say that, that this single photon is selfsuperposingly * omnipresent within an edgeless sphere, while it, FROM OUR POINT OF VIEW, is simultaneously moving "around-all-over" at the speed of light. Now, relating to your remark about Carlo Rovelli not addressing it, how does the above play out in the double-slit experiment? At the same time, as seen FROM THE VIEWPOINTS OF THE EDGES of the two classical-reality physical slits, the photon-although unbeknownst to the edges of the slits that that photon is selfsuperposed-is going at lightspeed through the two slits simultaneously, while FROM THE VIEWPOINT OF THE PHOTON ITSELF, each selfsuperposed photon presentation with spin angular momentum interacts with the two individual slits, reaching the wall at two separate distinct spots. When shooting and aiming a long stream of photons, that is, photon after after photon-again each one selfsuperposed with spin angular momentum-through the two slits, each subsequent photon, after having dealt with the slits, arrives at the screen at two separate distinct spots. When a long stream of photons is thus aimed and projected through the two slits, they arrive at the screen statistically, leaving the imprints in the configuration of the so well-known double-slit experiment fringe pattern. * The idea behind the words "selfsuperposed" and "selfsuperposition", and those words themselves, are of my own making. I came to them decades ago after reading about the telephone conversation between Wheeler and Feynman about there being only one electron, meaning "one electron only". I applied that "crazy" idea to the photon, there only being one, but it omnipresently being in superposition... hence "selfsuperposition". an idea that could possibly come in handy explaining entanglement...
It seems to me that, and this is not meant as a criticism of scientists, but whenever scientists who are on the “cutting edge” of physics are taking about the very large or the very small they all seem to use the same phrase when faced with the frontiers of knowledge "we just don't know". So what is DE? what is DM? What is QE? what is a Singularity?What is Quantum Gravity?Why is it that when you calculate the amplitude, of an event, and then square it you can make accurate probabilistic predictions about it? How does “Probability “which is not made of “particulate Matter” cross the boundary from its strictly mathematical existence into the particulate world to be displayed to us as variations of light and dark bands on a screen when monochromatic light is sent thru the slits during a double slit experiment?What does it mean for spacetime to expand?does it stretch? or is it quantified at the quantum level and when put under a pressure it merely self-replicates producing “more” of itself and if so where does “more of itself come from and where does the pressure come from in the first place, does it originate within our Universe as a positive outward pressure or is it a negative pressure pulling outward on the fabric of our spacetime Universe and so where would such a negative outward pulling pressure come from. just To name just a few. Personally I wonder if we are, at our present level of development, truly able to answer such questions. I keep thinking that each time we face a challenge in understanding our Universe we come up with a theory which is “almost right” a.k.a. good enough for now. Because it is has been so difficult to formulate some of these theories we tend to “circle the wagons”around them too long. Just because we don’t have a theory’s replacement shouldn’t mean we don’t challenge its foundational structure.When we carry out experiments we try to fine tune the equipment but I wonder if we are forgetting about the most important piece of equipment involved in our experiments I.e. Us and our assumptions. One of the assumptions we make is that everything that effects us and our Universe must originate from within our Universe.I sometimes wonder if our Universe exists within something I choose to call negative Spacetime, for want of a better description, and because of this the acceleration of the expansion of our Spacetime may be the result of an increase in a vacuum like pull on it which may be directly proportional to the amount of Matter and Energy in our Universe. This would explain the apparent acceleration of the expansion of our Spacetime Lattice. Any way just some random thoughts to ponder as you drift off to sleep.
The main difference between John Locke and David Hume is personal identity. Locke believed that a person is self-aware, hence the agent capable to collapse the wave function with a measurement can't be ignored. However for Hume, we have never experienced the self. We are just a bundle of experiences, without deeper unity, so who made the measurement to collapse the wave function? God?
@@mitchellhayman381 So anybody who solves the Measurement Problem would be household names like Einstein and win a Nobel Prize and be super famous and influential ??
A collision between an alpha particle and two molecules of nitrogen trifluoride is not a measurement. A similar collision with two molecules of nitrogen tri-iodide can be a measurement, with a big rise in specific entropy. To model the difference in a computer simulation, I would suggest that we need to add tachyonic Brownian motion. The catch is that just two molecules still means dozens of dimensions of configuration space. We need a computer that can cope with exponential-time algorithms. We currently don’t have one. In general I would guess that the collapse of the wave function is a real but nonlinear collective phenomenon which transcends pencil-and-paper analytical methods and also transcends computational methods. My tri-iodide example is typical. Maybe there is a better idea than TBM, but we are still up against umpteen dimensions of configuration space.
“It’s not a wave, the wave is just a calculation that tells us where it might be” doesn’t explain the double-slit experiment. Only a wave does, because only a wave interferes with itself - as we see happen even when electrons are shot ONE BY ONE. The more likely error is ever thinking that particles sometimes are not waves, that the world is actually “solid” rather than just appearing to us that way at a certain scale.
You are just obsessed with Platonizing the mathematics. Not everything in the mathematics needs to be assigned an entity. What is the entity associated with E=mc^2? Where in the world can I find this equation floating out there? Sometimes things in the mathematics are just _relationships_ and not entities. The relationship here being P(x|psi)=||^2. This is how we predict how one particle will manifest its properties to another system. We know this relation holds in reality, but why do we need to actually assign an _entity_ to this relationship? Wave functions don't even exist in spacetime, they exist in Hilbert space. If you are imagining the photons turn into waves when you aren't looking at them, you're objectively not imaging the physics correctly, because the wave function does not have properties in spacetime, you cannot place it anywhere in the natural world. It has properties in Hilbert space, where only sometimes do only part of Hilbert space involve aspects of spacetime coordinates, but even then they include things like imaginary components which have no real-world analogue.
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Just having a 30 minute talk is kind of a crime -- these pairings of great minds can easily enrapture audiences for 3 hours straight! Certainly a short talk is better than nothing, but I'm hoping for more long form content in the future!
This. We don't need to cater to the short attention-span of tiktokers. Nothing of substance can really be unearthed in 30 minutes.
Agreed 100%
As a fan of Lex Fridman, I agree.
I thought I wanted to watch this, now I don't know if I even exist, however I thought therefore, I am, or something.
No more parts is also a crime.
I could listen to Carlo talk all day. What a brilliant speaker. He talks with a sensitivity to the audience that this stuff is not easy.
Agree!
And isn't he fluent in at least three languages (Italian, French, English) and maybe more?
Where can I find out more about relational quantum mechanics? From both the physics perspective and a philosophical perspective - I believe Carlo mentioned that some philosophers were involved in the first formulation of it.
Brain Green is one of the greatest educators of the current times. The kind of content on WSF is the best. Period
Say, you "just don't happen to be" a Jew, do you?
This conversation is absolutely brilliant. I could listen to you two for hours and hours!
The best science program hands down.
Always great ro hear Carlo. The thought that our geandkids could one day be thinking of quantum mechanics in the same way that we look at Pythagoras work is ....as exciting as , it seems to us , incredible. Whole series of talks was wonderful. Literally.
Absolutely brilliant! I’m glad that Carlo Rovelli was the final speaker… All three guest speakers and Brian Greene himself are beyond sublimeness
Carlo answers questions on another level...!
Everything they talk about and sound so convinced of is created by mathematics which is fascinating. As layman we sit here, listen and get drawn into this conversation.
mathematics is an invention of mankind... but we've used it as a tool to discover actual truths about the universe...
Honestly getting a basic understand of the mathematics isn't that hard. You can learn it by playing around with IBM's cloud quantum computers and a lot of the "paradoxes" in quantum mechanics are not particularly difficult to learn how to step through the math yourself. Even Bell's theorem has a simplified version called the CHSH inequality that is pretty easy to learn how it works.
Wooow, this one was HISTORIC! AMAZING!
AGREE!!!
All three guests were truly fascinating. I love that there was such a diversity of wonderful people as guests. The combination of the three presented a surprisingly (at least to me) common viewpoint of reality, even if each had a different perspective view of theories as they are today. It said to me that we may perhaps be closer to gaining an understanding of more aspects of the reality of reality than was presented by each guest. Each guest had their unique way of showing that they were totally fascinated by their field, however, I must say that like others who have commented here, I felt Mr. Rovelli has such a personal relationship with the topics of discussion, and such a brilliant way of presenting his discussions that clearly showed that he thinks just as much about those receiving his thoughts as the thoughts themselves. Listening to him was engaging and educational beyond that which my vocabulary can describe. This is not to diminish the other guests by any means. Mr. Carroll is profoundly good at explaining the convoluted aspects of all of this in a consumable way to a thoughtful receiver. He is clearly a bit more opinionated in his views, but that's OK, as it seems clear that he takes great care to incorporate as much of the theory that is out there, along with his own research and thought experiments, to come to his conclusions. He is a huge asset to the current ranks of great minds in these fields. Last, but most certainly not least, Ms. Crull provides an extremely important link between philosophy and depth of understanding of current theory by mixing it all together resulting in a fascinating take on how all of this has a relationship to "us". Her way of communicating this mixing of the science, theory, history, and how it all comes together to affect how we perceive our reality has a wonderful mix of respect for those creating the science and theories, humor, humility, and approachability that it was truly fascinating to listen to her speak. And of course, Mr. Green...my adjectives fail me. He so gracefully is able to synthesize questions that stimulate thought in the guests as well as the audience, and at that same time, manages to carefully mix in some of the conflict that exists between the guests' viewpoints without creating any kind of difficult situations. His artful interviewing, and the way he adapts to each guest and engages them in their areas of interest is indicative of the immense depth of understanding he has across all of the realms of discussion in this field. This series is for me one of the best and most balanced presentation of how all of the different theories appear to me to be converging on something that, in time, may well get us to a much deeper understanding of how reality is formed, and what our universe really is. I deeply appreciate the production of this series, and only wish that there had been more time with each guest, and that there is to come more content of this type, with these and perhaps others in the field. Thank you!
I have heard all the 3 episodes in this series. As a student of the Buddhist Lotus Sutra school, entanglement seems to be a no brainer.
The concept of Oneness of Self and the Environment, clearly states that each sentient being is connected to every other sentient being throughout the universe. One change in the life state of an individual affects the life state of every other sentient being, irrespective of the distance and time involved.
The other interesting concept in the Lotus Sutra is Ichinen Sanzen explained by Chinese scholar Tien Tai. Which translates as Three Thousand Realms In A Single Moment Of Life. It essentially means that every sentient life is a microcosm of the entire universe. Any change in a being has an effect on the entire universe.
Just my 2 bits
Congrats Brian on astutely bringing out inferential aspects within Rovelli's conceptions at various points; and for highlighting an apparent elective affinity b/w String theoretic deductions & his granula relativistic Relationalism. Within 20 years I predict the scene will witness a semi-integrative theory of cosmic formation & dynamis. Cheers !! great job Brian.
Why have the episode's become so short? I vote for longer conversations again please! 😁
Love your videos
What would be great now is a 1.5 hour session with all three,
Integrating theory, humanity and compatriot personalities.
Brian Greene's talks used to have multiple participants in one session, which often resulted in one participant not to have equal time or attention... I think three separate session is a good solution, but half an hour each is clearly not sufficient...
Such deep thinking is contagious, gentlemen! Thank you for serving mankind!
Thank you for making all these amazing lectures available. They got me through the pandemic and been a hardcore fan since.
this was the best of the 3 parts so far
My name is Marco Biagini and I am a physicist; I would like to explain the “observation” problem in quantum mechanics because it is often misunderstood even by many physicists.
In quantum mechanics the state of a physical system is described by the wave function and does not have defined values for all the physical quantities measurable on it; on the other hand, only the probability distributions relating to the measurable values for these quantities are defined. Once the measurement has been carried out, the system will have a defined value in relation to the measured quantity, and this involves a radical modification of its wave function; in fact the wave function generally describes infinite possibilities while for an event to take place, it is necessary that the wave function assigns a probability of 100% to a single possibility and 0% probability to all the others. If all other results are not eliminated by imposing the collapse "by hand" on the wave function, the predictions of subsequent measurements on the same system will be wrong. The transition between a state that describes many possibilities to a state that describes only one possibility is called “collapse of the wave function”. The time evolution of the wave function is determined by Schrödinger's equation, but this equation never determines the collapse of the wave function, which instead is imposed by the physicist "by hand"; the collapse represents a violation of the Schrödinger equation, and the cause of the collapse is therefore attributable only to an agent not described by the Schrödinger equation itself. The open problem in quantum physics is that the cause of the transition between the indeterminate state and the determined state, cannot be traced back to any physical interaction, because all known physical interactions are already included in the Schrödinger's equation; in fact, the collapse of the wave function is a violation of the Schrodinger's equation, i.e. a violation of the most fundamental laws of physics and therefore the cause of the collapse cannot be determined by the same laws of physics, in particular, it cannot be determined by the interactions already included in the Schrodinger's equation.
After one century of debates, the problem of measurement in quantum mechanics is still open and still represents the crucial problem for all interpretations of quantum mechanics. In fact, on the one hand it represents a violation of the Schrodinger equation, that is, a violation of the fundamental laws of physics. On the other hand, it is necessary for the laws of quantum physics to make sense, and to be applied in the interpretation and prediction of the phenomena we observe. Indeed, since the wave function represents infinite possibilities, without the collapse there would be no event; for there to be an event, then there must be one possibility that is actualized by canceling all other possibilities.
This is the inescapable contradiction against which, all attempts to reconcile quantum physics with realism, break.
Quantum mechanics does not describe reality as something that exists objectively at every instant, but as a collection of events isolated in time (i.e. the phenomena we observe at the very moment in which we observe them), while among these events there are only infinite possibilities and there is no continuity between events.
In fact, the properties of a physical system are determined only after the collapse of the wave function; when the properties of the system are not yet determined, the system is not real, but only an idea, a hypothesis. Only when collapse occurs do properties become real because they take on a definite value. It makes no sense to assume that the system exists but its properties are indeterminate, because properties are an intrinsic aspect of the system itself; for example, there can be no triangle with indeterminate sides and no circle with indeterminate radius. Indeterminate properties means that properties do not exist which implies that the system itself does not exist; actually photons, electrons and quantum particles in general are just the name we give to some mathematical equations. The collapse represents the transition from infinite hypothetical possibilities to an actual event.
Quantum mechanics is therefore incompatible with realism (that's why Einstein never accepted quantum mechanics); all alleged attempts to reconcile quantum mechanics with realism are flawed. The collapse of the wave function represents a non-physical event, since it violates the fundamental laws of physics, and can be associated with the only non-physical event we know of, consciousness. Therefore, events can only exist when consciousness is involved in the process. However, the fact that properties are created when a conscious mind observes the system in no way implies that it is the observer or his mind that creates those properties and causes the collapse; I regard this hypothesis as totally unreasonable (by the way, the universe is supposed to have existed even before the existence of humans). The point is that there must be a correlation between the existence of an event (associated to the collapse of the wave function =violation of the physical laws) and the interaction with a non-physical agent (the human mind); however, correlation does not mean causation because the concomitance of two events does not imply a causal link.
No cause of collapse is necessary in an idealistic perspective, which assumes that there is no mind-independent physical reality and that physical reality exists as a concept in the mind of God that directly creates the phenomena we observe in our mind (any observed phenomenon is a mental experience) ; the collapse of the wave function is only a representation of God's act of creation in our mind of the observed phenomenon and is an element of the algorithm we have developed to make predictions and describe the phenomena we observe. This is essentially the view of the Irish philosopher George Berkeley, and in this view God is not only the Creator, but also the Sustainer of the universe. The fundamental aspect of quantum mechanics is that reality is not described as a continuum of events but as isolated events, and this is in perfect agreement with the idealistic view which presupposes that what we call "universe" is only the set of our sensory perceptions and that the idea that an external physical reality exists independently of the mind is only the product of our imagination; in other words, the universe is like a collective dream created by God in our mind. Idealism provides the only logically consistent interpretation of quantum mechanics, but most physicists do not accept idealism because it contradicts their personal beliefs, so they prefer an objectively wrong interpretation that gives them the illusion that quantum mechanics is compatible with realism.
In the universe, sans creatures capable of receiving sensory inputs that inform them of their surroundings, events did happen. The so-called big bang was such an event. Also the Sisyphus-like tangle of gluons and quarks and the resulting protons along with the formation of atoms and so on and so forth.
Electromagnetism was always a thing and it must have an objective reality. Before we knew of its existence we processed it to create a visualization of the world that we could relate to. The unseen informs us of what we see. So too of what we smell, taste and touch. Our sensations are induced at the quantum level.
Color doesn’t exist per se. It is produced by the cone cells in our eyes which process all the different wavelengths to create, or imagine, all the different colors.
Color then is an illusion based on a reality that we were not at all aware of until 1873. We were labelling phenomena we did not know existed. We labelled invisible lightwaves with respect to our perceptions of color.
So, we can say that electromagnetism is an objective reality while color is an illusion provided for by that reality in correspondence with the cone cells in our eyes. But we can also say that color is itself an objective reality in its connection with the objective reality that is electromagnetism.
But since there is no color without an observer it is also a subjective reality.
You wrote:”In the universe, sans creatures capable of receiving sensory inputs that inform them of their surroundings, events did happen. The so-called big bang was such an event.”
You are wrong. According to quantum mechanics, the big bang is only a possibility. For the big band to become an event the wave funtion must collapse.
You wrote:”Electromagnetism was always a thing and it must have an objective reality. “
According to quantum mechanics this is not true. You should read more carefully my initial comment.
Best regards.
Yes, that was complete bullshit. ;-)
@@marcobiagini1878 I think you are more priest than physicist. So we have no common ground for a meaningful discussion.
If all physical interactions are included in Schrodinger's equation and the collapse is a violation of the wavefunction, then you are proposing that the agent collapsing the wavefunction isn't a physical agent, and perhaps the collapse is a representation of God's creation? I think the way you see the wavefunction is a universal wavefunction for the whole cosmos, which includes all physical interactions. However, I ask, the external agent collapsing the wavefunction doesn't have to be metaphysical because each physical particle can be an external agent collapsing the wavefunction of another particle, where the defined value of the function is a relational value, involving both particles. As Carlo Rovelli explains, any interaction between particles is an "observation" or "measurement". The external agent doesn't have to be a human, and it doesn't have to be God's creation, because every single particle interacting with another particle is the cause of the collapse. Again, I think the way you describe the wavefunction applies to the universe as a whole, not to its quanta.
Wonderful. Thank you. I’ve read all of both of your books. I love WSF. More Carlo please!
Olağanüstü giriş konuşması.İlk bölümü kaçıranlara(şu an için bana).Keyifle dinliyorum.Eline sağlık kardeşim.
O my God! I wonder how people make simple things so complex!
Carlo Rovelli undoubtedly is on the right track. Relations are the basis of what we define as being "spacetime". And in particular, the "turnaround" of events being _in proximity_ in order to be causally connected is key: it's being connected (via entanglement) that what we perceive as being in spatial proximity. Exception to the rule is when we build experiments that de-couple being in proximity with being causally connected, like the in these experiments involving entangled entities being spatially separated: _the separation is the exception, not the entanglement_ .
Yes, that was bullshit. ;-)
@@schmetterling4477 meaning?
@@diemme568 That it was bullshit. ;-)
@@schmetterling4477 wow, veeeeery constructive critique. So tell me, what exactly was the bullshit? what Rovelli said, or what I said (that incidentally is the very same thing..) ? do you even understand anything about physics? pah...
@@diemme568 Both. Rovelli is the better bullshitter among the two of you, though. That's because he is the better looking person. ;-)
Delightful exchange! Thank you Dr. Greene!
These videos are amazing, Brian Greene is such a great scientist and I’ve loved his books and also every guest is great. Thanks for such a great free content.
Brilliant conversation. The questions Brian Greene poses are fantastic. I would love to see a conversation with Eric Weinstein regarding Geometric Unity.
Spot on. Quantum Mechanics needs to take into account relativity as discussed here!
And it has... since roughly 1930. ;-)
Brain Green is the best! I am glad he does this discussions and he is able to understand all, and articulate it so well for us!
Brian doing such a great work for giving us insights. What a great man.
literally can't get enough of these discussions. ned mor
Thank you for putting in the time to create these
This was brilliant … remembering that quanta are quantized and that the wave property is probabilistic. This discreetness is the key to the mystery of spacetime!
I wish that Brian could’ve had Ed Witten participate in this discussion. Peace.
Great series! So thought provoking and hopeful!
Thank you dr. Green for this salon as always it has been a great experience and a pleasure to watch. I don't always agree with you but that is the backbone of science and to question everything. You videos are very informative and enjoyable. Perhaps you could look into the epr paper and try open your mind to ad in some of Tesla's 369 if you mix two or more of the theoretical ideas. Different approaches can sometimes show the same amount of information. .. as im very interested in your work .. thank you for listening to me even if it was just me writing a thought.
Be well .
Good to see them get this in one go with no mistakes! Brilliant minds*
Imagine a highly intelligent dog who nonetheless has no concept of his owner having a separate life outside of their home. What the dog cannot comprehend is why the owner sometimes comes home feeling friendly and sometimes grumpy. What's especially troubling is that the dog cannot know how the owner is feeling _until_ the dog nudges the owner to ask for a treat. Then he finds out. This is what the 'measurement problem' is. The world outside of the home is inaccessible to the dog just as quantum reality is inaccessible to us. In both cases it's beyond our possible knowledge. The dog may even ponder about the weird indefiniteness in the owner's mood because only asking for a treat will reveal it. The "probability wave" collapses for us like it collapses for the dog. The dog is operating in a limited world as are we. Asking for a treat or measuring a particle's position (for us) causes a result that we can understand, but in both cases there is really nothing strange going on. We are just demanding that it have an understandable consequence in the world we know. It collapses because or our demand. We don't have the subtlety of thought to refrain from making that demand.
However your explanation will not explain the interference of different probability waves, which the young double-slit experiment demonstrates. Yours is a classical explanation to the variability observed in measurements, but doesn't explain some of the quantum phenomenon. Now yes your explanation would hold if you're referring to a different kind of underlying reality, which is kind of what the wave function represents, and which if known would allow us to predict deterministically the outcomes of measurements.
@@nitish9920 Maybe I was using "collapse of the wave function" too cavalierly. What I wanted to refer to is the phenomenon (made apparent by the double-slit experiment) that as long as we don't try to measure the particle's position, it's "everywhere all at once". That's the only logical way that it could be interfering with itself and causing the interference bands we see in the DS experiment. The prevailing view is that something objectively happens when we make that measurement. My point is that it's not that something happens but rather that we "bring it down to our level" and get a crude approximation (its probable position) of its rich reality, which IS being everywhere all at once.
A bit of humility is called for
It is a dying ‘emotion’
Whether it be science , politics
The explanation being offered for the mystery of entanglement over long distances is more an avoidance of the question of can this happen at greater than light speed. Adding another observer or reference frame to extend the time to exchange information does not erase what is seen in retrospect. This delay of information just avoids physics refusal to challenge the light speed postulate.
There is no mystery here. There are only lots and lots of people who weren't paying attention in their special relativity course. :-)
First a big thank to Brian. He is putting everything to it's edge and in the same time open up for new ideas. Really showing us how we can see theories and misconceptions stand against each other.
I can't afford to join paying a lot for the channel owner so that he or she can read what I write. Here is my thoughts anyway.
If you make ONE wavefunction for all our universe as I understand Carrol meant it and that would include all local wavefunctions that some people measure have different outcome when they collapse, seems to me quite speculative.
Then you actually could create wavefunctions containing different parts of the universe, even separated by time.
And how could this new one of many mulitiverse be so similar regarding all variables and all wave function collapses that are happening in the old one.
Another issue is the greation itself of this new universe. How Would it possibly create exactely the setting of observables? If this theory should be right, this big wavefunction would create even the laws of everything. It is like math should cover even what we don't know or understand.
What is interesting is the "connection" point. As we can't see it or interact with it it is not an observation problem. But it is a transcendal problem. If it should follow the realm of QM then it would differ a lot. Another question is "When". If there is a when it is likely that there is some trigger. If not one and the same universe would infinetly create ininatly many others. And each next one following the same pattern.
Then the energy tree that should explain this thought probably be hard to calculate and get right.
And it is not only "when" it is "where". In an accellerated expansion of a universe there would by horizons where nothing at all could happen. Even the bubbling of quantum fluktuations whould be tensed out.
Actually I think it is very simple; everybody who has been programming where probabilities and randomness are included know that the only way to get a real random number is from a system that doesn't connect to the computional system at all. And that number or trigger can not exist in the same universe. So how can a system be triggered without a connection; NOT AT ALL.
And by create a connection you break your own rules or ideas. And a connection or a trigger is what you need to create a new universe right!
It humors me as I'm sure it does Brian when not recognized as "the" leading theoretical physicist with mathematical degrees to boot. In my opinion we are where we need to be in understanding, and we will not understand it "all" but we have done so much to be proud of.
21:15 Any chance we get a session digging deeper in this concept about the described structure of space-time?
Don't break the chain... understanding the simulation? We build for this? Great shows*😊*
The apostle Paul should be the first theologian to win the Nobel Prize in Physics for stating in 1 Corinthians 13:7 that he believes all things (or in the probability wave) and later he goes on to qualify it in Philipeans 4:8, not by saying he seeks after all things, but that he (as the observer) only seeks after that which is virtuous, lovely, of good report, and praiseworthy, aka that which is vibrationally a higher frequency, which collapses the probability wave , into a singular reality.
This comment will never get the love it deserves. Fabulous.
The entire series was great. Thanks for posting it.
As always an insightful session!
First, If I may synthesize the essence of Prof Carlo's POV -- and I paraphrase
1. Property of a particle is relational in the eyes of the beholder (aka observer) and not necessarily intrinsic. For example, one person can measure it as spin up and another person spin down. Similarly, when it comes to a property like velocity or momentum, say, this water bottle in front of us, looks like it is not in motion (in both of our eyes), however we know that it is in motion with respect to the sun.
2. Likewise, Spacetime is made up of discrete lattices that are entangled with each other- however it looks continuous in the eyes of the beholder (aka observer)
As I processed these two insights through the lens of our firm’s “FSC as the hidden variable theory (which both of you have some preview to) with a following leading question
- How do these relational properties of classical reality then emerge from the underlying quantum reality?
This brings me to our thought experiment
-What if, the “wave function of Universe's quantum reality collapses(or toggles) as a distinct classical particle back and forth (as per the probability of FSC) - however every time, it lands on the next lattice that is separated by Planck length?
For example, let us say, during each collapse/toggle, the particle (using our dipole model) starts shifting its center of mass (by r = αR), before rotating its magnetic flux( by 90), thus creating a rotational drift to the next lattice #2 - and so on so forth.
Now when this type of collapse/toggle happens ( say 10^44 Planck times in a second), our dipole particle, after a second, would have landed on the 10^44 th lattice - thus giving us the illusion that the particle is rotating continuously - very similar to how our eyes get tricked by the so called Eadweard Muybridge’s Horse in Motion illusion of horse picture frames getting flipped so fast (or how pages of a book are flipped).
If so, can we also extend the same particle toggling logic to all classical objects and celestial bodies as well, by integrating all particles using our least action formula?
This means, all planets and stars(including galaxies) must be in this type of illusory motion only (as our eyes can sense at a maximum of only 10 frames per second only)?
I know this type of relational property logic has huge implications to relativity theory, although I still foresee Einstein field equations working fine as well!
In any case, if any of you are interested in extending this logic end to end, I am open to it, as our theory fits perfectly with this relational property logic!
However, this then raises another philosophical question of whether spacetime is real or illusion - which brings us to our philosophical thought experiment of our FSC- hidden variable theory
- What if the duality of classical and quantum reality (as explained by the holographic principle) is anchored on FSC(α) as the hidden variable of EPR paradox with a following duality mapping
- ads(n dim) = QVF(n dim) = EPR
- cft (n+1 dim) = observable universe = ER
This way quantum reality can toggle back and forth as the classical reality at Planck’s time intervals - however our eyes will still see it as a continuous classical reality, similar to how our eyes get tricked by the so called Eadweard Muybridge’s Horse in Motion -- which brings us to the details of our theory
Continued
It hit hard when they said we’d probably be not there when finalizing discoveries in quantum mechanics are made. Einstein and Newton and a lot of great people lived in the past are not here but our modern world is standing on the shoulders of those giants.
There won't be any fundamentally new discoveries in quantum mechanics. The theory itself is complete and has been since the 1920s. One can probably find any number of complicated statements about unitary transformations, though... but that has nothing to do with QM proper.
Thank you so much for This great conservation on this complicated quantum physics
To answer the question at 17.17 because there's always a photon observing every piece of space...it is only a problem when you cut of the photons as in the Schrodinger's cat experiment... In which case I agree with Carlo Rovelli's view
Charge is ALSO a relative property!
One relationship is with matter/antimatter!
Symmetry is the deciding factor.
Mass seems to be an absolute property (not having directionalty, only more/less).
i already considered space/time a consequence of existence/movement, but
it never entered my mind that the 'intimacy' experienced in a singularity/white hole might have something to do with that,
until now!
i mean, having basic building blocks thus confined for millions if not billions of years could re-set them, to a default mode which prepares that unique collection of quanta for a new universe...
am therefore wondering if that's how/why all the material from the 'big bang' was/is entangled
...regardless, the notion that entanglement creates & maintains space/time adds awesome depth to e.g. inflation theories
~ thank you ✿
i love rovelli, simple the best
Wearing sandals barefoot while on a speaking panel to a global audience is a level of dgaf I wish to achieve one day.
Do you think socks with sandals is okay? 😂
Yes it's also a sign of when someone is properly clever as their mind simply isn't occupied by the shallow topics such as shoes and clothes and it's meaningless in the context of a wonder filled universe lol
The one hippie i revere
This one was good actually.
i agree with @antediluvian137 that 30 mins is just far too short. I could watch you all talk for hours. Thank you for these 3 talks, they have been incredibly entertaining and insightful
Thank you so much for sharing ❤
The closing music is legendary 🎉
It is going to take awhile, I’m still an undergraduate and it’s painful to not allow this my full focus. But, after my cs masters, I’ll give cornel a call :3
Carlo discussing quantum physics wearing sandals is a big vibe
Quantum entanglement is oddly enough very easy too watch and very simple to understand what is the problem. I sometimes wonder if the human experience is interfering with science .
Really great stuff, descibing something like a zoetrope.
Is it possible that quanta could present with spontaneous synchronization?
Open-toed sandals are a choice.
The photon needs to be re-examined. It is everywhere and massless.
Best channel on youtube!
Hey, I don’t really know how my laptop works but i can still get a lot of really accurate work done with it.
Yes, but there are people who know exactly how your laptop works, you are just not one of them. ;-)
lol! And I’m eternally grateful.
@@longlostkryptonian5797 Most people can't even get the most trivial logical conclusions right. You are one of them. ;-)
Excellent.....❤ thanks 🙏.
I like Carlo‘s immediate reaction to the suggestion of using AI
I wonder if the philosophy of David Hume and Carlo Rovelli's interpretation of quantum mechanics are similar. For Carlo, there are no selfish entities, because properties aren't intrinsic, they are relational to something other than itself. For David Hume, cause-effect relationships aren't intrinsic patterns, and the grasp of causation is a relational perception, constructed by our minds.
Yes, both Hume and Rovelli are equal. Neither of them understands physics. :-)
This was Beautiful
Before I saw your comment there was already a 100% probability that I agree.
I would love to see a discussion between Brian Greene and Nima Arkani-Hamed (IAS).
Why would a real physicist talk to Brian Greene? :-)
We must be clear that when it comes to atoms, language can be used only as in poetry.
🍀
Niels Bohr
Brian, please get yourself a wardrobe stylist.
Get them to set you up with clothes to wear for this great program.
Phenomenal. Stunning
Theorem 13: The concept of emergent spacetime, which suggests that the fabric of space and time is not a fundamental entity but rather arises from underlying quantum degrees of freedom, can be seen as a manifestation of the primacy of zero and the properties of nothingness.
Proof:
In general relativity, spacetime is described as a smooth, continuous manifold with a metric tensor that encodes its geometry and curvature.
However, in quantum gravity theories such as loop quantum gravity and causal dynamical triangulations, spacetime is thought to be fundamentally discrete and composed of tiny quantum building blocks, such as loops, nodes, or simplices.
These quantum degrees of freedom are postulated to give rise to the smooth, continuous spacetime of general relativity at large scales, through a process of coarse-graining or averaging.
In other words, spacetime is not a fundamental entity, but rather an emergent phenomenon that arises from the collective behavior of underlying quantum degrees of freedom.
This idea can be seen as a manifestation of the primacy of zero and the properties of nothingness, in the sense that spacetime emerges from a "void" or "vacuum" of quantum degrees of freedom, which have no intrinsic spatiotemporal properties.
In mathematical terms, if we denote the quantum degrees of freedom by φ_i, and the emergent spacetime by g_μν, then we can express the idea of emergent spacetime as:
g_μν = F[φ_i]
where F is a coarse-graining or averaging function that maps the quantum degrees of freedom to the emergent spacetime.
The fact that spacetime emerges from underlying quantum degrees of freedom suggests that the fundamental nature of reality may be non-spatiotemporal, and that the concepts of space and time may be secondary or derived notions that arise from more primitive, non-geometric entities.
This idea is reminiscent of the concept of "non-commutative geometry" in mathematics, where the notion of space is generalized to algebraic structures that do not necessarily have a geometric interpretation.
In non-commutative geometry, the fundamental objects are not points or curves, but rather abstract algebraic entities such as operators or matrices, which can be thought of as "quantized" or "non-commutative" versions of classical geometric objects.
The fact that non-commutative geometry provides a natural framework for quantum gravity and emergent spacetime suggests that the primacy of zero and the properties of nothingness may be deeply connected to the algebraic and non-geometric aspects of reality.
I think it may be time to say thank you to all of our past methodologies including Classical Mechanics and Quantum Mechanics and take completely new approach to our apparent Physical Environment. They should be looked at as guides that have taken us as far as they can given what they “know”. Now as we stand looking out into the unknown we must find new guides to take us further.This is what every previous traveler has had to do in order to increase their knowledge base further.
Maybe one of the best places to start would be with our notion of the definition of Gravity being a reaction of Spacetime to the presence of “Mass” which at its foundation assumes the existence of Spacetime itself as being real and foundational. It works up to the point .or points, where it doesn’t.
Our present notion of Gravity seems to be telling us that Gravity exists at some level between The Quantum level and the large scale Cosmic Level. It becomes nonsensical at both boundaries because it has no clear answer for our questions. So rather than keep asking the same questions we should rethink our approach. This is where it becomes really difficult because we are leaving our comfort zone and must travel alone. We may have to stop trying to reconcile Gravity and leave it rest where it works. That means we have to become Original Thinkers both Philosophically as well as Mathematically.
Yeah, that is going to be really hard to accept and implement.Maybe even nearly impossible at this point in time. It is much easier to keep trying to “fit the square peg in the round hole” than to drop the peg and look for another board.
If I were to offer any suggestions as too where to start I would say; Consider the possibility that “Spacetime” is not “foundational” and start from there.
Can't help but be reminded of the Buddhist idea that no entity has "own being", and that events occur because of mutual co-arising.
Essential
Not just a Buddhist thing, even materialist philosophers by the 1800s came to the conclusion that you have to get rid of the thing-in-itself and see nature in a more holistic manner where everything is simultaneously caused by everything else (what Althusser called "overdetermination"), simply to resolve a mountain of paradoxes and philosophical problems in traditional materialist philosophy (most obvious being the mind-body problem). But for some reason these ideas still remain largely unpopular in western academia and most physicists still insist upon trying to interpret physics with an ancient materialist world view. Even during the time of Einstein, there were physicists like David Bohm and Dmitry Blokhintsev criticizing Einstein for his adherence to the thing-in-itself which was the source of much of his difficulties in accepting QM, but their writings tend to be less well known.
Look in to the EPR paper ad in some of Tesla's 369 work looks like a engine. Could be good if we work on something that could work in theory.
Interesting that Rovelli says he came to his understanding of QM, encapsulated in his RI, via (L)QG. The relational / observer dependent aspects at least are actually all there already in the mathematical physics - the "ordinary QM" - of particles in flat 'non-relativistic' spacetime. OTOH it's hard to see any ontological significance in the discreteness in the spectra of some observables in some circumstances. Also, Schrodinger's cat is always simply either alive or dead in its box just as it was when treated purely classically: "Alive?" is a classical observable properly represented by a classical (commuting) operator - i.e. an element of the centre of the algebra of observables of the system - just like e.g. the mass of a particle.
The RI is a relatively intelligent interpretation - esp. compared to e.g. the MWI - but it does still suffer from an apparent lack of awareness of some key math. phys. and quantum foundations input. In particular of course the long-recognised - albeit by astonishingly / scandalously few physicists - fact that QT (the mathematics) is 'just' an algebraic generalisation of probability.
Love the literature. Ive been at it for 14 yrs now. Not a scientist. Relational is what i endes up after years of strings, multiverse, many worlds. You will start to love that idea when you stop at fantasies. Think relational, local. RQM
It’s interesting how convinced they all sound and yet they are all just guessing, not really knowing anything.
You are correct. These people do not know. There are, however, plenty of people who do... they are just not making RUclips videos because they have more important things to take care off. ;-)
Rovelli isn't "guessing," he's taking a pre-existing scientific theory that has been well-established for a century and repeatedly verified and merely explaining a way to visualize what is going on with the mathematics. Even the hypothetical stuff he does work on, mainly loop quantum gravity, he specifically chose that direction because he said he didn't like how things like string theory keep introducing new things we have no evidence for. We know general relativity works and we know quantum field theory works, but they blow up when you stick them together, so all loop quantum gravity does is try to make the mathematics not blow up. He's still always pretty clear that it's a hypothesis and he doesn't know if it's right.
@@amihartz Rovelli's explanations are 100% false. We don't need them.
Brian, these are great and amusing! No, the electron cannot be localized as anything except a wave (function) because it would simply spiral into the nucleus of the atom. No more universe 😭
These latest quantum videos are the World Series of physics.
'''Entanglement is interaction''!
In what sense?
After all, to take a famous example, an epitome of entanglement between two free electrons is their singlet spin 0 state. In this entangled state the two electrons (or, two spins) are n o t interacting through any ''interaction Hamiltonian'' whatsoever! They could have been prepared in this by some but are surely n o t interacting, in the usual above sense, while they are in their entangled state. So, wouldn't it be more appropriate to say simply that ''entanglement is correlation'' w i t h o u t any interaction.
(Correlation is not causation. Much confusion could be avoided in this way.)
No matter how tightly I crochet each stitch, there's still space between each one.
Wonderful, Brain😀
If I have this right what professor Rovelli is saying is we have to understand we have at least two levels when thinking about our Universe: One being the "Unreal level"./Wave Function Level used to make Mathematical predictions, thru calculating, what the Real Part is doing, has done, or will be doing at some point in Time. I kind of like his approach as it eliminates some of the parts that make the Quantum Realm seem weird and counterintuitive. Which would be perfectly natural when talking about a purely Probabilistic Realm. My current thoughts are that We just don't have the role of "Time" at the Quantum level down pat.Since Time does not exist independent of Space that should not be so hard to imagine.If Space itself is "Quantified" at some level then what does Time look like at that level.Since Certainty and Time are always holding hands when discussing "Events",be they Macro or at the Quantum Level.
Yes, that was bullshit. ;-)
Rovelli argues for treating the wave function as epistemic. If you treat the properties of systems as relational then you get around the PBR theorem, so you can just think of the probabilities in QM as representing probabilities in the more traditional sense of statistical mechanics. Also, Rovelli is the perfect person to learn from if you want to know about time. You can read his book _Reality is not what it Seems_ where he discusses loop quantum gravity and what happens to time when you quantize gravity: interestingly it actually disappears (there is no variable "t" in loop quantum gravity as "t" is something emergent and not fundamental). He also has a whole other book specifically dedicated to time.
I would also like to hear Matthew Leifer's interpretation on the state of the art...
It's highly improbable to define infinity when humanity is firmly positioned in the middle of forever.
I deciphered the Ishango Bone using hidden variables, that form everything.
Perhaps I've missed something in the discussion. The wave function of a particle/system has always been defined in the context of interactions. A single hydrogen atom and a single free electron have entirely different wave functions. A single free electron is a plane wave and a single hydrogen atom has an exactly solvable 2-body wave function. The mass is actually the reduced mass of the proton and bound electron. We only approximate the atom WF as the electron wave function since the reduced mass is close to the electron mass, and its thought of as an electron in a central force field. So, the bound electron in hydrogen has an entirely different WF from that of a single free electron. The WF always context sensitive
The wave function was never defined at the level of a single system. It was always a description of an ensemble.
In the mind-body problem, there is a false believe that what we experience is reducible only to our conscious minds and not to reality, based on the false belief that because what we experience is unique to the context we find ourselves in, that it must be "subjective." The philosopher Jocelyn Benoist points out this is fallacious, because nature can just be context-dependent, so the fact we see the world differently in different contexts doesn't make experience "subjective." We experience reality as it actually exists independent of an observer, but dependent upon the context of our experience.
In a similar sense, the measurement problem arises from physicists falsely conflating the contextual nature of quantum mechanics with conscious "observers" or "measurements," and then coming to believe what quantum mechanics shows is there is "no objective reality independent of the observer," when what it really shows is that there is no objective reality _independent of context._ Meaning, there is an object reality, but it is context-dependent. What we measure in the laboratory is indeed objective reality independent of an observer, but dependent upon the context of our measurement.
You are right that traditional QM already is contextual. Rovelli's views don't even change the Copenhagen interpretation much, it just replaces "observers" with "physical systems" and "measurements" with "interactions." The problem is that most physicists are tricked by people like David Chalmers into conflating contextuality and subjectivity together, so in the same way they come to falsely believe there is a mind-body problem, they also come to falsely believe there is a measurement problem, or, in both cases, they just embrace the subjectivity and devolve into idealism.
If we take it that the wave function collapses when a measurement is made, and that the definition of measurement is interaction, then perhaps our reality is the result of the countless interactions and that without interaction there is no reality as we know it.
Wave functions can't collapse. They don't even exist except in your mind. :-)
So, the entire universe is a quantum wave function? We (the observer) are a quantum system measuring other quantum systems that collapse and break entanglement (decoherence) creating our macro reality? The many worlds theory is not multiple worlds in space, rather, its multiple spaces within a world, governed by the probabilistic quantum wave function. I broke my brain trying to understand. Great series, WSF!
No, it is not.
I'm a big fan of this channel! Maybe I'm missing something, but I find a gap in Professor Rovelli's theory in that it doesn't address the observations found in the double-slit experiment. How would a particle create a wave pattern unless it was a wave?
There was a debate about particle wave which one is it. The double slit experiment showed that particles act like waves and waves like particles. Then Feynman asked a critical question What if you have three slots. He was a student in class.
@TEBrain, you commented:
"...I find a gap in Professor Rovelli's theory in that it doesn't address the observations found in the double-slit experiment. How would a particle create a wave pattern unless it was a wave?"
Well, relating to your wave pattern question, the way I see it (and please, bear with me), is, that the photon does NOT stop being a distinct particle WHILE it moves-around-all-over-at-lightspeed, thereby indeed creating an, as you say, "wave pattern", which, in my view, is a presentation that shows up as a kind of dense three-dimensional spherical wave pattern.
Now, to begin responding to your remark about Carlo Rovelli not dealing with the double-slit experiment, the following is how I would answer you if you and I were there with him and Brian Greene... which is of course extremely unlikely, but then, hey... we can dream.
My response would be,
"Let's do a thought experiment starting off in the
world of classical physics, then transitioning to the
quantum physical world where we may very well be
able to find out how those two realities mix..."
Let's begin by visualising the following:
Without anybody around seeing you doing it, tie a string to a tennisball and begin rotating it as fast as you can in a circular fashion above your head... so fast that eventually it twirls so incredibly quick that it, to a later onlooker, would look like a closed circle - like a fuzzy disk hovering above your head.
Now, say, someone comes by, and that person watches you twirling that fuzzy disk above your head, and you ask him or her what it is that you are twirling. Of course that person would not know what it is... it is simply moving too fast to make it out.
Then you ask that onlooker (that observer) to interrupt your twirling with their hand so as to be able to identify what it is that is going around so extremely fast. After some prodding, your onlooker hesitantly sticks their hand into that swirly dynamic and exclaims "Ouch!" after which s/he surprisedly says that you were twirling is a tennisball.
Okay, simple enough...
Now imagine that you, one way or another, can rotate that ball REALLY FAST IN ALL DIRECTIONS: simultaneously up-down, left-right, back-forth, close-by, farther-away, diagonally this way and any other way - any which way!
Of course, you have to get yourself out of the way, but let's just for the sake of this thought experiment imagine that you can do that.
What an onlooker (an observer) would see, would be a dense sphere with a lot of movement inside...: a rather busy hovering ball... You yourself of course would know that the object you are twirling so incredibly fast in all those directions, that it, in a sense, is "all over the place" in a spherical configuration.
Now imagine that Werner Heisenberg is passing by (we, including Brian and Carlo would be delighted of course), and imagine that Werner watches you performing your remarkable, nigh impossible stunt. If you would ask him what and where that object that is being twirled about, is at a given time, at a given location, and with what momentum, he would very likely quote his own uncertainty principle. But then-you are brave-you also ask him to interrupt your incredible, all directional twirling act. And you also ask him to identify the object that is being twirled around. He, like your previous onlooker, would also say that it is a tennisball.
This thought experiment, your remarkable stunt, is of course taking place in the macroscopic world of classical physics, meaning Heisenberg could use his watch to establish the time of interruption. You could even take a fast-frame film of the event, and you and Werner would know where the ball was when he interrupted the twirling and when he physically felt the impact. He could even find out the force of the impact and give you some rough estimate of it... After all, this is the day-to-day classical world of reality...
NOW, let's transition into the world of quantum-physical reality...
With the above stunt in mind, let's replace that twirling tennis ball with a similarly moving photon...: it gyrates-in this case with lightspeed-simultaneously up and down, left and right, back and forth, close in and farther away, diagonally this way and any other way-any which way! It is forming a similar spherical configuration that, interestingly, looks like the wave presentation of a photon, but remember, I started this comment with:
"The photon does NOT stop being a distinct particle
WHILE it moves-around-all-over-at-light-speed,
thereby indeed creating an, as you say, "wave
pattern", which in my view is a presentation that
shows up as a kind of dense three-dimensional
spherical wave pattern."
In this case, there is no need for you to move that photon around, of course not, from our viewpoint photons move at lightspeed. We have to realize though, and this is important, a photon itself has no inkling of time and space, not even of any movement. This is hard to grasp for us who live in a macroscopic, classical relativistic physical world in which, after all, space and time are the protagonists.
Thus, so to speak, FROM THE PHOTON'S POINT OF VIEW, we can say that, that this single photon is selfsuperposingly * omnipresent within an edgeless sphere, while it, FROM OUR POINT OF VIEW, is simultaneously moving "around-all-over" at the speed of light.
Now, relating to your remark about Carlo Rovelli not addressing it, how does the above play out in the double-slit experiment?
At the same time, as seen FROM THE VIEWPOINTS OF THE EDGES of the two classical-reality physical slits, the photon-although unbeknownst to the edges of the slits that that photon is selfsuperposed-is going at lightspeed through the two slits simultaneously, while FROM THE VIEWPOINT OF THE PHOTON ITSELF, each selfsuperposed photon presentation with spin angular momentum interacts with the two individual slits, reaching the wall at two separate distinct spots.
When shooting and aiming a long stream of photons, that is, photon after after photon-again each one selfsuperposed with spin angular momentum-through the two slits, each subsequent photon, after having dealt with the slits, arrives at the screen at two separate distinct spots. When a long stream of photons is thus aimed and projected through the two slits, they arrive at the screen statistically, leaving the imprints in the configuration of the so well-known double-slit experiment fringe pattern.
* The idea behind the words "selfsuperposed" and "selfsuperposition", and those words themselves, are of my own making. I came to them decades ago after reading about the telephone conversation between Wheeler and Feynman about there being only one electron, meaning "one electron only". I applied that "crazy" idea to the photon, there only being one, but it omnipresently being in superposition... hence "selfsuperposition". an idea that could possibly come in handy explaining entanglement...
It seems to me that, and this is not meant as a criticism of scientists, but whenever scientists who are on the “cutting edge” of physics are taking about the very large or the very small they all seem to use the same phrase when faced with the frontiers of knowledge "we just don't know". So what is DE? what is DM? What is QE? what is a Singularity?What is Quantum Gravity?Why is it that when you calculate the amplitude, of an event, and then square it you can make accurate probabilistic predictions about it? How does “Probability “which is not made of “particulate Matter” cross the boundary from its strictly mathematical existence into the particulate world to be displayed to us as variations of light and dark bands on a screen when monochromatic light is sent thru the slits during a double slit experiment?What does it mean for spacetime to expand?does it stretch? or is it quantified at the quantum level and when put under a pressure it merely self-replicates producing “more” of itself and if so where does “more of itself come from and where does the pressure come from in the first place, does it originate within our Universe as a positive outward pressure or is it a negative pressure pulling outward on the fabric of our spacetime Universe and so where would such a negative outward pulling pressure come from. just To name just a few.
Personally I wonder if we are, at our present level of development, truly able to answer such questions. I keep thinking that each time we face a challenge in understanding our Universe we come up with a theory which is “almost right” a.k.a. good enough for now. Because it is has been so difficult to formulate some of these theories we tend to “circle the wagons”around them too long. Just because we don’t have a theory’s replacement shouldn’t mean we don’t challenge its foundational structure.When we carry out experiments we try to fine tune the equipment but I wonder if we are forgetting about the most important piece of equipment involved in our experiments I.e. Us and our assumptions.
One of the assumptions we make is that everything that effects us and our Universe must originate from within our Universe.I sometimes wonder if our Universe exists within something I choose to call negative Spacetime, for want of a better description, and because of this the acceleration of the expansion of our Spacetime may be the result of an increase in a vacuum like pull on it which may be directly proportional to the amount of Matter and Energy in our Universe. This would explain the apparent acceleration of the expansion of our Spacetime Lattice. Any way just some random thoughts to ponder as you drift off to sleep.
Sigo enamorada de ti Brian Greene ❤
Great Talk!. Question regarding Laser Cooling and how it may simulate Black Hole Event Horizon on a quantum scale here on earth?
The main difference between John Locke and David Hume is personal identity. Locke believed that a person is self-aware, hence the agent capable to collapse the wave function with a measurement can't be ignored. However for Hume, we have never experienced the self. We are just a bundle of experiences, without deeper unity, so who made the measurement to collapse the wave function? God?
Yes, both Locke and Hume were idiots. Why are you wasting your time on them? ;-)
Will solving the QM Measurement Problem he a huge achievement?? What past achievement will it be comparable to?🤔⁉
It would be a paradigm shift as big as Newton
@@mitchellhayman381 So anybody who solves the Measurement Problem would be household names like Einstein and win a Nobel Prize and be super famous and influential ??
Accounts of Near Death Experiences indeed answer this question in the affirmative.
A collision between an alpha particle and two molecules of nitrogen trifluoride is not a measurement. A similar collision with two molecules of nitrogen tri-iodide can be a measurement, with a big rise in specific entropy. To model the difference in a computer simulation, I would suggest that we need to add tachyonic Brownian motion.
The catch is that just two molecules still means dozens of dimensions of configuration space. We need a computer that can cope with exponential-time algorithms. We currently don’t have one.
In general I would guess that the collapse of the wave function is a real but nonlinear collective phenomenon which transcends pencil-and-paper analytical methods and also transcends computational methods. My tri-iodide example is typical. Maybe there is a better idea than TBM, but we are still up against umpteen dimensions of configuration space.
“It’s not a wave, the wave is just a calculation that tells us where it might be” doesn’t explain the double-slit experiment. Only a wave does, because only a wave interferes with itself - as we see happen even when electrons are shot ONE BY ONE. The more likely error is ever thinking that particles sometimes are not waves, that the world is actually “solid” rather than just appearing to us that way at a certain scale.
Why are you telling us that you weren't paying attention in high school? :-)
You are just obsessed with Platonizing the mathematics. Not everything in the mathematics needs to be assigned an entity. What is the entity associated with E=mc^2? Where in the world can I find this equation floating out there? Sometimes things in the mathematics are just _relationships_ and not entities. The relationship here being P(x|psi)=||^2. This is how we predict how one particle will manifest its properties to another system. We know this relation holds in reality, but why do we need to actually assign an _entity_ to this relationship? Wave functions don't even exist in spacetime, they exist in Hilbert space. If you are imagining the photons turn into waves when you aren't looking at them, you're objectively not imaging the physics correctly, because the wave function does not have properties in spacetime, you cannot place it anywhere in the natural world. It has properties in Hilbert space, where only sometimes do only part of Hilbert space involve aspects of spacetime coordinates, but even then they include things like imaginary components which have no real-world analogue.