Is Quantum Reality in the Eye of the Beholder?

Can we address mysteries of quantum mechanics by supposing that properties of objects long considered to have an independent existence are actually determined solely in relation to other objects or observers?

This program is part of the Big Ideas series, supported by the John Templeton Foundation.

Participants:
Carlo Rovelli

Moderator:
Brian Greene

00:00 - Introduction
03:06 - Beginning of the Main discussion
03:50 - How does Carlo Rovelli view the Quantum Measurement problem and Many Worlds theory?
12:47 - Relational quantum mechanics
17:27 - Does this approach apply to relativistic quantum mechanics
24:01 - What is needed to fully understand Quantum Mechanics?
28:30 - Summary

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#worldsciencefestival #quantummechanics #briangreene #carlorovelli #physics

[Antediluvian]

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!

[spnhm]

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.

[dinarwali]

Brain Green is one of the greatest educators of the current times. The kind of content on WSF is the best. Period

[MrVikingsandra]

This conversation is absolutely brilliant. I could listen to you two for hours and hours!

[multifokus]

Carlo answers questions on another level...!

[tamjammy]

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.

[vimaldixit]

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

[ottofrank]

Wooow, this one was HISTORIC! AMAZING!

[marcobiagini]

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.

[Onestringpuppet]

Why have the episode's become so short? I vote for longer conversations again please! 😁
Love your videos

[scottcarpenter]

Absolutely brilliant! I’m glad that Carlo Rovelli was the final speaker… All three guest speakers and Brian Greene himself are beyond sublimeness

[nyworker]

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.

[twols]

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!

[synx]

this was the best of the 3 parts so far

[MrBitterman]

Thank you for making all these amazing lectures available. They got me through the pandemic and been a hardcore fan since.

[alfadog]

Such deep thinking is contagious, gentlemen! Thank you for serving mankind!

[JohnMandalios]

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.

[GMC]

Wonderful. Thank you. I’ve read all of both of your books. I love WSF. More Carlo please!

[koljoy]

O my God! I wonder how people make simple things so complex!

[MoshkitaTheCat]

Delightful exchange! Thank you Dr. Greene!