Many-worlds does not Solve the Measurement Problem

Brian Greene's third interview is with Carlos Rovelli:

I'll now give you a brief 0:21 summary of where we have gotten so far all right in our first conversation with 0:26 philosopher Elise Crow we discussed the basics of quantum mechanics namely that 0:33 the theory has at its core the idea that the best you can ever do in our reality 0:39 is make probabilistic predictions ...

we also explored how through quantum 1:36 entanglement reality has what we call a nonlocal quality that is what you do 1:42 here can have an instantaneous Quantum impact on something way over there and 1:48 such non-locality we found can thread not just through space but also through time

all right in 1:56 our second conversation with physicist and author Sean Carol we explored a 2:01 number of proposed resolutions to the quantum measurement problem most notably 2:07 spontaneous collapse theories as well as the many worlds interpretation of 2:13 quantum mechanics in which every possible Quantum outcome actually 2:18 happens but each takes place in its own Quantum Universe

No. Nothing can have an instantaneous nonlocal impact, and many-worlds does not solve the measurement problem.

I am surprised Greene would say this, because the advocates of many-worlds theory do not even claim to solve the measurement problem.

They argue that there is a wave function of the universe, and that the function will explain everything we see. Any mystery might be answered by understanding this function better. But it does not tell us why we see one outcome.

Or so I thought. I asked ChatGPT:

The many-worlds interpretation (MWI) is a fascinating and controversial view in quantum mechanics. Let’s delve into it and explore how it relates to the quantum measurement problem.

The Quantum Measurement Problem

The measurement problem arises from the mysterious behavior of quantum systems during measurement or observation. Here’s a brief overview:

1. Wavefunction Collapse: Before a measurement, a quantum system exists in a superposition of all possible states described by its wave function. However, upon measurement, the wave function appears to “collapse” to a specific state, leading to the observed outcome. This collapse is puzzling because it seems to violate the unitary evolution of quantum mechanics.

2. Where Do Other Possibilities Go?: If all possible outcomes of a quantum measurement have real existence, why do we observe only one outcome? What happens to the other possibilities?

Many-Worlds Interpretation (MWI)

The MWI, proposed by physicist Hugh Everett, offers an intriguing solution to the measurement problem. Here are the key ideas:

1. Parallel Universes: According to the MWI, the universe doesn’t collapse into a single state during measurement. Instead, it branches into multiple parallel universes, each corresponding to a different measurement outcome. In other words, every possible outcome occurs in a separate universe.

2. Wave Function Never Collapses: In the MWI, there is no collapse of the wave function. Instead, the entire universe (including the observer) evolves as a superposition of all possible states. Each branch represents a different version of reality, with no need for collapse.

3. Replicas of You and Me: In these parallel universes, there exist replicas of you and me, leading other lives. Each replica experiences a different outcome of the measurement. These universes coexist but remain mutually isolated.

Controversy and Philosophical Implications

The MWI challenges our understanding of knowledge and reality:

Controversy: Debates about quantum interpretations can be passionate, and the MWI is no exception. Some physicists find it elegant, while others reject it due to its radical departure from classical intuition.

Epistemological Question: The MWI raises fundamental questions about what constitutes knowledge. It challenges us to consider what kind of theory we accept as a claim to understand the world.

In summary, the MWI provides an alternative perspective that avoids wavefunction collapse, but it remains a topic of ongoing debate. Whether it fully solves the measurement problem is still a matter of interpretation and personal preference12. Feel free to explore further or ask more questions! 😊

I cites this Quanta article:

Why the Many-Worlds Interpretation Has Many Problems ...

it seemed that the central problem for quantum mechanics was the mysterious rupture created by observation or measurement, which was packaged up into the rubric of “collapse of the wave function.” ...

But Bohr and colleagues didn’t bring wave function collapse into the picture just to make things difficult. They did it because that’s what seems to happen. When we make a measurement, we really do get just one result out of the many that quantum mechanics offers. Wave function collapse seemed to be demanded in order to connect quantum theory to reality.

So what Everett was saying was that it’s our concept of reality that’s at fault. We only think that there’s a single outcome of a measurement. But in fact all of them occur. We only see one of those realities, but the others have a separate physical existence too.

Okay, I guess the Everett do claim that they have solved somethiung here. As you can see, they have not.

New Greene Videos spread Quantum Misinformation

Physicist Brian Greene, known mainly for overhyping string theory, has new interviews of Elise Crull and Sean Carroll on quantum entanglement and related topics.

You should know to be suspicious when they say the Nobel Prize committee got something wrong. Carroll complains that they gave a prize for disproving hidden variables, even though Einstein, Bohm, and Bell believed in hidden variables.

Yes, the prize was for doing experiments to prove them wrong.

Greene lets Carroll plug his favorite, many-worlds theory. They claim it is somehow simpler to assume zillions of unobservale worlds.

They do put their finger on the heart of the problem -- the theory requires rejecting probabilities.

Usually, when a theory assigns a probability to an event, it is an estimate of the likelihood. of the event occurring versus not occurring. Carroll has to reject that whole way of thinking. He has to say all events occur, and deny that probabilities mean anything.

He admits that many-worlds does not match our real-world experience, but says we need more research on the foundations of Physics to figure it out.

He complains that universities do not want people like Bohm and Bell who are concerned with this stuff. Actually he admits that they did not want Bohm because he was a Commie, and got his degree under the Commie J. R. Oppenheimer.

They all give misleading descriptions of nonlocality. There is no quantum nonlocality in the sense that doing something in one place has an immediate effect on a distant place.

There has been no Nobel Prize for quantum nonlocality. They also complain that the textbooks do not explain quantum mechanics adequately. This should make you suspicious. How is it that these guys have some profound quantum insights that are not recognized by the Nobel committee or the textbooks?

I am afraid that people watch these videos and think that they are learning something. No, they are getting some fringe ideas that mainstream physicists say is wrong.

Update: Carroll says:

just say we have a wave function and not only the electron has a wave function but you and I are part of the wave 11:14 function of the universe and we just ask what would be predicted by the [Schroedinger] equation if if we went back to the has a wave function but you and I are part of the wave 11:21 classical Paradigm where we just have stuff and an equation yeah what would happen and the answer is that that part 11:28 of the wave function let's say that has the electrons spin up and spin down it doesn't disappear when you do a 11:34` measurement a measurement is clearly defined in this picture as a physical interaction between the Observer and the 11:40 system and the decoherence part is also important and what happens is you end up in a 11:46 superposition of the electron was spin up and I saw it spin up plus the 11:51 electron was spin down and I saw it spin down and ever's entire contribution was to say and that's okay and ... yeah it's the leanest and meanest version of quantum mechanics it's just there's a wave function and an equation everything else pops

This is a little hard to follow, but he says classical mechanics uses equations to make predictions, and many-worlds is just doing the same thing to use the Schroedinger equation to make predictions.

But the equations of classical mechanics can also be used to predict probabilities. When you do, and make an observation that rules out some possibilites, then the appropriate state functions are updated accordingly. No one says that the equations create parallel worlds. So classical and quantum mechanics are essentially the same in this respect.

Carroll would say that hte difference is that the probabilities are real and fundamental in quantum mechanics, but not classical mechanics. But that is just his personal philosophical opinion.

Baggot has a New Book on Quantum History

Jim Baggott wrote an essay plugging his latest book:

‘Shut up and calculate’: how Einstein lost the battle to explain quantum reality

By suppressing questions they considered too ‘philosophical’, post-war physicists created an unquestioning orthodoxy that influences science to this day.

I agree that Einstein lost the battle, and that mainstream physicists came to the conclusion that pursuing philosophical questions is an unscientific waste of time.

Quantum mechanics is an extraordinarily successful scientific theory, on which much of our technology-obsessed lifestyles depend. It is also bewildering. Although the theory works, it leaves physicists chasing probabilities instead of certainties and breaks the link between cause and effect. It gives us particles that are waves and waves that are particles, cats that seem to be both alive and dead, and lots of spooky quantum weirdness around hard-to-explain phenomena, such as quantum entanglement.

Yes, QM is successful and works. But it is nonsense to say it is deficient because it "leaves physicists chasing probabilities instead of certainties and breaks the link between cause and effect." All scientific theories do that, to the extent QM does.

How, then, is the correlation established? Do the particles somehow remain in contact, sending messages to each other or exerting influences on each other over vast distances at speeds faster than light, in conflict with Einstein’s special theory of relativity?

The alternative possibility, equally discomforting to contemplate, is that the entangled particles do not actually exist independently of each other. They are ‘non-local’, implying that their properties are not fixed until a measurement is made on one of them.

Both these alternatives were unacceptable to Einstein, leading him to conclude that quantum mechanics cannot be complete.

Those alternatives are also unacceptable to Bohr and most followers of the Copenhagen interpretation. The particles do exist locally, and are not in contact with distant particles.

The paradox occurs when Einstein tries to complete QM by adding some unobservable ideas. If you stick to Bohr's positivism, all is fine.

It seemed that dissidents faced serious repercussions. When US physicist John Clauser — a pioneer of experimental tests of quantum mechanics in the early 1970s — struggled to find an academic position, he was clear in his own mind about the reasons. He thought he had fallen foul of the ‘religion’ fostered by Bohr and the Copenhagen church:

Clauser was trying to disprove QM. Had he succeeded, he would have been a big hero. As it was, his work was not interesting to those who thought that QM was well-tested, and his research would not find anything new.

Yes, Clauser did eventually get a Nobel Prize, but not for discovering any new physics. Only for confirming what everyone knew. In particular, the Nobel committee did not criticize the Copenhagen interpration, or endorse Einsteinian completeness or nonlocality.

The Americanization of post-war physics meant that no value was placed on ‘philosophical’ debates that did not yield practical results. The task of ‘getting to the numbers’ meant that there was no time or inclination for the kind of pointless discussion in which Bohr and Einstein had indulged.

Yes, that was the Golden Age of American science. Doing good science, instead of the meaningless philosophical ideas that have diverted physicists today, such as string theory, many-worlds, etc.

These developments conspired to produce a subtly different kind of orthodoxy. In The Structure of Scientific Revolutions (1962), US philosopher Thomas Kuhn describes ‘normal’ science as the everyday puzzle-solving activities of scientists in the context of a prevailing ‘paradigm’. This can be interpreted as the foundational framework on which scientific understanding is based. Kuhn argued that researchers pursuing normal science tend to accept foundational theories without question and seek to solve problems within the bounds of these concepts. Only when intractable problems accumulate and the situation becomes intolerable might the paradigm ‘shift’, in a process that Kuhn likened to a political revolution.

Kuhn then wrote a book on a history of the discovery of QM, and he failed to find a paradigm shift or anything matching his wacky theory of scientific revolutions.

A persistent myth was created that suggests Bohr won the argument by browbeating the stubborn and increasingly isolated Einstein into submission. ...

My latest book Quantum Drama, co-written with science historian John Heilbron, explores the origins of this myth and its role in motivating the singular personalities that would go on to challenge it. Their persistence in the face of widespread indifference paid off, because they helped to lay the foundations for a quantum-computing industry expected to be worth tens of billions by 2040.

I will skip this book. He is peddling nonsense that got resolved decades ago. Questioning the Copenhagen interpretation has not led to any advances in quantum computing or anything else. I do not believe the quantum computing industry will be worth anything in 2040. It has no proven value so far.

All of the quantum computing researchers use the Copenhagen interpretation to design and carry out their experiments. There are a few who think that the results might be better understandable with many-theory, but many-worlds and non-local theories have had zero influence on the research. There is no chance that quantum computers will prove Einstein right, or Bohr wrong, or anything like that.

Critical Step in Quantum Networking

NewsL

Researchers have produced, stored, and retrieved quantum information for the first time, a critical step in quantum networking.

The ability to share quantum information is crucial for developing quantum networks for distributed computing and secure communication. Quantum computing will be useful for solving some important types of problems, such as optimizing financial risk, decrypting data, designing molecules, and studying the properties of materials.

“Interfacing two key devices together is a crucial step forward in allowing quantum networking, and we are really excited to be the first team to have been able to demonstrate this.” — Dr. Sarah Thomas

However, this development is being held up because quantum information can be lost when transmitted over long distances. One way to overcome this barrier is to divide the network into smaller segments and link them all up with a shared quantum state.

To do this requires a means to store the quantum information and retrieve it again: that is, a quantum memory device. This must ‘talk’ to another device that allows the creation of quantum information in the first place.

For the first time, researchers have created such a system that interfaces these two key components, and uses regular optical fibres to transmit the quantum data.

There is no commercial value in this or quantum networking. No one is going to use this to optimize financial risk, design molecules, or increase the secutiry of anything.

Higgs has died

Physicist Lawrence M. Krauss writs:

Higgs wrote up his idea in a two-page scientific paper entitled “Broken Symmetries and the Masses of Gauge Bosons.” It was initially rejected by the major European physics journals, as having no obvious relevance to physics. But then he added a paragraph mentioning a possible observable consequence of his idea and submitted his paper to the American physics journal, Physical Review Letters, where it was published on 19 October 1964. Similar ideas were explored by the physicists Robert Brout and François Englert, and independently by Gerald Guralnik, C.R. Hagen, and Tom Kibble, and these two groups also published their work in the same journal. But, perhaps as a result of that extra paragraph that predicted a physical consequence of his theory, it was Higgs’s name that became associated with the hypothesis, which ended up providing the cornerstone of the successful effort to unify two of the four known forces in nature: the weak and electromagnetic interactions. 

CERN discovered the Higgs particle in 2012, and he got the Nobel Prize in 2013, and it ruined his life.

Okay, but I do not see why Higgs had to predict the particle, and CERN find it, for him to get the prize.

The Higgs mechanism is essential to the Standard Model, and to all the cutting edge high-energy physics since about 1970.

The other ctitical piece was tHooft's renomalization of gauge theories in about 1970. That made gauge theories the only game in town, with SU(2) for the weak and SU(3) for the strong force. 'tHooft got the Nobel Prize in 1999. He should have also gotten the prize in the 1970s, when experiments confirmed the Standard Model.

Thank Gravitational Waves for Life

Phys.org reports:

Could it be that human existence depends on gravitational waves? Some key elements in our biological makeup may come from astrophysical events that occur because gravitational waves exist, a research team headed by John R. Ellis of Kings College London suggests.

In particular, iodine and bromine are found on Earth thanks to a particular nuclear process that happens when neutron stars collide. In turn, orbiting neutron star pairs inspiral and collide due to their emissions of energy in the form of gravitational waves. There may thus be a direct path from the existence of gravitational waves to the existence of mammals.

Humans are mostly made up of hydrogen, carbon and oxygen, with many additional trace elements. (There are 20 elements essential to human life.) Those with an atomic number less than 35 are produced in supernovae, implosions of stars that have exhausted their nuclear fuel and collapsed inward. The collapse results in an explosion that spews their atoms all over the universe.

But two elements are provided by other means—iodine, needed in key hormones produced by the thyroid, and bromine, used to create collagen scaffolds in tissue development and architecture. ...

Ellis and his colleagues calculate that the r-process has provided 96% of the abundance of 127I on Earth, an isotope essential for human life, and most of the abundance of bromine and gadolinium in the Earth's crust, plus all of the Earth's thorium and uranium and a fraction of the molybdenum and cadmium.

Seems farfetched, but interesting anyway. Here is the paper.

Update: Dr. Bee comments.

Sapolsky and Sam Harris on Free Will

Imagine that two schizophrenic have a discussion about hearing voices in their heads. They both agree that they hear voices, but then puzzle about how hard it is to convince others that the voices are real.

I used to thinjk that the anti-free-will advocates could not possibly believe what they are saying. Ordinary life requires making choices. Why do they get out of bed in the morning?

That is what this podcast is like:

We Really Don’t Have Free Will?: A Conversation with Robert M. Sapolsky (Episode #360)

Sam Harris speaks with Robert Sapolsky about the widespread belief in free will. They discuss the limits of intuition, the views of Dan Dennett, complexity and emergence, downward causation, abstraction, epigenetics, predictability, fatalism, Benjamin Libet, the primacy of luck, historical change in attitudes about free will, implications for ethics and criminal justice, the psychological satisfaction of punishing bad people, understanding evil, punishment and reward as tools, meritocracy, the consequences of physical beauty, the logic of reasoning, and other topics.

Robert M. Sapolsky is the author of several works of nonfiction, including A Primate’s Memoir, The Trouble with Testosterone, Why Zebras Don’t Get Ulcers, and most recently, Determined: A Science of Life without Free Will. His book titled Behave was a New York Times bestseller and named a best book of the year by The Washington Post and The Wall Street Journal. He is the John A. and Cynthia Fry Gunn Professor of biology, neurology, and neurosurgery at Stanford University and the recipient of a MacArthur Foundation “Genius Grant.” He and his wife live in San Francisco.

Okay, I am satisfied that some schizophrrenics hear voices in their heads, and Sapolsky and Harris have some other disorder controlling their brains. They adamantly argue that they have no choices in what they do.

Believe in free will or not as you please, but there is no law of Physics that requires the future to be determined by the past.