Monday, May 20, 2024

Einstein's Futile Search for Unified Field Theory

Sabine Hossenfelder posted her latest video:
Einstein’s Other Theory of Everything

Einstein completed his theory of general relativity in 1915 when he was 37 years old. What did he do for the remaining 40 years of his life? He continued developing his masterwork of course! Feeling that his theory was incomplete, Einstein pursued a unified field theory. Though he ultimately failed, the ideas he came up with were quite interesting. I have read a lot of old Einstein papers in the past weeks and here is my summary of what I believe he tried to do.

She insists on pronouncing his name INE-shtine. Maybe Germans pronounce it that way, but not Americans.

She summarizes Einstein's foolish and misguided unified field theories. If he did not already have a fancy reputation, this would be considered crackpot work.

She also mentions the more successful Kaluza–Klein theory:

In physics, Kaluza–Klein theory (KK theory) is a classical unified field theory of gravitation and electromagnetism built around the idea of a fifth dimension beyond the common 4D of space and time and considered an important precursor to string theory. In their setup, the vacuum has the usual 3 dimensions of space and one dimension of time but with another microscopic extra spatial dimension in the shape of a tiny circle. Gunnar Nordström had an earlier, similar idea.
This is also described as a failure. She says you need supersymmetry to make it work, but that has been rejected.

That theory is a minor variant of a 1918 H. Weyl proposal to unify gravity (general relativity) and electromagnetism. That was promptly attacked by Einstein, and mostly forgotten.

There the story ends. But not really. Einstein's ideas were, in fact, worthless, and led several generations of physicists astray. I wrote a whole book about it.

But Weyl's idea was essentially correct. In the modern Standard Model, that everyone accepts, there is an extra tiny circle at every spacetime point (event) to account for electromagnetism. In modern lingo, it is a circle bundle over a spacetime manifold. Gravity is a connection on the tangent bundle, and electromagnetism is a connection on the circle bundle. In both cases, the field is the curvature. It is the simplest and most natural relativistic theory.

Physicists studied Weyl and Kaluza-Klein for decades, without ever figuring out that they were just adding extra terms that ruined the theory. I guess they wanted to unify the gravity with the electromagnetism by hypothesizing some interactions, but that was just foolishness.

If Weyl were really smart, he would have conjectured using other Lie groups form the strong and weak interactions, alongside the circle for electromagnetism. Then we could have had the Standard Model, before quantization, about 50 years before we did.

One of the Lessons of the Standard Model is that all four forces (gravity, electromagnetism, weak, and strong) all have the same math structure (field strength is curvature of a bundle connection), but the force are essentially orthogonal. They do not have much to do with each other. There is some twisting between the weak and electromagnetism, but that's all. Many people thought that they would be unified like electricity and magnetism, where you cannot study one without the other.

Wednesday, May 15, 2024

Gravity is a Force

Physicists are sharply divided over whether gravity is a force. Oh, they refer to it as a force all the time, such as saying it is one of the four fundamental forces, but then say it is a fictitious force.

The excellent video channel Veritasium has explanation of Why Gravity is NOT a Force.

It is like the people who say that centrifugal force is not a force, but centripetal forces is.

Gravity has been considered a force since Newton in the 1600s, so the opposite view requires explanation.

Actually, it is not so clear that Newton believed that gravity was a force. He was very much against action-at-a-distance:

Newton famously struggled to find out the cause of gravity.[12] In a letter to Bentley, dated January 17 1692/3, he said:

You sometimes speak of Gravity as essential and inherent to Matter. Pray do not ascribe that Notion to me, for the Cause of Gravity is what I do not pretend to know, and therefore would take more Time to consider it. (Cohen 1978, p. 298)

In a subsequent letter to Bentley, dated February 25, 1692/3, he added:

It is inconceivable that inanimate Matter should, without the Mediation of something else, which is not material, operate upon, and affect other matter without mutual Contact…That Gravity should be innate, inherent and essential to Matter, so that one body may act upon another at a distance thro’ a Vacuum, without the Mediation of any thing else, by and through which their Action and Force may be conveyed from one to another, is to me so great an Absurdity that I believe no Man who has in philosophical Matters a competent Faculty of thinking can ever fall into it. Gravity must be caused by an Agent acting constantly according to certain laws; but whether this Agent be material or immaterial, I have left to the Consideration of my readers. (Cohen 1978, pp. 302-3)

Aristotle also denied that gravity was a force.
The Aristotelian explanation of gravity is that all bodies move toward their natural place.

There are two arguments that gravity is not a force. One says that you do not feel gravity in free fall. You feel it when you stand on the ground, but you are really feeling the force of the ground pushing you up.

The second is that general relativity teaches that gravity is just curvature of spacetime, not a force. This is a variation of Aristotle's argument.

A typical explanation:

“The one sentence statement of general relativity is that ‘gravity is the curvature of spacetime,’” explains Dr. Sean Carroll, assistant professor of physics at the University of Chicago. “Really, the differences come in understanding what that sentence means.”

Carroll says that origin of the theory of general relativity dates to 1905, when scientists, notably including Albert Einstein, realized that space and time are related characteristics of a four-dimensional existence. ...

However, within this new 4-D framework, says Carroll, Einstein could not understand gravity, and how it worked in spacetime. He decided that rather than being a force, like electromagnetism, gravity must be a property: a geometric curvature.

This stuff about Einstein believing that gravity is geometrical curvature is a modern invention. Yes, he used the equations for curvature, but did not subscribe to the geometric interpretation that is popular today.

General relativity differs very slightly from Newtonian gravity. It is silly to say one is a force and the other not. They are essentially the same.

My biggest quibble is with those who say electromagnetism is a force, but gravity is not. In modern physics, all of the four fundamental forces have geometrical interpretations, where the field strength is given by curvature. Test particles follow curvature, in all cases. Here is a recent paper explaining it. So if gravitational forces are fictitious because particles are just following curvature, then nothing else is a force either.

Those who deny that gravity is a force sometimes go one step farther, and deny causality. Eg, from the Stanford Encyclopedia:

Causation in Physics

What role, if any, do causal notions play in physics? On the one hand, it might appear intuitively obvious that physics aims to provide us with causal knowledge of the world and that causal claims are an integral part of physics. On the other hand, there is an influential philosophical tradition, dating back to Ernst Mach and to Bertrand Russell’s extremely influential article “On the Notion of Cause” (1912), denying the applicability or at least the usefulness of causal notions in physics. While this tradition is perhaps not as dominant today than it once was, there continues to be a lively and active philosophical debate on whether causal notions can play a legitimate role in physics and, if yes, what role that might be.

One part of this is that if you believe in determinism and the block universe, then the Big Bang caused everything, and nothing else had any influence.

I take the view that we have forces and causes. I am all in favor of the geometrical interpretation, but not to deny forces and causes.

While I think most physicists take a geometrical view, here is a new oddball paper:

A Puzzle About General Covariance and Gauge

Eleanor March, James Owen Weatherall

We consider two simple criteria for when a physical theory should be said to be "generally covariant", and we argue that these criteria are not met by Yang-Mills theory, even on geometric formulations of that theory. The reason, we show, is that the bundles encountered in Yang-Mills theory are not natural bundles; instead, they are gauge-natural.

Of course Yang-Mill (gauge) theories are generally convariant, as the theory is independent of any particular coordinates. If you change coordinates, then the equations of motion transform as you expect from vectors and tensors.

The paper makes the trivial point that if you change the coordinates, that does not necessarily tell you how to change the gauge. Yang-Mill theories are covariant over a change in coordinates and gauge.

These confusing arguments only obscure the fact that gravity, electromagnetism, strong, and weak forces all use the same geometrical constructions. Just the bundles are different. Gravity uses the tangent bundle on spacetime, while the other forces use U(1), SU(3), and SU(2) bundles. They are all covariant.

The Wikipedia article on general covariance says that Einstein popularized the term, but did not use it precisely. So I guess that is why some might think that it applies to general relativity, but not to other bundles.

Update: Here is a new paper explaining general covariance.

The free field then couples to the gauge field, producing an interaction term in the Lagrangian that is gauge-invariant. Neither the original electron field, nor the gauge field are gauge invariant, but the way they appear in the Lagrangian is through a gauge invariant term. One then proceeds to define gauge invariant things like the tensor field 𝐅:=d⁢𝐀 and claims that the physics of the theory is contained only in those objects.

Likewise, diffeomorphisms in GR are regarded as extra, unphysical degrees of freedom: the physics must be contained only in gauge-invariant quantities. This is in flagrant contrast with what experience tells us: in ‘real life’ things are constrained to fixed frames of reference, and one can measure ‘gauge-variant’ [8] quantities, such as the energy, proper time, the electric field, and so on.

Friday, May 10, 2024

Wilczek says Falling Cats have Free Will

Physicist Frank Wilczek is famous for helping explain the short range nature of the strong force, and now he wrote a strange paper on cats. No, not Schroedinger cats.
Free Will and Falling Cats

If we consider a cat to be an isolated mechanical system governed by T-invariant mechanics, then its ability to land on its feet after being released from rest is incomprehensible. It is more appropriate to treat the cat as a creature that can change its shape in order to accomplish a purpose. Within that framework we can construct a useful and informative of the observed motion. One can learn from this example.

He seems to be saying that it is impossible for a falling cat to land on its feet, unless it has free will.

He proves it is impossible, but then says cats have a loophole because "They can readily and selectively consume stored energy, notably by converting ATP into ADP, empowering mechanical motion accompanied by radiation of heat."

This is bizarre. The physics of falling cats is well-understood, and does not require free will or ATP or heat or anything like that. See A simple model for the falling cat problem. There is even a Wikipedia article on it.

The paradox is that the cat falls with zero angular momentum, a conserved quantity, and it is hard to see how it can get its feet down without some angular momentum. But as the above paper explains, the cat can twist its body without any net angular momentum.

Wilczek has some philosophical comments that went over my head, so maybe I am not fully appreciating his paper. After all, he has a Nobel Prize and I don't. What am I missing? He does cite a book on "Falling Felines and Fundamental Physics", so he must know that this is understood.

Wednesday, May 8, 2024

Carroll Eulogy for Dan Dennett

Physicist Sean M. Carroll released his latest AMA podcast. He starts with a eulogy.
Dan Dennett you know was not only a hugely important 1:02 philosopher for the 20 and 21st century uh and a mindscape guest but also a personal friend so that hit very hard I 1:09 was sitting at a table with Dan and a bunch of other philosophers just a few 1:15 weeks ago at Santa Fe
He particularly praised Dennett for giving philosophical defenses of Atheism and Darwinism, and saying the mind is just a machine, so consciousness and free will are just illusions. But he was very much against telling the hoi polloi that they have no free will, or they may decide that they have no moral responsibility for their actions.

In past generations, philosophers did not want to inform us that God is dead, or that we are descended from apes.

Next, Carroll praised counterfactual reasoning.

ml pickle says your recent guests have 21:43 pointed to counterfactual reasoning as a key element of human advancement either as mental time travel or considering the 21:49 consequences of different initial conditions or empathy for the plights of others Etc I've begun to notice how 21:55 often I do it and to suspect it's true that Ed ability for example and perhaps 22:00 our overall success as a species depend upon it however I can't tell if it is required or most efficient or if it just 22:07 happens to be what I personally do how important do you think counterfactual reasoning is to effective prediction as 22:13 individuals or to our past and future advancement as a species it's hard to answer I mean that 22:20 the answer is super important basically but when you ask you know how important is it I'm not quite sure what how to 22:26 quantify it right um but I do do think that this idea of counterfactual reasoning maybe the first time we talked 22:31 about it was with Malcolm mcgyver when he was talking about the the initial evolutionary development of the capacity 22:38 for counterfactual reasoning when fish climbed onto land and could suddenly see a lot further than they could before and 22:46 yeah you're right we've talked about um people who have been thinking more specifically about how humans use those 22:52 capacities um I you know it's hard to imagine something oh Carl friston we 22:58 actually also talked with about that issue cuz I was I remember joking with him that of my two cats Ariel and 23:04 calaban one seems to be capable of counterfactual reasoning and one does not calaban just seeks the local minimum 23:10 he just wants to be as happy as possible in the moment I don't think the idea of other moments ever occurs to him whereas 23:15 Ariel is the stereotypical cat who you know when you open a door that she demands to have open she's like I don't 23:21 know do I want to open that do I want to walk to that threshold I'm not quite sure she's always thinking about the 23:26 possible bad consequences Etc and our uh feral cat our outdoor cat Puck who has 23:32 uh hung around outside our yard for a while um he's super cautious right 23:38 because this is what is keeping him alive so he doesn't do anything until he like thinks about it 20 different ways 23:43 so somewhere that's that's close to when this capacity in some minor uh key was 23:49 first developed evolutionarily but anyway yeah absolutely possible AB absolutely crucial because I think that 23:57 I suspect and I'm just making stuff up I'm not an expert on this but I suspect that the parts of the brain that are 24:03 good at in general abstract symbolic reasoning are either the same as or 24:09 closely related to the parts of the brain that are that are good at counterfactual reasoning
I would agree with this, except that there is no way to reconcile this with his views on many-worlds theory. In many-worlds, all counterfactual scenarios happen, so there is no such thing as a counterfactual.

If he really believed in many-worlds, there would be no free will either. Every decision is just a splitting of the worlds, with both branches equally real.

He also expresses support for the anti-Israel protests currently going on at college campuses.

The podcast goes on for three more hours. Let me know if I missed anything good.

Monday, May 6, 2024

Unscientific American

James B. Meigs writes:
Science journalism surrenders to progressive ideology.

Michael Shermer got his first clue that things were changing at Scientific American in late 2018. The author had been writing his “Skeptic” column for the magazine since 2001. ...

Shermer dug his grave deeper by quoting Manhattan Institute fellow Heather Mac Donald and The Coddling of the American Mind authors Greg Lukianoff and Jonathan Haidt, who argue that the rise of identity-group politics undermines the goal of equal rights for all. Shermer wrote that intersectional theory, which lumps individuals into aggregate identity groups based on race, sex, and other immutable characteristics, “is a perverse inversion” of Martin Luther King’s dream of a color-blind society. For Shermer’s editors, apparently, this was the last straw. The column was killed and Shermer’s contract terminated. Apparently, SciAm no longer had the ideological bandwidth to publish such a heterodox thinker.

The article gives many examples.

I have criticized these SciAm trends for years.

Maybe the title should be Unscientific Unamerican, since the magazine is now owned by a British company.

Saturday, May 4, 2024

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.

Thursday, May 2, 2024

New Greene Videos spread Quandum 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.

Monday, April 29, 2024

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.

Monday, April 22, 2024

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.

Tuesday, April 16, 2024

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.

Thursday, April 4, 2024

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.

Monday, April 1, 2024

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.

Thursday, March 28, 2024

“Don’t be a monkey!”

Lawrence M. Krauss writes:
I vividly remember the first time he showed me his famous video of capuchin monkeys—later to feature in a TED talk that has 23 million views and counting — in which two capuchin monkeys, kept in adjoining cages, are fed treats for exhibiting a certain behaviour. The monkeys were perfectly happy performing their task for cucumbers until, one day, one of the monkeys was rewarded with a grape instead. When the monkey’s companion was given a cucumber for the same task, he immediately proceeded to throw a temper tantrum worthy of a three-year old child — even though, five minutes earlier, he had been content with that reward. 

I immediately recognized the behaviour in myself! I showed the video to my wife, and ever since then, whenever I start to feel envious of someone for receiving any sort of reward that appears to be greater than that which I had previously been perfectly happy to receive during a similar experience, I tell myself, or my wife tells me: “Don’t be a monkey!”

He vividly recalls this, because he watched a cherry-picked video. You can read more in the Wikipedia article on Inequity aversion in animals.

The experiment has been repeated many times, with mixed results. Female (but not male) capuchin monkeys showed the effect, and so did some other species. Many experiments failed to find the effect.

I think the most interesting part of this is watching humans, like Krauss, watch this video and interpretation, and somehow think that they know what is going on inside the monkey's mind. I think they are projecting their own views onto the monkeys.

It is not clear that the monkey is feeling envy, or disapproval of the inequitable reward. If the monkeys were really rejecting inequity, then maybe the monkey getting the grape would give it to the other monkey. No, that does not happen.

It is hard to see how this says anything about cooperation, as these monkeys are lousy at cooperating on anything.

As for envy, it is not clear that the monkey cares at all what the other monkey is getting. Maybe the monkey notices that she could be getting a grape, and then rejects the lesser reward in order to get the grape. Indeed, this experiment has been done with just one monkey, and it just shows that the monkey wiil show that it wants the better reward.

I just tried showing the video to a ten-year-old boy, and asked him what he saw. He said, "i see a monkey who wanted a grape." When I explained that the grownup scientist interpreted this as a monkey protesting pay unfairness, he looked puzzled, and did not see why anyone would think that.

The TED Talk has a slide saying the Pillars of Morality are Reciprocity/Fairness and Empathy/Compassion. This is a very left-wing view that I call Kindergarten Morality. Kindergarten teachers commonly tell kids that they all have to share the toys equally, and show compassion to all. Older kids usually understand that such equality is impractical, and other moral concepts are more important. For more on how leftists have crippled moral outlooks, see Jonathan Haidt's Moral foundations theory.

Monday, March 25, 2024

Stealing our cutting edge String Theory

Eric Weinstein tweeted:
Q: How do you know that String Theory isn’t working as physics despite expert assurances to the contrary?

A: No one at all is in any way worried about the Iranians, Russians or Chinese getting their hands on our cutting edge String Theory.

Ha ha. Do they worry about enemies stealing our fusion reactor or quantum computer technology? Maybe a little bit.

Our semiconductor, rocket, and AI technology? A lot.

Weinstein has his own pet theories to replace the Standard Model of high-energy physics, but it has gone nowhere.

Update: Here is a video clip with more from him and Lee Smolin. Smolin also has his pet theories that have gone nowhere. Their complaint is not just that string theory does not work, but that it gets more attention than other thoeries that do not work.

For someone negative on the whole high-energy research program, see Unziger.

Monday, March 18, 2024

Deutsch defends Many-Worlds Theory

New podcast: The Multiverse is REAL - David Deutsch.

He says the double-slit experiment conclusively proves the many-worlds theory. He accepts the parallel worlds for the same reason he accepts the existence of dinosaurs (millions of years ago). It is the only way to explain the evidence.

He admits that the photons are not really particles, and that any waves show a similar diffraction pattern. But he says that for the photon to behave as a wave, it must exist in multiple copies.

He also admits that all this has been known for decades, and yet most physicists do not accept this argument for many-worlds.

I do not see any merit to this argument. The double-slit experiment only proves that light, and other beams like electron beams, have wave properties. That's all. It is not even evidence for quantum mechanics, as this wave explanation was accepted before quantum mechanics was invented.

When asked about alternative theories, he says the von Neumann had this crazy idea that if you observe an electron in one place, then the possibility of it being somewhere else ceases to exist.

I do not see the problem with that. I do not even think the issue has anything to do with quantum mechanics. Anytime you estimate the probability of an event, and then observe it, that means that the other possibilities did not happen. That is how probabilities work.

He pushes quantum computing, but admits that he has not followed the latest technology.

I see the argument for many-worlds as nothing more than a rejection of probability theory. You could take any scientific theory that predicts probabilities, deny that the probabilities make any sense, and conclude that there are parallel worlds of unobserved possibilities.

That is all many-worlds theory is. I don't think that it even has anything to with quantum mechanics. It is only expressed in terms of quantum mechanics, because textbook QM emphasizes the probabilities. But other theories use probabilities the same way, and could have many-worlds interpretations.

Many-worlds thsoey is just the same as taking a science textbook, announcing some philosophical disagreement with probability theory, and redacting all the sections mentioning probability. It adds nothing. It just removes the theory's predictive power.

It is hard to see how any intelligent man takes many-worlds seriously. It offers nothing. Maybe they just don't understand probability theory, as I do not see anywhere that they recognize that they are just rejecting probability.

PBS TV has a news item:

How quantum computing could help us understand more about the universe

Scientists, researchers and some big companies are eager to jumpstart the next generation of computing, one that will be far more sophisticated and dependent on understanding the subatomic nature of the universe. But as science correspondent Miles O’Brien reports, it’s a huge challenge to take this new quantum leap forward.

A lot of hype. They admit that a fault tolerant quantum computer might be decade away. No one admits that it might be impossible.