Monday, September 25, 2023

The Essence of Relativity

Some say the essence of relativity is the Lorentz transformation, or the Minkowski metric, or the Michelson-Morley experiment, or the Einstein postulates. Here is my brief version.

Relativity is the study of the geometry of events in spacetime. An event is a position in three-dimensional space, along with a time. Euclidean geometry describes that space, but time is very different, as you can go back to the same position but not the same time. Relativity puts a non-euclidean geometry on spacetime that limits the speed of causality. Events can only affect nearby events if a light signal or slower signal can travel from one event to the other.

The first relativistic theory was devised by Maxwell in 1865. His electromagnetism theory used fields that propagate at the speed of light. This was in contrast to gravity, where similar inverse-square laws seem to act at a distance. He wondered whether this theory could detect the motion of the Earth. The Michelson-Morley experiment failed to do that in 1887, and seemed to show that the speed of light and the rest of Maxwell's theory was the same under inertial motion. Lorentz explained this by showing that motion modifies how we measure space and time.

Poincare and Minkowski showed in 1905-7 that there is a non-euclidean geometry on spacetime that underlies Maxwell's theory and explains the experiments. The theory can be expressed in equations that are covariant under the geometric symmetries. That geometric view came to dominate XX century Physics. It was important because it changed our understanding of space and time.

Einstein's chief contribution was to show that the Lorentz transformations could be derived from the principles that Lorentz and Poincare deduced from Maxwell and experiments. He never really accepted the geometric view.

Special relativity is the infinitesimal version of general relativity. Like a tangent line is the infinitesimal version of a smooth curve. In special relativity, the spatial part of spacetime is Euclidean, ie flat. Spacetime is curved in general relativity, and the Ricci curvature tensor is essentially the mass-energy.

When people say that relativity is non-euclidean, they usually mean that spacetime is curved from the gravity of mass. But the flat no-gravity tangents are also non-euclidean, because of the causality speed limit.

In my opinion, this non-euclidean geometry of flat special relativity spacetime is the true essence of relativity. It was what Minkowski explained in his wildly popular 1908 paper. That paper, along with experimental confirmations, is what sold physicists on relativity theory. Poincare's 1905 papers also had it, but were probably only understood by Minkowski and a few other mathematicians.

Most relativity historians ignore this essence, but see The Non-Euclidean Style of Minkowskian Relativity, by Scott Walter. It explains how Planck, Wien, Laub, Sommerfeld, Einstein, and German Physics journals all rejected the non-euclidean geometry approach around 1910-12. By then, Poincare and Minkowski were dead, and the biggest champion of it was Varicak.

General relativity was the natural generalization of special relativity, once the tools of Riemannian geometry were developed. Einstein's main contribution was to calculate the deflection of starlight during a solar eclipse, and the precession of Mercury's orbit.

The geometric view was accepted by most mathematical physicists from 1907 on, but rejected by Einstein and some later physicists, such as Steve Weinberg.

Thursday, September 21, 2023

Number 57 is Prime

So says the world's most famous mathematician, in a new paper. See page 27 where the authors apply their theory to example primes, 53 and 57. 53 is prime, but 57 is 19*3.

Apparently it is an inside joke among mathematicians to say 57 is prime, as if they cannot be bothered to check. See the Wikipedia article, where 57 is called the Grothendieck prime, as a math joke about the most famous abstract-thinking mathematician.

Monday, September 18, 2023

Big Oil Sued for Studying Uncertainty

There are lawsuits against Big Oil for supposedly deceiving us about climage change.

The London Guardian reports:

xxonMobil executives privately sought to undermine climate science even after the oil and gas giant publicly acknowledged the link between fossil fuel emissions and climate change, according to previously unreported documents revealed by the Wall Street Journal.

The new revelations are based on previously unreported documents subpoenaed by New York’s attorney general as part of an investigation into the company announced in 2015. They add to a slew of documents that record a decades-long misinformation campaign waged by Exxon, which are cited in a growing number of state and municipal lawsuits against big oil. ...

In 2008, Exxon pledged to stop funding climate-denier groups. But that very same year, company leadership said it would support the company in directing a scientist to help the nation’s top oil and gas lobbying group write a paper about the “uncertainty” of measuring greenhouse gas emissions.

The company’s preoccupation with climate uncertainty continued. Before one meeting with company scientists in 2012, one researcher expressed an interest in finding “‘skeptic’ arguments that we consider to be not yet disproven”.

Wow, there is some confusion here on what science is all about.

There cannot be anything wrong with an oil company hiring a scientist to write a paper on the uncertainty of measurements. Every science paper should estimate the uncertainty of whatever is being measured. And they should all examine skeptic arguments.

Of course industry-sponsored research may not agree with environmentalist-sponsored research. It should all be published anyway.

Thursday, September 14, 2023

White Males no longer welcome in Academia

Physicist Larry Krauss has the story:
Let’s start at the top. Six of the eight Ivy League universities—Harvard, Brown, Penn, Cornell, Dartmouth, and Columbia—now have female presidents, as do UC Berkeley and MIT.

MIT is a particularly striking case. Despite comprising many traditionally male-dominated STEM disciplines, its upper management team is largely female. The head of the MIT Corporation, the President, the Director of Research, the Provost, the Chancellor, and the Dean of Science are all women. The Institute’s core discipline, the School of Engineering, consists of eight departments, five of which are led by women. This is clearly not a coincidence, nor is it likely, given the demographics of the place, that this is simply the result of choosing the best people for those jobs. ...

We can see the results of this in the California State universities: the undergraduate student body at Cal State Los Angeles is 59 percent female, and 67 percent of its graduate students are female; Sonoma State is 63 percent female; San Diego State is 57 percent female; Humboldt State is 58 percent female; Cal State East Bay is 61 percent female. Nationwide, around 60 percent of students are female. ...

It is no surprise to see a high prevalence of Indian and Chinese students among this group, as East and South Asians have been outperforming white students for some time. What is perhaps more surprising is that the finalists included only one young Caucasian male.

A century ago, there were top-level respected female scientists, like Marie Curie and Emmy Noether. Supposedly women dropped out to have babies in the 1950s. By the 1970s, top colleges were aggressively recruiting female stusents and faculty. Now, 50 years later, there is no need.

Monday, September 11, 2023

Ehrenfest paradox and the Psychological Contraction

The Ehrenfest paradox was to apply special relativity to a rotating disc, and finding some geometrical oddities. It requires non-Euclidean geometry to resolve it. It is a good test of how well early physicists understood relativity. Einstein wrote about it many times.

Einstein historian Tilman Sauer wrote in 2007 about Einstein correspondence with Vladimir Varićak:

These were rebutted by Einstein in a response of 28 February 1910 in which he also, with reference to Ehrenfest’s paradox, referred to the rigidly rotating disk as the “most interesting problem” that the theory of relativity would presently have to offer. In his next two letters, dated 5 and 11 April 1910 respectively, Einstein argued against the existence of rigid bodies invoking the impossibility of superluminal signalling, and also discussed the rigidly rotating disk. A resolution of Ehrenfest’s paradox, suggested by Vari´cak, in terms of a distortion of the radial lines so as to preserve the ratio of π with the Lorentz contracted circumference, was called interesting but not viable. The radial and tangential lines would not be orthogonal in spite of the fact that an inertial observer comoving with a circumferential point would only see a pure rotation of the disk’s neighborhood.

About a year later, Einstein and Vari´cak corresponded once more. Vari´cak had contributed to the polemic between Ehrenfest and von Ignatowsky by suggesting a distinction between ‘real’ and ‘apparent’ length contraction. The reality of relativistic length contraction was discussed in terms of Ehrenfest’s tracing paper experiment, but for linear relative motion. According to Vari´cak, the experiment would show that the contraction is only a psychological effect whereas Einstein argued that the effect will be observable in the distance of the recorded marker positions. When Vari´cak published his note, Einstein responded with a brief rebuttal.17

Sauer is trying to be favorable to Einstein. Varicak wrote several papers on applying non-Euclidean geometry to special relativity, and Einstein rejected this approach. Varicak's explanation was viable, and better than Einstein's.

The idea that the Lorentz contraction was "psychological" appears to have originated in this 1909 American article:

Let us emphasize once more, that these changes in the units of time and length, as well as the changes in the units of mass, force, and energy which we are about to discuss, possess in a certain sense a purely factitious significance; although, as we shall show, this is equally true of other universally accepted physical conceptions. We are only justified in speaking of a body in motion when we have in mind some definite though arbitrarily chosen point as a point of rest. The distortion of a moving body is not a physical change in the body itself, but is a scientific fiction.

When Lorentz first advanced the idea that an electron, or in fact any moving body, is shortened in the line of its motion, he pictured a real ​distortion of the body in consequence of a real motion through a stationary ether, and his theory has aroused considerable discussion as to the nature of the forces which would be necessary to produce such a deformation. The point of view first advanced by Einstein, which we have here adopted, is radically different. Absolute motion has no significance. Imagine an electron and a number of observers moving in different directions with respect to it. To each observer, naïvely considering himself to be at rest, the electron will appear shortened in a different direction and by a different amount; but the physical condition of the electron obviously does not depend upon the state of mind of the observers.

Although these changes in the units of space and time appear in a certain sense psychological, we adopt them rather than abandon completely the fundamental conceptions of space, time, and velocity, upon which the science of physics now rests. At present there appears no other alternative.

This is all completely correct, but rejected by Einstein. Based on this paper, Varicak attributes the new view of space and time to Einstein, but Einstein published a rebuttal denying that his viewpoint was any different from Lorentz's.

The issue here is: Do rigid bodies really contract, or is the apparent contraction just an artifact of the non-euclidean geometry of spacetime?

Lorentz would say the former, while Minkowski proposed the latter in 1907 and that has been the preferred interpretation in textbooks ever since.

Poincare also proposed the latter in 1905, but said that the views were mathematically equivalent, so he would say that they were both correct. In his view, the contraction is "only apparent, something which would be due to our methods of ​measurement".

What would Einstein say? The latter view seemed to be attributed to him in the above 1909 paper, and repeated by Varicak in his 1911 paper on the Ehrenfest paradox, which says, "contraction is only an apparent, subjective phenomenon, caused by the manner of our clock-regulation and length-measurement." We can be pretty sure the attribution is incorrect, because Einstein published a rebuttal to that 1911 paper. Einstein corresponded with Varicak and was fascinated by the subject, so I think he was clearly favoring Lorentz's view during 1905-1911, at least. He could have accepted credit for the geometrical view, but he vigorously denied it.

This is the clearest evidence that Einstein did not understand and accept special relativity, as it has been explained by Minkowski in 1907 and every textbook since.

Marco Giovanelli has written a new paper on Appearance and Reality: Einstein and the Early Debate on the Reality of Length Contraction. It has a lot of historical info on this issue.

In Einstein’s theory, length contraction is a kinematic effect that depends on the definition of simultaneity; however, it is just as real as length contraction in Lorentz’s theory, where it is conceived as a dynamic effect due to the motion of a rod through the ether. The two theories derive the same quantitative measure for the contraction through different routes. To explain this point, Einstein resorts to his beloved comparison between relativity theory and thermodynamics:
One cannot ask whether the contraction should be understood as a consequence of the modification of molecular forces caused by motion or as a kinematic consequence arising from the foundations of the theory of relativity. Both points of view are justified. [letter to Varicak, 1911]
He also relates it to Bell's spaceship paradox.

Einstein is correct that different points of view about the contraction are justified. The first view, "a consequence of the modification of molecular forces caused by motion", is usually attributed to Lorentz. The second view refers to Einstein's 1905 two-postulate approach. Einstein appears to say that it is meaningless to say which is better.

The approaches were logically equivalent. Lorentz started from the Michelson-Morley experiment and Maxwell's equations, and deduced the contraction. Einstein postulated the constant speed of light and the Poincare relativity principle, and made the same deductions. Neither really analyzed the molecular forces. Lorentz did correctly believe that the forces were electromagnetic, and hence subject to his transformations.

What is missing from Einstein's 1911 comments is any recognition of the non-euclidean geometry view put forward by Poincare in 1905 and Minkowski in 1907.

In the writings of those years, Einstein appears to have still been reluctant to embrace Minkowski’s (1909) reduction of kinematics to geometry. Indeed, he presented the key result of relativity as the distinction between the geometric and the kinematic configuration of a body (Einstein, 1908, 1910, 1911a).29 (In modern terms, the distinction between the proper and the coordinate shape of a body.)
Einstein would often argue that his approach was not ad hoc. and hence superior to Lorentz's.
Lorentz complained that, in a popular article, Einstein had referred to the Lorentz-Fitzgerald contraction as a “hypotheses invented ad hoc” (Einstein, 1915, 707) to neutralize Michelson’s result (Lorentz to Einstein, Jan. 1, 1915; CPAE, Vol. 8, Doc. 43). Lorentz argued that such an objection might have applied to his first formulation of the contraction hypothesis. At a later stage, however, reacting to Poincaré’s criticism, Lorentz provided a coherent theory of matter from which length contraction can be derived as a consequence. Lorentz regretted not having stressed this more, as it would have left less of an impression of being an ad hoc hypothesis (Lorentz to Einstein, Jan. 1, 1915; CPAE, Vol. 8, Doc. 43).

Lorentz argued that Einstein’s approach was somewhat misleading from a “didactical” point of view (Lorentz to Einstein, Jan. 1, 1915; CPAE, Vol. 8, Doc. 43). If the contrac- tion is derived as a consequence of the new kinematics “and nothing more is added in commentary”, it could give rise to the suspicion that “only ‘apparent’ [scheinbare] things were involved here and not a real [wirkliche] physical phenomenon” (Lorentz to Einstein, Jan. 1, 1915; CPAE, Vol. 8, Doc. 43). ...

Once again, Einstein replied by alluding to a more subtle dialectic between the real and the apparent:

... Regarding the erroneous view that the Lorentz contraction was ‘merely apparent,’ [scheinbar] I am not free from guilt, without ever having myself lapsed into that error. It is real [wirklich], i.e., measurable with rods and clocks, and at the same time apparent [scheinbar] to the extent that it is not present for the co-moving observers.39 (Einstein to Lorentz, Jan. 23, 1915; CPAE, Vol. 8, Doc. 47)

So Einstein's differences with Lorentz were slight, and mostly have to do with Einstein trying to take credit for what Lorentz had already done. Einstein never says Lorentz was wrong, but he does say that the geometrical view is wrong:
Perhaps Mr. Varičak might admit—and thus in a way retract his assertion—that the Lorentz contraction is a ‘subjective phenomenon.’ But perhaps he might cling to the view that the Lorentz contraction has its roots solely in the arbitrary stipulations about the ‘manner of our clock regulation and length measurement.’ The following thought experiment shows the extent to which this view cannot be maintained. (Einstein, 1911d, 509)
Einstein is wrong here. The modern view is that our manner of clock regulation and length measurement corresponds to a non-euclidean geometry on spacetime. The contraction is subjective in the sense that it only shows up in the comparison between the true non-euclidean geometry and the more intuitive Euclidean geometry. That is what Poincare said in 1905, Minkowski in 1907, and Varicak in 1911. Einstein did not understand it.

I have posted many criticisms of Einstein's lack of originality. Many of these are not new, as Whittaker argued in a 1953 book that Lorentz and Poincare had all of special relativity. Lorentz said back in 1909 that Einstein just postulated what was previously proved. But I have not seen anyone else make the point I make here. That the modern geometrical view of relativity was explicitly rejected by Einstein as late as 1911.

Even when experts were starting to credit Einstein with the new geometrical view of relativity, he was adamantly denying it.

There are Einstein fans who claim that Lorentz and Poincare never really understood special relativity, based on post-1905 lectures or writings that supposedly showed confusion about fundamentals. Usually the argument is that Poincare occasionally chose an preferred reference frame. But of course choosing a preferred frame is not incorrect or contrary to modern thinking. Everyone chooses preferred frames all the time.

Einstein is not wrong either when he clings to a Lorentzian anti-geometry view. But he is contrary to modern thinking, and he was wrong to say that Varicak's "view cannot be maintained."

Einstein did eventually accept non-euclidean geometry, as Grossmann, Levi-Civita, and Hilbert convinced him that it was necessary for general relativity in 1913-1916. But he never really accepted the geometric view, and never accepted Varicak's argument.

If you are a physicist reading this, you might complain that I am a mathematician siding with other mathematicians -- Poincare, Varicak, Hilbert, Whittaker -- against the great physicist Einstein. Einstein's genius was in Physics, not Mathematics, and maybe it is unfair to judge him by mathematicians. Maybe so, but I am discussing the mathematical understanding of relativity, and Einstein's was deficient.

Einstein's special relativity did not have anything physically new. The physical predictions were the same as Lorentz's, and physicists called it the Lorentz-Einstein theory. The only appeal was his mathematical derivation. So yes, I think it is fair to judge his mathematics by mathematical standards.

It is hard to understand just what Einstein's view was. Giovanelli writes:

What is clear is that in the following months, Einstein made the first published reference to Ehrenfest’s thought experiment in a paper on gravitation published in February, where he pointed out that the geometry of the rotating disk is non-Euclidean (Einstein, 1912a, 356). Since a rotating system is equivalent to a system at rest in a suitable gravitational field, Einstein (1912b, 1064) soon began to realize that the traditional physical interpretation of coordinates as readings on rods and clocks could not be maintained in the presence of gravitation (see Stachel, 1989, for more detail).

After returning to Zurich, Einstein famously found a solution to the conundrum with the help of his friend Marcel Grossman. However, his struggles with the meaning of coordinates in physics continued during the Berlin period (Giovanelli, 2021).

In modern terminology, spacetime is a 4-dimensional manifold, with many coordinate systems possible, not necessarily having physical significance. Grossmann and others tried to convince him to use covariant tensors, but during 1913-15 he was persuaded by his Hole Argument that such things were impossible. It appears that Hilbert enlightened him to use covariant equations.

In the Lorentzian view, bodies really contract. In the Poincare-Minkowski-Varicak mathematician view, the contraction is an artifact of using coordinates that do not match the geometry. Einstein did not seem to be fully in either camp, and saying only that the contraction is required by the kinematics.

Here is an argument from the above 1909 article:

If our ideas possess a certain degree of artificiality, this is also true of others which have long since been adopted into mechanics. The apparent change in rate of a moving clock, and the apparent change in length and mass of a moving body, are completely analogous to that apparent change in energy of a body in motion, which we have long been accustomed to call its kinetic energy.
An object at rest has no kinetic energy. If you watch it from a moving frame, all of a sudden it has kinetic energy. Where did that energy come from? The energy is not real. It is just an artifact of the coordinates being used. It is just psychological. Not imaginary. If a brick hits you in the head, your pain will be real. The energy is measurable.

The best way to make sense of this is to say spacetime is a manifold with a non-euclidean geometry.

Tuesday, September 5, 2023

Celebrating the Prize for Bell Experiments

A new paper starts:
The 2022 Physics Nobel Prize was not quite like any other. While the Nobel prizes in physics are always of interest to the physics community, by a rule, they are merely a matter of curiosity for the general public. However, the latest Nobel award should pertain to all of us, ir- respective of the profession, and remind us that it’s been a time to rethink our basic worldviews.
No, it did not change anyone's worldview. The experiments only confirmed what had been conventional wisdom since 1930.
While there might not be a consensus on whether it is the idea of separability (locality) or reality that should give in, or maybe that we live in countless parallel universes, there is an absolute consensus in contemporary physics that the hopes of ever returning to anything resembling classical physics are long over.
Again, classical physics has been rejected since 1930.
Einstein, who still believed that the universe is something akin to a huge deterministic clockwork mechanism, was essentially the sole exception among this elite – and his expectations in this context were, as we have seen, explicitly proven wrong.
That's right, Einstein was one of the last holdouts, clinging to classical ideas that everyone else had rejected.
And, finally, once it was experimentally established that Bell’s inequalities are indeed violated in our universe, we encountered a truly unique situation in the entire history of science. Never before has humanity been in the necessity to abandon an entire paradigm because of a proof of mathematical nature that could guarantee that our previous scientific view – in a quite broad sense – was plainly wrong. ... We are speaking of abandoning the entire scientific worldview that was absolutely dominant for a few centuries (at least in exact sciences). It was dominant to the extent that we, for the most part, tacitly understood it surely must be the correct one, so that rarely anyone even bothered to question it.
People were saying this in around 1930, as the pre-1925 classical physics had been abandoned on atomic scales.

The paper quotes historical physicists, and discusses a range of Bell issues from many-worlds to superdeterminism.

It is indeed remarkable that everyone accepted the new quantum theory between 1925 and 1930. Everyone but Einstein. But it is old news, as has been for 90 years. It is almost as if someone concocted a new way to test relativity theory, and then all the science journals published essays about the reality of time.

Monday, August 28, 2023

We are not Empty

From the new movie:
Kitty Oppenheimer: Can you explain quantum mechanics to me?
  • J. Robert Oppenheimer: Well, this glass, this drink, this counter top, uhh.. our bodies, all of it. It's mostly empty space. Groupings of tiny energy waves bound together.
  • Kitty Oppenheimer: By what?
  • J. Robert Oppenheimer: Forces of attraction strong enough to convince us
  • [that]
  • J. Robert Oppenheimer: matter is solid, to stop my body passing through yours.
  • [gently places his palm against hers]
  • Mario Barbatti says this is all a big misconception, and the empty atom is a myth.

    I agree. Electrons can seem like point particles when observed, but in atoms they fill up orbitals.

    People like to say that solid matter is mostly empty space, but that is like saying fire is mostly cold. It is nonsense.

    People say galaxies are mostly empty space because they can collide, and the inhabitants barely notice as they pass through each other. But solid objects cannot pass through each other.

    Monday, August 21, 2023

    The Historical Acceptance of Negative Numbers

    Mathematician tries to trace the acceptance of negative numbers, in 2010 essay:
    I was flabbergasted when I first read Augustus De Morgan’s writings about negative numbers1. For example, in the Penny Cyclopedia of 1843, to which he contributed many articles, he wrote in the article Negative and Impossible Quantities:
    It is not our intention to follow the earlier algebraists through their different uses of negative numbers. These creations of algebra retained their existence, in the face of the obvious deficiency of rational explanation which characterized every attempt at their theory.
    In fact, he spent much of his life, first showing how equations with these meaningless negative numbers could be reworked so as to assert honest facts involving only positive numbers and, later, working slowly towards a definition of abstract rings and fields, the ideas which he felt were the only way to build a fully satisfactory theory of negative numbers. On the other hand, every school child today is taught in fourth and fifth grade about negative numbers and how to do arithm
    Wallis and Newton had fully accepted negative numbers by 1685.

    Closely related is the discovery of zero.

    It is repeated everywhere that the Indians invented zero and place notation and that the Arabs learned it from them and later transmitted this to Europe. It’s bizarre that such a misunderstanding should be widespread but in fact, the Babylonians invented place notation (albeit using base 60) and their arithmetic was used by many Greeks, e.g. Ptolemy. I hope I have made the case that the most substantial arithmetic discovery of the Indians – and independently the Chinese – was not merely that of zero but the discovery of negative numbers. Sadly this discovery was not absorbed in any but a superficial way by the Arabs.
    His essay has examples of famous mathematicians being leery about negative numbers. Also imaginary numbers, infinities, and other constructs.

    I am not sure how well these are accepted today, outside of Mathematics. If you read the business section of the newspaper, a company's loss is just a negative profit, but the articles hardly every express it that way.

    Friday, August 18, 2023

    FQXi Essay Contest Winners

    FQXi has announced its essay contest winners. They were supposed to answer: How Could Science be Different?

    First place is a tie between a silly feminist rant:

    Before delving into the discussion on science and feminism, we cannot avoid the issue of the absence of women in scientific research. It is a revealing issue and a good starting point. I prefer to leave it to other readings to discuss how millennia of patriarchy have led to this.

    Here, I want to start with today's data and from my perspective, wondering where women are in scientific research. For example, which country in the world has the highest percentage of women in the research world? The answer may surprise you. The first is Myanmar with 75.6%, followed by Venezuela with 61.4%, Azerbaijan with 59%, Mongolia with 57.5%, Tunisia with 55.4%... The first European country on the list is North Macedonia with 52.3%, while countries that prominently feature in the European scientific landscape in terms of resources and visibility such as Germany, France, and the Netherlands only reach a measly 28.0%, 27.0%, and 25.8%, respectively.

    No, not surprising. Countries fail to accomplish decent scientific research, if they let women dominate it.

    The other winning essay argues that science was able to distinguish subject and object from 1619 to 1925.

    The idea that we are Cartesian subjects, locked up in the ivory towers of our brains, unable to truly know anything or anyone outside of ourselves, has left us in a hyper-individualistic, solipsistic state, where nothing and no one is quite real, and nothing exactly matters. On the flipside, the idea that the world is made of objects, bumping around mechanistically in third person has allowed us to treat the planet as a resource rather than an unfolding, creative, and crucial part of our own embodied existence.

    ... how could science be different? is this: Science is different when philosophy is different. Science could have been different had Descartes never split the world, and science needs to be different for us to put it back together.

    This essay was more interesting to read, but still did not really tell us how science could be different.

    What these essays have in common is that they both do a lot of name-dropping. They both cite a lot of famous scholars. They also have a lot of vague and incoherent ramblings about how science is too objective.

    Monday, August 14, 2023

    The Truth behind Einstein Historian Stachel

    I just found this video:
    Christopher Jon Bjerknes celebrates the 20th anniversary of the release of his historic book ALBERT EINSTEIN THE INCORRIGIBLE PLAGIARIST and discusses his groundbreaking work on the history of the theory of relativity
    He says that the leading Einstein historian John Stachel was a Communist, and the son of the famous Jewish Communist Jack Stachel. Wikipedia does not mention the connection. I do not know why. According to the video, John Stachel was a hard-core Marxist Communist who spent several years supporting his father's Communist causes. His father went to prison for this work.

    Einstein was a member of Communist front organizations, and also was active in Jewish and Zionist causes.

    Wikipedia says:

    John Stachel (1995)[B 18] argued that there is a debate over the respective contributions of Lorentz, Poincaré and Einstein to relativity. These questions depend on the definition of relativity, and Stachel argued that kinematics and the new view of space and time is the core of special relativity, and dynamical theories must be formulated in accordance with this scheme. Based on this definition, Einstein is the main originator of the modern understanding of special relativity. In his opinion, Lorentz interpreted the Lorentz transformation only as a mathematical device, while Poincaré's thinking was much nearer to the modern understanding of relativity. Yet Poincaré still believed in the dynamical effects of the aether and distinguished between observers being at rest or in motion with respect to it. Stachel wrote: "He never organized his many brilliant insights into a coherent theory that resolutely discarded the aether and the absolute time or transcended its electrodynamic origins to derive a new kinematics of space and time on a formulation of the relativity principle that makes no reference to the ether".
    I had wondered how anyone could say such nonsense. Him being a Marxist doubletalker seems like a good explanation.

    The new view of space and time at the core of special relativity is Minkowski spacetime, and Einstein had nothing to do with it. Minkowski got it from Poincare, Poincare wrote it before EInstein wrote anything.

    Lorentz wrote about his transformations as explaining experiments. They were not only mathematical devices. Lorentz's papers were much more directly tied to experiment than Einstein's.

    Poincare did not believe that the aether had any observable effects, and argued that it would be discared as unnecessary. Einstein denied that he discarded the aether. Poincare was also the one to formulate the relativity principle, without reference to the aether, years ahead of Einstein.

    Stachel obviously knows all this. He studied Einstein all his life. He is just like one of those academic Marxists spewing complex lies to promote their ideological goals.

    Bjerknes tells a story about how someone destroyed a half-page from a Hilbert paper in order to give credit to Einstein for general relativity field equations. It might have been Stachel, it is not clear. According to the video, Stachel admits that he helped to cover it up.

    Friday, August 11, 2023

    Bose Discovered Photon Spin in 1924

    Bose–Einstein statistics are crucial in quantum mechanics for describing systems of multiple identical bosons, like photons. Wonder what Einstein had to do with it?

    A new paper tells the story:

    As we approach the centenary of the discovery of quantum statistics in 1924, it is important to revisit Bose’s original derivation of Planck’s law usually ignored in most standard presentations of Bose-Einstein statistics. It introduced not only the novel concept of the indistinguishability of photons but also of their intrinsic spin, a fact unknown to most physicists. ...

    On June 4, 1924 he sent a short paper ‘Planck’s Law and the Light-Quantum Hypothesis’ to Albert Einstein with the humble request, ‘You will see that I have tried to deduce the co- efficient 8πν2/c3 in Planck’s law independent of the classical electrodynamics, only assuming that the ultimate elementary regions in the Phase space have the content h3. I do not know sufficient German to translate the paper. If you think the paper worth publication, I shall be grateful if you arrange its publication in Zeitschrift f¨ur Physik’.

    In a post card dated 2nd July, 1924 Einstein wrote to Bose, ‘Dear Colleaugue, I have translated your work ... It signifies an important step forward and I liked it very much ...... You are the first to derive the factor quantum theoretically, even though because of the polarization factor 2 not wholly rigorously. It is a beautiful step forward’

    Bose not only derived the Planck law using the statistics, he descovered spin to account for that factor of 2. He later explained:
    ‘You know’, he said, ‘my deduction of the Planck law had a factor of 2 missing. So I proposed that it came from the fact that the photon had a spin, and that it can spin either parallel or antiparallel to its direction of motion. That would give the additional factor of 2. But the old man (meaning Einstein) crossed it out (‘budho k´et´e dil´e’ in Bengali, his mother tongue) and said it was not necessary to talk about spin, the factor of 2 comes from the two states of polarization of light.’
    Today we call this Bose-Einstein because Einstein translated the paper from English to German, recommended it for publication, and deleted one of the brilliant ideas.

    Now we know spin and polarization are the same thing, but we say spin for particles, and polarization for waves.

    Quantum spin has a long history of physicists denying that it was real. According to Wikipedia, W. Pauli introduced it in 1924 as an electron having "two-valuedness not describable classically". He first denied that it was spin, and then published a quantum spin theory in 1927.

    Tuesday, August 8, 2023

    Carroll Trashes Copenhagen Interpretation

    Physicist Sean M. Carroll posted his monthly AMA, and he answers a question about interpretations of quantum mechanics.

    He trashes the Copenhagen interpretation as being too vague and incoherent to be worthy of serious consideration.

    He says he favors the many-worlds interpretation, and then Bohmian mechanics as a distant second. He is so strongly in favor of many-worlds, that he says it is not worth time thinking about interpretations.

    This opinion is so crazy that it discredits much of what he says.

    Copenhagen is what the textbooks teach. We have about a trillion dollar sector based on QM, notably semiconductors and lasers, and it all uses Copenhagen. If that is not a scientific theory worthy of consideration, then something is wrong with your definition of theory.

    No one has ever used many-worlds or Bohmian to do a practical QM calculation. That is, $0 based on it.

    He is like someone saying that everyone should use teleportation for transportation, because cars do not meet his definition of a vehicle.

    In other podcasts, he argues that MWI is the most testable, because it could be refuting by refuting the Schroedinger equation. This is wrong because those textbook applications of QM use that equation, but do not use many-worlds. His many-worlds are not observable, so no one could ever say whether they obey equations or not.

    He previously had a long rambling over-opinionated podcast on whether there is a crisis in Physics. I tried to listen, but it was boring and stupid.

    Here is a recent paper on How Bohr's Copenhagen interpretation is realist and solves the measurement problem. It looks at what Bohr actually said and wrote, and says he did not believe that Schroedinger's cat was really in a superposition of alive and dead states, or some of the other views attributed to him, and that he had a sensible view of the real world.

    Wednesday, August 2, 2023

    Minkowski Space was the Revolution

    From a new paper on relativity:
    So, Copernicus, and later Galileo, revolutionized our view on movement, allowing us to become aware of the existence of movements that until then we were unaware of, and this not because they were hidden. As Edgar Allen Poe famously emphasized, the best place to hide something is often right out in the open. We humans were all openly moving together with the planet, but precisely because of that, we were not able to detect the planet’s motion. ...

    Einstein’s relativity is the next great revolution about motion, but similarly to Copernican revolution its acceptance does not appear to be easy, and it is the thesis we defend in this article that it has not been fully achieved, because what we physicists have not fully realized is that ‘Mikowski space’ is as real as its little brother ‘Newton space’, hence the material entities move much more and rather differently than the way Copernicus told us.

    The paper is really about Minkowski space, not Einstein's relativity. They are not the same.

    Minkowski's papers of 1907-8 built on those of Lorentz and Poincare. It is not clear that he learned anything from Einstein's famous 1905 paper.

    Poincare wrote in 1905 that he was proposing something revolutionary, like Copernicus. Minkowski also wrote that his spacetime was a whole new way of looking at the world. einstein rejected Minkowski's view for several years.

    Einstein did not claim any such radical break from the past. His theory was called Lorentz-Einstein theory, and both Lorentz and Einstein always denied that there were any significant differences between their relativity theories.

    Thursday, July 27, 2023

    Arguing for Retrocausality

    Aeon essay:
    Almost a century ago, physics produced a problem child, astonishingly successful yet profoundly puzzling. Now, just in time for its 100th birthday, we think we’ve found a simple diagnosis of its central eccentricity. ...

    The strangeness has a name – it’s called entanglement – but it is still poorly understood. Why does the quantum world behave this strange way? We think we’ve solved a central piece of this puzzle. ...

    More recently, we ourselves have written about the advantages of retrocausal approaches to QM, both in avoiding action at a distance, and in respecting ‘time-symmetry’, the principle that the microworld doesn’t care about the distinction between past and future. But an additional striking advantage of retrocausality seems to have been missed. It suggests a simple mechanism for ‘the characteristic trait of quantum mechanics’ (Schrödinger), ‘its weirdest feature’ (Weinberg) – in other words, for the strange connections between separated systems called quantum entanglement.

    It is amazing what mental gymnastics people will do to avoid accepting the quantum mechanics of 1927.

    The Heisenberg Uncertainty principle is a little strange, but these guys somehow think that it is better to assume that the future determines the past?

    Others prefer many-worlds, spooky action at a distance, or superdeterminism. They are all crazy.

    Finally, a note for readers who are worried that the cure is worse than the disease – that retrocausality opens the door to a menagerie of paradoxes and problems. Well spotted!

    Monday, July 17, 2023

    In Search of Quantum Utility in Computation

    Quantum supremacy has been claimed and attacked so many times in the last several years, it is hard to keep track of what we are supposed to think.

    Here is the latest from the expert:

    Speaking of making things common knowledge, several people asked me to blog about the recent IBM paper in Nature, “Evidence for the utility of quantum computing before fault tolerance.” So, uhh, consider it blogged about now! I was very happy to have the authors speak (by Zoom) in our UT Austin quantum computing group meeting. Much of the discussion focused on whether they were claiming a quantum advantage over classical, and how quantum computing could have “utility” if it doesn’t beat classical. Eventually I understood something like: no, they weren’t claiming a quantum advantage for their physics simulation, but they also hadn’t ruled out the possibility of quantum advantage (i.e., they didn’t know how to reproduce many of their data points in reasonable time on a classical computer), and they’d be happy if quantum advantage turned out to stand, but were also prepared for the possibility that it wouldn’t.

    And I also understood: we’re now in an era where we’re going to see more and more of this stuff: call it the “pass the popcorn” era of potential quantum speedups for physical simulation problems. And I’m totally fine with it—as long as people communicate about it honestly, as these authors took pains to.

    And then, a few days after our group meeting came three papers refuting the quantum speedup that was never claimed in the first place, by giving efficient classical simulations. And I was fine with that too.

    Scott Aaronson was probably the biggest proponent of quantum supremacy. He endorsed Google's announcement in 2019. Now he seems resigned to the possibility that the present state of uncertainty could go on for years, with researchers claiming quantum supremacy, and skeptics replicating the results on classical computers.

    Furthermore, he now admits the possibility that quantum computers could be built to have some utility, even if they are never shown to have any complexity advantage over classical computers.

    I remain a skeptic. Just to fully explain my position, I accept quantum mechanics. I accept Feynman's argument that quantum mechanical predictions cannot be simulated efficiently on a classical computer.

    This raises the possibility that a quantum system could be simulated on an analog quantum computer, and deliver an answer faster than digitally solving Schroedinger's equation. I accept that quantum computers could have some utility on such problems, and outperform digital simulations on a Turing machine.

    What I do not accept is that quantum mechanics has some sort of magic for improving the asymptotic complexity performance of ordinary digital computers on certain math problems. Maybe it will be proved someday, but I doubt it. If so, it is decades away, and current public key cryptography will be safe for a long time.

    Another Look at Bohr's Anti-Realist Realism

    de Ronde, Christiande Ronde writes in a new paper:
    Since its Greek origin, physics has been related to physis, namely, the totality of what is. The realist presupposition that gave birth to physics was the idea that theories provide knowledge about the logos (i.e., order) of reality through the creation of systematic, unified schemes capable to account for the multiplicity immanently found within experience (see for discussion [13, 14]). This was the case for more than two millennia of successful developments from Protagoras and Heraclitus to Plato and Aristotle, and then, up to modern times to Galileo and Newton. But even though modernity — with the creation of classical mechanics — could be regarded as the peak of the Greek theoretical realist program, this period can be also seen as the starting point of the anti-realist re-foundation of science. A process that would culminate in post-modern times, during the 20th century. As Karl Popper would famously describe the situation during the late 1950s:
    “Today the view of physical science founded by Osiander, Cardinal Bellarmino, and Bishop Berkeley, has won the battle without another shot being fired. Without any further debate over the philosophical issue, without producing any new argument, the instrumentalist view (as I shall call it) has become an accepted dogma. It may well now be called the ‘official view’ of physical theory since it is accepted by most of our leading theorists of physics (although neither by Einstein nor by Schrödinger). And it has become part of the current teaching of physics.” [43, pp. 99-100]
    Physical theories would then become to be regarded as an economy of ‘clicks’ in detectors not necessarily linked to the description of reality.
    Osiander is the one who wrote the preface to the 1543 Copernicus book, saying that astronomy models can be useful even the underlying motions are not true. He wrote that book's ideas were "not put forward to convince anyone that they are true, but merely to provide a reliable basis for computation." Bellarmino argued that Galileo had not actually proved the motion of the Earth. By 1950, everyone accepted that motion is relative.

    Bohr is the man famous for saying:

    There is no quantum world. There is only an abstract quantum physical description. It is wrong to think that the task of physics is to find out how nature is. Physics concerns what we can say about nature.
    People liked to put words in Bohr's mouth, so he may not have said exactly that.

    Apparently the philosophically issues over realism were not settled in 1950, as plenty of physicists and philosophers argue about it today. The word "realism" is a misomer, and the advocates of realism are usually trying to get us to believe in properties that cannot be observed. They are imaginary properties that help make a model work.

    Tuesday, July 11, 2023

    The Inexhaustible Nonsense of David Bohm

    A new paper tries to figure out whether a physicist was a determinist:
    If David Bohm is known for one thing, it is for developing a fully deterministic interpretation of quantum mechanics. ...

    On December 4, 1950, at the height of the cold war and the McCarthy era, Bohm was indicted for contempt of Congress, because of his affiliations with communism and his refusal to testify for the House Un-American Activities Committee (HUAC) (Freire 2019, 56-62). This led to him being suspended from his job at Princeton University. He had been a member of the communist party for a brief period in 1942, and although he had quickly become disappointed with the party, he had remained a Marxist. During the months he was suspended, Bohm had a lot of free time, which he used to develop an alternative interpretation of quantum physics (Bohm to Schatzman, 1952, in Besson 2018, 335).

    By July 1951, Bohm had sent his article, “A suggested interpretation of the quantum theory in terms of ‘hidden’ variables”, to Physical Review, where it was published in early 1952. In Bohm’s interpretation, which is similar to an earlier proposal by De Broglie, particles have a well-defined position and momentum at all times and thus a well-defined path, and their movement is guided by a quantum potential which is derived from the Schrödinger equation. This interpretation yields exactly the same predictions as the standard interpretation. It is indeed deterministic;

    They call it deterministic, but when it says a particle is in a particular place, it could really be miles away. QM predicts probablilities. If Bohm were really making the same predictions, then it would predict probabilities.

    Bohm sometimes called his interpretation "causal" byt it allows particles to be guided by action-at-a-distance from far-away ghosts. This is the opposite of what most people mean by causal.

    There is a Marxist element in Bohm’s conception of infinite levels of nature: Bohm himself directly connects it with dialectical materialism (Talbot 2017, 255). 4 In a later interview, Bohm said:
    I remember also, before leaving the United States, I picked up something in the Princeton library, some Soviet publication which mentioned Lenin saying that the electron was inexhaustible. (…). That sort of struck a chord because I said, ‘Well, not only the electron, but everything, all matter is inexhaustible’.5
    This refers to a passage from Lenin’s book Materialism and Empirio-criticism, in which Lenin argues against positivism. Lenin writes: “The electron is as inexhaustible as the atom, nature is infinite, but it infinitely exists” (Lenin 1947, 243). Also for Lenin, this meant that our knowledge of nature can never be complete. Bohm’s view of an infinite number of levels of nature was probably also influenced by Friedrich Engels, who also proposes a view according to which there are different levels of nature, with qualitatively new properties emerging at higher levels (Sheehan 1985, 34). Engels argues for materialism, but this is not a crude materialism but rather organicist and emergentist: there is always an emergence of qualitatively new properties. ...

    The book Causality and Chance in Modern Physics does not mention the names Engels, Marx, Lenin, Hegel, or the word ‘dialectical’, but it is very clearly based on dialectical materialism. In fact, in his correspondence from his time in Brazil, he mentions working on a book on dialectical materialism, which is probably this book (Talbot 2017, 291). ...

    Marxism is often associated with determinism, and especially with the idea that there are laws determining the development of society. But there are different schools in Marxist philosophy. Freire himself has pointed out that there was a variety of Marxist views on quantum physics,

    Bohm still has a cult following today. I am not sure why. He had a lot of bad ideas.

    Some people say quantum mechanics is nonlocal, because certain correlations cannot be explained by a classical theory. Bohm's theory really is nonlocal. Particles are influenced by distant ghosts. It contradicts almost everything we know about cause and effect.

    Einstein was also a determinist, a Zionist, and belonged to a bunch of Communist front organization. I do not know whether his leftist politics influenced his Physics.

    I prefer to judge Bohm and Einstein by their Physics. If you look to them for philosophical ideas, remember that these were terrible people with terrible politics.

    Update: There just appeared a similar paper, by different authors, also arguing that Bohm was anti-determinist, even though he is mostly famous for introducing a determinist alternative to quantum mechanics. It glosses over his Communism:
    After completing his PhD with Robert Oppenheimer at Berkeley in the 1940s and a post at the Institute of Advanced Studies in Princeton, in 1951, Bohm fell victim of the witch-hunt of McCarthyism because of his adherence to Marxism; this led him to a life of exile: firstly to Brazil, then to Israel, and finally to the UK, where he spent the rest of his life (see [25, 17] for biographies of Bohm).
    No, I don't think that he had anything to do with Sen. McCarthy, and I don't think McCarthy ever went after anyone for adhering to Marxism.

    I don't know why it matters whether Bohm was a determinist. Einstein was an avowed determinist. His opinions on the subject are not given much weight by either his fans or his detractors.

    Bohm has his followers at, and there is an upcoming conference on his ideas.

    Sunday, July 9, 2023

    Dr. Bee Plugs Superdeterminism Again

    Susan Hossenfelder is plugging superdeterminism again, on her weekly podcast:
    Why is quantum mechanics non-local? (I wish someone had told me this 20 years ago.)
    She correctly says that a lot of people say quantum mechanics is nonlocal, but by that, they mean that the wave function collapse is nonlocal. That is true, but not a physical nonlocality, she correctly says.

    She also correctly says that last year's Nobel Prize for Bell test experiments did not endorse any nonlocality, even though some reported it that way.

    Those experiments are consistent with:

    • Quantum mechanics, non-classical, local, Copenhagen
    • Nonlocal theories of hidden variables
    • Superdeterminism
    • Retrocausality
    • Many-worlds
    The latter four possibilities do not make any physical sense, but are mathematically possible, and some people like to talk about them.

    The only possibility ruled out by Bell tests is a local theory of classical hidden variables.

    Hossenfelder like superdeterminism, which in this video she calls "Violation of measurement independence". It means you can never randomize the inputs to an experiment, so you can never trust the outputs.

    She prefers superdeterminism to nonlocal theories of hidden variables. She acts as if those are the only two possibilities. However both have been rejected by almost everyone. It is a silly preference.

    I only post this because her podcasts get a lot of views, and people think that they are learning something. But she has fringe views that are contrary to almost all of modern science.

    Friday, July 7, 2023

    Simple Explanation of Relativity

    I got this from ChatGPT:
    Sure! I'd be happy to explain relativity to a 10-year-old. Here we go:

    Have you ever seen a fast-moving train pass by? When you're standing still on the platform, the train looks different to you than it does to someone sitting inside the train. That's because of something called relativity.

    Relativity is a fancy word that means things can look different depending on how fast you're moving. One important person who studied this was a scientist named Albert Einstein. He came up with two types of relativity: special relativity and general relativity.

    Special relativity talks about how things look when they move very, very fast, almost as fast as light. You see, nothing can move faster than light! Imagine you have a friend who's sitting in a spaceship and zooming past you at an incredible speed. If you could see inside the spaceship, you might notice something strange. Your friend's clock would be moving slower than yours, and even the shape of their spaceship might look different!

    General relativity, on the other hand, talks about how gravity affects things. Gravity is what keeps us on the ground and makes things fall down. According to Einstein's ideas, gravity is not just a force that pulls things, but it's also the way objects change the shape of space and time around them. So, if you had a really massive object like a planet or a star, it would make a dent in the space around it, kind of like a heavy ball sinking into a soft mattress.

    This bending of space and time is why objects move differently near really massive things. It's like when you roll a marble on a curved surface—it follows a different path than if it were on a flat surface. Planets move around the sun in curved paths because of this bending of space and time caused by the sun's gravity.

    So, in a nutshell, relativity is all about how things look and move depending on how fast they're going or how strong gravity is. It's a pretty cool idea, and it helps scientists understand how the universe works!

    I hope that helps you understand relativity a little better! If you have any more questions, feel free to ask.

    I intend to post my own attempt. This is about what I expected, but I don't think it really explains relativity.

    Monday, July 3, 2023

    Stating Goedel's Theorem with Less Confusion

    Here are Gödel's incompleteness theorems, according to Wikipedia:
    The first incompleteness theorem states that no consistent system of axioms whose theorems can be listed by an effective procedure (i.e., an algorithm) is capable of proving all truths about the arithmetic of natural numbers. For any such consistent formal system, there will always be statements about natural numbers that are true, but that are unprovable within the system. The second incompleteness theorem, an extension of the first, shows that the system cannot demonstrate its own consistency.
    This is often summarized as saying that there are mathematical truths that cannot be proved.

    The obvious implication is that logical proof from axioms is inadequate, as apparently there are other truths, and someone found them to be true somehow.

    I think this is confusing. How do we know those truths are true, if no one can prove them?

    Maybe it would be better to say: If an arithmetic system has a computable set of axioms, then there will be statements that are true in some models of the axioms, and false in others.

    It is called "incompleteness", because a complete theory would be able to prove or disprove every statement from the axioms.

    The point is that statements are true or false in some model, and the axioms allow many possible models.

    You might think that arithmetic could be given a set of axioms such that only one model is possible. But you cannot, and that was known before Goedel.

    Some say that Goedel proved that the axiomatic method does not work. But that is incorrect. The axioms do let you prove all the statements that are true in all the models.

    This is an important point, that is worth repeating. The axiomatic method would be defective if there were some statements that were true in all the models, but still could not be proved from the axioms. Goedel proved that was not possible.

    Here is a typical account, from a new paper:

    In 1931 Kurt G ̈odel shook mathematics (literally) to its foundations with his incompleteness theorems:

    I) No consistent finite set of axioms and rules11 can be used to prove all true theorems about the integers.

    Even worse:
    II) No consistent finite set of axioms and rules can prove itself to be consistent!

    (1I am avoiding necessary subtleties. To be more precise, G ̈odel’s theorem can be stated as: The set of provable statements, although not recursive, is recursively enumerable, whereas the set of true statements is not.)

    This absolutely contradicts Hilbert’s dream that one could axiomatize so as to prove or disprove any given mathematical claim. The first is frustrating, while the second unveils inescapable limitations in the possible formulation of axiomatic theories and indeed mathematical foundations:

    Formal, axiomatic set theory ... cannot be a final foundational theory for mathematics, [yet] nothing else [can] be. Hallett [30]
    Or as von Neumann put it in 1930:
    There can be no rigorous justification for classical mathematics.
    So how do mathematicians deal with this existential crisis in their subject? The only answer is that they learn to live with it.12
    A theorem is a proved statement. So I do not agree that not all true theorems can be proved. The theorems can be proved, by definition.

    Nothing can prove itself consistent, because inconsistent theories can prove anything. Goedel adds a subtle twist to that, but proving self-consistency was hopeless anyway.

    I tried to find the source of the von Neumann quote, but failed. He did some excellent work on axiomatizing mathematics, and justifying modern mathematics, so I doubt that he was saying that his own work was not rigorous.

    This paper has a very nice summary of the recent history of mathematical proofs, including computer-assisted proofs and wrong proofs that got published. He even mentions a famous mathematician who thought that the foundation of math might be inconsistent!

    Wednesday, June 28, 2023

    Tim Maudlin on Quantum Hidden Variables

    New Sean M. Carroll podcast:
    Mindscape 241 | Tim Maudlin on Locality, Hidden Variables, and Quantum Foundations

    Last year's Nobel Prize for experimental tests of Bell's Theorem was the first Nobel in the foundations of quantum mechanics since Max Born in 1954. Quantum foundations is enjoying a bit of a resurgence, inspired in part by improving quantum technology but also by a realization that understanding quantum mechanics might help with other problems in physics (and be important in its own right). Tim Maudlin is a leading philosopher of physics and also a skeptic of the Everett interpretation. We discuss the logic behind hidden-variable approaches such as Bohmian mechanics, and also the broader question of the importance of the foundations of physics.

    Maudlin is one of the more sensible philosophers of Physics. However, I must caution you.

    Carroll is a big believer in Many-worlds theory. Maudlin is not. Maudlin pushes Bohmian mechanics.

    They both say the Nobel Prize committee, and a lot of others, get Bell's theorem wrong. I explained here why the Nobel site is correct.

    I do not agree that the 2022 Nobel Prize has anything to do with quantum foundations. The prize citation said that it was for experimental work only. Those experiments only confirmed what everyone thought for 90 years.

    Maudlin says many Bohmians take pride in the theory being just an interpretation of QM, making all the same predictions. However he argues that new research may show a way for Bohmian mechanics to signal faster than light. If so, and experimentally verified, it would contradict QM and relativity.

    Carroll and Maudlin both complain that Physics departments do not take these foundational issues seriously. That is because very little worthwhile work has emerged.

    They discuss whether electrons and photons are really particles or fields. Maudlin says some believe that the fermions are particles, while the bosons are fields. I am not sure it matters. They are either particles that act like fields, or fields that act like particles.

    R.P. Feynman was famously a big believer in particles, as illustrated by Feynman diagrams. Other say the diagrams are just shorthands for field theory calculations. Carroll claims that Feynman was motivated in part by field theories having a vacuum energy, and dark energy had not been discovered yet. Maudlin had not heard that. I am skeptical.

    Maudlin made some sensible comments about the arrow of time. I expected Carroll to disagree, but he chickened out.

    My main issue with Maudlin is with Bohmian QM. He says that the experts rejected it for faulty reasons. I say they were legitimate reasons.

    Bohmian QM is nonlocal. In it, an electron has a position along with a ghost function some distance away. You get the satisfaction of saying the election has a definite position, but it does not do you any good because it is controlled by the ghost function. You can never study an electron in isolation because there is some ghost a thousand miles away that you know nothing about. And the electron might not really be in its Bohmian position.

    Carroll said that "hidden variables" is a misnomer because they are observable, not hidden. It is not true. The electron ghost cannot be observed. Science would never make any progress if particle were really controlled by distant ghosts. The whole theory is like having an equation with a mathematical solution that must be rejected for being unphysical.

    Maudlin would answer that Bell's theorem, along with the Bell test experiments, have proved that QM is nonlocal, so I should just get over it and embrace nonlocality.

    Nope. Bell showed that a theory making certain assumptions must give results differing standard QM results, and therefore be false. Those assumptions are locality, hidden variables, no retrocausality, no superdeterminism, and single outcomes.

    Maudlin would say that those are all reasonable assumptions for any acceptable theory, except for locality, so locality must be wrong.

    Carroll says that single outcomes must be wrong, so he believes in Many-worlds.

    I say hidden variables only make sense in a classical pre-quantum theory, and that is the wrong assumption.

    The hidden variable theory assumption is sometimes called realism, commuting variables, classical mechanics, or Bell's beables. The idea is that an intuitively realistic theory would allow the theory to be defined by commuting variables, so that knowing one does not interfere with knowing the others. QM famously has position and momentum as noncommuting observables, so you cannot know both at the same time.

    The Einstein EPR Elements of Physical Reality folks say that a theory with Heisenberg uncertainty is incomplete. The Bell-heads say that they are just assuming objective reality.

    That would have seemed like a reasonable assumption before Heisenberg declared otherwise in 1925.

    Heisenberg uncertainty, and noncommuting observables, seem strange at first, but we see something similar in all wave phenomena. Light and electrons are readily observed to act like waves. So I accept that. All the alternatives, such as action-at-a-distance, are so bizarre that I do not even see how science would develop if they were true.

    Mainstream Physics textbooks say QM is obviously right, and there is no need to bother with the sort of theories that Bohm and Bell were pursuing.

    Monday, June 26, 2023

    The Need for Interpretations of Relativity

    I posted comments on a Sabine Hossenfelder video on relativity a few months ago. Now here is another:
    The REAL Reason You Don't Understand Relativity

    Think Relativity is confusing? Well, it's not just you -- even the experts can't seem to agree on its meaning, and often get basic facts about the formalism completely wrong. Here, we critique one such renowned professional who, in claiming to be clarifying the standardized theory of relativity, turns out to actually be promoting a misguided personal interpretation. What is this expert's confusion exactly, and why are such misconceptions so prevalent amongst the physics community?

    Indeed, be cautious of posturers, gaslighters, stigmatizers, and Giordano-Bruno-burners who want to convince you that your inability to understand Relativity stems from your own deficient reasoning -- because when even the experts can't agree, you know there is something up...

    It makes an argument that quantum mechanics is mysterious, so we have multiple interpretations, and we need the same for relativity.

    You might say that the textbooks already provide two interpretations: Lorentzian and Einsteinian.

    It points out that Einstein's interpretation is confused. He rejected the aether, and then endorsed it years later. He rejected geometrization of spacetime. He had a peculiar explanation of the twin paradox.

    It also finds Hossenfelder\s explanation confusing.

    I am not sure where this guy is going with this argument. He promises another video to explain.

    The Wikipedia page on Lorentz ether theory says that it pre-dates Einstein and is experimentally indistinguishable from Einstein's special relativity. So you could say that these are two different interpretations of the same theory.

    But then I would say that Minkowski's geometrical spacetime theory is another interpretation still. It is more different from Einstein's, as Einstein's is from Lorentz's. Maybe these should be understood as three different interpretations of the same theory.

    Wikipedia says:

    In the absence of any way to experimentally distinguish between LET and SR, SR is widely preferred over LET, due to the superfluous assumption of an undetectable aether in LET, and the validity of the relativity principle in LET seeming ad hoc or coincidental.
    Einstein is indeed preferred over Lorentz, but I don't think that the reasoning is correct. Lorentz was the one to say that the aether was superfluous. And it was Einstein who made the relativity principle a postulate, instead of justifying it.

    People don't like to talk about interpretations of relativity, because it undermines Einstein's genius. If all Einstein did was to find another interpretation of an accepted theory of Lorentz, then what is the big deal?
    Sometimes the explanation is that Lorentz based his theory on Michelson-Morley and other experiments, and so his theory was "ad hoc or coincidental". Einstein based his on Lorentz's principles, and so his was paradigm shifting and revolutionary. At the time, everyone thought that Einstein's theory was just an elaboration of Lorentz's ideas.

    Here is a Wikipedia explanation on why the FitzGerald contraction was ad hoc:
    This hypothesis was partly motivated by Oliver Heaviside's discovery in 1888 that electrostatic fields are contracting in the line of motion. But since there was no reason at that time to assume that binding forces in matter are of electric origin, length contraction of matter in motion with respect to the aether was considered an Ad hoc hypothesis.

    No reason to think? FitzGerald and Lorentz appear to have thought that, and it is true that the binding forces in solids are electric. I would call it brilliant reasoning, not ad hoc.

    Minkowski spacetime is widly preferred over Einstein's interpretation, as it gives a coherent geometrical view that explains the paradoxes. It was based on Lorentz and Poincare, not Einstein.

    The key principle that is usually used to distinguish Einstein from Lorentz is to say there is no aether, which means that there is no preferred frame. Both Lorentz and Einstein accept the relativity principle, so all inertial frames are equivalent, but Lorentz might prefer one somehow. Einstein would say that none can be preferred.

    I am not sure that this reflects Lorentz's and Einstein's views accurately, but regardless, there is no scientific difference. It does not mean anything to say that there is no preferred frame. It is only meaningful to say that there is a symmetry between the frames.

    The Cosmic Microwave Background radiation gives a preferred frame for what is motionless. It is not a counterexample to special relativity. So it is confusing to say that special relativity does not allow a preferred frame.

    It is also said that Lorentz had an electromagnetic interpretation, while Einstein had a kinematic interpretation. Lorentz believed that electromagnetism underlies everything. Poincare wrote in 1905 that he was adopting an interpretation that relativity was about how we measure space and time, and that this was different from Lorentz's interpretation. So Poincare was the first with a spacetime interpretation.

    The Minkowski geometrical interpretation says that all the special relativity mysteries derive from the non-euclidean geometry of spacetime. That has dominated the textbooks since about 1910, even though Einstein spoke out against it.

    I guess that relativity has three interpretations. Lorentz relativity, based on Maxwell's equations and Michelson-Morley experiment. Einstein relativity, based on postulating what Lorentz and Poincare proved. Poincare-Minkowski relativity, based on a non-euclidean geometry on spacetime.

    Here is a 2014 paper on Poincaré on clocks in motion, that was just posted online. It goes into Poincare's unpublished writings in detail, and argues that he had a somewhat different interpretation of relativity from Einstein and Minkowski.

    Thursday, June 22, 2023

    How the Left is Corrupting Science

    Evolutionists used to complain endlessly on how religious believers were corrupting science by promoting Intelligent Design. It was all a big hoax. It never got into the schools or academia in any significant way.

    The Skeptical Inquirer has a new paper:

    Biology faces a grave threat from “progressive” politics that are changing the way our work is done, delimiting areas of biology that are taboo and will not be funded by the government or published in scientific journals, stipulating what words biologists must avoid in their writing, and decreeing how biology is taught to students and communicated to other scientists and the public through the technical and popular press. We wrote this article not to argue that biology is dead, but to show how ideology is poisoning it. The science that has brought us so much progress and understanding—from the structure of DNA to the green revolution and the design of COVID-19 vaccines—is endangered by political dogma strangling our essential tradition of open research and scientific communication. And because much of what we discuss occurs within academic science, where many scientists are too cowed to speak their minds, the public is largely unfamiliar with these issues. Sadly, by the time they become apparent to everyone, it might be too late.
    Scientific papers are being blocked because of politics. We know the problem is bad, because papers are even being retracted because of leftist politics. Quillette reports:
    In 2020, five psychologists asked the editors of PNAS to retract their study of racial bias in police shootings. PNAS, which stands for the Proceedings of the National Academies of Science, is one of the most prestigious multidisciplinary journals in the world. Retraction is an outcome no scholar wishes to experience because it signifies a serious research error and, as such, entails considerable reputational damage.

    Some observers have suggested that the retraction was politically motivated. The study, which showed no evidence of racial bias in police shootings, had been used in political debates in ways that challenged calls for radical police reform; calls that had grown louder in the aftermath of the murder of George Floyd. Heather Mac Donald, a research fellow at the conservative Manhattan Institute, claimed the article was retracted because she had cited it in a congressional hearing and in essays published in the Wall Street Journal and other right-leaning media outlets.

    Another paper was retracted because it drew attention to Rapid Onset Gender Dysphoria (ROGD).

    This is being compared to Soviet Lysenkoism. At least the Soviets thought that what they were doing was right. And they were not grooming small children.

    Monday, June 19, 2023

    Carroll says Many-Worlds is Falsifiable

    Physicist Sean M. Carroll is a guest on another podcast, and goes into detail on some of his favorite topics, like the Many-Worlds theory of quantum mechanics. If you are a fan of his, you have probably heard it all. I just want to mention a couple of things where he is way off base.

    He says there are a lot of "bad worries" about Everett MW, such as it being not falsifiable. It postulates other worlds that we cannot visit.

    His answer is that you can believe in the worlds because they can be described by the Schroedinger equation. MW could be falsified by disproving that equation. He then refuses to give any more arguments against MW, as he just wants to say what is good about it.

    This argument is really stupid. Say you have a cat in a superposition of alive and dead. Then you observe it dead. QM nows says you have a wave function of a dead cat. MW says you still have a live cat in a parallel universe.

    Somehow that live cat has to be postulated and taken on faith, as it is impossible to observe.

    Carroll would presumably say that QM cannot predict whether the cat is alive or dead, so MW is not a postulate, but just continuing to believe in that uncertainty even after you determine that the cat is dead.

    Got it? Idiotic.

    Many-Worlds is just like the following fantasy: There is no such thing as probability. Every time you say that there is a chance of several things happening, and you see one, then what really happened was that the world split into parallel worlds, with each thing happening in its own world. All things happened, and probability is just the illusion of getting disconnected from the other worlds.

    He goes on the argue that last years Nobel Prize committee got this wrong:

    The Northern Irish physicist John Stewart Bell (1928–1990), who worked at CERN, the European particle physics laboratory, took a closer look at the problem. He discovered that there is a type of experiment that can determine whether the world is purely quantum mechanical, or whether there could be another description with hidden variables. If his experiment is repeated many times, all theories with hidden variables show a correlation between the results that must be lower than, or at most equal to, a specific value. This is called Bell’s inequality.
    And also:
    John Clauser developed John Bell’s ideas, leading to a practical experiment. When he took the measurements, they supported quantum mechanics by clearly violating a Bell inequality. This means that quantum mechanics cannot be replaced by a theory that uses hidden variables.
    This is saying that Bell showed how QM can be distinguished from classical theories, and the prize was given for the experiment confirming QM.

    Carroll says this is wrong because Bell believed in the Bohmian hidden variable theory. He says that theory is wrong, but some people believe in it, so experiments do not rule it out.

    Bell's Theorem is a mathematical theorem, so it has technical hypotheses. Violating the hypotheses gives loopholes. The main ones are: action-at-a-distance, retrocausality, multiple outcomes, and superdeterminism. These are all outlandish, and my guess is that no one on the Nobel committee believes in any of them. The Nobel description is correct. It just skips over the unphysical loopholes.

    There is no need to go into any of this in a Nobel press release. They are clear that the prize is only being given for experimental work, and not for any endorsement of theoretical interpretaions by Bell or anyone else. Clauser thought that he would disprove QM, but instead he confirmed it.

    Wednesday, June 14, 2023

    How Max Born got a Nobel Prize

    New paper, also here:
    Rovelli, Carlo and Heilbron, John (2023) Matrix Mechanics Mis-Prized: Max Born's Belated Nobelization. [Preprint]

    We examine evaluations of the contributions of Matrix Mechanics and Max Born to the formulation of quantum mechanics from Heisenberg's Helgoland paper of 1925 to Born's Nobel Prize of 1954. We point out that the process of evaluation is continuing in the light of recent interpretations of the theory that deemphasize the importance of the wave function.

    Their main argument is that Born should have gotten a Nobel Prize in the 1930s, along with Heisenberg, Schroedinger, and Dirac. He got one much later for the probabilistic interpretation, but quantum mechanics was already using probability and Born's comment did not add much.

    I am not sure, but it is an interesting account of the early history of quantum mechanics.

    Monday, June 12, 2023

    Kaku Continues to Push Quantum Supremacy

    The world's biggest Physics charlatan gave a Google lecture: Michio Kaku | Quantum Supremacy | Talks at Google.

    He is entertaining to listen to, but he wildly distorts everything.

    YouTube is trying to limit its reputation for spreading misinformation, slaps on this disclaimer:

    Climate change
    United Nations
    Climate change refers to long-term shifts in temperatures and weather patterns, mainly caused by human activities, especially the burning of fossil fuels.
    This is pointless. The talk is not even about climate.

    I think the disclaimer is misleading. Humans are increasing the CO2 in the atmosphere, and that is probably responsible for most of the recent global warming. But the climate has been changing for millions of years, and I am not sure what it means to be mainly caused by humans.

    Here a company eager for quantum computers:

    Rolls-Royce runs simulations of the computational fluid dynamics (CFD when designing a jet engine) of the engine. A modern jet engine is a spinning maw of blades pulling in air at hundreds of miles per hour. Understanding how air moves through the engine as the turbine spins thousands of times per second is no simple feat for even the most powerful classical computers. Today, Rolls-Royce engineers have to scale down the CFD models or accept a lower level of detail. The firm believes quantum computing could pave the way toward more powerful and accurate simulations.

    Sadly, the quantum computers we have at our disposal in 2023 aren't up to the challenge. The most capable quantum computers used in research have just a few dozen qubits (quantum bits), and the results aren't particularly reliable.

    So it is doing simulations on Nvidia GPUs, like everyone else. There is no chance that those simulations will ever move to quantum computers.

    Wednesday, June 7, 2023

    More Doubts about Google Quantum Supremacy

    Gil Kalai has written another paper challenging Google's 2019 paper that was titled, “Quantum supremacy using a programmable superconducting processor”.

    Google's paper was published in the British science journal Nature, and made a big splash.

    He says:

    the supremacy claim has largely (but not fully) been refuted. There are also doubts regarding the claim that the Sycamore 2019 experiment represents a “programmable processor” as the calibration process and other matters weaken this.
    I am sure the Google folks would say that better results are on the way, and will see no need to respond.

    Monday, June 5, 2023

    Dr. Bee Denies Free WIll

    Sabine Hossenfelder explains a lot of science well, but she goes off the rails when discussing a favorite topic this week:
    I don't believe in free will. This is why.
    She covers the main issues, but omits her wacky belief -- she believes in superdeterminism. That is the belief that everything has been determined by the Big Bang, and that it is impossible to do a randomized scientific experiment. We are all slaves in a giant machine, and it is impossible to learn how the machine works.

    This belief is so crazy that it is enough to discredit everything she says. Maybe that is why she omits it in this video.

    She disagrees with the philosophers who say that free will is compatible with determinism. But then she says it is also incompatible with indeterminism! She is wrong about this. Free will means acting contrary to what others predict, so it appears as indeterminism.

    Her main argument is that physicists use equations to predict things, so everything is predictable by equations. The obvious exception is quantum mechanics, but she says the wave function is determined. She neglects to say that the wave function is not observable.

    Quantum mechanics is indeterministic. It does not rule out free will.

    The guy said to me: Why don't I kill myself tomorrow, because what is the point of anything? ... I am not a psychologist, I am a physicist. I don't know what to say to people with existential angst. Please see a psychologist. I am not a philosopher either.
    In essence, she is a preprogrammed robot, and she is not programmed to kill herself.

    She could give this answer to anything. Why does she believe in climate change? She is programmed to.

    I think that some people have libertarian free will, and some don't. Pres. Joe Biden probably had free will when he was younger, but appears to have lost that mental capacity. Sam Harris probably did also, before spending a year doing LSD experiments. When people like Hossenfelder and Harris deny that they have free will, we should take them seriously. Maybe they are just puppets, lacking the mental ability to make decisions on their own. They are like schizophrenics who hear and follow voices in their heads. q

    If you do not have free will, then you are not a fully conscious human being. Free will is the most obvious thing about your existence. Without free will, you are just a cog in a machine.

    Here is a interesting new video in favor of free will.

    Biologist Jerry Coyne summarizes Hossenfelder (and agrees):

    In October of 2020, Hossenfelder declared that libertarian free will — i.e., the “I-could-have-done-otherwise-using-my-volition” form — didn’t exist. I agree with her, of course, for we’re both “naturalists” and “hard determinists.” If you think matter obeys the laws of physics, which is universally accepted in science,  then there’s no room for mental lucubrations that could somehow tweak the laws of physics (Mental lucubrations are instantiations of physical law!) That’s why she (and I) think that, as far as libertarian free will is concerned, “it’s obvious that we don’t have it.”
    I believe in libertarian free will, but not in anything that breaks the laws of physics. If free will breaks the laws, which law? Where is that law published? Who got the Nobel Prize for such a huge discovery?

    There is no such law. Just a belief, by some, that the past determines the future. But there is no such law, and much of science is based on the possibility of unpredictable influences.

    She cites philosophers, but according to her data, only 11% say "no free will".

    Her answer is a good one: those people should see a psychologist. I manage to hang onto being a hard determinist, though of course I act as if I can make free decisions. We can’t live without feeling that way because that’s just the way our brains are constructed.
    At least he is honest here. It is like saying: As a schizophrenic, I hear voices in my head. I don't know why. Ask a psychologist. I follow the voices because of how my brain is constructed.

    A recent PBS TV Nova episode seems to be against free will:

    Your Brain: Who's in Control?

    Are you in control, or is your brain controlling you? Dive into the latest research on the subconscious with neuroscientist Heather Berlin. Sleepwalking, anesthesia, game theory, and more reveal surprising insights in this eye-opening journey to discover what’s really driving the decisions you make.

    The show presents evidence that your conscious decisions can be influenced by subconscious brain processes. I am sure that's true, but I don't think it has much to do with free will. You are still making a decision, even if you are not fully conscious of all aspects of it.

    Wednesday, May 31, 2023

    Bell's Theorem Assumes Classicality

    There is currently a debate on whether the Wikipedia article on Toggle the table of contents Bell's theorem should say that it proves nonlocality. It does not, but people keep arguing that it does. So did Bell, in his later life. The article correctly says:
    Bell's theorem is a term encompassing a number of closely related results in physics, all of which determine that quantum mechanics is incompatible with local hidden-variable theories given some basic assumptions about the nature of measurement.
    There are some hidden assumptions: no retrocausality, no parallel universes, and no superdeterminism.

    A new paper addresses this issue:

    Gomori, Marton and Hoefer, Carl (2023) Classicality and Bell's Theorem. [Preprint]

    A widespread view among physicists is that Bell's theorem rests on an implicit assumption of “classicality,” in addition to locality. According to this understanding, the violation of Bell’s inequalities poses no challenge to locality, but simply reinforces the fact that quantum mechanics is not classical. The paper provides a critical analysis of this view.

    It explains:
    Many physicists are unimpressed by Bell’s theorem. A widespread view is that Bell’s reasoning rests upon an implicit assumption of “classicality” that directly go against the fundamental principles of quantum mechanics (QM). According to such an understanding, the violation of Bell’s inequalities poses no challenge to our causal picture of the world (locality, in particular), but simply reinforces the fact that QM is not classical. One proponent of such a view is Reinhard Werner, who concisely puts it like this (Werner 2014a, p. 4):
    Bell showed (maybe against his own intentions ...) that classicality and locality together lead to false empirical conclusions. Of course, all the talk about the non-locality of quantum mechanics really says [is] that any classical extension violates locality ...
    In line with this picture, physicist have developed various interpretations of quantum theory that are claimed to be local and non-classical. Among recent variants are Werner’s operational quantum mechanics (Werner 2014a,b) and Robert Griffiths’s consistent histories approach (Griffiths 2020).

    Others object to this view. Criticizing Werner’s position about the EPR argument and Bell’s theorem, Tim Maudlin (2014b, pp. 1-2) writes:

    Werner thinks that Bell and Einstein and I have all tacitly made an assumption of which we are unaware, an assumption he labels C for ‘classicality’. ... Werner concedes that Bell proved that any classical theory that violates his inequalities must be non-local. But deny classicality and the arguments no longer go through.
    That's right. Assuming a local hidden variable theory is essentially the same as assuming classicality. QM does not make that assumption, so Bell's theorem says nothing about QM. Several QM interpretations are local. QM physicists are correct that Bell's theorem has no relevance to them.

    The Nobel Prize was recently given to Bell theorem tests, but the citation pointedly avoid saying that anyone proved nonlocality.

    The paper goes on to make these points.

  • Bell does indeed assume classicality. It prefers to say that he has "standard causal-statistical assumptions", and these imply classicality. So it is correct to say Bell's theorem is about classical mechanics, not QM.
  • Some people define locality in a way that assumes classicality. For those people, all non-classical theories are nonlocal by definition, and this has nothing to do with Bell's theorem. It is just a wrong definition.
  • Philosophers and physicists are at an impasse, with physicists following QM and philosophers pursuing what they would like to believe.

    It ends with:

    As philosophers, we would only ask that the physicists refrain from making two sorts of statements (i) Saying that the QM treatment of EPRB is perfectly local (though they can perfectly well say that the QM treatment is not overtly non-local!). (ii) Saying that Bell did not prove what many philosophers think he proved, because he made a tacit and inappropriate presupposition of “classicality” in his argument.
    This is funny. The whole paper explains that leading QM interpretations are local, and that Bell made a classicality assumption. The assumption is explicit in Bell's earlier papers, and concealed in his later ones, but it is always made.

    In other words, physicists tell the truth, and it embarrasses philosophers who cling to mystical beliefs in nonlocality.