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.