History Biographies, History, Philosophy of Physics

[Swamp Thing]

History of the scanning electron microscope

 

[pines-demon]

Schwinger’s time at Colombia
https://www.physics.columbia.edu/sites/default/files/content/Schwinger Article.pdf
Chapter 2 of Climbing the Mountain by Mehra and Milton

Columbia is a university, Colombia is a country in South America

 

[Swamp Thing]

Millikan's experimental confirmation of Einstein's photoelectric effect & equation

 

[Hornbein]

I have read that re-analysis of Eddington's eclipse data that allegedly confirmed general relativity were inconclusive.

 

[gmax137]

I have read that re-analysis of Eddington's eclipse data that allegedly confirmed general relativity were inconclusive.

Source?

I don't have any idea, but Wiki says

It has been claimed that Eddington's observations were of poor quality, and he had unjustly discounted simultaneous observations at Sobral, Brazil, which appeared closer to the Newtonian model, but a 1979 re-analysis with modern measuring equipment and contemporary software validated Eddington's results and conclusions.[12] The quality of the 1919 results was indeed poor compared to later observations, but was sufficient to persuade contemporary astronomers. The rejection of the results from the expedition to Brazil was due to a defect in the telescopes used which, again, was completely accepted and well understood by contemporary astronomers.[13]

12. Kennefick, Daniel (5 September 2007). "Not Only Because of Theory: Dyson, Eddington and the Competing Myths of the 1919 Eclipse Expedition". Studies in History and Philosophy of Science Part A. arXiv:0709.0685. Bibcode:2007arXiv0709.0685K. doi:10.1016/j.shpsa.2012.07.010. S2CID 119203172.

13. Kennefick, Daniel (1 March 2009). "Testing relativity from the 1919 eclipse – a question of bias". Physics Today. 62 (3): 37–42. Bibcode:2009PhT....62c..37K. doi:10.1063/1.3099578.

 

[Hornbein]

Source?

It has been claimed that Eddington's observations were of poor quality,

 

[sbrothy]

Polish Astrophysics: The First Half-Century, 1923-1973

"An attempt is made to evaluate progress of the Polish astrophysical research of stars and of the inter-stellar medium (ISM) on the basis of scientific paper citations in the ADS database. Rather modest citation levels were observed in the years before the mid-1950's. In the years 1958 - 1973, thanks to the partly opened foreign contacts and to strong support from astronomers of the older generation, work of a number of young, energetic enthusiasts reached the world science levels and formed a strong basis for the well recognized, international successes of the next generations."

 

[sbrothy]

Some Things I Have Learned From Detlef Dürr

The Discovery of Neptune Revisited

 

[sbrothy]

Revolutionizing Quantum Mechanics: The Birth and Evolution of the Many-Worlds Interpretation

Not my favorite interpretation, but then again I fear my understanding of the subject is somewhat shallow.

 

[sbrothy]

I admit this one is pretty sought but at least it is history-related.

Jan Veth's paintings of Jacobus Kapteyn

"Jacobus C. Kapteyn is regarded as one of the coryfees of the University of Groningen. Part of his legacy is two paintings of him by Dutch painter Jan Pieter Veth. One, showing him at his desk, decorates the Kapteyn Room in the Kapteyn Astronomical Institute, and the other one, displaying him in academic attire, is in the University's gallery of professors in the central Academy Building. The first was offered to the Kapteyns on the occasion of his 40-th anniversary as professor in 1918 and the second to the University after his retirement in 1921.
It has been suggested that there must have been a third portrait that now is lost. Former director Adriaan Blaauw has proposed that the one in the Academy Building actually was first offered in 1918, but at Mrs. Kapteyn's request replaced by the one now in the Kapteyn Room. The first version was then later adapted to the requirements of the gallery of professors by Veth himself by overpainting it with academic attire. A preliminary trial version by Veth, in the possession of Kapteyn's greatgrandson, shows what it would have looked like before the adaption.
The following reports on new evidence: the biography of Jan Veth that historian Johan Huizinga, friend of Veth, wrote, and letters Veth wrote to his wife while he was working on these paintings. This provides strong support of Blaauw's sequence of events with a few modifications. No third painting has ever been produced."

 

[sbrothy]

A Triumvirate of AI Driven Theoretical Discovery by Yang-Hui-He

Subject:
History and Overview (math.HO); Artificial Intelligence (cs.AI); High Energy Physics - Theory (hep-th); History and Philosophy of Physics (physics.hist-ph)

Synopsis:
"Recent years have seen the dramatic rise of the usage of AI algorithms in pure mathematics and fundamental sciences such as theoretical physics. This is perhaps counter-intuitive since mathematical sciences require the rigorous definitions, derivations, and proofs, in contrast to the experimental sciences which rely on the modelling of data with error-bars. In this Perspective, we categorize the approaches to mathematical discovery as "top-down", "bottom-up" and "meta-mathematics", as inspired by historical examples. We review some of the progress over the last few years, comparing and contrasting both the advances and the short-comings in each approach. We argue that while the theorist is in no way in danger of being replaced by AI in the near future, the hybrid of human expertise and AI algorithms will become an integral part of theoretical discovery."

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I find this interesting (although admittedly much of it goes over my head). Specifically, what surprises me with the author's angle is that, as I've understood the usefulness of AI, it is useful mostly within language and graphics. Disciplines which somewhat came as a surprise to those who foresaw that AI (and perhaps machine learning) would show their strengths within mathematics and logic. That it turns out to be so helpful in the realm of mathematics and physics somewhat surprises me. It might be a tall order to ask you to conclude something from a single arXiv preprint but can it really be so?

 

[sbrothy]

I'ts not that I think people are unable to find the physics.hist-ph section on arXiv themselves. (Though I've seen some pretty derogatory comments from physicists regarding philosophy in general.), but it's like I've worked up a pretty good inertia so I migh as well continue:

Myths of German Graphite in World War II, with Original Translations

"We re-examine the common narrative that a 1941 experimental error by physicists Walther Bothe and Peter Jensen led Germany to abandon graphite as a reactor moderator during World War II. We first detail the history of both German and American graphite experiments, noting that the Americans faced similar setbacks but succeeded only at the end of a costly 18-month graphite purification program. We then use Monte Carlo N-Particle simulations to reconstruct Bothe's 1941 experiment. We find the thermal absorption cross section of Bothe's Siemens electrographite to be 12.2 mb, in contrast to his reported 7.9 mb. This discrepancy arises because the neutrons in Bothe's experiment did not reach thermal equilibrium, leading to an underestimation of neutron absorption. Additionally, despite misconceptions that the Germans were unaware of boron impurities, we share evidence that Wilhelm Hanle accurately measured boron and cadmium impurities in the electrographite. To support our findings, we provide 9 excerpted and 3 complete English translations of classified wartime reports by Heisenberg, Joos, Bothe, Jensen, Höcker, Hanle, and Kremer. Our work aims to illuminate the rational constraints behind Germany's decision to forgo graphite moderation.""

 

[sbrothy]

The elision of the subject and the manifestation of the world

(Quantum Physics (quant-ph); History and Philosophy of Physics (physics.hist-ph)

"Owing to the contextuality of the properties of quantum objects, quantum mechanics does not appear to countenance the elision of the thinking and perceiving subject. If quantum objects owe their properties to the experimental conditions in which they are observed, the experimental apparatus cannot owe its properties to the quantum objects of which it is commonly said to be composed. It follows that neither quantum objects nor measuring instruments can be regarded as property-carriers existing independently of conscious subjects. However, if the difference between the classical domain and the quantum domain is understood as essentially the difference between the manifested world and what is instrumental in its manifestation, the elision of the subject can again be achieved."

 

[sbrothy]

I’m really sceptic about this “teleparallel gravity”. Am I way off the mark if it kinda reminds me of homeopathy?

 

[renormalize]

I’m really sceptic about this “teleparallel gravity”. Am I way off the mark if it kinda reminds me of homeopathy?

Yes, I'd say you're off the mark. Teleparallel gravity is a theory of spacetime torsion, and it is both well-founded and regularly studied. For example, take a look at: The Geometrical Trinity of Gravity and the references therein.

 

[sbrothy]

Yes, I'd say you're off the mark. Teleparallel gravity is a theory of spacetime torsion, and it is both well-founded and regularly studied. For example, take a look at: The Geometrical Trinity of Gravity and the references therein.

I see. Thank you. I guess I saw "tele"-something and thought Madame Blavatsky.

 

[sbrothy]

Perusing this one:

The Origin of Dark Matter and the Cosmological Constant, the mathematics of which, I admit, is way way above my meager education I found this, friendlier and more historical, account on Dark Matter.

How Dark Matter Came to Matter.

Now as I mentioned the math in the first one there gave me serious pause so I can vouch for neither accuracy nor rigorousness (wow, I spelled that correctly?!). In principle the same goes for the second but that one is at least mostly “just” history.

EDIT: Heh. I like the spelling error in the first one: “At the time of the Big Bank [sic…]”

 

[sbrothy]

Yes, I'd say you're off the mark. Teleparallel gravity is a theory of spacetime torsion, and it is both well-founded and regularly studied. For example, take a look at: The Geometrical Trinity of Gravity and the references therein.

Following your breadcrumb there (I’m guessing more than one is needed for calling it an actual trail.) indeed led me back to some papers I've encountered before. Specifically the Einstein-Cartan torsion approach.

In the process I stumbled across this one:

The changing faces of the Problem of Space in the work of Hermann Weyl.

Which reminds me.... The twistor/spinor work Peter Woit currently seems to be caught up in (for lack of a better term, as I know I'm in way over my head here), which he seems to have "inherited" or continued from Roger Penrose... is that related to this "torsion" concept?

 

[sbrothy]

Princeton seminars on physics and philosophy. (physics.hist-ph)

"These are lectures notes prepared for a series of seminars I am invited to give at Princeton Philosophy Department in November 2024. They cover the conceptual structure of quantum gravity, the relational interpretation of quantum mechanics, the structure of time, its orientation and the openness of the future, the physical underpinning of information and meaning, and some general considerations on the fact that concepts evolve, on perspectivalism and anti-foundationalism."


This may look a little random but it's by Carlo Rovelli, so I'm thinking it's probably worth a read.

 

[Astronuc]

There is a documentary series, The People Profiles, which may be a channel supported by Patreon.

Charles Darwin (12 Feb 1809 - 19 Apr 1882) - Evolution vs Creation Documentary




It's an interesting narrative.

 

[sbrothy]

Occasionally I can understand the dislike STEM educated people harbors towards philosophy. Especially if it touches on the subject matter they themselves are educated in, and the "so-called" philosopher hasn't taken the time and effort to understand the grisly details of the aforementioned matter. It's a little like if I wrote a long treatise on the interpretation of QM (and likely had it accepted only on viXra :) ).

Sometimes though, someone burns through and you can see they actually did their homework. Even if I can't follow the mathematics all the way I appreciate these papers more. It's somewhat like appreciating a fine piece of art even if, according to creators and reviewers, I don't have the necessary qualifications for doing so.

Another, more loose, analogy is that sometimes a piece of music will mean more to me if I hear it in a lossless format like WAV/FLAC as opposed to a 256 kbit/s mp3. Or even if I hear my little sister singing Händel's Messiah as opposed to hearing it somewhere randomly. I can then find the exact version that *really* talks to me from all the versions out there.

This one is almost there but I suspect it's a few steps short:

Is time one-dimensional?

It's a tough (and possible unfair) question to put to you, but is my suspicion right?

 

[sbrothy]

It all suddenly came back to me. Regarding that torsion thing that was connected to Einstein-Cartan theory (wiki link intentionally left out, I'm getting the hang of it! :) )

Here's a relatively easy read which fits nicely in the Sci-Fi corner of the site and touches upon Einstein and torsion:

Lectures on Faster-than-Light Travel and Time Travel

That was were Smolin's "fecund universe" / "Cosmological Natural Selection" idea came from. That every black hole leads to another universe with (potentionally?) different constants.

Old papers (On cosmic natural selection., The status of cosmological natural selection), and if I remember correctly it never really flew, although I think the idea was poetically beautiful.

But again with the intuition and beauty not being good guidelines. Why would the universe want to be beautiful? Nature certainly isn't. (After having seen a nature program and read about the Fig Wasp I'm never eating a fig again!)

And regarding Woit he's running with Penrose's Twistor theory I think. More info at his blog. Probably buried beneath a deep disregard for string theory. :)

 

[Hornbein]

My wet blanket view is that with the alleged multiverse we have no data whatsoever to go on so theories may florish unimpeded. Perhaps when said data somehow arrives then all or almost all of those theories will be thrown out.

It's like the attempts to translate ancient Egyptian hieroglyphics. When the Rosetta stone was dug up and translated all the prior attempts were found to be off base.

So I can't get all that excited about this kind of thing. If other people find it fun, go for it. Maybe I'll throw in my speculations some day.

 

[sbrothy]

My wet blanket view is that with the alleged multiverse we have no data whatsoever to go on so theories may florish unimpeded. Perhaps when said data somehow arrives then all or almost all of those theories will be thrown out.

It's like the attempts to translate ancient Egyptian hieroglyphics. When the Rosetta stone was dug up and translated all the prior attempts were found to be off base.

So I can't get all that excited about this kind of thing. If other people find it fun, go for it. Maybe I'll throw in my speculations some day.

You’re right. It’s almost pure speculation but I actually think Smolin’s idea there was falsifiable and, indeed, was falsified. Don’t hang me up on it, it’s in the papers there somewhere I think. But yes, it has zero practical applicability but any explanation, or indeed even hint, at why the cosmos is what it is is welcome with me.

 

[sbrothy]

Julian Hirniak, an early proponent of periodic chemical reaction

In this article we present and discuss the work and scientific legacy of Julian Hirniak, the Ukrainian chemist and physicist who published two articles in 1908 and 1911 about periodic chemical reactions. Over the last 110+ years, his theoretical work has often been cited favorably in connection with Alfred Lotka's theoretical model of an oscillating reaction system. Other authors have pointed out thermodynamic problems in Hirniak's reaction scheme. Based on English translations of his 1908 Ukrainian and 1911 German articles, we show that Hirniak's claim (that a cycle of inter-conversions of three chemical isomers in a closed reaction vessel can show damped periodic behavior) violates the \textit{Principle of Detailed Balance} (i.e., the Second Law of Thermodynamics), and that Hirniak was aware of this Principle. We also discuss his results in relation to Lotka's first model of damped oscillations in an open system of chemical reactions involving an auto-catalytic reaction operating far from equilibrium. Taking hints from both Hirniak and Lotka, we show that the mundane case of a kinase enzyme catalyzing the phosphorylation of a sugar can satisfy Hirniak's conditions for damped oscillations to its steady state flux (i.e., the Michaelis--Menten rate law), but that the oscillations are so highly damped as to be unobservable. Finally, we examine historical and factual misunderstandings related to Julian Hirniak and his publications.

 

[sbrothy]

Albeit a little dated, I like this one too for it’s overview/historic appeal:

Progress toward fusion energy breakeven and gain as measured against the Lawson criterion


The Lawson criterion is a key concept in the pursuit of fusion energy, relating the fuel density n, pulse duration τ or energy confinement time τE, and fuel temperature T to the energy gain Q of a fusion plasma. The purpose of this paper is to explain and review the Lawson criterion and to provide a compilation of achieved parameters for a broad range of historical and contemporary fusion experiments. Although this paper focuses on the Lawson criterion, it is only one of many equally important factors in assessing the progress and ultimate likelihood of any fusion concept becoming a commercially viable fusion-energy system. Only experimentally measured or inferred values of n, τ or τE, and T that have been published in the peer-reviewed literature are included in this paper, unless noted otherwise. For extracting these parameters, we discuss methodologies that are necessarily specific to different fusion approaches (including magnetic, inertial, and magneto-inertial fusion). This paper is intended to serve as a reference for fusion researchers and a tutorial for all others interested in fusion energy.

 

[sbrothy]

Sorry about the detour. Here I’m back within my comfort zone:

Dominic Welsh: his work and influence.

We review the work of Dominic Welsh (1938-2023), tracing his remarkable influence through his theorems, expository writing, students, and interactions. He was particularly adept at bringing different fields together and fostering the development of mathematics and mathematicians. His contributions ranged widely across discrete mathematics over four main career phases: discrete probability, matroids and graphs, computational complexity, and Tutte-Whitney polynomials. We give particular emphasis to his work in matroid theory and Tutte-Whitney polynomials.

—————————————————————-

And totally unrelated (and also somewhat dated), here’s a paper about things that go BANG:

Acoustic Methods for Evaluation of High Energy Explosions.

Two independent acoustic methods were used to verify the results of earlier explosion energy calculations of Chelyabinsk meteoroid. They are: estimations through a path length of infrasound wave and through maximum concentration of the wave energy. The energy of this explosion turned out the same as in earlier calculations, and it is close to 58 Mt of TNT. The first method, as well as evaluations through seismic signals and barograms, have confirmed the energy of Tunguska meteoroid explosion at 14.0 - 14.5 Mt level. Moreover, there is a good agreement between acoustic estimations and other data for the explosion energy of another meteoroid that was ended its flight over the southern part of Indian Ocean, and for two catastrophic volcanoes explosions - Bezymyanny and Krakatoa.

I mean who can resist a paper that rates the “Tsar Bomba” as a minor explosion?!

EDIT: I mean in the context of importance.

Not me, obviously.

 

[Frabjous]

Condon “Tunneling - How It Started” A personal account of the early history of tunneling and the contribution of Ronald W. Gurney.
Am. J. Phys. 46, 319–323 (1978)
Also here
https://archive.org/details/selectedpopularw0000cond/page/332/mode/2up

A sad story.

 

[sbrothy]

Maybe these "biographies" would fit into a thread of their own.

(Arxiv): Lars Brink: November 12, 1943 - October 29, 2022

Lars Brink Colleague, Friend and Collaborator

Seems to be a followup….

 

[sbrothy]

This post by @bhobba mentions Matthew Saul Leifer and I remembered he have had some sociological/philosophical thoughts so I dug this up:

Against Fundamentalism.

In this essay, I argue that the idea that there is a most fundamental discipline, or level of reality, is mistaken. My argument is a result of my experiences with the "science wars", a debate that raged between scientists and sociologists in the 1990's over whether science can lay claim to objective truth. These debates shook my faith in physicalism, i.e. the idea that everything boils down to physics. I outline a theory of knowledge that I first proposed in my 2015 FQXi essay on which knowledge has the structure of a scale-free network. In this theory, although some disciplines are in a sense "more fundamental" than others, we never get to a "most fundamental" discipline. Instead, we get hubs of knowledge that have equal importance. This structure can explain why many physicists believe that physics is fundamental, while some sociologists believe that sociology is fundamental.
This updated version of the essay includes and appendix with my responses to the discussion of this essay on the FQXi website.

 

[sbrothy]

Fritz Haber is a fascinating and tragic figure. On one hand, his eponymous process saved 2.7 billion human lives by some estimates. However he also led the German chemical weapons program in World War One and developed Zyklon B, which the Nazis used some 25 years later to murder his surviving family members

Fritz Haber: The Damned Scientist

In the gallery of famous people tracing their origins to Wrocław, few are as controversial, as complex, or as tragic as Fritz Haber, ever more distant in the flux of time, yet still stirring emotions. He developed a method for the direct synthesis of ammonia from its elements and later pioneered chemical warfare on the battlefields of the First World War.

 

[sbrothy]

Again: It’s not that I think you’re incapable of finding “History and Philosophy of Physics” on arXiv yourselves. It’s more that I suspect you don’t visit it very often.

This looks like an interesting one though:

Feynman 1947 letter on path integral for the Dirac equation.

“In 1947, four months before the famous Shelter Island conference, Richard Feynman wrote a lengthy letter to his former MIT classmate Theodore Welton, reporting on his efforts to develop a path integral describing the propagation of a Dirac particle. While these efforts never came to fruition, and were shortly abandoned in favor of a very different method of dealing with the electron propagator appearing in in QED, the letter is interesting both from the historical viewpoint of revealing what Feynman was thinking about during that period just before the development of QED, and for its scientific ideas. It also contains at the end some philosophical remarks, which Feynman wraps up with the comment, ``Well enough for the baloney.'' In this article I present a transcription of the letter along with editorial notes, and a facsimile of the original handwritten document. I also briefly comment on Feynman's efforts and discuss their relation to some later work.”

EDIT:
Feynman: “Now I would like to add a little hooey. The reason I am so slow […]”

Riiiight.

 

[sbrothy]

This one is spurred by reading this thread:

Views on Complex Numbers:


A Brief Tour Through the History of Complex Numbers.

I don’t know if it’s wise to link back. I’ll refrain from now. I have another paper from Copenhagen University lined up as soon as I find out if it’s publicly available…

EDIT:

Ah, they’re books, and not new ones either (I don’t remember the rules on links to stuff behind paywalls and books but, I’d rather post them now before I forget the links and search terms that brought me there):


Caspar Wessel and the Complex Numbers

Arround Caspar Wessel and the Geometric Representation of Complex Numbers. Proceedings of the Wessel and the Geometric Representation of Complex Numbers (sic)

EDIT2: Heh, “[…]proceeedings of the Wessel[…]”.

 

[sbrothy]

I may be going out on a tangent here. After all it isn't supposed to be a thread with papers just looking intriguing to me personally. Hope you'll bear with me on these, though:

A typology of activities over a century of urban growth. (physics.soc-ph)

Contemporary literature on the dynamics of economic activities in growing cities mainly focused on a few years or decades time frames. Using a new geo-historical database constructed from historical directories with about 1 million entries, we present a comprehensive analysis of the dynamics of activities in a major city, Paris, over almost a century (1829-1907). Our analysis suggests that activities that accompany city growth can be classified in different categories according to their dynamics and their scaling with population: (i) linear for everyday needs of residents (food stores, clothing retailers, health care practitioners), (ii) sublinear for public services (legal, administrative, educational), (iii) superlinear for the city's specific features (passing fads, specialization, timely needs). The dynamics of these activities is in addition very sensitive to historical perturbations such as large scale public works or political conflicts. These results shed light on the evolution of activities, a crucial component of growing cities.

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Projections of Earth's technosphere. I. Scenario modeling, worldbuilding, and overview of remotely detectable technosignatures. (physics.soc-ph)

This study uses methods from futures studies to develop a set of ten self-consistent scenarios for Earth's 1000-year future, which can serve as examples for defining technosignature search strategies. We apply a novel worldbuilding pipeline that evaluates the dimensions of human needs in each scenario as a basis for defining the observable properties of the technosphere. Our scenarios include three with zero-growth stability, two that have collapsed into a stable state, one that oscillates between growth and collapse, and four that continue to grow. Only one scenario includes rapid growth that could lead to interstellar expansion. We examine absorption spectral features for a few scenarios to illustrate that nitrogen dioxide can serve as a technosignature to distinguish between present-day Earth, pre-agricultural Earth, and an industrial 1000-year future Earth. Three of our scenarios are spectrally indistinguishable from pre-agricultural Earth, even though these scenarios include expansive technospheres. Up to nine of these scenarios could represent steady-state examples that could persist for much longer timescales, and it remains possible that short-duration technospheres could be the most abundant. Our scenario set provides the basis for further systematic thinking about technosignature detection as well as for imagining a broad range of possibilities for Earth's future.

"[...] futures studies [...]"?

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I must admit I initially thought this last one was some kind of April Fool's joke what with words like "panpsychism" and "panprotopsychism" in the title and synopsis! They seem to be legit (philosophical) terms though (Stanford Encyclopedia of Philosophy on Panpsychism). I'm not really sure how serious to take it, though. I admit I haven't read it yet as looks like a masochcist's dream of a mix between Proust, Kant and Driesch:

Quantum panprotopsychism and the structure and subject-summing combination problem. (q-bio.NC)

In a previous paper, we have shown that an ontology of quantum mechanics in terms of states and events with internal phenomenal aspects, that is, a form of panprotopsychism, is well suited to explaining the phenomenal aspects of consciousness. We have proved there that the palette and grain combination problems of panpsychism and panprotopsychism arise from implicit hypotheses based on classical physics about supervenience that are inappropriate at the quantum level, where an exponential number of emergent properties and states arise. In this article, we address what is probably the first and most important combination problem of panpsychism: the subject-summing problem originally posed by William James. We begin by identifying the physical counterparts of the subjects of experience within the quantum panprotopsychic approach presented in that article. To achieve this, we turn to the notion of subject of experience inspired by the idea of prehension proposed by Whitehead and show that this notion can be adapted to the quantum ontology of objects and events. Due to the indeterminacy of quantum mechanics and its causal openness, this ontology also seems to be suitable for the analysis of the remaining aspects of the structure combination problem, which shows how the structuration of consciousness could have evolved from primitive animals to humans. The analysis imposes conditions on possible implementations of quantum cognition mechanisms in the brain and suggests new problems and strategies to address them. In particular, with regard to the structuring of experiences in animals with different degrees of evolutionary development.[/I]

EDIT:

“[…]she [a panpsychist] needn’t hold that literally everything has a mind, e.g., she needn’t hold that a rock has mental properties (just that the rock’s fundamental parts do).” —— Stanford
?!!!!

 

[sbrothy]

A note on the notion of now and time flow in special relativity

With special relativity, we seem to be facing a conundrum. It is a very well-tested theory; in this way, the Minkowski spacetime must be "capturing" essential features of space and time. However, its geometry seems to be incompatible with any sort of global notion of time. We might only have local notions of now (present moment) and time flow, at best. In this note, we will explore the possibility that a pretty much global notion of now (and time flow) might be hiding in plain sight in the geometry of the Minkowski spacetime.

Is it just me or is this guy "arguing" for a special reference frame? I thought this pretty much amounted to flogging a dead horse.

Wiki has something to say on the subject though I wont link to it. It has been hammered into me that such a frame does not exist, but perhaps philosophy is "special" in this regard?

 

[sbrothy]

I know I’m not doing myself any favors trying to keep this thread serious but I simply couldn’t stand for the title and statistical subject matter:

Bayesian Analysis of Epidemics - Zombies, Influenza, and other Diseases

Mathematical models of epidemic dynamics offer significant insight into predicting and controlling infectious diseases. The dynamics of a disease model generally follow a susceptible, infected, and recovered (SIR) model, with some standard modifications. In this paper, we extend the work of Munz et.al (2009) on the application of disease dynamics to the so-called “zombie apocalypse”, and then apply the identical methods to influenza dynamics. Unlike Munz et.al (2009), we include data taken from specific depictions of zombies in popular culture films and apply Markov Chain Monte Carlo (MCMC) methods on improved dynamical representations of the system. To demon- strate the usefulness of this approach, beyond the entertaining example, we apply the identical methodology to Google Trend data on influenza to establish infection and recovery rates. Finally, we discuss the use of the methods to explore hypothetical intervention policies regarding disease outbreaks.

 

[sbrothy]

Reading this thread discussing infinity, where Hilbert’s Hotel is mentioned, led me to these (It’s pretty heavy stuff though, IMHO.):


Une initiation au concept de l'infini

In this article, we explore the notion of infinity by studying Cantor's contribution to this field. A brief history of set theory is given. As an example of infinity, we consider Hilbert's famous hotel. A graphical construction is used to demonstrate the countability of rationals. Cantor's diagonal procedure is explored, demonstrating that the infinity of real numbers is greater than that of integers. There is therefore a hierarchy of infinities, enabling us to elaborate on the continuum hypothesis, which remains an unsolved problem in mathematics.


Some paradoxes of Infinity revisited

In this article, some classical paradoxes of infinity such as Galileo's paradox, Hilbert's paradox of the Grand Hotel, Thomson's lamp paradox, and the rectangle paradox of Torricelli are considered. In addition, three paradoxes regarding divergent series and a new paradox dealing with multiplication of elements of an infinite set are also described. It is shown that the surprising counting system of an Amazonian tribe, Pirahã, working with only three numerals (one, two, many) can help us to change our perception of these paradoxes. A recently introduced methodology allowing one to work with finite, infinite, and infinitesimal numbers in a unique computational framework not only theoretically but also numerically is briefly described. This methodology is actively used nowadays in numerous applications in pure and applied mathematics and computer science as well as in teaching. It is shown in the article that this methodology also allows one to consider the paradoxes listed above in a new constructive light.

 

[sbrothy]

Condon “Tunneling - How It Started” A personal account of the early history of tunneling and the contribution of Ronald W. Gurney.
Am. J. Phys. 46, 319–323 (1978)
Also here
https://archive.org/details/selectedpopularw0000cond/page/332/mode/2up

A sad story.

There seems to be more to arXiv than I initially, and naively I might add, thought. Thanks!

 

[sbrothy]

I admit the quality has suffered a kind of inflation lately but I think this really must be on topic and a good read:

Blaschke, Osgood, Wiener, Hadamard and the Early Development of Modern Mathematics in China.

In ancient times, China made great contributions to world civilization and in particular to mathematics. However, modern sciences including mathematics came to China rather too late. The first Chinese university was founded in 1895. The first mathematics department in China was formally opened at the university only in 1913. At the beginning of the twentieth century, some Chinese went to Europe, the United States of America and Japan for higher education in modern mathematics and returned to China as the pioneer generation. They created mathematics departments at the Chinese universities and sowed the seeds of modern mathematics in China. In 1930s, when a dozen of Chinese universities already had mathematics departments, several leading mathematicians from Europe and USA visited China, including Wilhelm Blaschke, George D. Birkhoff, William F. Osgood, Norbert Wiener and Jacques Hadamard. Their visits not only had profound impact on the mathematical development in China, but also became social events sometimes. This paper tells the history of their visits.

 

[sbrothy]

Clean philosophy here:

The physicists philosophy of physics

I argue that research in physics operates under an implicit community philosophy, and I offer a definition I think physicists would accept, by and large. I compare this definition to what philosophers, sociologists, and historians of science, with physicists, say we are doing.


"Physicists do not tend to see much use for philosophy. Weinberg (1992) expresses the feeling in the chapter Against Philosophy in his book, Dreams of a Final Theory:

Physicists do of course carry around with them a working philosophy. For most of us, it is a rough-and- ready realism [but] we should not expect [philosophy] to provide today’s scientists with any useful guidance about how to go about their work or what they are likely to find."​

As I've mentioned before I'm not sure how true this is. It smells of a rather broad generalization.

EDIT:

Here’s what looks like the source for quick reference. (The chapter in question I mean.)

 

[sbrothy]

Seems to be quite a lot of music threads in this forum. In that context this seems very apt:

Music, Immortality, and the Soul

(20 Sep 2024 / History and Philosophy of Physics (physics.hist-ph))

Music has been called the temporal art par excellence. Yet, as this paper explains, it is also the atemporal art par excellence. The contradiction is, however, only apparent, and a result of viewing music from two possible perspectives. That it has these two perspectives is the focus of this paper. In particular, the way in which these two aspects of music allow it to function as a kind of conduit between transcendent and immanent; immaterial and material. This can help explain the power of music to touch places deep in the soul (the part of us that transcends matter and time), that other forms of art struggle to reach. A somewhat similar debate occurs in looking at mathematics from an ontological point of view. In particular the treatment of the real numbers. There are curious properties of real numbers that seem to put them, like music, in the realm of the transcendent: in terms of the amount of information to specify them, one requires infinite computer time since there is no repeating pattern to their decimal expansions. One must simply evolve the sequence, working through it, despite the fact that it might have a perfectly situated home in Platonia. In other words, bringing them into this world demands a temporal element. We explore these and other links to a variety of issues in physics, ultimately arguing for dual-aspect monism."

EDIT: More and more I understand physicist's animosity towards philosophy when it flies so high it begins to talk about "souls" and "immortality". I mean maybe step down and out from your ivory-tower and walk for a while in normal people's shoes. Taking QM as a hostage to talk about reincarnation or something similar is just plain silly. I'm not saying this particular paper goes that far but, admittedly, some of the authors of these papers seem to have their heads in the clouds.

EDIT2: What I like are those philosophical papers that are unfortunately far apart when the author obviously understand the mathematics and makes some points QM interpretation-wise. But yeah, they aren't all that common.

 

[sbrothy]

Build up some inertia there and these two not only seem to fit together but also seem to be relevant considering contemporary news:

Emergence of echo chambers in a noisy adaptive voter model

(19 Sep 2024 / Physics and Society (physics.soc-ph); Adaptation and Self-Organizing Systems (nlin.AO))

Belief perseverance is the widely documented tendency of holding to a belief, even in the presence of contradicting evidence. In online environments, this tendency leads to heated arguments with users ``blocking'' each other. Introducing this element to opinion modelling in a social network, leads to an adaptive network where agents tend to connect preferentially to like-minded peers. In this work we study how this type of dynamics behaves in the voter model with the addition of a noise that makes agents change opinion at random. As the intensity of the noise and the propensity of users blocking each other is changed, we observe a transition between 2 phases. One in which there is only one community in the whole network and another where communities arise and in each of then there is a very clear majority opinion, mimicking the phenomenon of echo chambers. These results are obtained with simulations and with a mean-field theory.

Trust in society: A stochastic compartmental model

(19 Sep 2024 / Physics and Society (physics.soc-ph); Probability (math.PR))


This paper studies a novel stochastic compartmental model that describes the dynamics of trust in society. The population is split into three compartments representing levels of trust in society: trusters, skeptics and doubters. The focus lies on assessing the long-term dynamics, under `bounded confidence' i.e., trusters and doubters do not communicate). We state and classify the stationary points of the system's mean behavior. We find that an increase in life-expectancy, and a greater population may increase the proportion of individuals who lose their trust completely. In addition, the relationship between the rate at which doubters convince skeptics to join their cause and the expected number of doubters is not monotonic -- it does not always help to be more convincing to ensure the survival of your group. We numerically illustrate the workings of our analysis. Because the study of stochastic compartmental models for social dynamics is not common, we in particular shed light on the limitations of deterministic compartmental models.
In our experiments we make use of fluid and diffusion approximation techniques as well as Gillespie simulation.



And yeh, I'll stop for now.

 

[sbrothy]

Not really on-topic here but I remember someone, somewhere else, asking how to employ AI in practical teaching. Rather than adding noise to someone else's discussion I'll just leave this one here:

Democratizing Signal Processing and Machine Learning: Math Learning Equity for Elementary and Middle School Students

Signal Processing (SP) and Machine Learning (ML) rely on good math and coding knowledge, in particular, linear algebra, probability, and complex numbers. A good grasp of these relies on scalar algebra learned in middle school. The ability to understand and use scalar algebra well, in turn, relies on a good foundation in basic arithmetic. Because of various systemic barriers, many students are not able to build a strong foundation in arithmetic in elementary school. This leads them to struggle with algebra and everything after that. Since math learning is cumulative, the gap between those without a strong early foundation and everyone else keeps increasing over the school years and becomes difficult to fill in college. In this article we discuss how SP faculty and graduate students can play an important role in starting, and participating in, university-run (or other) out-of-school math support programs to supplement students' learning. Two example programs run by the authors (CyMath at ISU and Ab7G at Purdue) are briefly described. The second goal of this article is to use our perspective as SP, and engineering, educators who have seen the long-term impact of elementary school math teaching policies, to provide some simple almost zero cost suggestions that elementary schools could adopt to improve math learning: (i) more math practice in school, (ii) send small amounts of homework (individual work is critical in math), and (iii) parent awareness (math resources, need for early math foundation, clear in-school test information and sharing of feedback from the tests). In summary, good early math support (in school and through out-of-school programs) can help make SP and ML more accessible.

EDIT:

Oh, and to maybe "add some makeup to an ugly pig" (to slaughter a metaphor in translation) this one at least looks somewhat on-topic:

Majorana and the bridge between matter and anti-matter

This short essay aims to offer a discursive presentation of three scientific articles by Ettore Majorana highlighting the fundamental importance of one of them - the last one - for the investigation of the intimate constitution of matter. The search for evidence to support Majorana's thesis is the prime motivation of the conference "Multi-Aspect Young Oriented Advanced Neutrino Academy" at the G.P. Grimaldi Foundation in Modica, Sicily.

 

[sbrothy]

I don't know if this count as a "controversy" or downright plagiarism but it looks like Hans Christian Ørsted - whom every Danish schoolkid is taught is a national treasure up there with Niels Bohr as he supposedly discovered electromagnetism - apparently pretty much stole the idea from Gian Domenico Romagnosi (boldness added):

[...] It is sometimes assumed that he [Gian Domenico Romagnosi] found a relationship between electricity and magnetism, about two decades before Hans Christian Ørsted's 1820 discovery of electromagnetism. However, his experiments did not deal with electric currents, and only showed that an electrostatic charge from a voltaic pile could deflect a magnetic needle. However, as Joseph Hamel has pointed out, Romagnosi's discovery was documented in the book by Joseph Izarn, Manuel du Galvanisme (1805), where a galvanic current (courant galvanique) is explicitly mentioned]. [...]

The following information was gleaned from historum.com. While it might not be a creditable source I tried to verify the claims individually and they seem to be corroborated by the Springer article though it's behind a paywall and in Italian (I'm that good! Dunnng-Kruger Effect anyone?!). I provided the reference for completeness sake.

• A first paper written by Romagnosi¹ was published on the Gazzetta di Trento 3 August 1802
• A second paper written by Romagnosi² was published on the Gazzetta di Rovereto August 13 August 1802.
• Romagnosi, in October 1802, sent his paper to Paris (Academie des Sciences, 1802)³
• A private letter written by Romagnosi in 1827 ³, commenting on Oersted's experiment and claiming priority in the discovery of electromagnetism.

1.) In Italian
2.) Paywalled Springer link. In Italian.
3.) Seems to be mentioned in the Springer article but I don't have full access and I don't understand Italian.


Some additional "proof":


Romagnosi and Volta’s Pile: Early Difficulties in the Interpretation of Voltaic Electricity
Speculation and Experiment in the Background of Oersted's Discovery of Electromagnetism
Gian Domenico Romagnosi’s Forgotten Experiment on the Magnetic Effect of Currents in 1802

If this is true it is a very little known fact in Denmark and actually pretty embarrassing. I know this kind of thing goes on in science all the time but that really doesn't make it better.

EDIT: Admittedly, it could be an independent discovery. That kind of thing also goes on in science all the time.

EDIT2: Fixed link.

 

[sbrothy]

Book Review: 'Background Independence in Classical and Quantum Gravity', by James Read

Elegance, Facts, and Scientific Truths

I argue that scientific determinism is not supported by facts, but results from the elegance of the mathematical language physicists use, in particular from the so-called real numbers and their infinite series of digits. Classical physics can thus be interpreted in a deterministic or indeterministic way. However, using quantum physics, some experiments prove that nature is able to continually produce new information, hence support indeterminism in physics.

 

[pines-demon]

I do not know if this fits here, but in view of the recent Nobel Prize in Physics, this is an interesting video. Is John Hopfield giving a presentation in a conference in 1983 a year after his key paper on Hopfield networks:

Clearly in the words of a physicist. A spin glass Hamiltonian is used to explain it.

 

[pines-demon]

This semi-auto-biographical text is a great read:

• Whatever Happened to Solid-State Physics? - J.J. Hopfield, Annu. Rev. Condens. Matter Phys., 2014

 

[Hornbein]

This semi-auto-biographical text is a great read:

• Whatever Happened to Solid-State Physics? - J.J. Hopfield, Annu. Rev. Condens. Matter Phys., 2014

This site can’t be reached​

Check if there is a typo in whatever%20happened%20to%20solid-state%20physics

• If spelling is correct, try running Windows Network Diagnostics.

DNS_PROBE_FINISHED_NXDOMAIN

 

[pines-demon]

Updated

 

[sbrothy]

I was a little inebrieated but found this note in my pocket when I came home:

"Nobel chemistry, David Baker, John Jumper, Demis Hassabis, "something with proteins".

I need to sober up before I unpack that.

EDIT:

https://www.nobelprize.org/prizes/chemistry/2024/press-release/

Jumping the shark...