studiot Posted March 17, 2019 Posted March 17, 2019 1 hour ago, taeto said: The imagined "perfect" vacuum presumably has no magnetic permeability nor electric permittivity, hence the speed of light is infinite therein. This is an even more difficult position to defend than your last version. Especially without evidence. preferably of a mathematical nature.
taeto Posted March 17, 2019 Author Posted March 17, 2019 3 minutes ago, studiot said: This is an even more difficult position to defend than your last version. Especially without evidence. preferably of a mathematical nature. I thought that permittivity and permeability would be observed physical quantities. How would you gather mathematical evidence of their quantitative values? Anyway, Eise already presented mathematical evidence, to argue that if either magnetic permeability or electric permittivity vanishes, then the speed of light becomes infinite.
swansont Posted March 17, 2019 Posted March 17, 2019 1 hour ago, taeto said: I suspect that you miss the point. The actual vacuum has positive magnetic permeability and electric permittivity. Which we can both measure. The imagined "perfect" vacuum presumably has no magnetic permeability nor electric permittivity, hence the speed of light is infinite therein. If you for some reason believe that a vacuum could conceivably act like that, then you would have to admit that there would be no absolute bound to the speed of light. The suggestion seems to be that the actually observed vacuum is a "contaminated" version of such an idealized vacuum. The actual vacuum has stuff in it which slows down light to a finite speed. We do actually observe such a "contamination" in the shape of QM effects. Such a vacuum doesn’t exist. One might ”believe” that it does, but that’s not based on science.
taeto Posted March 17, 2019 Author Posted March 17, 2019 1 minute ago, swansont said: Such a vacuum doesn’t exist. One might ”believe” that it does, but that’s not based on science. Remember we are talking pre 1930. Did Einstein at that time have reason to believe in a "pure" vacuum, of the really empty kind, or in a "contaminated" vacuum, of the QM type? And if he was certain of which, then what is the experimental evidence which he would have had?
studiot Posted March 17, 2019 Posted March 17, 2019 11 minutes ago, taeto said: I thought that permittivity and permeability would be observed physical quantities. How would you gather mathematical evidence of their quantitative values? Anyway, Eise already presented mathematical evidence, to argue that if either magnetic permeability or electric permittivity vanishes, then the speed of light becomes infinite. Really? Consider the following thought experiment. Since it is a thought experiment I have the luxury of perfect (i prefer the term ideal) components. I have two perfectly conductive metal parallel plates, each of area 1 sq cm, supported in an ideal vacuum exacltly 1cm apart. They are connected, via ideal short wires, to an ideal 1V battery. Please explain mathematically (Eise did not do this) what the capacitance of this arrangement is, if as you maintain, epsilon nought is zero.
swansont Posted March 17, 2019 Posted March 17, 2019 7 minutes ago, taeto said: Remember we are talking pre 1930. Did Einstein at that time have reason to believe in a "pure" vacuum, of the really empty kind, or in a "contaminated" vacuum, of the QM type? And if he was certain of which, then what is the experimental evidence which he would have had? You tell me. What evidence supports the notion that the permittivity and permeability coukd be zero?
taeto Posted March 17, 2019 Author Posted March 17, 2019 1 minute ago, studiot said: Consider the following thought experiment. Since it is a thought experiment I have the luxury of perfect (i prefer the term ideal) components. I have two perfectly conductive metal parallel plates, each of area 1 sq cm, supported in an ideal vacuum exacltly 1cm apart. They are connected, via ideal short wires, to an ideal 1V battery. Please explain mathematically (Eise did not do this) what the capacitance of this arrangement is, if as you maintain, epsilon nought is zero. The problem with that, I think, is that there is no "uncontaminated" vacuum between the plates. If there were, the experiment might come out differently than what it actually does. 3 minutes ago, swansont said: You tell me. What evidence supports the notion that the permittivity and permeability coukd be zero? Now, in 2019? Why is that relevant?
studiot Posted March 17, 2019 Posted March 17, 2019 (edited) 4 minutes ago, taeto said: The problem with that, I think, is that there is no "uncontaminated" vacuum between the plates. If there were, the experiment might come out differently than what it actually does. That is just wriggling. The basic definition of the capacitance assumes an ideal vacuum. Quote What does epsilon naught mean? - Quora https://www.quora.com/What-does-epsilon-naught-mean 19 Mar 2015 - Also called the permittivity of free space, it is an ideal physical constant that represents the absolute dielectric permittivity of a vacuum. In other words, epsilon naught quantifies the ability of a vacuum to allow electric field lines to flow through Edited March 17, 2019 by studiot
taeto Posted March 17, 2019 Author Posted March 17, 2019 2 minutes ago, studiot said: That is just wriggling The basic definition of the capacitance assumes an ideal vacuum. Is "an ideal vacuum" a perfect vacuum in some classical sense, or in a QM sense? Those are distinct, no?
studiot Posted March 17, 2019 Posted March 17, 2019 My vacuum has nothing whatsoever to do with QM. This is a thread about Einstein, Relativity and Pre Nazi Germany. Relativity is fully compatible with Electrodynamics (or the other way round if you prefer) when the later is suitably written. Eise did point out that this was Einstein's big breakthrough.
taeto Posted March 17, 2019 Author Posted March 17, 2019 (edited) 28 minutes ago, swansont said: You tell me. What evidence supports the notion that the permittivity and permeability coukd be zero? Now I suspect that you are just trolling me. The point is, that in the pre-1930 discussion there might be present a concept of a kind of "pure vacuum", really literally with nothing in it, no permittivity, no permeability, no stuff whatsoever. Just like school children are taught today everywhere. Which we well know nowadays is not the case, but I want to keep it open that at least some people at that time might have believed this to be the case. Einstein definitely had lots of evidence to support that the actual vacuum has nonzero permittivity and permeability. He obviously had no experimental evidence to support what a hypothetical "pure vacuum" without QM phenomena happening would behave like, because such a thing did not exist then either. Edited March 17, 2019 by taeto
studiot Posted March 17, 2019 Posted March 17, 2019 13 minutes ago, taeto said: Now I suspect that you are just trolling me. The point is, that in the pre-1930 discussion there might be present a concept of a kind of "pure vacuum", really literally with nothing in it, no permittivity, no permeability, no stuff whatsoever. Just like school children are taught today everywhere. Which we well know nowadays is not the case, but I want to keep it open that at least some people at that time might have believed this to be the case. Einstein definitely had lots of evidence to support that the actual vacuum has nonzero permittivity and permeability. He obviously had no experimental evidence to support what a hypothetical "pure vacuum" without QM phenomena happening would behave like, because such a thing did not exist then either. No one is trolling you. Of course there was a concept of pure vacuum pre 1930. The constant we are talking about was introduced by Coulomb in 1785, although he used different units from modern SI ones, they were definitely not zero.
swansont Posted March 17, 2019 Posted March 17, 2019 1 hour ago, taeto said: Now, in 2019? Why is that relevant? In 1930. 50 minutes ago, taeto said: Now I suspect that you are just trolling me. A convenient evasion, so that you don’t have to answer. Why is zero permittivity and permeability a reasonable model? 50 minutes ago, taeto said: The point is, that in the pre-1930 discussion there might be present a concept of a kind of "pure vacuum", really literally with nothing in it, no permittivity, no permeability, no stuff whatsoever. Just like school children are taught today everywhere. Which we well know nowadays is not the case, but I want to keep it open that at least some people at that time might have believed this to be the case. School cho]ildren are taught that today? 50 minutes ago, taeto said: Einstein definitely had lots of evidence to support that the actual vacuum has nonzero permittivity and permeability. He obviously had no experimental evidence to support what a hypothetical "pure vacuum" without QM phenomena happening would behave like, because such a thing did not exist then either. So, with no evidence, the claim would seem to be without basis.
Eise Posted March 18, 2019 Posted March 18, 2019 9 hours ago, beecee said: While I certainly appreciate the research you have undertaken, the fact remains that Germany at that time, and prior, was being dominated by anti semitism and that the Nazis were already well and truly indulging in thuggery to get there point across. I nowhere denied that there were antisemitic critiques on Einstein. But 'A Hundred Authors Against Einstein' doesn't seem to be a symptom of it. If some of the authors were antisemitically motivated, they do not show it in the book. 10 hours ago, beecee said: Your own Wiki link says "the contributions to the book are a mixture of mathematical–physical incompetence, hubris," and "Hans Reichenbach described the book as an "accumulation of naive errors", and as "unintentionally funny", can also likely be construed as due to antisemitism. I do not see why one would do that, except one knows more about the motivations of the authors and/or editors. I think you should apply the same rigidity to history as to any other science. Maybe there is more behind the book, but until now I did not find any hint in that direction. 10 hours ago, taeto said: I suspect that you miss the point. The actual vacuum has positive magnetic permeability and electric permittivity. Which we can both measure. The imagined "perfect" vacuum presumably has no magnetic permeability nor electric permittivity, hence the speed of light is infinite therein. If you for some reason believe that a vacuum could conceivably act like that, then you would have to admit that there would be no absolute bound to the speed of light. Hmmm. Wouldn't it be a little bit too speculative for Lasker to suppose that a 'real' vacuum has a magnetic permeability and electric permittivity of zero?
beecee Posted March 18, 2019 Posted March 18, 2019 (edited) 1 hour ago, Eise said: I nowhere denied that there were antisemitic critiques on Einstein. But 'A Hundred Authors Against Einstein' doesn't seem to be a symptom of it. If some of the authors were antisemitically motivated, they do not show it in the book. "Doesn't seem to be" may have been all part of a plot, knowing the possible repercussions from a regime that openly indulged in thuggery. Taking that with the facts that only 12 months earlier, Einstein had been lauded as the Newton of his age for the confirmation of his prediction, based upon GR, that light would be bent by the gravitational field of the sun. Quote I do not see why one would do that, except one knows more about the motivations of the authors and/or editors. Granted, none of us were privileged as to the motivations, but when one examines the fanatical antisemitism of the Nazi's and open thuggery they indulged in, plus the situation as reported being full of mathematical incompetence, hubris," and an accumulation of naive errors, as being unintentionally funny, one might wonder how learned scientists would leave themselves so open for criticism in later ages. Quote I think you should apply the same rigidity to history as to any other science. I believe I have, and I believe that has been supported in the link I gave. https://arxiv.org/ftp/arxiv/papers/1111/1111.2194.pdf Quote Maybe there is more behind the book, but until now I did not find any hint in that direction. And all I'm proposing, without having any inside first hand knowledge, is that due to the climate in Germany at that time, antisemitism, along with other reasons already mentioned, need be on the table when looking for motivation. Questions I would be asking, and I don't think I have researched this as thoroughly as you, are where were the hundred authors residing at the publishing of this hundred authors against Einstein, and why did they go to the extent of anti Einstein meetings to poo poo SR/GR when from where I sit, the science did not detract or interfere with the NAZI regime and manifest, other then Einstein was a Jew. Edited March 18, 2019 by beecee
Eise Posted March 18, 2019 Posted March 18, 2019 2 hours ago, beecee said: "Doesn't seem to be" may have been all part of a plot, knowing the possible repercussions from a regime that openly indulged in thuggery. Hmm. It may have. Or it may not have. Even in 1931, the year the book was published, the Nazis were not in power yet. That took another 2 years. 3 hours ago, beecee said: Taking that with the facts that only 12 months earlier, Einstein had been lauded as the Newton of his age for the confirmation of his prediction, based upon GR, that light would be bent by the gravitational field of the sun. This is from the article you linked. But it describes thing that happened in 1920, not in 1931. 3 hours ago, beecee said: Granted, none of us were privileged as to the motivations, but when one examines the fanatical antisemitism of the Nazi's and open thuggery they indulged in, plus the situation as reported being full of mathematical incompetence, hubris," and an accumulation of naive errors, as being unintentionally funny, one might wonder how learned scientists would leave themselves so open for criticism in later ages. Wikipedia had an interesting observation here: Quote As regards the average age of the authors: 57% were substantially older than Einstein, one third was around the same age, and only two persons were substantially younger. I think the easiest explanation, that most authors believe that RT is wrong, is that they firmly stand in the Newtonian tradition. Also, as an example, the text that should have been included from Ehrenfest, was from 1912. Somehow, I do not believe he was still a relativity-skepticist in 1931. 3 hours ago, beecee said: I believe I have, and I believe that has been supported in the link I gave. As said, this is about the situation in 1921. 3 hours ago, beecee said: And all I'm proposing, without having any inside first hand knowledge, is that due to the climate in Germany at that time, antisemitism, along with other reasons already mentioned, need be on the table when looking for motivation. Certainly, I agree antisemitism should be on the table, because it might have played a role, but if we do not discover that, then we cannot confirm that antisemitism was the motivation to publish the book. 3 hours ago, beecee said: Questions I would be asking, and I don't think I have researched this as thoroughly as you, are where were the hundred authors residing at the publishing of this hundred authors against Einstein Again from Wikipedia: Quote It contains very short texts from 28 authors, and excerpts from the publications of another 19 authors. The rest consists of a list that also includes people who only for some time were opposed to relativity. So only 28 authors really wrote something for the book. And 'people who only for some time were opposed to relativity' does not point exactly to antisemitism. Probably they just learned the RT better a few years later.
studiot Posted March 18, 2019 Posted March 18, 2019 (edited) On 3/14/2019 at 2:42 PM, taeto said: It would be historically interesting if they were already in 1928 in a position to influence the publications of reputable scientists. What would be the mechanism by which this is possible? I don't find it at all suprising that prior to the rise of Stark and the 'Aryan Physics' movement, (1933) when many prominent Jewish academics were replaced by non Jews in Germany that pressure groups had existed for a substantial number of years. Such activity has many precedents in history and even today. Some of this is bloodthirsty and some more 'civilised'. For instance The Protestants burned Bruno at the stake. The Catholics threatened and perhaps tortured Galileo The French Revolution executed Lavoisier whilst Fourier flourished. Both the Tsarists and the Soviets condemned scientists to the gulags (sharashka). All of these were carried out by authoritarian regimes in the height of their powers. But that poser but did not come overnight - it took years in the developing. I also said more 'civilised' The US Presidency clears out most of the heads of departments with an outgoing President, to be replaced by those in favour with the incoming, regardless of how good they were in office. I suppose you couldc all this more civilised because heads no longer roll as they used to in ancient civilisations and past european clearouts. Edited March 18, 2019 by studiot
beecee Posted March 18, 2019 Posted March 18, 2019 6 hours ago, Eise said: Hmm. It may have. Or it may not have. Even in 1931, the year the book was published, the Nazis were not in power yet. That took another 2 years. This is from the article you linked. But it describes thing that happened in 1920, not in 1931. Making the point that even in 1920, 12 months after Einstein gained "Newton like notoriety" after GR was validated, fanatical antisemitism was evident. Quote Certainly, I agree antisemitism should be on the table, because it might have played a role, but if we do not discover that, then we cannot confirm that antisemitism was the motivation to publish the book. Agreed, we have a number of hypotheticals and are both looking back at this in hindsight. My thoughts are, supported I believe by what I have presented, is that antisemitism, was consciously or unconsciously, part of such a fanatical exercise as publishing a "book" entitled "A Hundred Authors Against Einstein" If antisemitism was not the prime motivator, it would have been more prudent and correct to entitle the book, "A Hundred Authors Against Relativity"
swansont Posted March 18, 2019 Posted March 18, 2019 From what I've read (and this may be wrong), there were not 100 essays in the book. Some authors are listed there without having provided any details of their disagreement. "Published in 1931, it contains short essays from 28 authors, and published excerpts from 19 more. The balance was a list of 53 people who were also opposed to relativity for various reasons." http://weeklysciencequiz.blogspot.com/2013/01/a-hundred-authors-against-einstein.html Do we know what the motivations are of people who only signed their name? The fact that there is apparently no overt anti-Semitism in the writings does not eliminate that as a motivation. The best you can say is "We don't know" regarding the motivation of over half of the people, unless they published critiques elsewhere and someone tracks them down.
taeto Posted March 18, 2019 Author Posted March 18, 2019 1 hour ago, swansont said: Do we know what the motivations are of people who only signed their name? The fact that there is apparently no overt anti-Semitism in the writings does not eliminate that as a motivation. The best you can say is "We don't know" regarding the motivation of over half of the people, unless they published critiques elsewhere and someone tracks them down. That is an interesting comment. I cannot come up with many examples of "opponents" of relativity from the first half of the 20'th century who were obviously anti-semitic. It did not really kick in as a popular item until late. I could volunteer numerous examples that I have encountered and/or engaged of current day anti-Einstein cranks who are very openly anti-semitic (as well as anti-Cantor cranks, for that matter). These days, it seems a vastly more popular thing. Admittedly, it is usually easier to identify a crank in our time, because it has to deny a hugely larger compound of observational evidence than was present 75 years ago. In previous times, they seemed somehow more timid and less attracted to public exposure. So that might skew the statistics.
Eise Posted March 19, 2019 Posted March 19, 2019 9 hours ago, swansont said: From what I've read (and this may be wrong), there were not 100 essays in the book. Some authors are listed there without having provided any details of their disagreement. Well, there might be about 100 text fragments in the book. As I showed, most are very short, some are more than 10 years old and just quotations. Some of these authors might not even have known that a text fragment of them was inserted in the book, and even changed their minds in the meantime. And this is a telling citation from your link: Quote The book was not a reaction against Einstein from the physics community—only one physicist had contributed. Nor was it supported by the younger generation—only two of the contributors were much younger than Einstein. It was a dying cry from the old guard of science that felt left behind by the new physics and incompetent because they didn’t know what to do with it. Before Einstein published his work, Newton’s theories were gospel among the scientific community. Einstein had the temerity to use space and time as a way to think of our Universe, not just an a priori condition in which we lived. There we have it all: people who can't understand relativity, or people who are so stuck in Kantianism (last sentence), virtually no physicists. 10 hours ago, swansont said: Do we know what the motivations are of people who only signed their name? Maybe they did not even sign, but were just quoted. 10 hours ago, swansont said: The best you can say is "We don't know" regarding the motivation of over half of the people, unless they published critiques elsewhere and someone tracks them down. Full ack.
swansont Posted March 19, 2019 Posted March 19, 2019 2 hours ago, Eise said: Maybe they did not even sign, but were just quoted. True. I had been under the impression these were solicited, but it's certainly possible it was just a collection of quotes/writings.
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