Talk:Ernst Mach

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Contents 1 Content removal 2 Marx's Influence 3 Mach's number 4 Mach's financial status 5 Humor 6 Machism please? 7 Was he an atheist? 8 Plagiarism 9 Chunk 10 Concerning the School/tradition

[edit] Content removal

I've reverted extensive content removal by 64.21.98.130. I see no acceptable reason for such an action, and 64.21.98.130 doesn't provide any. Furthermore, this IP seems to be used for vandalism (see past edits). I've posted a warning on the IP's talk page. // Pathoschild 12:05 29 September 2005

[edit] Marx's Influence

Can anyone cite the influence of Marx on Mach?

[edit] Mach's number

It is my understanding that c is the speed of light. v being the velocity, Mach should be v/speed of sound which I abreviated as ss. If this is incorrect I appologise, but as it stands: c/v it read to me as speed of light/velocity - which makes no sense.

indeed, c is confusing because we usually read it as the speed of light. sometimes we read it as some other constant, but hardly ever as the speed of sound (which is not a constant since it changes with the changing pressure inside the medium the sound travels through). also ss is flawed since physicists never use s for speed but always v for the latin word velocitas (speed).

i have changed Machs number to v_p/v_s because the same phrase says "velocity of projectile" and "velocity of sound". now even non-physicists can understand what the variables stand for.

if you really want to use c and v then it should also be written as v/c and not as c/v.

(PS. please sign your discussion contribution by typing ~~~~ at the end)

-- ActiveSelective 07:27, 20 January 2006 (UTC)

I have seen Mach's number written as M = v/a, where a is the local speed of sound, and v is the speed of the object relative to the surrounding air (In the fifth edition of Introduction to Flight by John D. Anderson). However the v_p/v_s notation seems clear enough. zipz0p 13:38, 16 March 2006 (UTC)

I notice the first set of links at the bottom of the article are not working. I came to this article hoping to find information on Mach's experimental setup for photographing shock waves produced by bullets. I recall seeing a schematic, I think of Mach's setup, which involved pair of spark gaps in series, powered by a Lyden jar capacitor. One gap was partly bridged by a candle flame. Muzzle blast from the gun was directed to the candle flame to bridge the first gap, causing the spark to jump both gaps. This was a plasma trigger. With some adjustment, the spark would occur when the bullet was between the second gap and the camera, producing the image. If anyone knows of a reference showing this clever setup, it might make a nice link or addition. If I find one, I'll link it. Tomligon (talk) 03:41, 29 January 2008 (UTC)

[edit] Mach's financial status

Does any one know what money status was Ernst Mach? like was he rich or poor

Yes, i know. He was not rich, not poor, but one in the better-paid middle class. It was none of the extremes. But how is this interesting for the article?

(PS. please sign your discussion contribution by typing ~~~~ at the end)

-- ActiveSelective 07:32, 20 January 2006 (UTC)

Socioeconomic status is an interesting side-note. It can be interesting to see how ingenious and resourceful a person was. It is easier to gain good schooling and to learn useful background if one starts from a wealthy or at least well-to-do background. Particularly before the age of the abundance of scholarships that there are now, it would have been difficult for him to get the education he did without money. So, in conclusion, adding a note in the introduction of his past and history about his socioeconomic background could be interesting. If I remember, I'll look up a short history on him in one of my books and do it myself when I have time.

-- zipz0p 01:53, 31 March 2006 (UTC)

[edit] Humor

The folly of basing Scientific Research on unobservables events. Ernst Mach did not believe in the theory of the atom, saying that "atom" is just a word and nothing more.

Mach went on. If you do believe in the atom, what would happen? Well physics will generate many many results. Physicists will construct models of the atom and then they will find out that these model do not work.

So then physicists will replace the models with newer mathematical models because mathematical terms can be stretch to fit any data. And then physicists will end up saying that "because we can't observe it, we can't measure it. So the position might be this and the energy is probably that."

Then the physicists will be driven to the theory that the energy comes and goes more or less at random. All sorts of trash will appear in their theory. There will be "elementary particles" with strange names and anti-matter which ought to be there but isn't. These "particles" would either behaving like a wave or discrete particles depending on the observable outcome. So the laws of physics will degenerate into mumbo jumbo.

Any theory must be capable of ultimate verification by observable events. Otherwise, it is not understandable and therefore is mere words.Lestrade 02:06, 6 November 2006 (UTC)Lestrade

[edit] Machism please?

I would like to see a section here on Machism as it is antagonized in Marxist criticism, cf. Lukacs' 'What is Orthodox Marxism?' Also for the time being the search term 'Machism' should redirect here (to Ernst Mach). (I'm not sure how to do this on my own.)

[edit] Was he an atheist?

I have heard that he rejected the existence of God.

[edit] Plagiarism

According to Wikipedia watch (see [1]), some text of this article (as of October 2006) appeared to be plagiarized from Britannica. It seems that the relevant portions of this article have been rewritten. --Aleph-4 09:54, 23 April 2007 (UTC)

A large portion of the Physics section appears to be from http://utf.mff.cuni.cz/Relativity/Mach.htm —Preceding unsigned comment added by 68.82.147.132 (talk) 00:56, 12 May 2008 (UTC)

[edit] Chunk

I removed the following chunk of text - reads like an essay and there may be some OR in it.

The question is, did Mach deny the relevance of the a priori apropos of some of its possible significances or did he deny the a priori all together? If we are able to conclude the former (rather than the positivist position: the latter), then we will be in a good position to suggest that a great mind such as Mach's would never have denied the significance of Kantian doctrine for an understanding of the scientific endeavor (including the significance of the a priori).

Mach's central text, as far as this debate is concerned, is his quasi-textbook entitled, "The Science of Mechanics." Thankfully, we can cut to the chase here as there are only a couple times that a priori or a posteriori are mentioned and, to complicate things further, it is always in the same vain; Mach denies the use of any a priori in arriving at the concepts that make up law-based propositions. In one of his only explicit mentions of the a priori in the Mechanics, Mach writes, "All this[, the derivation of the valid application of certain laws within certain circumstances,] has often led men to attribute knowledge of this kind to an entirely different source, namely, to view it as existing a priori in us (previous to all experience). That this opinion is untenable was fully explained in our discussion of the achievements of Stevinus. (p.83)" The specific 'achievements of Stevinus,' though they are indispensable so far as Mach's narrative of mechanics is concerned, is dispensable as far as his treatment of the a priori is concerned and so the reader's time will not be wasted with such explanation. With our goal in mind, it is only necessary to understand here that Stevinus arrived at a special application (static) application of a special law (a law of equilibrium, retrospectively derivative from the law of the composition of forces) that he could only have arrived at through experiment in the physical world. He could not pull a 'Bernoullian' trick, as Mach would have it; that is, he could prove the applicability of the law of the parallelogram of forces to the real world just because such a law is mathematically demonstrable prior to experience in the world; i.e. just because the law is a priori.

A HA! exclaim the positivists, so Mach does throw the a priori to the wolves. Well, no, unfortunately for the positivists, that is not true. A more careful reading or, might one even go so far as to say, any fair reading of Mach's text at all, would reveal that Mach only denies the a priori in a specific sense: in knowing how to validly or, in his terminology, 'economically' apply laws to the physical world. Only experience can tell us that, Mach insists, so don't go believing you can fly because you can dream about it--Mach warns the Bernoullians of the world. This, however, seems to be the advice of every great mind of the period, from Poincaré to Einstein. Not-a-one of them would advocate for such a pre-experiential application of the concepts of the a priori and, surprise-surprise, neither would Kant.

Some, such as Hans Reichenbach, suggest, however, that there is a more subtle strain in Mach's conception of the way that laws arise and are validly applied. Such academics insist that Mach's conception of the inception of physical law is based upon empirical circumstance, is empirically given, and therefore contingent only upon circumstance. This tendency towards the given, which is so central to logical atomism, is nowhere to be found in Mach!

Mach is all about the 'imagination': the Kantian constructor of concept. Therefore it is no surprise that Mach acclaims Newton and his universal law of gravity. This law is, for Mach, forever true and applicable (universal). Yet this law is of a synthetic a priori nature: the very consideration that lead Kant to embark upon the Critique of Pure Reason. Furthermore, Mach's text is rich with suggestions as to the timelessness of laws, be it those of Gallileo or those of Newton (which, as he later points out, are to be conflated/subsumed one in the other). What is contingent for Mach is not what Newton called a 'law', but what he called a 'proposition'; namely that the law of gravity take on the form of the inverse square. Yet experience has proved it to be so, and therefor, though it may be a synthetic statement that's application to the world would have been arbitrary and audacious otherwise, because experience has validated it, it has taken on a synthetic a priori nature (which it could not have done without experience). This is the place that Mach reserves for the a priori for, at the same time that it is implied by his text, he never suggests or says otherwise. Indeed, it is worth considering Mach's one explicit mention of Kant within his entire text.

Mach writes, "It is scarcely necessary to remark that in the reflections here presented Newton has again acted contrary to his expressed intention only to investigate actual facts. (p.229)" He is here speaking of Newton's conceptions of Absolute Space and Absolute Time. Newton's example of the rotating bucket is invoked to delineate between the cetrifugal forces acting on the water and the forces of the rotating bucket as not indicating anything about Absolute Space, as he imagines Newton thought it did, but merely of the relative action of complex forces upon the water.

Newton's point, however, could be read to mean that, while we are repeatedly confronted by the action of complex forces, the fact that, as scientists, we are made to consider the potential of relative motions in an infinite regress (the bucket acting upon the water at the same time as the relatively stationary earth actus upon it, etc.---why stop at the earth?) and so we are faced with a humbling fact: as far as our finite minds might consider relative motions, there seems to be the infinite possibility of further considerations of relativity. "But if we take our stand on the basis of facts," Mach admits, "we shall find we have knowledge only of relative spaces and motions. (p.232)" How then, is the scientist to decipher the outline of a law-like proposition, such as that of the inverse square, in the face of this daunting relativity?

Newton thus concludes that we must assume that the relativity stops somewhere, that there is such a thing as an absolute space and an absolute time, for by such a conclusion the scientist is once again liberated to act as if the propositions that he constructs as he observes the relative motions of physical phenomena have absolute/universal significance: the universal gravitation that Mach so enthusiastically applauds. "No one is competent to predicate things about absolute space and absolute motion; they are pure things of thought, pure mental constructs, that cannot be produced in experience. (p.229)" Precisely, Mr. Mach, that is precisely what they are, however, he writes of the Absolutes as, "idle metaphysical conception[s]. (p.224)" Mach understands the necessity of relinquishing man's grip on attempting to nail down relativity from its infinite regress, as he writes, "It is certainly fortunate for us, that we can, from time to time, turn aside our eyes from the overpowering unity of the All, and allow them to rest on individual details, (p.235)" and so one has to wonder exactly why Mach took such an aversion to such utterances of the absolutes: poetic utterances, metaphysical concepts and practical ones at that.

The answer stares us in the face: Mach, for whatever reason(s), was hellbent on keeping metaphysics separate from science. Is this symptomatic of a poor understanding of the relation between metaphysics and science in the long-time established Kantian doctrine, or is this a symptom of a time period in which ghosts like the ether and the atom haunted physics? I am inclined, at this point, to suggest the latter, for (while Mach seems to have supported the ether) we have Mach's rabid anti-atomism as at least one salient symptom of what may fairly be portrayed as a desire to keep physics pure of the kinds of dialectical illusions that Kant illustrates in his antinomies (atoms versus plenum). Mach concludes, "No one is warranted in extending these principles beyond the boundaries of experience. In fact, such an extension is meaningless, as no one possesses the requisite knowledge to make use of it. (p.229)" Admittedly, this is an alarmingly dismissive tone when one considers the subtlety of the Newtonian conception... Mach explains, "No one is competent to say how the experiment would turn out if the sides of the vessel increased in thickness and mass till they were ultimately several leagues thick. The one experiment only lies before us, and our business [as physicists] is, to bring it into accord with the other facts known to us, and not with the arbitrary fictions of our imagination. (p.232)" But what of our business as metaphysicians? While Mach is thankful for our ability to act as if we observe absolute motions (though we know epistemologically that our knowledge reflects only relative motions), he warns, "But we should not omit, ultimately to complete and correct our views by a thorough consideration of the things which for the time being we left out of account (in our practical discursions into the realm of the absolues).

In an appended remark, Mach reveals, "I regard... Newton's distinction as an illusion. (p.543)" This remark is revealing because, while he shows that he understands the necessity of acting as if motions that we observe occur in absolute space, he is here demonstrating that he does not understand Newton to be alluding to this practical necessity. Perhaps his admiration for Newton as a 'first rate philosopher' falls short of affording Newton the subtle reading that his words demand (for such an interpretation of his words is possible). Or perhaps Mach has resigned such a subtle reading to the persistent co-opting of Newton by his contemporaries in the name of cruder reading (Streintz's criticism of Mach seems to suggest this latter position). In any case, Mach does portray Newton as having been sloppy in form as he writes, "Like the commander of an army, a great discoverer cannot stop to institute petty inquiries regarding the right by which he holds each post of vantage he has won... Newton might well have expected of the two centuries to follow that they should further examine and confirm the foundations of his work. (p.245)"--i.e. clean it up, not in substance but in presentation, for, as Mach writes, "[Newton] was, as it is possible to prove, not perfectly clear himself (in his writings) concerning the import and especially concerning the source of his principles. (p.244)"

Mach says what Newton ought to have said (and, of course, can be read as having said). However, there is one last point in treating of the philosophy underlying Mach's scientific endeavor, and that is whether he was actually aware that his well grounded treatment of the a priori (negative) kept the a priori within the bounds that Kant intended it to be: for that he certainly did. That is, was Mach aware of the positive place of the a priori within his own exposition or was he unwittingly re-inventing the wheel? Signs point to no, that he was not aware of his inherited philosophical foundation, as he writes, "Newton might well have expected... that, when times of greater scientific tranquillity should come (Mach is here implying the future after even his own time), the principles of the subject might acquire an even higher philosophical interest than all that is deducible from them. (p245)" What is there left to imagine in terms of deducing from principles, if all phenomenal deductions are excluded, than a 'transcendental' deduction of the Kantian variety? The evidence seems to suggest that Mach didn't so much deny the significance of the Kantian doctrine, but merely that he wasn't aware of the full implications of that doctrine.

WLU 20:07, 19 June 2007 (UTC)

[edit] Concerning the School/tradition

I think it's absolutely nonsense to say that Mach was "School/tradition - Analytic philosophy". No such school or tradition existed at his lifetime. Yes, it's a popular thing these days to call almost everybody retroactively either an analytic philosopher or a continental philosopher, but I don't think it's fair historically. That claim should either be supported by a good and reliable source, or removed. Androg (talk) 23:24, 3 April 2008 (UTC)