IMG83

Ernst Mach

practical with pcrhaps thc caceptiun of Wittgcnstcin who is in somc way also a poct.⁴⁵

Pascual Jordan (1902-) has probably bccn thc most outspokcn

Machist among all thc quantum thcorists who havc contributcd to or acccptcd thc Copenhagcn intcrprctation: "Ycs, hc [Mach] strongly influcnccd mc. Basically, cvcn today I am still a follower of Mach, though of coursc I am critical on points of detail. But fundamcntally I have constructcd my physical thinking an Mach's conccptions, which havc latcr proved most hclpful in thc undcrstanding of quantum me-chanics and thc thcory of rclativity.^ł’⁴⁰

Jordan was one of thc vcry fcw followcrs of Mach who dared publish articles and books honoring thc Austrian professor and Judenfreund in Nazi Germany⁴⁷ Most Austrian and German celcbrations of the hundredth annivcrsary of Mach’s birth, which were to takc place in 1938, were discouraged or canceled, but Jordan in Fcstung Rostock continued to sing Mach’s praises.

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Ernst Mach rejected Einstcin’s thcory of relativity partly because of its reliancc on multidimcnsional geometries.⁴⁸ It is morę than likcly that hc would have rejected much of quantum thcory on thc same grounds. Both Mach and Dingler prcdictcd that the usc of "/j-dimen-sions” and thc likc would rcsult in logical paradoxcs and scrious prób-lems of intcrprctation. Dingler at least lived long cnough to conclude “I told you so” and Mach would surcly havc joincd thc chorus.⁴⁹ Mach bclievcd that all mathcmatical symbolism should havc a elear “physical meaning," but ncithcr muhidimensionality nor particle-wavc duality allow this. Nor would Mach have bcen amuscd by causal indeter-minism.

Multidimcnsionality madę forcc-orientcd causal cxplanation literally unimaginable, but this was not a problem for Mach sincc he rejected forccs as causes in any casc, but thc Copenhagcn statistical approach with its refusal to allow that particular particlc-waves could bc under-stood in causal fashion of any kind, would havc bccn a most provocativc red flag for him. Mach bclicvcd that causcs were mathcmatical func-tions and that such functions could bc found to relate all “phenomena.” The notion that particle-wavcs were cxcmpt from functional deter-minism cxccpt on a statistical basis conflicted with his positivistic bc-

3*6

lief that all problcms were cithcr solvable or “mcaninglcss." If par* ticular particle-waves were real, then they had to be undcrstandable in functional terms, and if they were not real, then such an ambiguously defined notion should bc abandoned in favor nf what did less violence to conceptual rationality. Mach wanted clarity, but cven though the Copenhagen intcrprctation was largcly phenomenalistie in cpistcmol-ogy, it has not yet provided this.

XI

As might have becn cxpccted, quantum thcory in generał and thc Copenhagen intcrprctation in particular provcd godsends to a number of prcviously rejected “scicntific’' ideas. Gustav jaumann, for cxamplc, and his "Briinn schooi" of continuum physics now had at least a partial defensc in thc continuity aspeets of the quantum statistical approach, to thc cxtcnt that cven after Jaumann's death in 1924 his colleaguc Erwin Lohr was still ablc to kccp this lingering vcrsion of antiatomism alive.⁰⁰ Indced, in a sense, it was fitting that Mach’$ birthplace should havc bccn thc last stronghold of “purc" Machist science.⁵¹ In 1945 with the Russian “libcration,” another philosophical orientation, of course, took charge. In a philosophical sense, it might be interesting to notę that Czcchoslovakia, with its long history of “Machism" and "Rrentanoid" thought (it was thc last major European bastion of Machist philosophy after Hitlcr’s rise to power) was probably thc least prepared of any nation for an invasion of “dialcctical materialism." But be that as it may, Lenin had finally gained yet another mcasure of revcnge against “Machism.”⁵²

Spcaking of Communist philosophy, it too has reccntiy bccome gratcful for the Copenhagcn interpretation. The notion of a “dialcctical process in naturę" uscd to bc an embarrassment for Soviet and other lcft-wing scicntists, but now, the particlc-wavc duality seemed to prove that thcrc rcally were "contradictions in naturę." And who knows, perhaps still cleverer quantum physicists will evcmually discovcr a "dialcctical synthesis" to "rcconcilc" thc duality and thus help further “the inevitable course of world history."

But scriously, lest one bc carricd away by the implausibility of the Copenhagen intcrprctation of quantum physics, one must at least ad-mit, that rcgardlcss of how uninformativc its “physical meaning" may bc, quantum thcory as a mathcmatical system docs work.^M And