IMG58

Ernst Mach

that oncc again, physicists would (ocus thcir attcntion on thc sensory charactcr ot thc natural world and on thc ambiguous status of idealized relations such as "physicaT spacc and timc.

Mach's certainty as to thc thrce-dimensional naturę of sensory or "physiological” spacc was matchcd by his unccrtainty as to thc fuli charactcr of "physiological,” “metric,” and ‘‘physical” spacc. “Physiological" spacc had ncvcr been thoroughly investigatcd without idcali-zation; “metric” spacc was only limited by human imagination and mathematical i n genui ty, and "physical” space was a merę relation, but Mach never defincd what he meant by relations. Furtlicrmorc, whatcvcr “physical” spacc was, u was both idealized and subjcct, un-likc "metric” spacc, to the need for scicntific "economy," hencc Mach’s inclination to restriet "physical" spacc to the three dimensions of physiological or "nativistic" space.¹⁸

Boltzmann had oncc despaired ovcr thc immediatc futurc of his kinctic theory of gases (1898), but reinained confidcnt that in thc morc distant futurę physicists would comc to thcir seuses and acccpi his contributions. Ii wa$ now Machs tum (1910), though from an op-positc point of view, to see “folly” control his disciplinc, but likc Boltzmann he rcmained optimistic with respcct to the rcmotc futurę.¹⁹

In short, Mach was sustained during his last years by his funda-mcntal belief in thc soundness of phcnomenalistically oriented cxperi-mcntal physics and by his confidence in human progress, his faith that thc “stupidities” of undisciplincd theoretical physics would cven-tually shatter the field into thc understanding that describc-and-relatc-the-appcaranccs physics was not only a dcsirablc scicntific goal, but was also a rcliable scicntific meihod, and thc only appropriatc method for expcrimental physics.

By thc end of 1910 an acute obscrver could suspect that Einstcin s theory was wcll on its way to bccoming a ncw physical orthodoxy. Einstein and Minkowski were attracting too much attcntion to be used simply as ncgativc allics against carlicr physical vicws. Furthermore, Einstein had just obtaincd a chair at thc Univcrsity of Praguc, which Mach had hoped would go to Gustav Jaumann. His response was nevcr to mention Einstein again in any of his publications during his lifetimc.

Mach rcvised his Science of Mechanics in 1912. He repeated his opposition to thc usc of multidimcnsional geometries in physics in thc following unmistakablc words:

2OO

The spacc of sight and touch is three-dimensional: that, no one evcr yet doubted. If, now, it should be found that bodics vanish from this spacc, or ncw bodics get into it, thc qucstion might scicntifically be discusscd whether it would facilitatc and promotc our insight into things to eonceisc cxpcricntial spacc as part of a four-dimcnsional or inulu-dimcnsional spacc. . . . Evcryonc is frcc to set up an opinion and to adduce proof in support of it. Whcthcr, though, a scicntist shall find it worth his whilc to enter into scrious invcstigation$ of opinions so advanced, is a qucstion which his rcason and instinct alonc can dccidc. If thcsc things, in the end, should turn out to be truć, I shall not be ashamed of bcing thc last to belicve thcm.“°

In his revision, Mach discusscd Paul Gcrbcr’s attempt to relatc gravitation and clcctromagnctism, and he praiscd Hugo Dinglcr in thc most flattering terms: "I mysclf—scvcnty-four ycars old and strucle down by a gravc malady—shall not causc any morc revolutions. But I hopc for important progress from a young mathcmatician, Dr. Hugo Dinglcr, who judging from his publications, has proved that he has attaincd to a frcc and unprcjudiced suivcy of both sides of science [i.c., the empirical and logical].”²¹

But not a word was mentioned about Einstein, Minkowski, Philipp Frank, or the theory of rclativity.

IV

Einstcin’s lcttcrs to Mach on August 9 and 17, 1909, the articles ac-companying them, and cvcn his pcrsonal visit to Mach, all apparcntly failed to influence Mach away from supporting his former assistant, Gustav Jaumann, for the open chair in theoretical physics at the Um-versity of Prague. Jaumann, who was still tcaching at the Brunn Tcch-nical Univcrsity, suggested that thc sclcction committee ask for outside cvaluations from other physicists.²² Anton Lampa, a member of the commission, obliged and wrote to Mach in February 1910:

I don’t havc to assure you that Jaumann’s mental gifts secm to mc to be l>cyond qucstion and that his entire way of thinking is quitc sympathetk from my point of vicw. I considcr the purc phcnoincaological repnesenta tion of theoretical physics as ideał, as it approximately exists in thermo-dynamics. Jaumann starts from the desire to construct such a phenomcuo-logical representation for thc theory of clectricity. ... He thercforc re-jecis thc atomie and clcctton theories and trics to cxtcn«i MaxwclTs field cquations. . . .⁸⁸