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Ernst Mach

ics, which had not been fillcd during his two-ycar abscncc in Lcipz.ig, and Mach’s professorship in thc philosophy of science as wcll. Boltz-mann cagcrly acccpted, and his pessimism yaiiishcd in the tumultuous applause from thc overflowing audience which greeted his reappear-ancc at thc Univcrsity of Yicnna. His initial physics lccturc in 1902 started with his charactcristic, partly unintcntional, humor. He said that there was no need to pay thc usual compliments to his predecessor sińce hc was his own predecessor. His inaugural philosophy lccture in 1903 bccamc a public cvent attendcd by several professors. Alois Hofler wrotc: “I was . . . one of thc 600 listeners of both first lectures of Boltzmann on ‘naturę philosophy’ [October 26 and 27, 1903J. An unchaincd storm of laughtcr greeted his opening words: ‘How have I comc to tcach philosophy?’ And thc laughtcr re-erupted from scntcnce to sentence.” ¹² Ludwig Flamm remembered: “The lectures of Boltzmann on naturę philosophy were immcnscly popular, but his lectures on thcoretical physics were also wcll attendcd.’’¹³

Lise Meitncr rccalled:

I was able to hcar his lectures from 1902 until his dcath in 1906. . . . Boltzmann had no inhibitions whatcvcr about showing his enthusiasm whilc he spokc, and this naturally carried his listeners along. Hc was also vcry fond of introducing rcmarks of an cntircly pcrsonal character into his lectures—I particularly remember how in dcscribing the kinctic theory of gases, Hc told us how much difficulty and opposition hc had eneountered bccausc hc had been convinccd of thc rcal existcnce of atoms, and how hc had bccn attackcd from thc philosophical sidc, without always understand-ing what thc philosophers had against him.¹⁴

Sonic of Boltzmann’$ students, however, were confused or ofTended by his “pcrsonal” rcmarks. Gabriele Rabcl, for example, was so upset that she cvcn sent a letter to Mach to find out if what Boltzmann was saying was truć. “From thc side of a prominent university tcachcr [i.c., Boltzmann] I havc hcard you rcpeatedly character i zed—and to-day once again—as a sensualist or evcn a psychomonist, as one, for whom thc world exists only as perceptions, and who views thc psyche as the only rcality.” ¹⁵

Mach tried to placate her by mentioning that words can be used and understood in different ways. That she remained disturbed, however, is elear cnough from thc fact that she published her letter and that of Mach almost twenty ycars later to illustrate how important pcoplc could “misunderstand” Machs ideas.

If "profcssional philosophers” were irritated by Mach occupying ^: “Brcntano’s chair,” and they were, imagine their rcaction when Boltz-mann sat in it. "Boltzmann?" Even Mach's supporters were aghast at I this newest jokc.^,fl Surcly this meant thc end of philosophy.

Kor were science students any thc less dividcd and upset ovcr Boltz mann’s tenacious defense of thc “outmodcd” atomie "hypothcsis." i Thosc who dislikcd philosophy gcnerally supported Boltzmann and | those with an interest in philosophy, Mach; other students were simply confused or tried to bclicve that thc ideas of Mach and Boltzmann were basically compatiblc with cach other. Who was ‘‘modern” and who “old-fashioned” was also a matter of disputc, or rather of per-spectivc. Herc arc somc divcrsc quotations from scicntists who were Vicnna students shortly before or after thc tum of thc ccntury.

Lisc Meitner preferred Boltzmann:

Lampa was an cxcellent expcrimcntalist, hut as an enthusiastie foliower of Mach, was rather sceptiral of thc modern dcvclopmcnts of physics.¹⁷

A pro-Mach student dcclarcd (1906):

It was wcll known, that the wholc atomie theory was only a picture, but hc [Boltzmann’ held on to it as a convcnicnt hypothcsis. He thereby found himsclf in opposition to Ostwald, Ernst Mach and most other physicists. who for thc most part arc cncrgcticists, which mcans that they make no spccial assumptions with rcspect to typc of matter \Stoff], but try to under-stand all physical processcs mcrcly with thc help of conccpts of purc cnergy. Boltzmann is thc last grea: rcprescntativc of thc atomie theory in thc physical world.¹⁸

Ludwig Flamm rccallcd:

//. Machc confcsscs that hc suffered at that timc and for many ycars afterwards bccausc hc had had two teachcrs with such different scicntific vicws as Boltzmann and Mach. Hc thinks that if Mach himsclf had not taught that thc cxperimental physicist nced not troublc himsclf too much about cpistcmological matters, that hc would have suffered cvcn morc from this [intcllcctual] discord.¹⁹

Philipp Frank rcminisced:

Also, strange as it was, in Vicnna thc physicists were all followcrs_ef Nfach and foliowers of Boltzmann. It wasn*t thć casc thsft pcoptc would holćTany antipathy against Holtzmann*s thcor> of atoms bccausc of Mach. And I don’t cvcn think that Mach had any antipathy. At least it did not play as important a role as is often thought. I was always interested in thc

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