IMGt1

Ernst Mach

hnncc a vcry pertinent rcmark that one could F. Hajck, madc by c •    transyerse wavc if one struck a scrics

obtain a ^^^uspended lead pieccs at well-timcd intcrvals, one of pcndul

.K». nthrr.

III

Betwccn .867 and .879 Mach published four books and « least sixty-o Ldc7» Most of thesc con.ribut.ona wmt on sc.ent.fie subjeets, f    _work r^mmthn Oj Energy {&jĄ was at least as „tuch

Iphicd ^enufic,tK«riBpitr^uc^Uthor to the aeademie Lr the first Ume as a philosopher. he book howeeer, attracted

-r~TT^s~koselv wrinrrrr^d    spcculative attack on the

^E^nkaltheory of hcat and the alomic "hypothesis" did not impress ” _ny phvsicists. Nor did philosophers tako significan, notice of it.

Three books, largely bascd on Mach’s «pmmental work, wcrc pub-lished within the nest three years: Opncal-Acousncal Inoesttgonont (.873), Contribt.tions to Doppler r Theory o lane and Coor Change through Alorenren, (.874). and Outlines oj the Theory oj the Motor Sensationt (1S75Among the numerous esper.mcnts that Mach was carrying out at this tinae those he conducted on motor sensations werc probably the most imporlant, and are coeercd m the next chaptcr. His ballistic Work and pressurc pattern invest.gat.ons are tnuched on in the chaptcr on shock waves.

IV

Mach was fortunatc in scvcral of his students. Ćcnek Strouhal (ścięła) studied math and physics at Praguc betwcen 1869 and 1873.-° During his first ycar he attended Machs elasses. “Mach, who was then 31, fascinated Strouhal with his elear and fundarncntal lectures. At that time [1869] therc was no Pral{til(er to conduct cxperiments during the lec turę, and the listeners were happy when afterward the assistants would carry out demonstrations with some of the yarious laboratory cquipmcnt availablc. Mach came to like Strouhal so much that a vcry cordial relationship developed.”-¹

Strouhal continucd to work under Mach after he reccived his doctor’s degree. His blabilitation thesis on frictional tones clcarly revcaled Machs continuiiig influence. After a short stay at Wiirzburg, Strouhal

returncci to Prague in 1882 and bccamc the professor f physics in the new Czech university. Indced Stroi l 1 ^CXpcrimcrUal known tor the similarity of his tcaching style to th ^ Tx* ^bccamc Czech professor bccamc Rector of his university _in ,    / ^Ch* ^Thc

hal i* l>'^{st known in scicnce for} joint publicaiions wilTri,'⁹?⁴' ^S'^r°^U‘ c. Barus, on the magnetic and galvantc propenie* of stcel '-tT'™*"’ lications contained the ingenious method of calibratin _h.^httCP^ub-for the manufacturc of permanent magnets for _meas_Ur"⁸    Wircs

which wcrc uscd for many decades.” ²²    ln*> ^lnsrrumcnts

Another young Czech that Mach got along with verv w II Ćenck (Vincenc) Oeofak (1848-1922). "[He wasi one of^ n most gifted students.” ²³ DvoSk rccallcd those carly dav$ in “^d his former teachcr: "Thank you vcry much for y„„_r photograp^hićh I remember from the timc we were in Praguc, where I wh₀ 7 so littlc skilied in city culturc, camc to your laboratory to    ^ ^

of new ideas and to learn how to expcrimcnt with fcw _mcnns ’ chanical assistancę. It was truły a wonderful timc!^,,2‘ \    7 ^mC’

Mrs. Irena Seidlerov4, a noted Czech historian of science gained World famę by a number of expcrimcntal studi« concernin the mechanical efTccts of acoustic waves which demonstrated the _łnaf ogy betwccn acoustic and clectromagnetic evcnts, and proved the cor reetness of the mechanical theory of the ether. Howcver, latcr was proved that the whole subject was far morę complcx."²⁵ Dv!.Hk was also known for his “acoustic rcaction whcel” and for his attempts to improvc on striation photographic dcviccs.

Dr. Scidlerova has commcntcd on Macb’s influence on the develop-ment of Czech physics:

Optics and acoustics bccamc first gradc disciplines due mainly to E. Mach who established a tficniatically spccialized school.²⁰

^{Mach a,so su}PP^{licd lhc} unpuke to Kold*ek’s dcvclopmcm of MaxwtUs theory. Almost simultaneously with Hcrtz’s expcriments, i c , _{at a ralhcr}

confuscd situation, F. Kolanek proved the correctness of Maxwcll's conccp fion^of his clectromagnetic theory of light dispersfon, thc cx_Plaration oi thc dispersion ot axcs, dichroism and circular bircfringence.³⁷

She also has criticized sonie aspects of Machs influence, however.

^Thc prevailing philosophical vicws, Machism on thc one hand, thc dcnial of the atomie theory (Scydlcr) hascd on FcchncFs phUosophy and culmi.ut-ing in Walds encrgcticism on the other, often acted as retarding influcnccs on thc work of Czech physicists.²*

43