Helmholtzn.
/ˈhɛlmhɒlts/, /ˈhɛlmhəʊlts/, U.S. /ˈhɛlmˌhoʊlts/ Physics.
Used attributively with reference to various devices and theories invented by Helmholtz.
ΘΚΠ
the world > matter > physics > science of sound > [adjective] > describing device or theory
Lissajous1877
Helmholtzian1890
Helmholtz1930
the world > matter > physics > electromagnetic radiation > electricity > electrically induced magnetism > electromagnetic induction > [noun] > induction coil > types of coil
inductorium1875
Tesla coil1896
basket winding1910
pancake coil1910
honeycomb coil1921
basket coil1923
Helmholtz1962
1856 Proc. Royal Soc. 8 301 Plan of observation for receiving a message.—The instrument which I propose is Helmholtz's galvanometer.
1930 R. Paget Human Speech 8 The ocarina is, I believe, the only well-known wind instrument which operates on the principle of the ‘Helmholtz’ resonator.
1940 Chambers's Techn. Dict. 409/2 Helmholtz galvanometer, Helmholtz resonance, Helmholtz resonator.
1962 D. R. Corson & P. Lorrain Introd. Electromagn. Fields v. 215 A pair of Helmholtz coils consists of two identical circular current loops placed coaxially so as to obtain uniformity of the magnetic induction B in the region midway between the loops.
Derivatives
Helmˈholtzian adj.
ΘΚΠ
the world > matter > physics > science of sound > [adjective] > describing device or theory
Lissajous1877
Helmholtzian1890
Helmholtz1930
1890 W. James Princ. Psychol. II. xx. 170 The Helmholtzian theory is probably not the last word in the physiology of hearing.
1920 G. B. Shaw How to become Musical Critic (1960) 311 The Helmholtzian chords of Scriabin.
Draft additions March 2006
Helmholtz free energy n. [described by Helmholtz 1882, in Sitzungsber. der Königl. Preuss. Akad. der Wissensch. zu Berlin 33] the thermodynamic function A = U − TS (where U is the internal energy, T the temperature, and S the entropy of the system), representing the amount of energy that can be converted into work at constant temperature; also called work function.Cf. free energy n. 2.
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1902 Encycl. Brit. XXVIII. 167/2 The available energy thus defined differs from E−Tϕ, the free energy of Helmholtz.]
1919 Jrnl. Amer. Chem. Soc. 41 986 The negative of the differential of the function of Gibbs, or of the Helmholtz free energy, is defined as [etc.].
1937 M. W. Zemansky Heat & Thermodynamics xi. 195 The Helmholtz function is sometimes called the ‘Helmholtz free energy’, or the ‘free-energy’, but these names are confusing since another function..is also called by some authors the free energy.
1967 E. U. Condon & H. Odishaw Handbk. Physics (ed. 2) v. i. 8/1 A system held at constant volume and constant temperature will spontaneously move toward lower values of A. At equilibrium the Helmholtz free energy is a minimum.
2002 Proc. National Acad. Sci. U.S.A. 99 14168/1 The difference, at constant volume..and temperature..between the Helmholtz free energy of the virtually incompressible protein–PEG–water system and the pure water system.
Draft additions September 2006
Helmholtz function n. (also (rare) Helmholtz's function) (a) [described by Helmholtz in Monatsberichte der Königl. Preussischen Akad. der Wissensch. zu Berlin (1868) 224)] Mathematics the transformation of the complex plane Z = 1/ π(ez + z + 1), which arises in the representation of fluid flow through a spout with infinite plane walls (disused); (b) Physical Chemistry the equation expressing Helmholtz free energy.
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1901 Ann. Math. 2 73 If we now allow ε to approach 0 as its limit Z′ approaches Helmholtz's function, Z1.
1908 Ann. Math. 9 77 These functions..effect transformations similar to the Z′'s and Z′′'s obtained from the hyperbolic sine and the Helmholtz function.
1937 M. W. Zemansky Heat & Thermodynamics xi. 195 The Helmholtz function is sometimes called the ‘Helmholtz free energy’, or the ‘free-energy’.
1997 Proc. Royal Soc. A. 453 2136 The Helmholtz function, A, (which is related to the internal energy, U, in the same way that the Gibbs function is related to the enthalpy) must be used for the infrared monitored dissociation.
Draft additions January 2010
Helmholtz resonator n. (also Helmholtz' resonator, Helmholtz's resonator) [described by Helmholtz in 1859 in Gelehrte Anzeigen der Königl. Bayerischen Akad. der Wissensch. 48 553] Physics a hollow object designed to have a strong resonance at a particular pitch and no other significant resonances.As invented by Helmholtz it consisted of a hollow sphere with a short narrow neck. The resonant frequency depends on the volume of the sphere and the length and area of the neck.
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1865 Q. Jrnl. Sci. 2 595 To distinguish them accurately and determine their intensity and pitch, requires an artificial help, which is supplied by the resonators of Helmholtz.]
1867 C. Brooke Elements Nat. Philos. (ed. 6) Index 841/2 Helmholtz' resonator. [text on p. 297 has The Resonator of Helmholtz.]
1873 Harper's Mag. Aug. 467/1 Two of Helmholtz's resonators, vibrating to the note given by the two bodies, are placed near the bodies.
1908 E. H. Barton Text-bk. Sound 381 If two open organ pipes and a Helmholtz resonator, all of the same pitch, are available, the phenomena of beats may be strikingly exhibited.
1924 E. Paul & C. Paul tr. C. Baudouin Contemp. Stud. iv. 203 Symbolist art is like Helmholtz's resonators which isolate the overtones of a musical note, and make them perceptible in isolation.
1975 G. J. King Audio Handbk. vi. 143 The vented enclosure exhibits the characteristics of a Helmholtz resonator.
2001 S. Hardingham London: Guide to recent Archit. (ed. 5) i. 12 The walls are lined with horizontal fins called Helmholtz resonators to absorb frequencies of sound which might build up..throughout the vast internal spaces.
This entry has not yet been fully updated (first published 1976; most recently modified version published online March 2022).
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