Poyntingn.

Brit.

/ˈpɔɪntɪŋ/, U.S.

/ˈpɔɪn(t)ɪŋ/

Origin: From a proper name. Etymon: proper name Poynting.

Etymology: < the name of John Henry Poynting (1852–1914), English physicist, who developed the concepts ( Philos. Trans. 1884 (Royal Soc.) 175 (1885) 343, Philos. Trans. 1885 (Royal Soc.) 176 (1886) 277, etc.).

Physics.

1. Poynting's theorem n. the theorem that the rate of flow of electromagnetic energy through a closed surface is equal to the integral over the surface of the Poynting vector.

ΘΚΠ

the world > matter > physics > electromagnetic radiation > electricity > electrically induced magnetism > [noun] > field > effect, theory

Poynting's theorem1893

Nernst effect1901

1893 J. J. Thomson Notes Res. Electr. & Magn. p. xiii Poynting's theorem.

1967 W. H. Watson Understanding Physics Today 148 In an electromagnetic field of optical frequency we infer the field strength from a measurement of the energy flux using Poynting's theorem.

1997 SIAM Jrnl. Appl. Math. 57 419 Electromagnetic energy density is given by the scalar quantity ½(E.D + H.B), which follows on physical grounds from Poynting's theorem.

2. Poynting vector n. (also Poynting's vector) the vector product of the electric and magnetic field strengths at any point, which can often be interpreted as describing the magnitude and direction of the flow of electromagnetic energy.

ΘΚΠ

the world > matter > physics > electromagnetic radiation > electricity > electrically induced magnetism > [noun] > field > equation, formula

field equation1889

Maxwell's equation1907

Poynting vector1913

1913 L. Silberstein Vectorial Mech. i. 45 The flux of electromagnetic energy, per unit time and unit area, i.e. the so-called Poynting-vector.

1931 H. T. Davis Philos. & Mod. Sci. 257 That which makes the wire from the battery glow must be regarded..as a flow of something moving like a stream from the storehouse of the ether into matter along the mysterious lengths of Poynting's vector.

1962 D. R. Corson & P. Lorrain Introd. Electromagn. Fields xi. 399 The Poynting vector for sunlight is approximately 1·4 kilowatts/meter² at the surface of the earth.

1996 Nature 2 May 28/1 At those positions where the amplitude of the electric field is largest (the positions which contribute the most to the average energy flow) the Poynting vector is not parallel to the wave vector.

This entry has been updated (OED Third Edition, December 2006; most recently modified version published online March 2022).

单词	poynting
释义	Poyntingn. Brit. /ˈpɔɪntɪŋ/, U.S. /ˈpɔɪn(t)ɪŋ/ Origin: From a proper name. Etymon: proper name Poynting. Etymology: < the name of John Henry Poynting (1852–1914), English physicist, who developed the concepts ( Philos. Trans. 1884 (Royal Soc.) 175 (1885) 343, Philos. Trans. 1885 (Royal Soc.) 176 (1886) 277, etc.). Physics. 1. Poynting's theorem n. the theorem that the rate of flow of electromagnetic energy through a closed surface is equal to the integral over the surface of the Poynting vector. ΘΚΠ the world > matter > physics > electromagnetic radiation > electricity > electrically induced magnetism > [noun] > field > effect, theory Poynting's theorem1893 Nernst effect1901 1893 J. J. Thomson Notes Res. Electr. & Magn. p. xiii Poynting's theorem. 1967 W. H. Watson Understanding Physics Today 148 In an electromagnetic field of optical frequency we infer the field strength from a measurement of the energy flux using Poynting's theorem. 1997 SIAM Jrnl. Appl. Math. 57 419 Electromagnetic energy density is given by the scalar quantity ½(E.D + H.B), which follows on physical grounds from Poynting's theorem. 2. Poynting vector n. (also Poynting's vector) the vector product of the electric and magnetic field strengths at any point, which can often be interpreted as describing the magnitude and direction of the flow of electromagnetic energy. ΘΚΠ the world > matter > physics > electromagnetic radiation > electricity > electrically induced magnetism > [noun] > field > equation, formula field equation1889 Maxwell's equation1907 Poynting vector1913 1913 L. Silberstein Vectorial Mech. i. 45 The flux of electromagnetic energy, per unit time and unit area, i.e. the so-called Poynting-vector. 1931 H. T. Davis Philos. & Mod. Sci. 257 That which makes the wire from the battery glow must be regarded..as a flow of something moving like a stream from the storehouse of the ether into matter along the mysterious lengths of Poynting's vector. 1962 D. R. Corson & P. Lorrain Introd. Electromagn. Fields xi. 399 The Poynting vector for sunlight is approximately 1·4 kilowatts/meter² at the surface of the earth. 1996 Nature 2 May 28/1 At those positions where the amplitude of the electric field is largest (the positions which contribute the most to the average energy flow) the Poynting vector is not parallel to the wave vector. This entry has been updated (OED Third Edition, December 2006; most recently modified version published online March 2022). < n.1893
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