In the case when the molecular dipoles of water suspended in the atmospheric vacuum satisfy the state of an ideal gas, their density [n.sub.0] under the normal atmospheric conditions used in the first approximation can be taken equal to the Loschmidt
number numerically equal to [N.sub.L]=2.68 x [10.sup.25] [m.sup.-3] .
Such a conclusion is of basic importance since it overcomes the so-called Loschmidt
paradox, i.e., the objection raised by Loschmidt
in 1876  regarding the original Boltzmann formulation of his namesake kinetic equation and H-theorem .
Normalizing this result with the Loschmidt
constant (2.69 x 1019 molecules [cm.sup.-3], 0 [degrees]C, 1 atm), we obtain for the tropospheric N[O.sub.2] layer column thickness 1.4 x [10.sup.-5] cm, which we denote, following Gueymard's (1998) nomenclature, as 0.014 matm cm ([equivalent to] 0.014 DU).
In Germany, this number is called the Loschmidt
constant, named after a colleague of Boltzmann's.
Es precisamente el elevado numero de grados de libertad de los sistemas de comportamiento irreversible lo que permite a los defensores de la linea boltzmanniana enfrentar la paradoja de Loschmidt
. (9) Llamando [U.sub.t] al operador que expresa la microevolucion mecanica del sistema, y [[GAMMA].sub.0] a la region correspondiente al macroestado inicial de no equilibrio, luego de un tiempo suficientemente largo, [[GAMMA].sub.0] evolucionara mecanicamente hacia una region [[GAMMA].sub.t] manteniendo su medida constante de acuerdo con el teorema de Liouville:
Dr Michael Crampton, reader in chemistry at Durham University, has been awarded the Josef Loschmidt
prize for Excellence in Physical Organic Chemistry by the Royal Society of Chemistry.
318), these sections contain 'the most thorough discussion in the literature of the attempt to derive Second Law behavior from the cosmological entropic asymmetry.' The natural idea is to redefine positive time as the direction in which most thermodynamical processes occur, but Loschmidt
's reversibility objection(10) shows that for an isolated system with no beginning and end there is no statistical asymmetry in thermodynamic behaviour.(11) Periods of equilibrium are occasionally interrupted by chance fluctuations to states of lower entropy (and, of course, the larger the fluctuation the rarer it is) and returns to equilibrium.
In 1865 the Austrian chemist Johann Joseph Loschmidt
(1821-1895) used Maxwell's kinetic theory of gases (see 1859) to calculate what that number ought to be.
Following NCW/SNC, there was a series of three lectures by Alfred Bader, presented by the McGill Chapter of Sigma Xi, on October 25-26, entitled: "The History of Sigma-Aldrich", "Adventures of a Chemist Collector: Chemistry in Art Restoration" and "Joseph Loschmidt
- The Father of Molecular Modelling".
The former have the seemingly more devastating difficulty of dealing with Poincare's recurrence theorem and Loschmidt
's reversibility objection.