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For the paradigm of the quantum double-slit experiment (DSE), we apply Ockham's Razor to interpret quantum observations and to evaluate terminology associated with wave-particle duality. One finds that the Correspondence Principle (CP), combined with classical wave DSEs, e.g., Young [1804], is sufficient to separate and anticipate the observed quantum particle and wave phenomena. The empirical approach of Ockham infers that individual quanta are only whole particles during transit from source to detector; an individual quantum never acts as a wave. The wave nature of quanta emerges only in the distribution of large numbers of single-quantum observation events. That is, the "measurement problem" is no problem at all; "particle" and "wave" derive from separate and different aspects of a set of observations. Such artificial constructs as wave function collapse are irrelevant to the observation of individual quanta, each of which acts as a whole "particle" from emission to measurement. The histogram of detected events is a collective property identical to a classical wave interference pattern in the limit of large numbers, as the CP decrees. For a specific quantum, Ockham's Razor renders irrelevant any hypothesis regarding wave- or particle-like behavior of the quantum in the region between emission and detection. To analyze actual data sets consisting of a large number of identical observation events and to predict future DSEs, the CP of standard quantum (wave) mechanics is sufficient: in the limit, the distribution of observations approaches the continuous density defined by the standard quantum mechanical wave function. Scientific progress beyond this picture requires new, relevant experiments. From the DSE, Ockham's Razor infers that a theoretical quantum system consists of at least one quantum particle plus a wave function specifying the distribution of a large number of such particles., Comment: 25 Pages, 1 Figure. Revisions from original: Figure significantly redrawn to eliminate irrelevant elements and notation and to improve alignment of horizontal symmetry axis. Appendix added to define key terms. Wording of manuscript modified to render more specific and to reduce potential ambiguity. Inferred definition of quantum system added explicitly. Experiments referenced

The authors investigate the ideal, nondriven multifluid equations of motion to identify consistent (i.e., truly stationary), mechanically static models for composition profiles within the thermosphere. These physically faithful functions are necessary to define the parametric core of future empirical atmospheric models and climatologies. Based on the strength of interspecies coupling, the thermosphere has three altitude regions: (1) the lower thermosphere (herein z < ~100 km), in which all species move together at the composite fluid velocity with an effective particle mass equal to the average particle mass of the composite fluid; (2) the upper thermosphere (herein z > ~200 km), in which the species flows are approximately uncoupled; and (3) a transition region in between, where the effective species particle mass and the effective species vertical flow interpolate between the solutions for the upper and lower thermosphere. We place this view in the context of current terminology within the community, i.e., a fully mixed (lower) region and an upper region in diffusive equilibrium (DE). The latter condition, DE, currently used in empirical composition models, does not represent a truly static composition profile in the presence of finite thermal diffusion. Rather, species by species hydrostatic balance is a consistent (i.e., stationary) static representation of vertical thermospheric composition profiles., Comment: 26 pages

The new NRLMSISE-00 model and the associated NRLMSIS database now include the following data: (1) total mass density from satellite accelerometers and from orbit determination, including the Jacchia and Barlier data; (2) temperature from incoherent scatter radar, and; (3) molecular oxygen number density, [O2], from solar ultraviolet occultation aboard the Solar Maximum Mission (SMM). A new component, 'anomalous oxygen,' allows for appreciable O(+) and hot atomic oxygen contributions to the total mass density at high altitudes and applies primarily to drag estimation above 500 km. Extensive tables compare our entire database to the NRLMSISE-00, MSISE-90, and Jacchia-70 models for different altitude bands and levels of geomagnetic activity. We also investigate scientific issues related to the new data sets in the NRLMSIS database. Especially noteworthy is the solar activity dependence of the Jacchia data, with which we investigate a large O(+) contribution to the total mass density under the combination of summer, low solar activity, high latitudes, and high altitudes. Under these conditions, except at very low solar activity, the Jacchia data and the Jacchia-70 model indeed show a significantly higher total mass density than does MSISE-90. However, under the corresponding winter conditions, the MSIS-class models represent a noticeable improvement relative to Jacchia-70 over a wide range of F(sub 10.7). Considering the two regimes together, NRLMSISE-00 achieves an improvement over both MSISE-90 and Jacchia-70 by incorporating advantages of each.

Using a novel Fourier fitting method we combine two years of mid-latitude temperature measurements at 87 km from the High Resolution Doppler Imager, the Colorado State University lidar, and the Peach Mountain Interferometer. After accounting for calibration bias, significant local-time variations on the order of 10 K were observed. Stationary planetary waves with amplitudes up to 10 K were observed during winter, with weaker wave amplitudes occurring during other seasons. Because of calibration biases among these instruments, we could estimate the annual mean temperature to no better than 193.5 plus or minus 8.5 K.

A study is presented on the effect of embedded supersonic flows and the resulting emerging shock waves on phenomena associated with MHD turbulence, including reconnection, the formation of current sheets and vortex structures, and the evolution of spatial and temporal correlations among physical variables. A two-dimensional model problem, the Orszag-Tang (1979) vortex system, is chosen, which involves decay from nonrandom initial conditions. The system is doubly periodic, and the initial conditions consist of single-mode solenoidal velocity and magnetic fields, each containing X points and O points. The initial mass density is flat, and the initial pressure fluctuations are incompressible, balancing the local forces for a magnetofluid of unit mass density. Results on the evolution of the local structure of the flow field, the global properties of the system, and spectral correlations are presented. The important dynamical properties and observational consequences of embedded supersonic regions and emerging shocks in the Orszag-Tang model of an MHD system undergoing reconnection are discussed. Conclusions are drawn regarding the effects of local supersonic regions on MHD turbulence.

The numerical investigation of the Orszag-Tang vortex system in compressible magnetofluids will consider initial conditions with embedded supersonic regions. The simulations have initial average Mach numbers 1.0 and 1.5 and beta 10/3 with Lundquist numbers 50, 100, or 200. The behavior of the system differs significantly from that found previously for the incompressible and subsonic analogs. Shocks form at the downstream boundaries of the embedded supersonic regions outside the central magnetic X-point and produce strong local current sheets which dissipate appreciable magnetic energy. Reconnection at the central X-point, which dominates the incompressible and subsonic systems, peaks later and has a smaller impact as M increases from 0.6 to 1.5. Similarly, correlation between the momentum and magnetic field begins significant growth later than in subsonic and incompressible flows. The shocks bound large compression regions, which dominate the wavenumber spectra of autocorrelations in mass density, velocity, and magnetic field.

A brief review is presented of work done over the last eight years investigating the fundamental physics of plasmas and magnetic fields under conditions similar to those that are thought to be present in the outer layers of the solar atmosphere, including the transition region and the corona. The models used to study the coronal structures and the thermal instability in the solar atmosphere are discussed. The results of studies of magnetic energy release in the corona and MHD turbulence in the solar wind are examined.