Speed Calculator

An apparatus for measuring the velocity of a vehicle traveling between first and second measured points. The apparatus includes a cylindrical housing having an open top for receiving a transparent disk. Indicia representing speed calibrations is circumferentially spaced adjacent an outer perimeter of the disk. A stopwatch is carried in the housing below said disk and has a rotatable hand which rotates at a predetermined rate under the indicia. A lamp is carried below the stopwatch for illuminating the indicia carried on the transparent disk. The stopwatch is started when the vehicle passes a first reference point and stopped when the vehicle passes the second reference point. Thus, when the hand is stopped, such points to the calibrated indicia on said disk indicating the velocity of a vehicle

Magnetospheric Multiscale Observations of Markov Turbulence on Kinetic Scales

In our previous studies we have examined solar wind and magnetospheric plasmas turbulence, including Markovian character on large inertial magneto-hydrodynamic scales. Here we present the results of statistical analysis of magnetic field fluctuations in the Earth's magnetosheath based on Magnetospheric Multiscale mission at much smaller kinetic scales. Following our results on spectral analysis with very large slopes of about -16/3, we apply Markov processes approach to turbulence in this kinetic regime. It is shown that the Chapman-Kolmogorov equation is satisfied and the lowest-order Kramers-Moyal coefficients describing drift and diffusion with a power-law dependence are consistent with a generalized Ornstein-Uhlenbeck process. The solutions of the Fokker-Planck equation agree with experimental probability density functions, which exhibit a universal global scale invariance through the kinetic domain. In particular, for moderate scales we have the kappa distribution described by various peaked shapes with heavy tails, which with large values of kappa parameter are reduced to the Gaussian distribution for large inertial scales. This shows that the turbulence cascade can be described by the Markov processes also on very small scales. The obtained results on kinetic scales may be useful for better understanding of the physical mechanisms governing turbulenceComment: accepted to Astrophys. J. 2 November 2022, 17 pages, 7 figure

Gurnis, McComas receive Macelwane Medals

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95077/1/eost9813.pd

If you leave, don\u27t leave now: The role of gender, sociosexuality, and fear of being single on desire to engage in breakup sex

Experiencing a romantic breakup is often a complicated and emotional experience, and in many cases, this emotional ambivalence leads to people having “breakup sex” with their ex-partners. To better understand this complicated relationship stage, we sampled 987 single adults to understand how individual differences in sociosexuality and fear of being single predict one\u27s desire to have breakup sex and previous breakup sex experience. We observed that both men and women who reported more unrestricted sociosexual orientations reported greater desire for breakup sex. However, women—but not men—who reported greater fear of being single reported a greater desire for breakup sex. Lastly, those who reported a more unrestricted sociosexual orientation were more likely to have had breakup sex in the past. Results suggest that both men\u27s and women\u27s desire for casual sex impacts engagement in breakup sex and that women\u27s desire is also motivated by their fear of being single

Assessing the time dependence of reconnection with Poynting's theorem: MMS observations

We investigate the time dependence of electromagnetic-field-to-plasma energy conversion in the electron diffusion region of asymmetric magnetic reconnection. To do so, we consider the terms in Poynting's theorem. In a steady state there is a perfect balance between the divergence of the electromagnetic energy flux $\nabla \cdot \vec{S}$ and the conversion between electromagnetic field and particle energy $\vec{J} \cdot \vec{E}$. This energy balance is demonstrated with a particle-in-cell simulation of reconnection. We also evaluate each of the terms in Poynting's theorem during an observation of a magnetopause reconnection region by Magnetospheric Multiscale (MMS). We take the equivalence of both sides of Poynting's theorem as an indication that the errors associated with the approximation of each term with MMS data are small. We find that, for this event, balance between $\vec{J}\cdot\vec{E}=-\nabla\cdot\vec{S}$ is only achieved for a small fraction of the energy conversion region at/near the X-point. Magnetic energy was rapidly accumulating on either side of the current sheet at roughly three times the predicted energy conversion rate. Furthermore, we find that while $\vec{J}\cdot\vec{E}>0$ and $\nabla\cdot\vec{S}<0$ are observed, as is expected for reconnection, the energy accumulation is driven by the overcompensation for $\vec{J}\cdot\vec{E}$ by $-\nabla\cdot\vec{S}>\vec{J}\cdot\vec{E}$. We note that due to the assumptions necessary to do this calculation, the accurate evaluation of $\nabla\cdot\vec{S}$ may not be possible for every MMS-observed reconnection event; but if possible, this is a simple approach to determine if reconnection is or is not in a steady-state.Comment: Resubmitted to GRL after minor rev. on 1 February 201