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The spins of planetary bodies are not stagnant; they evolve in response to both external and internal forces. One way a planet's spin can change is through true polar wander. True polar wander is the reorientation of a planetary body with respect to its angular momentum vector, and occurs when mass is redistributed within the body, changing its principal axes of inertia. True polar wander can literally reshape a world, and has important implications for a variety of processes—from the long-term stability of polar volatiles in the permanently shadowed regions of airless worlds like the Moon and Mercury, to the global tectonic patterns of icy worlds like Pluto. In this dissertation, we investigate three specific instances of planetary true polar wander, and their associated consequences. In Chapter 2 we investigate the classic problem of the Moon's dynamical figure. By considering the effects of a fossil figure supported by an elastic lithosphere, and the contribution of impact basins to the figure, we find that the lunar figure is consistent with the Moon's lithosphere freezing in when the Moon was much closer to the Earth, on a low eccentricity synchronous orbit. The South Pole-Aitken impact basin is the single largest perturbation to the Moon’s figure and resulted in tens of degrees of true polar wander after its formation. In Chapter 3 we continue our analyses of the lunar figure in light of the discovery of a lunar ”volatile" paleopole, preserved in the distribution of hydrogen near the Moon's poles. We find that the formation and evolution of the Procellarum KREEP Terrain significantly altered the Moon’s orientation, implying that some fraction of the Moon’s polar volatiles are ancient—predating the geologic activity within the Procellarum region. In Chapter 4 we investigate how the formation of the giant, basin-filling glacier, Sputnik Planitia reoriented Pluto. This reorientation is recorded in both the present- day location of Sputnik Planitia (near the Pluto-Charon tidal axis), and the tectonic record of Pluto. This reorientation likely reflects a coupling between Pluto’s volatile cycles and rotational dynamics, and may be active on other worlds with comparably large, mobile volatile reservoirs. Finally, in Chapter 5 we consider the broader context of these studies, and touch on future investigations of true polar wander on Mercury, Venus, Mars, Vesta, Ceres, and other worlds in our solar system.

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Julie Otsuka's novel When the Emperor Was Divine (2002) retells the trauma of the Japanese American imprisonment through the lens of fictional characters taken from their "white house on the wide street in Berkeley not far from the sea" to "the scorched white earth of the desert" (74, 23). The Topaz Internment Camp in Utah's Sevier Desert, where these characters were forcibly relocated, sits on the site of an ancient inland sea, Lake Bonneville, which submerged that barren desert ground some ten thousand years ago. The paleolake serves as a displaced but active character in Otsuka's novel that shapes the characters' understanding of their traumatic experience and their ability to work through it. Rather than serving as an actor in disorientation, the ancient sea actually enables reorientation, affording the characters a new understanding of self and place. In developing this sea-oriented analysis of the internment, I call upon theory from trauma scholars Judith Herman and Dominick LaCapra and archipelagic thinkers like Epeli Hau'ofa and Kathy Jetñil-Kijiner, who have reoriented our understandings of islands, continents, and the concept of home. With these thinkers as interlocutors, my archipelagic reading of When the Emperor Was Divine advances a model for understanding the ocean as a mediator and a symbol through which traumatic experiences are acted out, worked through, refracted, and reoriented. This essay relies on the interaction of"”or the potential for mutual illumination between"”two emergent arenas of study: critical desert studies and critical ocean and island studies. It thus becomes a frame through which archipelagic thought can become a collaborator for the contingent working through of trauma and, ultimately, a reimagination of notions of home and reorientation.

Philosophiae Doctor - PhD / The Coulomb excitation of 66Ge has been performed for the rst time using \safe" bombarding energies at the HIE-ISOLDE facility at CERN in July 2017. A particle- coincidence experiment using the MINIBALL array and double-sided silicon detectors has allowed the determination of transitional and diagonal matrix elements in 66Ge, yielding new measurements of the reduced transition probability connecting the ground state, 0+1 , and the rst excited state, 2+1 , or B(E2; 2+1 ! 0+1 ) value, and the spectroscopic quadrupole moment of the 2+1 state, QS (2+1 ). A relatively large B(E2) = 29:4(30) W.u. has been extracted using beam-gated data at forward angles { less sensitive to secondorder e ects { as compared with the adopted value of 16:9(7) W.u., but in closer agreement with modern large-scale shell-model calculations using a variety of e ective interactions and beyond-mean eld calculations presented in the current work. / 2022

Raman vibrational bands are sensitive to fluctuations in the molecular environment. Variations in the bandwidth and peak position can then be utilized to monitor molecular forces and interactions present in condense phases. Nuclear Magnetic Resonance (NMR) provides a convenient probe for the study of molecular reorientation in liquids since nuclear spin relaxation times are dependent on the details of molecular motion. Presented here is the solvent study of the Raman bandwidths and frequency displacements of the mode of the compounds CH3MCI3 (M = C, Si, Ge, Sn) in a number of solvents of widely varying molecular structure. Also, a detailed isotope dilution study of the modes in CH2CI2/CD2CI2 mixtures is presented. In this set of experiments, I observed broadening of the v1 mode of CH2C12 upon dilution,which is the first experimental observation of such behavior. The temperature-dependent carbon-13 relaxation times and nuclear Overhauser enhancements in neat dichloromethane were measured. In this study we found that the molecular reorientation of this molecule was highly anisotropic, but could be well characterized assuming quasi-symmetric top behavior. In addition, in order to gain a more complete understanding of the reorientational dynamics in dichloromethane, we analyzed the 13-C NMR relaxation of CH2CI2 both in "inert" solvents of differing viscosities and in interactive solvents of varying Lewis basicities. Various theoretical models were also applied in order to characterize dichloromethane1s reorientational dynamics.

Ce travail de thèse consiste en l'étude détaillée des conséquences matérielles et ondulatoires de l'application d'un faisceau laser sur l'orientation d'un film de cristal liquide nématique dans un cadre bien particulier, dénommé la réorientation optique "topologique". Cela correspond en pratique à une situation où la lumière donne naissance à un défaut d'orientation pour le champ de directeur, dont la nature dépend des caractéristiques du champ lumineux excitateur (polarisation, phase, intensité). Après avoir introduit la notion de réorientation optique topologique, identifié et discuté les conditions expérimentales permettant son apparition, le rôle de l'état de polarisation est étudié. Le cas d'un faisceau singulier, structuré en phase ou en polarisation, est ensuite traité. Enfin, la mise en évidence de nouveaux effets nonlinéaires, statique et dynamique, est démontrée. / This thesis deals with a detailed study of the material an optical waves aspects of the lightinducedreorientation of a nematic liquid crystal film in a particular framework, called the optical“topological” reorientation. In practice, it corresponds to a situation where a laser beaminduces an orientational topological defect for the director field, whose nature depends on thecharacteristics of the excitation light field (polarization, phase, intensity). First, the concept oftopological optical reorientation is introduced and the experimental conditions for its appearanceare discussed and experimentally verified. Then, the role of the polarization state of a Gaussianlight beam excitation is investigated, followed with the more complex situation of singular lightbeams with structured phase or polarization. Finally, we report on self-induced nonlinear opticalmanifestations of the topological reorientation, which include the experimental identificationand discussion of novel singular phenomena such as nonlinear spin-orbit interaction of light andself-induced vortex beam precession.

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