Jamming Criticality Revealed by Removing Localized Buckling Excitations

Recent theoretical advances offer an exact, first-principle theory of jamming criticality in infinite dimension as well as universal scaling relations between critical exponents in all dimensions. For packings of frictionless spheres near the jamming transition, these advances predict that nontrivial power-law exponents characterize the critical distribution of (i) small inter-particle gaps and (ii) weak contact forces, both of which are crucial for mechanical stability. The scaling of the inter-particle gaps is known to be constant in all spatial dimensions $d$ -- including the physically relevant $d=2$ and 3, but the value of the weak force exponent remains the object of debate and confusion. Here, we resolve this ambiguity by numerical simulations. We construct isostatic jammed packings with extremely high accuracy, and introduce a simple criterion to separate the contribution of particles that give rise to localized buckling excitations, i.e., bucklers, from the others. This analysis reveals the remarkable dimensional robustness of mean-field marginality and its associated criticality.Comment: 12 pages, 4 figure

Let Him Hold You: Spiritual and Social Support in a Catholic Convent Infirmary

American Catholic nuns have been found to age more ‘successfully’ than their lay counterparts, living longer, healthier, and happier lives.  Two of the key factors contributing to the nuns’ physical and mental wellbeing are the spiritual support they experience from the divine and the social support they provide for and receive from each other in the convent.  I argue that by integrating the divine into their everyday interactions, the nuns engage in phenomenological meaning-making process through which mundane care interactions are rendered sacred. This communicative process, I argue, contributes to the nuns’ overall wellbeing by providing an enriched form of care and support, thereby enhancing their end-of-life experience

First Passage Time for Many Particle Diffusion in Space-Time Random Environments

The first passage time for a single diffusing particle has been studied extensively, but the first passage time of a system of many diffusing particles, as is often the case in physical systems, has received little attention until recently. We consider two models for many particle diffusion -- one treats each particle as independent simple random walkers while the other treats them as coupled to a common space-time random forcing field that biases particles nearby in space and time in similar ways. The first passage time of a single diffusing particle under both of these models show the same statistics and scaling behavior. However, for many particle diffusions, the first passage time among all particles (the `extreme first passage time') is very different between the two models, effected in the latter case by the randomness of the common forcing field. We develop an asymptotic (in the number of particles and location where first passage is being probed) theoretical framework to separate out the impact of the random environment with that of sampling trajectories within it. We identify a new power-law describing the impact to the extreme first passage time variance of the environment. Through numerical simulations we verify that the predictions from this asymptotic theory hold even for systems with widely varying numbers of particles, all the way down to 100 particles. This shows that measurements of the extreme first passage time for many-particle diffusions provide an indirect measurement of the underlying environment in which the diffusion is occurring

Let Him Hold You: Spiritual and Social Support in a Catholic Convent Infirmary

American Catholic nuns have been found to age more ‘successfully’ than their lay counterparts, living longer, healthier, and happier lives.  Two of the key factors contributing to the nuns’ physical and mental wellbeing are the spiritual support they experience from the divine and the social support they provide for and receive from each other in the convent.  I argue that by integrating the divine into their everyday interactions, the nuns engage in phenomenological meaning-making process through which mundane care interactions are rendered sacred. This communicative process, I argue, contributes to the nuns’ overall wellbeing by providing an enriched form of care and support, thereby enhancing their end-of-life experience