572,871 research outputs found
Coulomb Force as an Entropic Force
Motivated by Verlinde's theory of entropic gravity, we give a tentative
explanation to Coulomb's law with an entropic force. When trying to do this, we
find the equipartition rule should be extended to charges and the concept of
temperature should be reinterpreted. If one accepts the holographic principle
as well as our generalizations and reinterpretations, then Coulomb's law, the
Poisson equation and the Maxwell equations can be derived smoothly. Our attempt
can be regarded as a new way to unify the electromagnetic force with gravity,
from the entropic origin. Possibly some of our postulates are related to the
D-brane picture of black hole thermodynamics.Comment: discussion and bibliography update
Cosmic Steps in Modeling Dark Energy
The past and recent data analyses gave some hints of steps in dark energy.
Considering the dark energy as a dynamical scalar field, we investigate several
models with various steps: a step in the scalar potential, a step in the
kinetic term, a step in the energy density and a step in the equation-of-state
parameter w. These toy models provide a workable mechanism to generate steps
and features of dark energy. Remarkably, a single real scalar can cross w=-1
dynamically with a step in the kinetic term.Comment: 6 pages, 5 figures, structure improved, reference added, results
unchange
Regimes and Resilience in the Modern Global Food System
Much public discourse surrounding the modern global food system operates on the assumption of the primary agency of individual consumers in ensuring an equitable and sustainable food supply. However, this approach fails to account for the larger structural forces of the system which frame the limits of how we interact with and are affected by our food system. Taking a closer look at the global economic, political, cultural, and environmental forces that have collectively shaped historical food regimes reveals the deeper structural patterns that currently determine how we produce, distribute, and consume food around the world. Due to the underlying structural processes of increasing distancing and standardization, we have become highly disembedded from our food system and will need to look for clues from past periods of transition between food regimes to better position ourselves to work towards a global restructuring of, and human reembedding in, the modern global food system
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