891 research outputs found
Quantum Mechanics as Classical Physics
Here I explore a novel no-collapse interpretation of quantum mechanics which
combines aspects of two familiar and well-developed alternatives, Bohmian
mechanics and the many-worlds interpretation. Despite reproducing the empirical
predictions of quantum mechanics, the theory looks surprisingly classical. All
there is at the fundamental level are particles interacting via Newtonian
forces. There is no wave function. However, there are many worlds.Comment: 25 page
Forces on Fields
In electromagnetism, as in Newton's mechanics, action is always equal to
reaction. The force from the electromagnetic field on matter is balanced by an
equal and opposite force from matter on the field. We generally speak only of
forces exerted by the field, not forces exerted upon the field. But, we should
not be hesitant to speak of forces acting on the field. The electromagnetic
field closely resembles a relativistic fluid and responds to forces in the same
way. Analyzing this analogy sheds light on the inertial role played by the
field's mass, the status of Maxwell's stress tensor, and the nature of the
electromagnetic field.Comment: 26 pages, 2 figure
The Mass of the Gravitational Field
By mass-energy equivalence, the gravitational field has a relativistic mass
density proportional to its energy density. I seek to better understand this
mass of the gravitational field by asking whether it plays three traditional
roles of mass: the role in conservation of mass, the inertial role, and the
role as source for gravitation. The difficult case of general relativity is
compared to the more straightforward cases of Newtonian gravity and
electromagnetism by way of gravitoelectromagnetism, an intermediate theory of
gravity that resembles electromagnetism.Comment: 39 pages, 1 figur
Killer Collapse: Empirically Probing the Philosophically Unsatisfactory Region of GRW
GRW theory offers precise laws for the collapse of the wave function. These collapses are characterized by two new constants, λ and σ. Recent work has put experimental upper bounds on the collapse rate, λ. Lower bounds on λ have been more controversial since GRW begins to take on a many-worlds character for small values of λ. Here I examine GRW in this odd region of parameter space where collapse events act as natural disasters that destroy branches of the wave function along with their occupants. Our continued survival provides evidence that we don't live in a universe like that. I offer a quantitative analysis of how such evidence can be used to assess versions of GRW with small collapse rates in an effort to move towards more principled and experimentally-informed lower bounds for λ
Marine flora and fauna of the Eastern United States Anthozoa: Acitniaria, Corallimorpharia, Ceriantharia, and Zoanthidea
This key includes 60 species of sea anemones and their relatives in the orders Actiniaria, Corallimorpharia, Ceriantharia, and Zoanthidea. Species from the intertidal zone, continental slope, and deep sea are included over a geographic range from Atlantic Canada to approximately South Carolina. In addition to the illustrated key itself, characteristics of each species are summarized in tabular form, including morphology, distribution, and types and sizes of cnidae. Ecological and taxonomic information on each species are also included in an annotated species list. (PDF file contains 76 pages.
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