65,274 research outputs found
Disregarding the 'Hole Argument'
Jim Weatherall has suggested that Einstein's hole argument, as presented by
Earman and Norton (1987), is based on a misleading use of mathematics. I argue
on the contrary that Weatherall demands an implausible restriction on how
mathematics is used. The hole argument, on the other hand, is in no new danger
at all.Comment: 19 pages, 4 figure
Ambient temperature catalyst for hydrogen ignition
Low cost, ambient temperature catalyst for reacting hydrogen gas with air in a catalytic cell near the point of evolution at a controlled rate is announced
Kramers degeneracy without eigenvectors
Wigner gave a well-known proof of Kramers degeneracy, for time reversal
invariant systems containing an odd number of half-integer spin particles. But
Wigner's proof relies on the assumption that the Hamiltonian has an
eigenvector, and thus does not apply to many quantum systems of physical
interest. This note illustrates an algebraic way to talk about Kramers
degeneracy that does not appeal to eigenvectors, and provides a derivation of
Kramers degeneracy in this more general context.Comment: 5 page
Dual strain gage balance system for measuring light loads
A dual strain gage balance system for measuring normal and axial forces and pitching moment of a metric airfoil model imparted by aerodynamic loads applied to the airfoil model during wind tunnel testing includes a pair of non-metric panels being rigidly connected to and extending towards each other from opposite sides of the wind tunnel, and a pair of strain gage balances, each connected to one of the non-metric panels and to one of the opposite ends of the metric airfoil model for mounting the metric airfoil model between the pair of non-metric panels. Each strain gage balance has a first measuring section for mounting a first strain gage bridge for measuring normal force and pitching moment and a second measuring section for mounting a second strain gage bridge for measuring axial force
Silent emergency alarm system for schools and the like
An emergency alert system is described. In a school each classroom (or other area) is instrumented with a hidden microphone and receiver tuned to a non-audible frequency. The receivers' outputs are connected to a central display unit in the school's administrative office. Each instructor is provided with a small concealable transmitter which, when hand activated by the instructor upon the occurrance of any emergency, generates a non-audible signal at the receiver's tuned frequency
Lepton Asymmetries in FCNC Decays of {\Lambda}b
Lepton polarization asymmetries for the flavor-changing neutral current
(FCNC) dileptonic decays of {\Lambda}b baryons are calculated using
single-component analytic (SCA) and multicomponent numerical (MCN) form
factors. We show that these polarization asymmetries are insensitive to the
transition form factors and, thus, the effects of QCD in the nonperturbative
regime. Therefore, these observables can provide somewhat model independent
ways of extracting the Wilson coefficients.Comment: 3 pages, 2 tables, 1 figure, To appear in the proceedings for the
Eleventh Conference on the Intersections of Particle and Nuclear Physics
(CIPANP 2012
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