The spin-statistics connection in classical field theory

The spin-statistics connection is obtained for a simple formulation of a classical field theory containing even and odd Grassmann variables. To that end, the construction of irreducible canonical realizations of the rotation group corresponding to general causal fields is reviewed. The connection is obtained by imposing local commutativity on the fields and exploiting the parity operation to exchange spatial coordinates in the scalar product of classical field evaluated at one spatial location with the same field evaluated at a distinct location. The spin-statistics connection for irreducible canonical realizations of the Poincar\'{e} group of spin $j$ is obtained in the form: Classical fields and their conjugate momenta satisfy fundamental field-theoretic Poisson bracket relations for 2$j$ even, and fundamental Poisson antibracket relations for 2$j$ oddComment: 27 pages. Typos and sign error corrected; minor revisions to tex

Graded contractions and bicrossproduct structure of deformed inhomogeneous algebras

A family of deformed Hopf algebras corresponding to the classical maximal isometry algebras of zero-curvature N-dimensional spaces (the inhomogeneous algebras iso(p,q), p+q=N, as well as some of their contractions) are shown to have a bicrossproduct structure. This is done for both the algebra and, in a low-dimensional example, for the (dual) group aspects of the deformation.Comment: LaTeX file, 20 pages. Trivial changes. To appear in J. Phys.

Line-Drawing, Embryonic Stem Cell Research, and the Dickey-Wicker Amendment

Human embryonic stem cell (hesc) research is the culmination of a multi-step process: creating an embryo through in vitro fertilization (IVF), deciding whether to donate or destroy embryos left over from that process, harvesting stem cells from embryos donated for research, and finally doing research with the stem cells themselves. Each of these points presents different ethical issues. For those for whom human embryos command relatively little moral weight, this entire process is acceptable. But for those who consider embryos the moral equivalent of persons ,and also for those for whom embryos, while not equal in importance to born humans, do carry a great deal of weight, everything depends on when in that process one comes to a moral crossroads. I argue that the line drawn by NIH in its response to the Dickey-Wicker Amendment, is not morally defensible. I also argue that for those who wish to stop or at least to decrease the destruction of embryos for stem cell research, the moral crossroads occurs much earlier: with the creation of those embryos in the fertility clinics