Symmetry matters

Interitem Symmetry Matters!

A 901 rotation of a display can turn a relatively easy visual search into a more difficult one. A series of experiments examined the possible causes of this effect, including differences in overall item shape and response mapping (Experiment 1), the interpretation of scene lighting (Experiment 2), the axis of internal symmetry of the search items (Experiment 3), and the axes of interitem symmet...

Symmetry Matters for Sizes of Extended Formulations

In 1991, Yannakakis [14] proved that no symmetric extended formulation for the matching polytope of the complete graph Kn with n nodes has a number of variables and constraints that is bounded subexponentially in n. Here, symmetric means that the formulation remains invariant under all permutations of the nodes of Kn. It was also conjectured in [14] that “asymmetry does not help much,” but no c...

Symmetry matters: photodissociation dynamics of symmetrically versus asymmetrically substituted phenols.

We report a combined experimental (H (Rydberg) atom photofragment translational spectroscopy) and theoretical (ab initio electronic structure and vibronic coupling calculations) study of the effects of symmetry on the photodissociation dynamics of phenols. Ultraviolet photoexcitation to the bound S1((1)ππ*) state of many phenols leads to some O-H bond fission by tunneling through the barrier un...

Symmetry of Fullerene C_60

Philosophy matters in brain matters

PURPOSE Although most neuroscientists and physicians would argue against Cartesian dualism, Descartes's version of the psyche/soma divide, which has been controversial since he proposed it in the seventeenth century, continues to haunt contemporary neurological diagnoses through terms such as functional, organic, and psychogenic. Drawing on my own experiences as a person with medically unexplai...