Greenland proposes a counterfactual definition of a cause which is framed in terms of alternative actions with different potential outcomes. He suggests that, under this framework, social conditions – such as socioeconomic status, sex, or race – present a quandary for causal inference. They cannot be considered as causes unless they can be reframed in terms of alternative actions. Greenland's a...

We reiterate that geological observations do not require Grand Canyon carving coeval with Colorado River integration. (U-Th)/He data from the western canyon, totaling 29 reproducible analyses from six samples and two labs, compellingly support an ancient canyon. Three dispersed analyses from one anomalous sample do not refute this conclusion, nor do the claimed shortcomings of our modeling have...

(Dated: February 1, 2008) A normal-fluid component varying as T is observed at very low temperatures in superfluid He and He-He mixture films adsorbed in alumina powder. The normal fluid appears to arise from thermally excited third sound that has one-dimensional propagation characteristics. A Landau model of third sound excitations in an infinite cylindrical pore by Saam and Cole provides good...