Corrections and clarifications.
The News & Comment article "DOE ponders yet more uses for SSC" (13 May, p. 898) by Christopher Anderson incompletely identified the source of a proposal to use Superconducting Super Collider magnets to measure the refractive index of light in a strong magnetic field. The principal investigator is Talso Chui at the Jet Propulsion Laboratory, California Institute of Technology, in collaboration with researchers from a group of institutions in the United States and the Republic of China.