Some suggested substitutions were alunite for bauxite to make alumina, molybdenum and/or nickel for cobalt, and aluminum alloy automobile radiators for copper alloy automobile radiators.[11] Materials can be eliminated without material substitutes, for example by using discharges of high tension electricity to shape hard objects that were formerly shaped by mineral abrasives, giving superior performance at lower cost,[12] or by using computers/satellites to replace copper wire (land lines).