noun A theoretical high-speed transportation system, proposed by Elon Musk, in which pressurized capsules ride on an air cushion driven by linear induction motors and air compressors through reduced-pressure tubes.
noun A control structure in which a loop repeats until either a stopping condition is met or all possible values of the looping index have been checked.
noun A quantum mechanical paradox resulting from the observer being a product of the observations that it makes.