What is Prime Radiant

A compact device whose circuitry Hari Seldon designs and Yugo Amaryl cleverly assembles, the Prime Radiant for the first time allows psychohistorians to glimpse darkness and light in their science, still as though through frosted glass, but better than through lead. The Prime Radiant looks like a dark, opaque cube but until activated. Then it displays equations, relationships, and numbers, shimmering in the air