Contact

by Carl Sagan

They had spent the morning in a last-minute comparison of notes and interpretations of the new data. The continuing Message transmission had reached an important new stage. Diagrams were being transmitted from Vega the way newspaper wirephotos are transmitted. Each picture was an array raster. The number of tiny black and white dots that made up the picture was the product of two prime numbers. Again prime numbers were part of the transmission. There was a large set of such diagrams, one following the other, and not at all interleaved with the text. It was like a section of glossy illustrations inserted in the back of a book. Following transmission of the long sequence of diagrams, the unintelligible text continued. From at least some of the diagrams it seemed obvious that Vaygay and Arkhangelsky had been right, that the Message was in part at least the instructions, the blueprints, for building a machine. Its purpose was unknown.