1954 - X-RAC - new electric computer analyzes architecture of atomic structures

Just before the photo above was shot three Pennsylvania State University scientists fed a long list of numbers, mathematical formulas and measurements into their strange and awesome machine. Their problem: to analyze for the Navy the exact atomic structure of a new, insufficiently-understood explosive compound, a task that migh ordinarily take months or even years to complete. But inside the machine more than 4,000 tubes and switches swung into action, calculating with lightning speed, automatically sorting and resorting the numbers and solving the almost unmanageable formulas. Then, in a single second, the machine flashed the complete answer to the problem on a TV-like screen. There, for the scientists to look at, was a detailed picture showing what kind of atoms are in the compound and how these atoms are arranged.

The machine which solved this problem is called X-RAC, for X-ray Analogue Computer. Invented by Dr. Ray Pepinsky and paid for by the Office of Naval Research, X-RAC is a hybrid. It combines X-ray studies, television and a huge electronic brain, bringing them to bear on knotty problems of atomic analysis. Before X-RAC can get to work on a particular compound to unravel the mysteries of its structure, the scientists must sibject the material to X-ray analyses. The results are expressed mathematically, in a form that X-RAC can understand and work with. After juggling the symbols according to the formulas, X-RAC's circuits create electrical vibrations analogus to vibrations that would be produced by X-ray beams striking the electron shells of the original atoms. These vibrations produce the final pattern on X-RAC's screen.