Erik Holmberg, a young astronomer at the Lund Observatory in Sweden, conducted the first simulation of a universe. In the absence of efficient digital computers, he made do as best he could. He distributed 37 light bulbs to represent the distribution of gravitational force in each galaxy. Each bulb had a sensor on each side, for a total of four. He then moved the two galaxies in a straight line toward each other, simulating the collision of galaxies and the forces on each side of each galaxy. He thus demonstrated that the collision of two spiral galaxies often forms an elliptical galaxy.
