Interstellar space is characterized by the existence of three all pervading fields of force denoted respectively as gravitational, electric, and magnetic. Einstein in his general theory of relativity demonstrates mathematically that these three force fields are but different aspects of one universal field. To the average man, however, these three natural forces will always appear as separate distinct entities.
©1930 by Iowa State Teachers College
Science Bulletin: Vol. 2:
8, Article 6.
Available at: https://scholarworks.uni.edu/science_bulletin/vol2/iss8/6