A correlation is a single numerical value that is used to describe the relationship between two variables. All correlations have strength and direction. When two variables have a positive correlation, that means the two variables move in the same direction. The closer a positive correlation is to 1, the stronger it is.
William Gilbert discovered electricity, not Nikola Tesla. Nikola Tesla invented things. not discovered electricity. Again, William Gilbert discovered it and named it. He did this in the 1600s. It wasn't Nikola Tesla.
History of Electricity - William Gilbert. 1  The history of electricity begins with William Gilbert, a physician who served Queen Elizabeth the first of England. 2  Inspired and educated by William Gilbert several Europeans inventors, Otto von Guericke of Germany, Charles Francois Du Fay of France, and Stephen Gray of England, expanded the knowledge.