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.
Alessandro Volta-Example of Voltic Pile. Photograph courtesy of the National Library of Medicine. In 1800, Alessandro Volta of Italy built the voltaic pile and discovered the first practical method of generating electricity.Count Volta also made discoveries in electrostatics, meteorology and pneumatics.hotograph courtesy of the National Library of Medicine. In 1800, Alessandro Volta of Italy built the voltaic pile and discovered the first practical method of generating electricity.