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.
Nikola Tesla designed the first hydroelectric power plant at Niagara Falls, New York which started producing electrical power in 1895. This was the beginning of the electrification of the United States and the rest of the world. Today, Teslaâs AC electricity is lighting and powering the globe.