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.
The light bulb was made by thomas Edison with the light bulb connected to electric currents. The first electric light was made in 1800 by Humphry Davy, an English scientist.â¦ He experimented with electricity and invented an electric battery.