“the wonderful form of cosmic order”

The normal distribution is a continuous probability distribution famous for its symmetric, bell-shaped curve. Values cluster around the mean, while increasingly extreme values become progressively less likely in either direction. Its shape is determined entirely by two quantities: the mean sets the center, and the standard deviation controls the spread. Many measurements influenced by numerous small independent effects naturally approximate this pattern, which helps explain its extraordinary reach. The familiar 68–95–99.7 rule shows how tightly observations concentrate around the mean. It is used primarily in statistics, scientific research, and quality control.