ABSTRACT
Correlations can be either positive or negative. If a positive correlation, when one variable increases the other increases, and a decrease in one means a decrease in the other. The measurement of light intensity reaching the ground will be affected by the vagaries of cloud movements, changes in local humidity and atmospheric pressure, and sunspot and sun flare activity. There is a filter on the transmitter to temper noise (fluctuations due to flow turbulence). Even though turbulence in the flowing fluid should provide random fluctuations at time interval, the “averaging” by a first-order filter retains some of the prior values, creating autocorrelation. Correlation analysis is a simple way to identify strong relations, as a clue about postulating or affirming or rejecting mechanistic cause and effect conjectures. Correlation does not necessarily mean that there is a linear relation between variables.
