Autocorrelation magnitude reveals how long signal features persist

Evidence

It gets more interesting if we lower the righthand column by some number of entries and leave the lefthand column alone. Now is there a correlation of a given entry in the left column with the one straight across in the right column? If the elements of the list are random numbers, clearly not. If, for example, each number represents the temperature taken on the hour at a given spot, we would expect them to be correlated: a hot afternoon remains hot for several hours, for example, and maybe it tends to remain hot, on average, for a few days. — Eric J. Heller, Why You Hear What You Hear- An…, 388

Categorization

• QUESTION: The persistence of warm afternoons over days is a memory-timescale concept worth chasing in how the ear/brain extract periodicity.
• SHARE: The hot-afternoon-stays-hot-for-days framing of autocorrelation lag makes a crisp, shareworthy analogy for a physics or signal-processing friend.