Some examples of time series analysis
From Physiki
A famous long-term record of atmospheric CO2 from Mauna Loa
A tiltmeter is lowered into a borehole (such as pictured here)
This instrument measures its orientation relative to the local gravity.
These data are courtesy of Dr. Judah Levine
tilt measurements and volcano monitoring
You know what this is.
What happens if you try to play a constant tone? Say, a low C.