Sound travels at a finite speed because medium mass introduces time delays between molecules.

Evidence

Because of the mass of the golf balls, there will be a time lag before they start moving from the action of the connecting springs. This means that the disturbance caused by moving the first golf ball will take some time to travel down to the other end. If the golf ball at the beginning is returned to its original position, the whole process just described will happen again, except that the golf balls will be pulled rather than pushed and the connecting springs will have to expand rather than compress. At the end of all this, the system will end up with the golf balls having the same average spacing that they had before they were pushed and pulled. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 51

Because of the mass of the golf balls, there will be a time lag before they start moving from the action of the connecting springs. This means that the disturbance caused by moving the first golf ball will take some time to travel down to the other end. If the golf ball at the beginning is returned to its original position, the whole process just described will happen again, except that the golf balls will be pulled rather than pushed and the connecting springs will have to expand rather than compress. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 51

Categorization

• XREF: Connects to the whole physics foundation of why sound has speed at all, relevant to echo and delay phenomena in the reader’s listening practice.
• corroborated: 3 independent passages support this claim — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 51