Demonstrate Void Space in Uncompacted Gravel

What happens here

To demonstrate the need for compaction, the narrator gathers a handful of the 3/4 inch limestone and places it on a concrete block, imitating how rock might be dumped into a foundation (e.g., for a patio) without compaction. He points out the significant amount of air space trapped between each individual stone, which is referred to as 'void space.' This void space is the primary reason compaction is necessary, even for hard materials like rock.

Goal: Visually understand the concept of 'void space' in loose gravel