What I hear in this statement is more towards the domains of research engineering as opposed to theoretical physics. Sand piles are of course the bridge between the two ;)
Bridges are an engineering topic, most coastal areas lie on sedimentary rocks, and wormholes, a theoretical physics topic, are also called "Einstein–Rosen bridges."
In other words, while bridges are bridges between sand piles and sand piles, sand piles are bridges between bridges and bridges.
This can be a scientific rather than an engineering discipline, insofar as it's concerned with understanding the behavior of systems, rather than creating a solution which makes a system behave according to our wishes.
We have a limited understanding of "order" or patterns arising out of systems with many aggregating interactions, and often focusing on relatively idealized and isolated systems.