Absence of background is strategic. It’s related to the aether problem since the aether seems to be a background―a canvas on which physics painted in the days when no one saw it as a snare and a delusion.
A relational theory is one that has events that have no background, only a relation. As in, for example, A links to B. It can go on to say, B links to C. ‘Link’ being a relation. There must be nothing that can say where or when A or B or C are to be found. If there is a way to say, there is a background.
Both general relativity and quantum mechanics depend upon a background. Smolin is on record saying GR’s background-independent; and that it is not. He explains that it has much less background than QM. But it isn’t totally relational, not in the sense that he himself defines. Smolin favors a relational strategy. He would have physicists cut down the background of existing theories piece by piece. It’s a plan for birth that’s based on being partly pregnant. A theory that assumes even a tiny bit of background is not relational.
The Background Problem is it is impossible to build a theory of the entire universe within a background, but it seems impossible to build a theory without one. Where does one begin?