[waps]

I think we're largely making the same point : that science is largely based on a utilitarian definition of truth. A somewhat more direct way to state that is that scientific truth is simply

"What works for me"

And nothing more.

I do disagree on one point though. The standard model doesn't just "lack" gravity. It describes a world without gravity. Therefore that gravity exists must mean that the standard model is wrong. It describes a universe that is most certainly not the one we live in. I therefore find it hard to describe that theory as true. It is more akin to "currently the best-known least-wrong theory". Even best-known has to be in there since, for example, relativity theory was known long before Einstein got his ball rolling, and Newton's equation was known before the apple fell. So we do likely know about better theories than the standard model, we just currently have no way to distinguish them from either the standard model, or (more likely) the better theories are just failing to get enough attention from well-publicized physicists. Of course, when you don't know exactly which theories are in fact better, their existence doesn't matter.