A little later, as I was carried through the camshaft region I asked another silica particle what to make of it. He didn't know either, but he said we'd be passing through the bearings and on to the filter again before long and we could try to circulate a little closer next time. Sure enough, before long we were back inside the filter canister where I discovered they were iron and other metallic particles and they were not having a party. They were shouting for help. Not at all.
Oil filters do, however, have their limitations.
Again, it is the old trade off between restricting too much, and allowing too much unrestricted oil flow. Of course, there are by-pass filters that effectively eliminate particles smaller than me. That, my friend, is a subject I don't want to get into. Oil filters and air filters play a critical role in preserving engine life. For lube shops they are a logical source of add-on sales, always in the customer's best interest.