Perseveration with demonstrably false arguments. This is illustrated for creationism by the ability to construct an Index to Creationist Claims which describes the plethora of such false arguments, rebutted over and over in the scientific literature but persisted in by creationists.

To get down to the matter at hand.

The train crawled through an unlovely smokescape of towering chimneys and squatting kilns.

A final step is to polish the rough as-grown diamond layer on [the] culet of the designer anvil to smooth the surface and shape the culet so that is suitable for high-pressure experiments.