Despite it being called "double spacing", TeX's inter-sentence spacing is actually only about 1.25x the inter-word spacing (before justification stretching is a

Despite it being called "double spacing", TeX's inter-sentence spacing is actually only about 1.25x the inter-word spacing (before justification stretching is applied, at least). The argument is really just over whether or not the space after a sentence should be wider than the space after a word, and not how much wider it should be if so.