Do models of the expansion of space-time manifest that expansion by an increase in Plank-length, or by additional Plank-lengths appearing in between existing particles? I think it must be the latter because the Plank-length is not an empirically measured value and the constants it derives from do not change. IIRC anyway. Same question for inflation, if the answer is any different. If I think of a black hole and the whole Hawking entropy / hologram thing, as the black hole grows, it adds Plank areas to its horizon, so my intuition tells me that its sensible to think of expansion and inflation both as processes that add Plank lengths (additional Plank lengths each of the same size I mean) to all dimensions. Actually, for all I can imagine, the value of an individual Plank length may be observed by some entity outside our space-time to fluctuate wildly and I might have no way to notice. Maybe its even a silly question I'm asking.