Slow Glass (Scenedow)
The most important effect, in the eyes of the average individual, was that light took a long time to pass through a sheet of slow glass. A new piece was always jet black because nothing had yet come through, but one could stand the glass beside, say, a woodland lake until the scene emerged, perhaps a year later. If the glass was then removed and installed in a dismal city flat, the flat would%u2014for that year%u2014appear to overlook the woodland lake.From Light of Other Days, by Bob Shaw. Published by Analog in 1968
Slow Glass (Scenedow) by Bob Shaw from Light of Other Days