1877, from German, literally "eternity."
Those found, he goes off with ponderous serenity into the ewigkeit.
Her determination of two hours ago had vanished into the ewigkeit.
To-night he is strapped on to an army aeroplane and launched into the ewigkeit.
ewigkeit was therefore originally time, and “for all time” came naturally to mean “for all eternity.”
All we know is that they flew into the ewigkeit and are "missing."
When another week has rolled by and disappeared into the ewigkeit, vary the menu.
In a few hours they leave the house again on their march through the ewigkeit, which they enliven with criminal proceedings.
James, if you run into the ewigkeit by way of a wire fence or a tree, I'll come every night and haunt you!