▁showed ▁already ▁in ▁his ▁school ▁time ▁great ▁interest ▁in ▁physics , ▁mathematics ▁and ▁electric ity . ▁▁ ▁In ▁World ▁War ▁I , ▁he ▁served ▁as ▁volunte er ▁at ▁the ▁front ▁from ▁ 1 9 1 4 ▁to ▁ 1 9 1 8 . ▁Short ly ▁before ▁end ▁of ▁war , ▁he ▁was ▁taken ▁prisoner ▁and ▁spent ▁one ▁year ▁in ▁English ▁capt ivity . ▁After ▁his ▁release , ▁he ▁started ▁studying ▁physics ▁at ▁the ▁Albert us - Univers ität ▁Kon igs berg ▁and ▁as ▁of ▁ 1 9 2 0 ▁at ▁the ▁Techn ische ▁Hoch schule ▁Dan zig . ▁In ▁the ▁last ▁sem ester ▁he ▁was ▁assistant ▁at ▁the ▁Phys ikal ische ▁Institut ▁in ▁Dan zig ▁and ▁passed ▁his ▁di pl oma ▁exam ination ▁in ▁Techn ical ▁Physics . ▁▁ ▁In ▁ 1 9 2 2 , ▁Sch ack ▁moved ▁to ▁Düsseldorf ▁and ▁became ▁one ▁year ▁later ▁employee ▁at ▁the ▁fuel ▁and ▁power ▁department ▁of ▁the ▁Verein ▁Deutsch er ▁Eisen h ütt en le ute ▁( Associ ation ▁of ▁German ▁Ste el ▁Man ufact ur ers ). ▁In ▁the ▁same ▁year , ▁he ▁married ▁Dor othe a ▁Sch u hm acher , ▁with ▁whom ▁he ▁had ▁three ▁children . ▁▁ ▁In ▁ 1 9 2 4 , ▁he ▁wrote ▁his ▁dis sert ation ▁“ Ü ber ▁die ▁Stra hl ung ▁der ▁Feuer g ase ▁und ▁ihre ▁prakt ische ▁Um set zung ” ▁( About ▁the ▁Rad iation ▁of ▁F iring ▁G ases ▁and ▁their ▁practical ▁Im plementation ). ▁Em phas is ▁was ▁the ▁prove