▁Ein ar ▁Bi il mann ▁and ▁spect ro scop ist ▁Alex ▁Lang s eth ; ▁and ▁just ▁the ▁union ▁of ▁spect ro sc opy ▁and ▁synth etic ▁organ ic ▁chem istry ▁formed ▁the ▁basis ▁for ▁Bak ' s ▁later ▁scientific ▁work . ▁ ▁Bak ' s ▁contribution ▁to ▁the ▁field ▁began ▁early ▁with ▁his ▁prize ▁winning ▁submission ▁to ▁the ▁University ▁of ▁C open hagen ' s ▁call ▁for ▁papers ▁on ▁the ▁subject ▁of ▁organ ic ▁chemical ▁elements ▁that ▁won ▁him ▁the ▁Gold ▁Medal . ▁Bak ▁continued ▁to ▁build ▁upon ▁this ▁work ▁in ▁his ▁doctor al ▁th esis ▁" The ▁In ternal ▁M ole cular ▁Pot ential " ▁which ▁served ▁as ▁the ▁for er un ner ▁of ▁numerous ▁treat ises ▁on ▁mole cular ▁dynamics , ▁the ▁theoretical ▁basis ▁for ▁the ▁understanding ▁of ▁the ▁mole cular ▁v ibration ▁and ▁rot ational ▁spect ra . ▁He ▁was ▁awarded ▁the ▁D . Ph il . ▁in ▁ 1 9 4 3 . ▁ ▁Short ly ▁after ▁the ▁Second ▁World ▁War , ▁Bak ▁tra ve led ▁to ▁Ber keley , ▁California ▁( 1 9 4 6 – 4 7 ) ▁where ▁he ▁in ▁collaboration ▁with ▁W . ▁D . ▁G w inn ▁built ▁the ▁first ▁mic row ave ▁spect ro graph , ▁an ▁instrument ▁that ▁could ▁be ▁realized ▁thanks ▁to ▁components ▁developed ▁originally ▁for ▁use ▁in ▁advanced ▁war - time ▁rad ar ▁systems ▁( K ly str on ▁oscill ator ). ▁This ▁work ▁involved ▁a ▁considerable ▁amount ▁of ▁vac u um - t ube ▁electron ics ▁and ▁the