▁ ▁Phot otr ans istor ▁In ▁ 1 9 4 8 ▁Sh ive ▁invent ed ▁the ▁phot otr ans istor ▁that ▁used ▁a ▁beam ▁of ▁light , ▁instead ▁of ▁a ▁wire , ▁as ▁the ▁em itter ▁of ▁a ▁point ▁contact ▁trans istor , ▁generating ▁holes ▁that ▁flow ▁to ▁the ▁collect or . ▁Bell ▁L abs ▁announced ▁the ▁in vention ▁in ▁ 1 9 5 0 . ▁The ▁phot otr ans istor ▁was ▁eventually ▁used ▁in ▁the ▁nation wide ▁direct ▁distance ▁d ial ing ▁system . ▁ ▁Sh ive ▁wave ▁machine ▁ ▁Sh ive ▁was ▁a ▁gift ed ▁lect urer , ▁and ▁became ▁Director ▁of ▁Education ▁and ▁Training ▁at ▁Bell ▁Tele phone ▁Labor ator ies . ▁He ▁was ▁responsible ▁for ▁curr icul um ▁and ▁administration ▁of ▁educational ▁programs ▁provided ▁to ▁employees ▁of ▁Bell ▁Labor ator ies . ▁ ▁In ▁this ▁new ▁role , ▁he ▁invent ed ▁the ▁Sh ive ▁wave ▁machine ▁( also ▁known ▁as ▁the ▁Sh ive ▁wave ▁generator ). ▁The ▁wave ▁generator ▁illustr ates ▁wave ▁motion ▁using ▁a ▁series ▁of ▁steel ▁ro ds ▁joined ▁by ▁a ▁thin ▁t ors ion ▁wire ▁which ▁transm its ▁energy ▁from ▁one ▁rod ▁to ▁the ▁next . ▁The ▁high ▁moment ▁of ▁in ert ia ▁of ▁each ▁rod ▁ens ures ▁the ▁wave ▁takes ▁several ▁seconds ▁to ▁traverse ▁the ▁entire ▁series ▁of ▁ro ds , ▁making ▁the ▁dynamics ▁easily ▁visible . ▁The ▁motion ▁is ▁analog ous ▁to ▁high - fre quency ▁waves ▁that ▁are ▁invisible ▁to ▁the ▁human ▁eye , ▁such ▁as ▁elect romagnet ic ▁waves ▁on ▁a ▁transmission