. ▁One ▁of ▁his ▁interests ▁was ▁in ▁trying ▁to ▁gain ▁information ▁from ▁the ▁polar ization ▁of ▁light ▁scattered ▁from ▁the ▁surfaces ▁of ▁solid ▁bodies ▁in ▁the ▁Sol ar ▁System . ▁This ▁involved ▁comparison ▁of ▁labor atory ▁measurements ▁on ▁samples ▁of ▁known ▁characteristics ▁against ▁astronom ical ▁observations . ▁This ▁led ▁to ▁analysis ▁of ▁data ▁collected ▁by ▁the ▁P ione er ▁ 1 0 ▁and ▁P ione er ▁ 1 1 ▁space craft ▁( target ed ▁at ▁Jup iter ▁and ▁Sat urn ), ▁which ▁was ▁un fin ished ▁at ▁his ▁death . ▁It ▁was ▁continued ▁by ▁Tom ▁Ge h rel s ▁of ▁the ▁University ▁of ▁Arizona ; ▁where ▁Ge ake ▁had ▁held ▁the ▁post ▁of ▁adj unct ▁professor . ▁ ▁Ref ract ometer ▁invent ions ▁▁ ▁Ge ake ▁invent ed ▁the ▁first ▁linear ▁direct - reading ▁ref ract ometer ▁for ▁liqu ids , ▁which ▁is ▁said ▁to ▁have ▁found ▁many ▁practical ▁applications . ▁He ▁designed ▁the ▁" UM IST ▁Ref ract ometer " ▁sub system ▁for ▁the ▁Cass ini – H u yg ens ▁pro be , ▁which ▁reached ▁Sat urn ' s ▁moon ▁T itan ▁after ▁his ▁death ▁in ▁ 2 0 0 4 . ▁He ▁also ▁invent ed ▁a ▁spectral ▁differenti ating ▁ref ract ometer . ▁ ▁Family ▁and ▁death ▁▁ ▁Ge ake ▁worked ▁in ▁U M IST ▁physics ▁department ▁for ▁ 3 5 ▁years . ▁He ▁died ▁on ▁ 3 ▁June ▁ 1 9 9 8 ▁after ▁ret iring ▁in ▁ 1 9 9 2 ▁with ▁the ▁title ▁of ▁reader . ▁In