, ▁a ▁field ▁which ▁S male , ▁Bow en ' s ▁dis sert ation ▁ad visor , ▁expl ored ▁and ▁bro aden ed ▁in ▁the ▁ 1 9 6 0 s . ▁As ▁studied ▁by ▁S male , ▁a ▁dynam ical ▁system ▁compr ises ▁a ▁manifold ▁ ▁and ▁a ▁smooth ▁mapping ▁ ▁... ▁As ▁Po inc ar é ▁emphas ized , ▁there ▁is ▁no ▁general ▁procedure ▁for ▁this , ▁and ▁therefore ▁one ▁must ▁resort ▁to ▁describing ▁average , ▁typical , ▁or ▁most ▁probable ▁behavior . ▁ ▁Bow en ' s ▁work ▁is ▁an ▁important ▁part ▁of ▁the ▁program ▁of ▁express ing ▁these ▁vague ▁ideas ▁in ▁mathemat ically ▁precise ▁and ▁useful ▁ways . ▁ ▁Bow en ▁was ▁just ▁ 3 1 ▁years ▁old ▁when ▁he ▁died ▁in ▁Santa ▁Rosa ▁of ▁a ▁c ere br al ▁hem or rh age ▁" at ▁the ▁start ▁of ▁what ▁was ▁to ▁have ▁been ▁a ▁vac ation ▁trip ." ▁ ▁Ber keley ' s ▁Mathemat ics ▁Department ▁Chair man ▁John ▁L . ▁K elle y ▁called ▁Bow en ▁a ▁" remark able , ▁brilliant ▁professor ▁and ▁super b ▁teacher ." ▁ ▁Dennis ▁S ull ivan ▁wrote , ▁in ▁the ▁issue ▁of ▁Publications ▁Math ém atiques ▁de ▁l ' I H É S ▁dedicated ▁to ▁Bow en ' s ▁memory , ▁R uf us ▁was ▁special , ▁and ▁I ▁could ▁close ▁with ▁Mike ▁Sh ub ' s ▁comment , ▁" Don ' t ▁forget ▁to ▁say ▁that ▁we ▁all ▁liked ▁him ". ▁ ▁Post hum ous ▁honor ▁Since ▁ 1