 At Chicago , Graves met and married Elizabeth Riddle , a physics major there , who was known as " Diz " . Elizabeth Riddle Graves earned her Ph.D. , writing her thesis on " Energy Release from Beryllium @-@ 9 ( Alpha , Alpha ) Lithium @-@ 7 and the Production of Lithium @-@ 7 " . Graves remained at the University of Chicago as a research fellow and an assistant professor until 1939 , when he moved to the University of Texas . Unfortunately , Elizabeth was unable to secure a job there as well due to its anti @-@ nepotism rules . 
