ode . ▁From ▁the ▁above ▁discussion , ▁only ▁one ▁percent ▁of ▁the ▁energy ▁needs ▁to ▁be ▁transferred ▁to ▁produce ▁an ▁explos ion , ▁but ▁explaining ▁how ▁that ▁one ▁percent ▁of ▁transfer ▁occurs ▁has ▁proven ▁extremely ▁difficult , ▁even ▁though ▁the ▁particle ▁interactions ▁involved ▁are ▁believed ▁to ▁be ▁well ▁understood . ▁In ▁the ▁ 1 9 9 0 s , ▁one ▁model ▁for ▁doing ▁this ▁involved ▁con ve ct ive ▁over turn , ▁which ▁suggests ▁that ▁con ve ction , ▁either ▁from ▁neut r inos ▁from ▁below , ▁or ▁inf alling ▁matter ▁from ▁above , ▁comple tes ▁the ▁process ▁of ▁destroy ing ▁the ▁pro gen itor ▁star . ▁He avier ▁elements ▁than ▁iron ▁are ▁formed ▁during ▁this ▁explos ion ▁by ▁neut ron ▁capture , ▁and ▁from ▁the ▁pressure ▁of ▁the ▁neut r inos ▁pressing ▁into ▁the ▁boundary ▁of ▁the ▁" neut r inos phere ", ▁seed ing ▁the ▁surrounding ▁space ▁with ▁a ▁cloud ▁of ▁gas ▁and ▁dust ▁which ▁is ▁rich er ▁in ▁heavy ▁elements ▁than ▁the ▁material ▁from ▁which ▁the ▁star ▁originally ▁formed . ▁ ▁Ne ut r ino ▁physics , ▁which ▁is ▁mode led ▁by ▁the ▁Standard ▁Model , ▁is ▁cru cial ▁to ▁the ▁understanding ▁of ▁this ▁process . ▁The ▁other ▁cru cial ▁area ▁of ▁investigation ▁is ▁the ▁hyd rod ynam ics ▁of ▁the ▁pl asma ▁that ▁makes ▁up ▁the ▁dying ▁star ; ▁how ▁it ▁behav es ▁during ▁the ▁core ▁collapse ▁determ ines ▁when ▁and ▁how ▁the ▁shock wave ▁forms ▁and ▁when ▁and ▁how ▁it ▁st alls ▁and ▁is ▁re ener g ized