le ason ▁is ▁an ▁American ▁academic . ▁He ▁is ▁the ▁Hugh es - R og ers ▁Professor ▁of ▁English ▁and ▁chair ▁of ▁the ▁English ▁department ▁at ▁Pr inc eton ▁University . ▁He ▁is ▁the ▁author ▁of ▁two ▁books . ▁ ▁References ▁ ▁Category : L iving ▁people ▁Category : Am her st ▁College ▁al umn i ▁Category : Univers ity ▁of ▁California , ▁Los ▁Angeles ▁al umn i ▁Category : Pr inc eton ▁University ▁fac ulty ▁Category : Year ▁of ▁birth ▁missing ▁( l iving ▁people ) <0x0A> </s> ▁Blo ch ' s ▁theorem ▁may ▁refer ▁to : ▁ ▁For ▁the ▁theorem ▁named ▁after ▁Felix ▁Blo ch ▁on ▁wave ▁functions ▁of ▁a ▁particle ▁in ▁a ▁periodic ▁potential , ▁see ▁Blo ch ▁wave ▁ ▁For ▁the ▁theorem ▁in ▁complex ▁variables ▁named ▁after ▁André ▁Blo ch , ▁see ▁Blo ch ' s ▁theorem ▁( complex ▁variables ) ▁ ▁The ▁Block ▁theorem ▁highlight s ▁the ▁fact ▁that ▁an ▁electron ▁in ▁a ▁metal ▁will ▁be ▁in ▁a ▁periodic ▁potential . ▁Its ▁potential ▁energy ▁is ▁maximum ▁in ▁between ▁atoms ▁and ▁minimum ▁( ~ 0 ) ▁near ▁an ▁atom . <0x0A> </s> ▁The ▁Bal eng ▁Tower ▁() ▁is ▁a ▁tower ▁in ▁F ux ing ▁District , ▁T ao y uan ▁City , ▁Taiwan . ▁ ▁Architecture ▁The ▁ 2 9 . 5 ▁meters ▁high ▁tower ▁was ▁constructed ▁in ▁a ▁former ▁fort ▁built ▁during ▁the ▁Japanese ▁rule ▁of ▁Taiwan . ▁It ▁was ▁constructed ▁on ▁an ▁alt itude ▁of ▁ 1 , 3 1 4 ▁meters ▁above ▁sea ▁level . ▁The