▁Pir ani ▁re vised ▁the ▁general ▁audience ▁book ▁" The ▁ABC ▁of ▁Rel ativity ", ▁originally ▁written ▁by ▁Ber tr and ▁Russell ▁in ▁ 1 9 2 5 . ▁He ▁continued ▁revis ions ▁up ▁to ▁ 2 0 0 2 . ▁In ▁the ▁ 1 9 9 0 s ▁he ▁began ▁writing ▁books ▁aim ed ▁at ▁the ▁general ▁audience , ▁e . g . ▁" Int rodu cing ▁the ▁Un iverse ", ▁translated ▁into ▁French ▁as ▁" L ' A stronom ie ▁sans ▁asp ir ine " ▁( astr onomy ▁without ▁asp ir in ). ▁ ▁Political ▁views ▁Pir ani ▁was ▁polit ically ▁active ▁in ▁the ▁ 1 9 7 0 s ▁and ▁ 1 9 8 0 s , ▁had ▁a ▁left ▁lean ing ▁st ance , ▁and ▁opposed ▁the ▁un checked ▁use ▁of ▁science ▁for ▁military ▁purposes . ▁▁ ▁Al ong ▁with ▁Maurice ▁Wil kins ▁he ▁was ▁involved ▁in ▁the ▁British ▁Society ▁for ▁Social ▁Res p ons ibility ▁in ▁Science . ▁ ▁In ▁ 1 9 7 1 ▁Pir ani ▁told ▁the ▁New ▁Scient ist ▁that ▁during ▁an ▁academic ▁visit ▁to ▁the ▁University ▁of ▁North ▁Carolina ▁issues ▁about ▁sla very ▁and ▁the ▁American ▁civil ▁war ▁" hit ▁him ▁in ▁the ▁face " ▁and ▁upon ▁his ▁return ▁to ▁England ▁he ▁joined ▁the ▁Scient ists ▁of ▁the ▁Left ▁and ▁the ▁Camp aign ▁for ▁N uc lear ▁Dis arm ament ▁and ▁became ▁a ▁political ▁activ ist . ▁Pir ani ▁studied ▁dis arm ament ▁and ▁founded ▁the ▁Science ▁Forum ▁as ▁a ▁group ▁of ▁scient ists