▁continued ▁to ▁refer ▁simply ▁to ▁the ▁new ▁method ▁as ▁the ▁" rel ativity ▁principle ". ▁And ▁in ▁an ▁important ▁over view ▁article ▁on ▁the ▁relativ ity ▁principle ▁( 1 9 0 8 a ), ▁Ein stein ▁described ▁SR ▁as ▁a ▁" union ▁of ▁Lor ent z ' s ▁theory ▁and ▁the ▁relativ ity ▁principle ", ▁including ▁the ▁fundamental ▁assumption ▁that ▁Lor ent z ' s ▁local ▁time ▁can ▁be ▁described ▁as ▁real ▁time . ▁( Y et , ▁Po inc ar é ' s ▁contributions ▁were ▁rarely ▁mentioned ▁in ▁the ▁first ▁years ▁after ▁ 1 9 0 5 .) ▁All ▁of ▁those ▁expressions , ▁( L or ent z - E in stein ▁theory , ▁relativ ity ▁principle , ▁relativ ity ▁theory ) ▁were ▁used ▁by ▁different ▁phys ic ists ▁altern ately ▁in ▁the ▁next ▁years . ▁ ▁Following ▁Plan ck , ▁other ▁German ▁phys ic ists ▁quickly ▁became ▁interested ▁in ▁relativ ity , ▁including ▁Arnold ▁Sommer feld , ▁Wilhelm ▁Wien , ▁Max ▁Born , ▁Paul ▁Ehren fest , ▁and ▁Alfred ▁Buch erer . ▁von ▁La ue , ▁who ▁learned ▁about ▁the ▁theory ▁from ▁Plan ck , ▁published ▁the ▁first ▁definit ive ▁mon ograph ▁on ▁relativ ity ▁ ▁in ▁ 1 9 1 1 . ▁By ▁ 1 9 1 1 , ▁Sommer feld ▁alter ed ▁his ▁plan ▁to ▁speak ▁about ▁relativ ity ▁at ▁the ▁Sol v ay ▁Congress ▁because ▁the ▁theory ▁was ▁already ▁considered ▁well ▁established . ▁ ▁Kauf mann - B uch erer ▁experiments ▁Kauf mann ▁( 1 9 0 5