relativity  
noun [ U ] uk/ˌrel.əˈtɪv.ə.ti/ us/ˌrel.əˈtɪv.ə.t̬i/
  (IN PHYSICS)     
  physics specialized相对论 
either of two theories of physics giving the relationship between space, time, and energy, especially for two objects moving in different ways
   (STATE OF BEING RELATIVE)     
 formal相对性 
the state of being judged in comparison with other things and not by itself