Qeybta hoose ka dibna ka jawaab su'aasha ka dibna afka la mid ah sida marinka: Passage: Isku mid ahaanshaha u dhexeeya mass iyo tamarta, sida lagu muujiyay formula E = mc2, waa cawaaqibka ugu caansan ee relativity gaarka ah. In relativity, mass iyo tamarta waa laba siyaabood oo kala duwan oo lagu qeexayo hal tiro jirka. Haddii nidaamka jirka uu leeyahay tamarta, waxa kale oo uu leeyahay mass u dhiganta, iyo qeybta kale. Gaar ahaan, dhammaan sifooyinka jidhka oo la xiriira tamarta, sida heerkulka ama ku xirnaanta nidaamka tamarta sida nuucles ama molecules, waxay gacan ka geystaan in jidhka ee mass, oo sidaas daraaddeed u dhaqmaan sida ilaha culeyska. In relativity gaarka ah, tamarta waxaa si dhow la xidhiidha xuddun. Just sida meel iyo waqti yihiin, in aragtida, dhinacyo kala duwan oo ka mid ah hay'ad dheeraad ah oo loo yaqaan, spacetime, tamarta iyo tamarta waa uun dhinacyo kala duwan oo ka midaysan, afar-
mass, energy, momentum, pressure and tension (cufnaanta, tamarta, xawliga, cadaadiska iyo xiisadda)