big bang theory
ˌbig <ʃOŋð style="font-weight:normal">'bang <ʃOŋð style="font-weight:normal">ˌtheorynoun
1. the big bang theory the idea that the universe began with a single large explosion (the 'big bang'), and that the pieces are still flying apart〔关于宇宙起源的〕大爆炸理论;
⇒steady state theory