from when i was 10-11 years old, i have been told that there was a big bang and the universe has been expanding because of it. but my curiosity grew and wanted to know what caused it. but i was surprised to know that 'nothing' happened before the big bang. as i know there is a cause for everything. but the big bang dosen't. i 'think' that the interaction of the particals and their antiparticles caused the annihilation which we call 'big bang'.(please correct me if i have not used the right terms or if it dosen't make sence. i'm 14 and am still learning.) please tell me what you think caused the big bang. your views.