The most accepted theory about the origin of the universe is the Big Bang Theory.Big Bang TheorySinasabing nagsimula ang universe sa isang napakaliit, mainit, at siksik na punto (singularity).Biglang sumabog ito mga 13.8 bilyong taon na ang nakalipas, at mula roon ay lumawak at patuloy na lumalawak ang universe hanggang ngayon.Dito rin nagsimula ang oras, espasyo, at matter.Other Theories (less accepted)Steady State Theory – Universe has no beginning or end, laging nag-e-expand habang may bagong matter na nalilikha.Oscillating Universe Theory – Universe expands, then contracts, and the cycle repeats.