The Big Bang theory is the leading scientific model explaining the universe's origin and evolution. It describes how the cosmos began from an extremely hot,...
The Big Bang theory is the prevailing scientific model for the origin and evolution of the universe, positing that it began from an extremely hot, dense singularity about 13.8 billion years ago and has been expanding ever since.
Primary evidence includes the observed expansion of the universe (Hubble's Law), the detection of the cosmic microwave background (CMB) radiation, and the observed abundance of light elements (hydrogen, helium) throughout the cosmos.
No, it wasn't an explosion *in* space, but rather the rapid expansion *of* space itself. Every point in the early universe began expanding away from every other point, not from a central explosion into existing space.
Immediately after an initial rapid inflation, the universe cooled sufficiently for fundamental particles to form, followed by the creation of simple atoms (hydrogen and helium) within the first few hundred thousand years, eventually leading to star and galaxy formation.