Science Common Sense

584 - What is the Big Bang theory, and what does it explain about the universe?

The Big Bang Theory is the idea that the universe started with a huge explosion around 13.8 billion years ago. Before this explosion, there was nothing, and all the matter and energy in the universe were squished into a tiny point.

The Big Bang explains how the universe began expanding and cooling down, eventually forming galaxies, stars, and planets, including Earth. It also explains why galaxies are moving away from each other and why the universe is still growing.

Imagine a big balloon inflating – that's kind of like what happened in the Big Bang. The universe is still expanding like that balloon, and scientists think it will keep growing forever.