That’s a good question, but more importantly, it’s one of the biggest, most soul-searching questions we could ever ask. It’s also a question that doesn’t have an answer… yet (unless you’re religious of course). The exact origins of the Big Bang remains a mystery in the scientific world but there are plenty of theories – let’s take a look at them.
The Big Bang theory is used to explain the growth of the universe. However, there are a lot of things it doesn’t explain; such as, why are so many unconnected parts of the universe so similar? Add to that the fact that we don’t even know what happened in the instant after the Big Bang, and we find ourselves in the worst kind of pickle – an existential one.
The theory that is used to ‘wrap’ these problems up is the ‘inflationary model’ of the universe. It states that the universe went through an intense period of expansion very early in its life, like a chubby cosmic baby or an ever-expanding balloon. Other scientists prefer to believe that there was nothing, and the big bang was an event that just occurred out of nowhere. A more recent theory proposes that our universe isn’t the first and we’re one of many universes in a continuous cycle of expansion, then collapse. In fact, in 2011 a group of scientists won a Nobel prize for proving that the universe’s rate of expansion is accelerating. It implies (but doesn’t prove) that the universe will get too big for its boots and collapse (or alternatively grow gradually colder and die). Not a very cheering thought, but we’ll hopefully be long dead before that happens…
How about more sci-fi-esque theories of the universe? ‘String theory’ presumes that our universe has more than the three dimensions we can touch and see – maybe even ten or more that we can’t see. Unless you’re taking substances you shouldn’t, we can only perceive the universe in a three dimensional space. Scientists have taken this theory and argued that the universe exists within a three dimensional space (or ‘brane’) and it can’t interact with other universes that exist within a different dimensional space. Occasionally though, universes in different dimensions but next to one another would collide, causing a Big Bang.
There are many more theories concerning the beginning of the universe, each incorporating elements of one another or shooting off on tangents. What I’ve tried to highlight is this: there are still no answers that can explain what set off the Big Bang. Scientists have spent their lives trying to work it out, and many more will do the same. Maybe we’ll never know.
How tragically romantic.
Thanks for your question!
Answer by Matt Powell
Question from Jodine via Facebook
If you want a comprehensive (if somewhat complex) explanation of pre-Big Bang theories, read it here: http://scienceblogs.com/startswithabang/2012/10/15/what-happened-before-the-big-bang/