Ask Tappity: Science Questions for Kids > What Was the Big Bang?
What Was the Big Bang?
Did the Big Bang really start the whole universe? And what exactly was it, anyway? Watch this video to find out, or read our explanation below!
The Universe is Expanding
About 100 years ago, a scientist named Edwin Hubble made an amazing discovery - every galaxy in the universe was speeding away from us. What gives? Do we stink? Well, turns out, every galaxy is moving away from every other galaxy because the universe itself is expanding. Imagine a balloon with a bunch of dots marked on it. As the balloon expands, the dots all get farther away from one another. That’s sort of like what’s happening with our universe, all the time!
That Means the Universe Used To Be Smaller
If the universe is getting bigger and bigger, then if we turn back time, the universe used to be smaller than it is today, and everything used to be closer. And if we keep going back, and back, the universe must have been smaller, and smaller. Far enough back - about 13.7 billion years ago - everything in the entire universe would have been smushed together in a teeny tiny space, smaller than an atom.
So, What’s the Big Bang?
Well, pretty much that! The Big Bang Theory is the theory that the universe is constantly expanding, and has been since for about 13.7 billion years, from an infinitesimally small point. The “Big Bang” itself is also sometimes used to describe the first initial super-fast expansion of the universe from that tiny point.
Universe Facts for Kids
Questions about the Universe? Look no further!
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No one knows! The Big Bang is a theory that is supported by lots of evidence we have now, but it only goes so far. To about .000000000000000000000000000000000001 seconds after the universe started inflating - past that, everything is so squished together that nothing we know about physics works anymore, and nobody has any idea what happened. That’s what physicists are working on now!
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Nobody knows! One theory is that the universe goes through an infinite series of inflations and contractions.
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The observable universe, which is the amount of the universe we can see, is about 93 billion light years in diameter. There's lots more universe outside of that, but scientists aren't sure how big it is - just that it's way, way bigger.
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Very cold - about -454.81 degrees Fahrenheit, which is only 2 degrees above absolute zero, the coldest it's possible to be.
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If the universe is expanding, it makes sense to ask what exactly it’s expanding into. Again, no one knows, but one theory is that our universe is just one of many universes, all very far apart from one another and set in a sort of “super-universe.”
More Answers to Space Questions from Kids
What’s at the center of the Milky Way? What’s the fastest thing in the universe? The Tappity Astronomy Library has interactive lessons with answers to those questions and more!
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