When we look at other stars and galaxies, the colours indicate that they are all moving away from each other at vast speeds. There is lots of other evidence from physics — astronomy and radio astronomy — and interstellar chemistry that points to the universe expanding from a small very highly compressed mass about 13 or 14 billion years ago. This is what scientists call the big bang. As the universe expanded, it also cooled, and gases clumped together to form galaxies, solar systems, stars and planets.
There’s a lot of evidence for this, as Kieran mentions. Actually “Big Bang” was a phrase made up by an astronomer to kind of make fun of the theory. The name stuck. Things are expanding, and the light reaching us now from galaxies a long way away shows us what they were like in the past (the light takes a while to get here) and they are in a young phase. There’s also a “cosmic microwave background” that you can see with the right instruments, which looks exactly like what you’d expect if there had been a big bang.
“But it’s all pretty weird. If the universe used to be smaller, what was “outside it”? What is it expanding into? Apparently these questions don’t really mean anything, and to understand why requires a bit of study of physics. For example, it’s thought that time was “created” with the big bang, so there was no “before”. Cool, but is it right? You’d need to read about it and make up your own mind.
A TV show about science geeks which I am watching right now.
It is also a theory for how the Universe developed early on, in which a small, hot and very dense ball of something rapidly expanded outward, creating the Universe which we are in. It explains what might have happened since that moment, but doesn’t tell us anything about what happened before, or why it happened at all.
Though the interesting thing is that it’s agreed that the universe is expanding so what is outside of it? And do we need another word instead of universal to describe everything because the universe really isn’t everything because there’s something bigger?
When we look at other stars and galaxies, the colours indicate that they are all moving away from each other at vast speeds. There is lots of other evidence from physics — astronomy and radio astronomy — and interstellar chemistry that points to the universe expanding from a small very highly compressed mass about 13 or 14 billion years ago. This is what scientists call the big bang. As the universe expanded, it also cooled, and gases clumped together to form galaxies, solar systems, stars and planets.
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There’s a lot of evidence for this, as Kieran mentions. Actually “Big Bang” was a phrase made up by an astronomer to kind of make fun of the theory. The name stuck. Things are expanding, and the light reaching us now from galaxies a long way away shows us what they were like in the past (the light takes a while to get here) and they are in a young phase. There’s also a “cosmic microwave background” that you can see with the right instruments, which looks exactly like what you’d expect if there had been a big bang.
“But it’s all pretty weird. If the universe used to be smaller, what was “outside it”? What is it expanding into? Apparently these questions don’t really mean anything, and to understand why requires a bit of study of physics. For example, it’s thought that time was “created” with the big bang, so there was no “before”. Cool, but is it right? You’d need to read about it and make up your own mind.
0
A TV show about science geeks which I am watching right now.
It is also a theory for how the Universe developed early on, in which a small, hot and very dense ball of something rapidly expanded outward, creating the Universe which we are in. It explains what might have happened since that moment, but doesn’t tell us anything about what happened before, or why it happened at all.
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The Big Bang Theory is summed up in this song. http://www.youtube.com/watch?v=HxDcOxXQI-k
No really, it is. 🙂
Though the interesting thing is that it’s agreed that the universe is expanding so what is outside of it? And do we need another word instead of universal to describe everything because the universe really isn’t everything because there’s something bigger?
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